feat(schedule): support random cover source for scheduled and manual publish

Add a cover mode to schedule tasks so auto-publish can pick a random cover
image instead of a fixed one, scoped to all images or a specific folder.

- migration: add cover_mode / cover_random_scope / cover_random_folder_id
  columns and check constraints on schedule_tasks
- backend: validate cover mode/scope/folder on create & update; the dispatch
  worker resolves a random active image (signed asset URL) at enqueue time
- frontend: new CoverSourceSelector component wired into GenerateTaskDrawer
  and PublishArticleModal, plus coverSource i18n strings

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/admin-web/src/components/CoverSourceSelector.vue

@@ -0,0 +1,343 @@
+<script setup lang="ts">
+import { imagesApi } from '@/lib/api'
+import type { ScheduleCoverMode, ScheduleCoverRandomScope } from '@geo/shared-types'
+import { useQuery } from '@tanstack/vue-query'
+import { computed, watch } from 'vue'
+import { useI18n } from 'vue-i18n'
+
+const props = withDefaults(
+  defineProps<{
+    mode: ScheduleCoverMode
+    randomScope: ScheduleCoverRandomScope
+    randomFolderId: number | null
+    disabled?: boolean
+  }>(),
+  {
+    disabled: false,
+  },
+)
+
+const emit = defineEmits<{
+  'update:mode': [value: ScheduleCoverMode]
+  'update:randomScope': [value: ScheduleCoverRandomScope]
+  'update:randomFolderId': [value: number | null]
+}>()
+
+const { t } = useI18n()
+
+const foldersQuery = useQuery({
+  queryKey: ['images', 'folders', 'cover-source'],
+  enabled: computed(() => !props.disabled),
+  queryFn: () => imagesApi.listFolders(),
+})
+
+const folderOptions = computed(() =>
+  (foldersQuery.data.value ?? []).map((folder) => ({
+    label: `${folder.name} (${folder.image_count})`,
+    value: folder.id,
+  })),
+)
+
+watch(
+  () => props.mode,
+  (mode) => {
+    if (mode === 'specific') {
+      emit('update:randomFolderId', null)
+    }
+  },
+)
+
+watch(
+  () => props.randomScope,
+  (scope) => {
+    if (scope === 'all') {
+      emit('update:randomFolderId', null)
+    }
+  },
+)
+
+function updateMode(value: string | number): void {
+  emit('update:mode', value === 'random' ? 'random' : 'specific')
+}
+
+function updateScope(value: string | number): void {
+  emit('update:randomScope', value === 'folder' ? 'folder' : 'all')
+}
+
+function updateFolder(value: number | null): void {
+  emit('update:randomFolderId', value ?? null)
+}
+</script>
+
+<template>
+  <div
+    class="cover-source-selector-panel"
+    :class="{ 'cover-source-selector-panel--disabled': disabled }"
+  >
+    <!-- Top part: Compact Low-profile controls stacked vertically with comfortable spacing -->
+    <div class="cover-source-selector__controls">
+      <!-- Mode selection row -->
+      <div class="control-group">
+        <span class="control-label">封面模式</span>
+        <div class="custom-segmented">
+          <button
+            type="button"
+            class="custom-segmented__item"
+            :class="{ 'custom-segmented__item--active': mode === 'specific' }"
+            :disabled="disabled"
+            @click="updateMode('specific')"
+          >
+            {{ t('coverSource.specific') }}
+          </button>
+          <button
+            type="button"
+            class="custom-segmented__item"
+            :class="{ 'custom-segmented__item--active': mode === 'random' }"
+            :disabled="disabled"
+            @click="updateMode('random')"
+          >
+            {{ t('coverSource.random') }}
+          </button>
+        </div>
+      </div>
+
+      <!-- Scope selection row (Only for Random Mode) -->
+      <div v-if="mode === 'random'" class="control-group anim-fade-in">
+        <span class="control-label">图片来源</span>
+        <div class="custom-segmented">
+          <button
+            type="button"
+            class="custom-segmented__item"
+            :class="{ 'custom-segmented__item--active': randomScope === 'all' }"
+            :disabled="disabled"
+            @click="updateScope('all')"
+          >
+            {{ t('coverSource.randomAll') }}
+          </button>
+          <button
+            type="button"
+            class="custom-segmented__item"
+            :class="{ 'custom-segmented__item--active': randomScope === 'folder' }"
+            :disabled="disabled"
+            @click="updateScope('folder')"
+          >
+            {{ t('coverSource.randomFolder') }}
+          </button>
+        </div>
+      </div>
+
+      <!-- Folder select row (Only for Random + Folder Scope) -->
+      <div v-if="mode === 'random' && randomScope === 'folder'" class="control-group anim-fade-in">
+        <span class="control-label">选择目录</span>
+        <a-select
+          class="cover-source-selector__folder"
+          size="default"
+          :value="randomFolderId"
+          :options="folderOptions"
+          :loading="foldersQuery.isPending.value"
+          :disabled="disabled"
+          :placeholder="t('coverSource.folderPlaceholder')"
+          allow-clear
+          @change="updateFolder"
+        />
+      </div>
+    </div>
+
+    <!-- Bottom part: Visual Preview or Gradient Placeholder shown below controls -->
+    <div class="cover-source-selector__preview-area anim-fade-in">
+      <div v-if="mode === 'random'" class="random-gradient-card">
+        <div class="random-gradient-card__badge">
+          <svg viewBox="0 0 24 24" width="16" height="16" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round">
+            <polyline points="16 3 21 3 21 8" />
+            <line x1="4" y1="20" x2="21" y2="3" />
+            <polyline points="21 16 21 21 16 21" />
+            <line x1="15" y1="15" x2="21" y2="21" />
+            <line x1="4" y1="4" x2="9" y2="9" />
+          </svg>
+        </div>
+        <span class="random-gradient-card__text">随机抽取中</span>
+      </div>
+      <div v-else class="specific-preview-container">
+        <slot name="specific-preview"></slot>
+      </div>
+
+      <!-- Hint text for Random Mode -->
+      <div v-if="mode === 'random'" class="control-hint anim-fade-in">
+        <svg viewBox="0 0 24 24" width="13" height="13" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="control-hint__icon">
+          <circle cx="12" cy="12" r="10" />
+          <line x1="12" y1="16" x2="12" y2="12" />
+          <line x1="12" y1="8" x2="12.01" y2="8" />
+        </svg>
+        <span>{{ t('coverSource.randomHint') }}</span>
+      </div>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.cover-source-selector-panel {
+  display: flex;
+  flex-direction: column;
+  gap: 20px;
+  width: 100%;
+}
+
+.cover-source-selector-panel--disabled {
+  opacity: 0.6;
+  pointer-events: none;
+}
+
+.cover-source-selector__controls {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+
+.cover-source-selector__preview-area {
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
+  align-items: flex-start;
+  margin-top: 8px;
+}
+
+.random-gradient-card {
+  position: relative;
+  width: 200px;
+  height: 112px;
+  border-radius: 10px;
+  background: linear-gradient(135deg, #4f46e5, #06b6d4);
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  overflow: hidden;
+  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.15);
+  border: 1px solid rgba(255, 255, 255, 0.1);
+}
+
+.random-gradient-card__badge {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 34px;
+  height: 34px;
+  border-radius: 50%;
+  background: rgba(255, 255, 255, 0.18);
+  backdrop-filter: blur(8px);
+  -webkit-backdrop-filter: blur(8px);
+  color: #ffffff;
+  margin-bottom: 6px;
+  border: 1px solid rgba(255, 255, 255, 0.2);
+  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
+  animation: float 3s ease-in-out infinite;
+}
+
+.random-gradient-card__text {
+  font-size: 11px;
+  font-weight: 600;
+  color: rgba(255, 255, 255, 0.95);
+  letter-spacing: 0.05em;
+  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
+}
+
+.specific-preview-container {
+  width: 200px;
+  height: 112px;
+}
+
+.control-group {
+  display: flex;
+  align-items: center;
+  gap: 20px;
+}
+
+.control-label {
+  font-size: 13px;
+  font-weight: 500;
+  color: #64748b;
+  width: 72px;
+  flex-shrink: 0;
+}
+
+.custom-segmented {
+  display: inline-flex;
+  padding: 3px;
+  background: #f1f5f9;
+  border-radius: 8px;
+  border: 1px solid #e2e8f0;
+}
+
+.custom-segmented__item {
+  padding: 6px 16px;
+  border: none;
+  border-radius: 6px;
+  background: transparent;
+  font-size: 13px;
+  font-weight: 500;
+  color: #475569;
+  cursor: pointer;
+  transition: all 0.15s ease;
+  outline: none;
+}
+
+.custom-segmented__item:hover:not(:disabled) {
+  color: #0f172a;
+}
+
+.custom-segmented__item--active {
+  background: #ffffff;
+  color: #0f172a;
+  font-weight: 600;
+  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
+}
+
+.cover-source-selector__folder {
+  width: 260px;
+  max-width: 100%;
+}
+
+.control-hint {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  font-size: 13px;
+  color: #64748b;
+  margin-top: 4px;
+}
+
+.control-hint__icon {
+  color: #3b82f6;
+  flex-shrink: 0;
+}
+
+.anim-fade-in {
+  animation: fadeIn 0.2s ease-out forwards;
+}
+
+@keyframes float {
+  0%, 100% {
+    transform: translateY(0);
+  }
+  50% {
+    transform: translateY(-4px);
+  }
+}
+
+@keyframes fadeIn {
+  from {
+    opacity: 0;
+    transform: translateY(3px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+@media (max-width: 640px) {
+  .random-gradient-card, .specific-preview-container {
+    width: 100%;
+  }
+}
+</style>

apps/admin-web/src/components/GenerateTaskDrawer.vue

@@ -13,6 +13,8 @@ import type {
   KolSubscriptionPromptCard,
   KolVariableDefinition,
   PromptRuleSimple,
+  ScheduleCoverMode,
+  ScheduleCoverRandomScope,
   ScheduleEnterpriseSiteTarget,
   ScheduleKind,
   ScheduleTargetType,
@@ -24,6 +26,7 @@ import { computed, reactive, ref, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 
 import CoverPickerModal from '@/components/CoverPickerModal.vue'
+import CoverSourceSelector from '@/components/CoverSourceSelector.vue'
 import KnowledgeGroupSelect from '@/components/KnowledgeGroupSelect.vue'
 import KolDynamicForm from '@/components/kol/KolDynamicForm.vue'
 import KolPlatformTags from '@/components/kol/KolPlatformTags.vue'
@@ -113,6 +116,9 @@ const form = reactive({
   enterpriseSiteCategoryIds: {} as Record<number, string>,
   enterprisePublishType: 'publish' as SchedulePublishType,
   coverEnabled: false,
+  coverMode: 'specific' as ScheduleCoverMode,
+  coverRandomScope: 'all' as ScheduleCoverRandomScope,
+  coverRandomFolderId: null as number | null,
   coverAssetUrl: '',
   coverFileName: '',
   coverImageAssetId: null as number | null,
@@ -469,10 +475,14 @@ function hydrateForm(): void {
   enterpriseTargets.forEach((target) => {
     void loadEnterpriseCategories(target.site_id)
   })
-  form.coverAssetUrl = isSchedule.value ? resolveApiURL(task?.cover_asset_url) : ''
+  form.coverMode = isSchedule.value ? (task?.cover_mode ?? 'specific') : 'specific'
+  form.coverRandomScope = isSchedule.value ? (task?.cover_random_scope ?? 'all') : 'all'
+  form.coverRandomFolderId = isSchedule.value ? (task?.cover_random_folder_id ?? null) : null
+  form.coverAssetUrl =
+    isSchedule.value && form.coverMode === 'specific' ? resolveApiURL(task?.cover_asset_url) : ''
   form.coverFileName = deriveCoverFileName(form.coverAssetUrl)
   form.coverImageAssetId = isSchedule.value ? (task?.cover_image_asset_id ?? null) : null
-  form.coverEnabled = Boolean(form.coverAssetUrl)
+  form.coverEnabled = form.coverMode === 'random' || Boolean(form.coverAssetUrl)
   form.enableWebSearch = task?.enable_web_search ?? false
   form.generateCount = task?.generate_count ?? 1
   form.scheduleKind = task?.schedule_kind ?? 'daily'
@@ -505,7 +515,8 @@ function selectDefaultSubscriptionPrompt(): void {
 
 function buildSchedulePayload() {
   const coverEnabled = form.autoPublish && effectiveScheduleCoverEnabled.value
-  const coverAssetUrl = coverEnabled ? form.coverAssetUrl.trim() : ''
+  const coverMode = coverEnabled ? form.coverMode : 'specific'
+  const coverAssetUrl = coverEnabled && coverMode === 'specific' ? form.coverAssetUrl.trim() : ''
   const publishAccountIds =
     form.autoPublish && form.publishTargetTab === 'media_accounts' ? form.publishAccountIds : []
   const publishEnterpriseSiteTargets =
@@ -530,6 +541,12 @@ function buildSchedulePayload() {
     publish_enterprise_site_targets: publishEnterpriseSiteTargets,
     cover_asset_url: coverAssetUrl || null,
     cover_image_asset_id: coverAssetUrl ? form.coverImageAssetId : null,
+    cover_mode: coverMode,
+    cover_random_scope: coverEnabled && coverMode === 'random' ? form.coverRandomScope : 'all',
+    cover_random_folder_id:
+      coverEnabled && coverMode === 'random' && form.coverRandomScope === 'folder'
+        ? form.coverRandomFolderId
+        : null,
     enable_web_search: form.targetType === 'prompt_rule' ? form.enableWebSearch : false,
     generate_count: form.generateCount,
   }
@@ -691,6 +708,7 @@ function handleScheduleCoverPicked(payload: {
   form.coverFileName = payload.fileName
   form.coverImageAssetId = payload.assetId ?? null
   form.coverEnabled = true
+  form.coverMode = 'specific'
 }
 
 function handleRemoveScheduleCover(): void {
@@ -699,6 +717,15 @@ function handleRemoveScheduleCover(): void {
   form.coverImageAssetId = null
 }
 
+function handleScheduleCoverModeChange(value: ScheduleCoverMode): void {
+  form.coverMode = value
+  if (value === 'random') {
+    form.coverAssetUrl = ''
+    form.coverFileName = ''
+    form.coverImageAssetId = null
+  }
+}
+
 function handleScheduleCoverToggle(checked: boolean): void {
   if (scheduleCoverRequired.value) {
     form.coverEnabled = true
@@ -783,11 +810,21 @@ function validateForm(): boolean {
     if (
       form.publishTargetTab === 'media_accounts' &&
       scheduleCoverRequired.value &&
+      form.coverMode === 'specific' &&
       !form.coverAssetUrl.trim()
     ) {
       message.warning(t('custom.messages.missingScheduleCover'))
       return false
     }
+    if (
+      effectiveScheduleCoverEnabled.value &&
+      form.coverMode === 'random' &&
+      form.coverRandomScope === 'folder' &&
+      !form.coverRandomFolderId
+    ) {
+      message.warning(t('coverSource.randomEmpty'))
+      return false
+    }
   }
 
   return true
@@ -1454,32 +1491,52 @@ function normalizeJsonRecord(value: Record<string, unknown>): Record<string, Jso
             </p>
 
             <div v-if="effectiveScheduleCoverEnabled" class="generate-task-drawer__cover-body">
-              <div class="generate-task-drawer__cover-preview-wrap">
+              <CoverSourceSelector
-                <button
+                :mode="form.coverMode"
-                  type="button"
+                :random-scope="form.coverRandomScope"
-                  class="generate-task-drawer__cover-preview"
+                :random-folder-id="form.coverRandomFolderId"
-                  @click="coverPickerOpen = true"
+                @update:mode="handleScheduleCoverModeChange"
-                >
+                @update:random-scope="form.coverRandomScope = $event"
-                  <template v-if="form.coverAssetUrl">
+                @update:random-folder-id="form.coverRandomFolderId = $event"
-                    <img :src="form.coverAssetUrl" alt="cover preview" />
+              >
-                  </template>
+                <template #specific-preview>
-                  <template v-else>
+                  <div v-if="form.coverAssetUrl" class="generate-task-drawer__cover-preview-card animate-fade-in">
-                    <span class="generate-task-drawer__cover-plus">+</span>
+                    <img :src="form.coverAssetUrl" alt="cover preview" class="generate-task-drawer__cover-img" />
-                    <span>{{ t('custom.task.coverUpload') }}</span>
+                    <div class="generate-task-drawer__cover-overlay">
-                  </template>
+                      <button
-                </button>
+                        type="button"
+                        class="generate-task-drawer__overlay-btn"
+                        @click="coverPickerOpen = true"
+                      >
+                        更换
+                      </button>
+                      <button
+                        type="button"
+                        class="generate-task-drawer__overlay-btn generate-task-drawer__overlay-btn--danger"
+                        @click.stop="handleRemoveScheduleCover"
+                      >
+                        移除
+                      </button>
+                    </div>
+                  </div>
 
-                <button
+                  <button
-                  v-if="form.coverAssetUrl"
+                    v-else
-                  type="button"
+                    type="button"
-                  class="generate-task-drawer__cover-remove"
+                    class="generate-task-drawer__cover-upload-placeholder animate-fade-in"
-                  :aria-label="t('article.editor.coverRemove')"
+                    @click="coverPickerOpen = true"
-                  :title="t('article.editor.coverRemove')"
+                  >
-                  @click.stop="handleRemoveScheduleCover"
+                    <div class="generate-task-drawer__upload-icon">
-                >
+                      <svg viewBox="0 0 24 24" width="20" height="20" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round">
-                  <MinusCircleFilled />
+                        <rect x="3" y="3" width="18" height="18" rx="2" ry="2" />
-                </button>
+                        <circle cx="8.5" cy="8.5" r="1.5" />
-              </div>
+                        <polyline points="21 15 16 10 5 21" />
+                      </svg>
+                    </div>
+                    <span class="generate-task-drawer__upload-text">{{ t('custom.task.coverUpload') }}</span>
+                  </button>
+                </template>
+              </CoverSourceSelector>
             </div>
           </div>
         </template>
@@ -2075,71 +2132,125 @@ function normalizeJsonRecord(value: Record<string, unknown>): Record<string, Jso
 }
 
 .generate-task-drawer__cover-body {
-  display: flex;
+  margin-top: 16px;
-  margin-top: 12px;
 }
 
-.generate-task-drawer__cover-preview-wrap {
+.generate-task-drawer__cover-preview-card {
   position: relative;
-  width: 176px;
+  width: 200px;
-  flex: 0 0 176px;
+  height: 112px;
+  border-radius: 10px;
+  overflow: hidden;
+  border: 1px solid #e2e8f0;
+  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
 }
 
-.generate-task-drawer__cover-preview {
+.generate-task-drawer__cover-img {
+  width: 100%;
+  height: 100%;
+  object-fit: cover;
+  display: block;
+}
+
+.generate-task-drawer__cover-overlay {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  background: rgba(15, 23, 42, 0.6);
   display: flex;
   align-items: center;
   justify-content: center;
-  gap: 8px;
+  gap: 10px;
-  width: 100%;
+  opacity: 0;
-  min-height: 124px;
+  transition: opacity 0.2s ease-in-out;
-  padding: 0;
+  backdrop-filter: blur(4px);
-  border: 1px dashed #d1d5db;
+  -webkit-backdrop-filter: blur(4px);
-  border-radius: 8px;
+}
-  background: #f9fafb;
+
-  color: #6b7280;
+.generate-task-drawer__cover-preview-card:hover .generate-task-drawer__cover-overlay {
-  font-size: 13px;
+  opacity: 1;
+}
+
+.generate-task-drawer__overlay-btn {
+  padding: 4px 12px;
+  font-size: 12px;
+  font-weight: 600;
+  color: #0f172a;
+  background: #ffffff;
+  border: none;
+  border-radius: 6px;
+  cursor: pointer;
+  transition: all 0.15s ease;
+  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
+}
+
+.generate-task-drawer__overlay-btn:hover {
+  background: #f1f5f9;
+  transform: scale(1.03);
+}
+
+.generate-task-drawer__overlay-btn--danger {
+  color: #ffffff;
+  background: #ef4444;
+}
+
+.generate-task-drawer__overlay-btn--danger:hover {
+  background: #dc2626;
+}
+
+.generate-task-drawer__cover-upload-placeholder {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  width: 200px;
+  height: 112px;
+  padding: 12px;
+  border: 1.5px dashed #cbd5e1;
+  border-radius: 10px;
+  background: #f8fafc;
+  color: #64748b;
   cursor: pointer;
-  overflow: hidden;
   transition: all 0.2s ease;
 }
 
-.generate-task-drawer__cover-preview:hover {
+.generate-task-drawer__cover-upload-placeholder:hover {
-  border-color: #6366f1;
+  border-color: #3b82f6;
-  background: #f5f3ff;
+  color: #3b82f6;
-  color: #6366f1;
+  background: #f0f6ff;
 }
 
-.generate-task-drawer__cover-preview img {
+.generate-task-drawer__upload-icon {
-  display: block;
+  margin-bottom: 6px;
-  width: 100%;
+  color: #94a3b8;
-  height: 124px;
+  transition: color 0.2s;
-  object-fit: cover;
-}
-
-.generate-task-drawer__cover-plus {
-  font-size: 20px;
-  line-height: 1;
-}
-
-.generate-task-drawer__cover-remove {
-  position: absolute;
-  top: 8px;
-  right: 8px;
   display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  width: 28px;
-  height: 28px;
-  border: none;
-  border-radius: 999px;
-  background: rgba(17, 24, 39, 0.7);
-  color: #fff;
-  cursor: pointer;
-  transition: background 0.2s ease;
 }
 
-.generate-task-drawer__cover-remove:hover {
+.generate-task-drawer__cover-upload-placeholder:hover .generate-task-drawer__upload-icon {
-  background: rgba(17, 24, 39, 0.9);
+  color: #3b82f6;
+}
+
+.generate-task-drawer__upload-text {
+  font-size: 12px;
+  font-weight: 600;
+}
+
+.animate-fade-in {
+  animation: fadeIn 0.2s ease-out forwards;
+}
+
+@keyframes fadeIn {
+  from {
+    opacity: 0;
+    transform: translateY(3px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
 }
 
 .generate-task-drawer__time-wrapper {

apps/admin-web/src/components/PublishArticleModal.vue

@@ -16,6 +16,8 @@ import type {
   EnterpriseSitePublishResponse,
   GateDecisionLiteral,
   PublishRecord,
+  ScheduleCoverMode,
+  ScheduleCoverRandomScope,
 } from '@geo/shared-types'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/vue-query'
 import { message, notification } from 'ant-design-vue'
@@ -23,10 +25,12 @@ import { computed, ref, watch, watchEffect } from 'vue'
 import { useI18n } from 'vue-i18n'
 
 import CoverPickerModal from '@/components/CoverPickerModal.vue'
+import CoverSourceSelector from '@/components/CoverSourceSelector.vue'
 import {
   articlesApi,
   complianceApi,
   enterpriseSitesApi,
+  imagesApi,
   mediaApi,
   publishJobsApi,
   resolveApiURL,
@@ -86,6 +90,9 @@ const enterpriseCategoriesBySiteId = ref<Record<number, EnterpriseSiteCategory[]
 const enterpriseSiteCategoryIds = ref<Record<number, string>>({})
 const enterprisePublishType = ref<PublishType>('publish')
 const coverEnabled = ref(false)
+const coverMode = ref<ScheduleCoverMode>('specific')
+const coverRandomScope = ref<ScheduleCoverRandomScope>('all')
+const coverRandomFolderId = ref<number | null>(null)
 const coverAssetUrl = ref('')
 const coverFileName = ref('')
 const coverImageAssetId = ref<number | null>(null)
@@ -161,6 +168,9 @@ watch(
       enterpriseCategoriesBySiteId.value = {}
       enterpriseSiteCategoryIds.value = {}
       enterprisePublishType.value = 'publish'
+      coverMode.value = 'specific'
+      coverRandomScope.value = 'all'
+      coverRandomFolderId.value = null
       coverAssetUrl.value = ''
       coverFileName.value = ''
       coverImageAssetId.value = null
@@ -418,7 +428,10 @@ const publishModalVisible = computed(() => props.open && !coverPickerOpen.value)
 const coverRequired = computed(() => coverUploadRequired(selectedPlatformIds.value))
 const effectiveCoverEnabled = computed(() => coverRequired.value || coverEnabled.value)
 const normalizedCoverValue = computed(() =>
-  effectiveCoverEnabled.value ? coverAssetUrl.value.trim() : '',
+  effectiveCoverEnabled.value && coverMode.value === 'specific' ? coverAssetUrl.value.trim() : '',
+)
+const randomCoverEnabled = computed(
+  () => effectiveCoverEnabled.value && coverMode.value === 'random',
 )
 const publishMutation = useMutation({
   mutationFn: () => runPublishFlow(),
@@ -524,7 +537,7 @@ const okDisabled = computed(() => {
   ) {
     return true
   }
-  if (coverRequired.value && !normalizedCoverValue.value) {
+  if (coverRequired.value && !normalizedCoverValue.value && !randomCoverEnabled.value) {
     return true
   }
   if (mandatoryAdmissionBlocking.value) {
@@ -681,12 +694,12 @@ async function runPublishFlow(ackRecordId?: number) {
   if (!selectedAccountIds.value.length) {
     throw new Error('no_accounts_selected')
   }
-  if (coverRequired.value && !normalizedCoverValue.value) {
+  if (coverRequired.value && !normalizedCoverValue.value && !randomCoverEnabled.value) {
     throw new Error('cover_required_for_selected_platforms')
   }
 
   const freshDetail = await loadLatestPublishArticleDetail()
-  const article = await persistCoverIfNeeded(freshDetail)
+  const article = await persistCoverIfNeeded(freshDetail, await resolvePublishCoverOverride())
   const articleVersionId = article.current_version_id ?? detailQuery.data.value.current_version_id
   if (!articleVersionId) {
     throw new Error('invalid_article_version')
@@ -735,7 +748,7 @@ async function runEnterpriseSitePublishFlow(
   }
 
   const freshDetail = await loadLatestPublishArticleDetail()
-  const article = await persistCoverIfNeeded(freshDetail)
+  const article = await persistCoverIfNeeded(freshDetail, await resolvePublishCoverOverride())
   const articleVersionId = article.current_version_id ?? detailQuery.data.value.current_version_id
   if (!articleVersionId) {
     throw new Error('invalid_article_version')
@@ -860,6 +873,14 @@ function handlePublishError(error: unknown) {
     message.warning(t('media.publish.messages.coverRequired'))
     return
   }
+  if (normalized === 'cover_random_folder_required') {
+    message.warning(t('coverSource.randomEmpty'))
+    return
+  }
+  if (normalized === 'cover_random_empty') {
+    message.warning('随机封面范围内暂无可用图片')
+    return
+  }
   if (normalized === 'compliance_needs_ack' || normalized === 'compliance_block') {
     return
   }
@@ -911,12 +932,21 @@ async function handleEnterprisePublishSuccess(
   }
 }
 
-async function persistCoverIfNeeded(detail: ArticleDetail): Promise<ArticleDetail> {
+type PublishCoverOverride = {
-  const currentUrl = resolveApiURL(detail.cover_asset_url).trim()
+  url: string
-  const nextUrl = normalizedCoverValue.value.trim()
+  assetId: number | null
-  const currentAssetId = detail.cover_image_asset_id ?? null
+}
 
-  if (currentUrl === nextUrl && currentAssetId === coverImageAssetId.value) {
+async function persistCoverIfNeeded(
+  detail: ArticleDetail,
+  override?: PublishCoverOverride | null,
+): Promise<ArticleDetail> {
+  const currentUrl = resolveApiURL(detail.cover_asset_url).trim()
+  const nextUrl = override ? override.url.trim() : normalizedCoverValue.value.trim()
+  const currentAssetId = detail.cover_image_asset_id ?? null
+  const nextAssetId = override ? override.assetId : coverImageAssetId.value
+
+  if (currentUrl === nextUrl && currentAssetId === nextAssetId) {
     return detail
   }
 
@@ -924,10 +954,47 @@ async function persistCoverIfNeeded(detail: ArticleDetail): Promise<ArticleDetai
     title: detail.title?.trim() || t('article.untitled'),
     markdown_content: detail.markdown_content ?? '',
     cover_asset_url: nextUrl || null,
-    cover_image_asset_id: coverImageAssetId.value,
+    cover_image_asset_id: nextAssetId,
   })
 }
 
+async function resolvePublishCoverOverride(): Promise<PublishCoverOverride | null> {
+  if (!randomCoverEnabled.value) {
+    return null
+  }
+  if (coverRandomScope.value === 'folder' && !coverRandomFolderId.value) {
+    throw new Error('cover_random_folder_required')
+  }
+  const baseParams = {
+    folder_id: coverRandomScope.value === 'folder' ? coverRandomFolderId.value : undefined,
+    page: 1,
+    page_size: 100,
+  }
+  const firstPage = await imagesApi.list(baseParams)
+  if (!firstPage.items.length) {
+    throw new Error('cover_random_empty')
+  }
+  const pageCount = Math.max(1, Math.ceil(firstPage.total / baseParams.page_size))
+  const response =
+    pageCount > 1
+      ? await imagesApi.list({
+          ...baseParams,
+          page: Math.floor(Math.random() * pageCount) + 1,
+        })
+      : firstPage
+  if (!response.items.length) {
+    return {
+      url: firstPage.items[0].url,
+      assetId: firstPage.items[0].id,
+    }
+  }
+  const picked = response.items[Math.floor(Math.random() * response.items.length)]
+  return {
+    url: picked.url,
+    assetId: picked.id,
+  }
+}
+
 function successDescription(result: CreatePublishJobResponse): string {
   const created = result.created_task_ids.length
   const existing = result.existing_task_ids.length
@@ -1144,7 +1211,9 @@ function cmsTypeLabel(cmsType: string): string {
 }
 
 function normalizeEnterprisePlatformId(cmsType: string): string {
-  const normalized = String(cmsType ?? '').trim().toLowerCase()
+  const normalized = String(cmsType ?? '')
+    .trim()
+    .toLowerCase()
   switch (normalized) {
     case 'pbootcms':
       return 'pbootcms'
@@ -1246,6 +1315,7 @@ function handleCoverPicked(payload: {
   coverFileName.value = payload.fileName
   coverImageAssetId.value = payload.assetId ?? null
   coverEnabled.value = true
+  coverMode.value = 'specific'
 }
 
 function handleRemoveCover(): void {
@@ -1254,6 +1324,15 @@ function handleRemoveCover(): void {
   coverImageAssetId.value = null
 }
 
+function handleCoverModeChange(value: ScheduleCoverMode): void {
+  coverMode.value = value
+  if (value === 'random') {
+    coverAssetUrl.value = ''
+    coverFileName.value = ''
+    coverImageAssetId.value = null
+  }
+}
+
 async function handleModalOk(): Promise<void> {
   if (okDisabled.value) {
     return
@@ -1838,32 +1917,52 @@ function decisionAlertType(result: ComplianceCheckResult | null | undefined) {
         </p>
 
         <div v-if="effectiveCoverEnabled" class="publish-modal__cover-body">
-          <div class="publish-modal__cover-preview-wrap">
+          <CoverSourceSelector
-            <button
+            :mode="coverMode"
-              type="button"
+            :random-scope="coverRandomScope"
-              class="publish-modal__cover-preview"
+            :random-folder-id="coverRandomFolderId"
-              @click="coverPickerOpen = true"
+            @update:mode="handleCoverModeChange"
-            >
+            @update:random-scope="coverRandomScope = $event"
-              <template v-if="coverAssetUrl">
+            @update:random-folder-id="coverRandomFolderId = $event"
-                <img :src="coverAssetUrl" alt="cover preview" />
+          >
-              </template>
+            <template #specific-preview>
-              <template v-else>
+              <div v-if="coverAssetUrl" class="publish-modal__cover-preview-card animate-fade-in">
-                <span class="publish-modal__cover-plus">+</span>
+                <img :src="coverAssetUrl" alt="cover preview" class="publish-modal__cover-img" />
-                <span>{{ t('media.publish.coverUpload') }}</span>
+                <div class="publish-modal__cover-overlay">
-              </template>
+                  <button
-            </button>
+                    type="button"
+                    class="publish-modal__overlay-btn"
+                    @click="coverPickerOpen = true"
+                  >
+                    更换
+                  </button>
+                  <button
+                    type="button"
+                    class="publish-modal__overlay-btn publish-modal__overlay-btn--danger"
+                    @click.stop="handleRemoveCover"
+                  >
+                    移除
+                  </button>
+                </div>
+              </div>
 
-            <button
+              <button
-              v-if="coverAssetUrl"
+                v-else
-              type="button"
+                type="button"
-              class="publish-modal__cover-remove"
+                class="publish-modal__cover-upload-placeholder animate-fade-in"
-              :aria-label="t('article.editor.coverRemove')"
+                @click="coverPickerOpen = true"
-              :title="t('article.editor.coverRemove')"
+              >
-              @click.stop="handleRemoveCover"
+                <div class="publish-modal__upload-icon">
-            >
+                  <svg viewBox="0 0 24 24" width="20" height="20" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round">
-              <MinusCircleFilled />
+                    <rect x="3" y="3" width="18" height="18" rx="2" ry="2" />
-            </button>
+                    <circle cx="8.5" cy="8.5" r="1.5" />
-          </div>
+                    <polyline points="21 15 16 10 5 21" />
+                  </svg>
+                </div>
+                <span class="publish-modal__upload-text">{{ t('media.publish.coverUpload') }}</span>
+              </button>
+            </template>
+          </CoverSourceSelector>
         </div>
       </section>
     </div>
@@ -2758,71 +2857,125 @@ function decisionAlertType(result: ComplianceCheckResult | null | undefined) {
 }
 
 .publish-modal__cover-body {
-  display: flex;
+  margin-top: 16px;
-  margin-top: 12px;
 }
 
-.publish-modal__cover-preview-wrap {
+.publish-modal__cover-preview-card {
   position: relative;
-  width: 176px;
+  width: 200px;
-  flex: 0 0 176px;
+  height: 112px;
+  border-radius: 10px;
+  overflow: hidden;
+  border: 1px solid #e2e8f0;
+  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
 }
 
-.publish-modal__cover-preview {
+.publish-modal__cover-img {
+  width: 100%;
+  height: 100%;
+  object-fit: cover;
+  display: block;
+}
+
+.publish-modal__cover-overlay {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  background: rgba(15, 23, 42, 0.6);
   display: flex;
   align-items: center;
   justify-content: center;
-  width: 100%;
+  gap: 10px;
-  min-height: 124px;
+  opacity: 0;
-  padding: 0;
+  transition: opacity 0.2s ease-in-out;
-  border: 1px dashed #d1d5db;
+  backdrop-filter: blur(4px);
-  border-radius: 8px;
+  -webkit-backdrop-filter: blur(4px);
-  background: #f9fafb;
+}
-  color: #6b7280;
+
-  font-size: 13px;
+.publish-modal__cover-preview-card:hover .publish-modal__cover-overlay {
-  gap: 8px;
+  opacity: 1;
+}
+
+.publish-modal__overlay-btn {
+  padding: 4px 12px;
+  font-size: 12px;
+  font-weight: 600;
+  color: #0f172a;
+  background: #ffffff;
+  border: none;
+  border-radius: 6px;
+  cursor: pointer;
+  transition: all 0.15s ease;
+  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.08);
+}
+
+.publish-modal__overlay-btn:hover {
+  background: #f1f5f9;
+  transform: scale(1.03);
+}
+
+.publish-modal__overlay-btn--danger {
+  color: #ffffff;
+  background: #ef4444;
+}
+
+.publish-modal__overlay-btn--danger:hover {
+  background: #dc2626;
+}
+
+.publish-modal__cover-upload-placeholder {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  width: 200px;
+  height: 112px;
+  padding: 12px;
+  border: 1.5px dashed #cbd5e1;
+  border-radius: 10px;
+  background: #f8fafc;
+  color: #64748b;
   cursor: pointer;
-  overflow: hidden;
   transition: all 0.2s ease;
 }
 
-.publish-modal__cover-preview:hover {
+.publish-modal__cover-upload-placeholder:hover {
-  border-color: #6366f1;
+  border-color: #3b82f6;
-  color: #6366f1;
+  color: #3b82f6;
-  background: #f5f3ff;
+  background: #f0f6ff;
 }
 
-.publish-modal__cover-preview img {
+.publish-modal__upload-icon {
-  display: block;
+  margin-bottom: 6px;
-  width: 100%;
+  color: #94a3b8;
-  height: 124px;
+  transition: color 0.2s;
-  object-fit: cover;
-}
-
-.publish-modal__cover-plus {
-  font-size: 20px;
-  line-height: 1;
-}
-
-.publish-modal__cover-remove {
-  position: absolute;
-  top: 8px;
-  right: 8px;
-  width: 28px;
-  height: 28px;
-  border: none;
-  border-radius: 999px;
-  background: rgba(17, 24, 39, 0.7);
-  color: #fff;
   display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  cursor: pointer;
-  transition: background 0.2s;
 }
 
-.publish-modal__cover-remove:hover {
+.publish-modal__cover-upload-placeholder:hover .publish-modal__upload-icon {
-  background: rgba(17, 24, 39, 0.9);
+  color: #3b82f6;
+}
+
+.publish-modal__upload-text {
+  font-size: 12px;
+  font-weight: 600;
+}
+
+.animate-fade-in {
+  animation: fadeIn 0.2s ease-out forwards;
+}
+
+@keyframes fadeIn {
+  from {
+    opacity: 0;
+    transform: translateY(3px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
 }
 
 @media (max-width: 900px) {

apps/admin-web/src/i18n/messages/zh-CN.ts

@@ -69,6 +69,15 @@ const zhCN = {
       },
     },
   },
+  coverSource: {
+    specific: '指定图片',
+    random: '随机图片',
+    randomAll: '全部图片',
+    randomFolder: '指定文件夹',
+    folderPlaceholder: '选择图片文件夹',
+    randomHint: '发布时会从所选范围随机抽取一张封面图。',
+    randomEmpty: '请先选择随机图片文件夹',
+  },
   nav: {
     workspace: '工作台',
     articleCreation: '文章创作',

packages/shared-types/src/index.ts

@@ -2132,6 +2132,8 @@ export type ScheduleTargetType = 'prompt_rule' | 'kol_subscription_prompt'
 export type ScheduleKind = 'daily' | 'weekly'
 export type ScheduleTimeMode = 'fixed' | 'random_window'
 export type ScheduleDispatchStatus = 'success' | 'failed' | string
+export type ScheduleCoverMode = 'specific' | 'random'
+export type ScheduleCoverRandomScope = 'all' | 'folder'
 
 export interface ScheduleTask {
   id: number
@@ -2159,6 +2161,9 @@ export interface ScheduleTask {
   auto_publish_platforms: string[]
   cover_asset_url: string | null
   cover_image_asset_id: number | null
+  cover_mode: ScheduleCoverMode
+  cover_random_scope: ScheduleCoverRandomScope
+  cover_random_folder_id: number | null
   enable_web_search: boolean
   generate_count: number
   start_at: string | null
@@ -2194,6 +2199,9 @@ export interface ScheduleTaskRequest {
   publish_enterprise_site_targets?: ScheduleEnterpriseSiteTarget[]
   cover_asset_url?: string | null
   cover_image_asset_id?: number | null
+  cover_mode?: ScheduleCoverMode
+  cover_random_scope?: ScheduleCoverRandomScope
+  cover_random_folder_id?: number | null
   enable_web_search?: boolean
   generate_count?: number
   start_at?: string

server/internal/scheduler/schedule_dispatch_worker.go

@@ -16,6 +16,7 @@ import (
 	sharedcache "github.com/geo-platform/tenant-api/internal/shared/cache"
 	"github.com/geo-platform/tenant-api/internal/shared/config"
 	"github.com/geo-platform/tenant-api/internal/shared/messaging/rabbitmq"
+	"github.com/geo-platform/tenant-api/internal/shared/publicasset"
 	sharedschedule "github.com/geo-platform/tenant-api/internal/shared/schedule"
 	tenantapp "github.com/geo-platform/tenant-api/internal/tenant/app"
 )
@@ -60,6 +61,9 @@ type dueScheduleTask struct {
 	PublishEnterpriseSiteTargets []tenantapp.ScheduleEnterpriseSiteTarget
 	CoverAssetURL                *string
 	CoverImageAssetID            *int64
+	CoverMode                    string
+	CoverRandomScope             string
+	CoverRandomFolderID          *int64
 	EnableWebSearch              bool
 	GenerateCount                int
 	StartAt                      *time.Time
@@ -378,6 +382,7 @@ func (w *ScheduleDispatchWorker) claimDueSchedules(ctx context.Context, runtimeC
 		       subscription_prompt_id, brand_id, name, cron_expr, schedule_days, schedule_time_mode,
 		       random_window_start::text, random_window_end::text, generation_input_json,
 		       auto_publish, publish_account_ids, publish_enterprise_site_targets, cover_asset_url, cover_image_asset_id,
+		       cover_mode, cover_random_scope, cover_random_folder_id,
 		       enable_web_search, generate_count, start_at, end_at, next_run_at
 		FROM schedule_tasks
 		WHERE deleted_at IS NULL
@@ -410,6 +415,7 @@ func (w *ScheduleDispatchWorker) claimDueSchedules(ctx context.Context, runtimeC
 			scheduleDaysJSON                 []byte
 			publishAccountIDsJSON            []byte
 			publishEnterpriseSiteTargetsJSON []byte
+			coverRandomFolderID              pgtype.Int8
 			startAt                          pgtype.Timestamptz
 			endAt                            pgtype.Timestamptz
 			nextRunAt                        pgtype.Timestamptz
@@ -435,6 +441,9 @@ func (w *ScheduleDispatchWorker) claimDueSchedules(ctx context.Context, runtimeC
 			&publishEnterpriseSiteTargetsJSON,
 			&task.CoverAssetURL,
 			&task.CoverImageAssetID,
+			&task.CoverMode,
+			&task.CoverRandomScope,
+			&coverRandomFolderID,
 			&task.EnableWebSearch,
 			&task.GenerateCount,
 			&startAt,
@@ -460,6 +469,13 @@ func (w *ScheduleDispatchWorker) claimDueSchedules(ctx context.Context, runtimeC
 		}
 		task.PublishAccountIDs = decodeDueSchedulePublishAccountIDs(publishAccountIDsJSON)
 		task.PublishEnterpriseSiteTargets = tenantapp.DecodeScheduleEnterpriseSiteTargets(publishEnterpriseSiteTargetsJSON)
+		task.CoverRandomFolderID = int64PtrFromInt8(coverRandomFolderID)
+		if task.CoverMode == "" {
+			task.CoverMode = tenantapp.ScheduleCoverModeSpecific
+		}
+		if task.CoverRandomScope == "" {
+			task.CoverRandomScope = tenantapp.ScheduleCoverRandomScopeAll
+		}
 		if task.GenerateCount <= 0 {
 			task.GenerateCount = 1
 		}
@@ -587,6 +603,10 @@ func (w *ScheduleDispatchWorker) dispatch(parent context.Context, task dueSchedu
 }
 
 func (w *ScheduleDispatchWorker) enqueueDueGeneration(ctx context.Context, task dueScheduleTask, generateCount int) (*tenantapp.GenerateFromRuleResponse, error) {
+	coverAssetURL, coverImageAssetID, err := w.resolveDueScheduleCover(ctx, task)
+	if err != nil {
+		return nil, err
+	}
 	switch task.TargetType {
 	case "", tenantapp.ScheduleTargetPromptRule:
 		if task.PromptRuleID == nil || *task.PromptRuleID <= 0 {
@@ -603,8 +623,8 @@ func (w *ScheduleDispatchWorker) enqueueDueGeneration(ctx context.Context, task
 			AutoPublish:                  task.AutoPublish,
 			PublishAccountIDs:            task.PublishAccountIDs,
 			PublishEnterpriseSiteTargets: task.PublishEnterpriseSiteTargets,
-			CoverAssetURL:                task.CoverAssetURL,
+			CoverAssetURL:                coverAssetURL,
-			CoverImageAssetID:            task.CoverImageAssetID,
+			CoverImageAssetID:            coverImageAssetID,
 			EnableWebSearch:              task.EnableWebSearch,
 			GenerateCount:                generateCount,
 			ScheduledFor:                 task.ScheduledFor,
@@ -631,8 +651,8 @@ func (w *ScheduleDispatchWorker) enqueueDueGeneration(ctx context.Context, task
 			AutoPublish:                  task.AutoPublish,
 			PublishAccountIDs:            task.PublishAccountIDs,
 			PublishEnterpriseSiteTargets: task.PublishEnterpriseSiteTargets,
-			CoverAssetURL:                task.CoverAssetURL,
+			CoverAssetURL:                coverAssetURL,
-			CoverImageAssetID:            task.CoverImageAssetID,
+			CoverImageAssetID:            coverImageAssetID,
 			GenerateCount:                generateCount,
 			ScheduledFor:                 task.ScheduledFor,
 		})
@@ -648,6 +668,82 @@ func (w *ScheduleDispatchWorker) enqueueDueGeneration(ctx context.Context, task
 	}
 }
 
+func (w *ScheduleDispatchWorker) resolveDueScheduleCover(ctx context.Context, task dueScheduleTask) (*string, *int64, error) {
+	if !task.AutoPublish {
+		return nil, nil, nil
+	}
+	if task.CoverMode != tenantapp.ScheduleCoverModeRandom {
+		return task.CoverAssetURL, task.CoverImageAssetID, nil
+	}
+	image, err := w.pickRandomScheduleCoverImage(ctx, task)
+	if err != nil {
+		return nil, nil, err
+	}
+	coverURL := buildScheduleCoverAssetURL(image.ObjectKey, w.assetTokenSecret())
+	return &coverURL, &image.ID, nil
+}
+
+type scheduleCoverImage struct {
+	ID        int64
+	ObjectKey string
+}
+
+func (w *ScheduleDispatchWorker) pickRandomScheduleCoverImage(ctx context.Context, task dueScheduleTask) (scheduleCoverImage, error) {
+	if w == nil || w.pool == nil {
+		return scheduleCoverImage{}, errors.New("schedule random cover lookup unavailable")
+	}
+
+	var row pgxRow
+	if task.CoverRandomScope == tenantapp.ScheduleCoverRandomScopeFolder {
+		if task.CoverRandomFolderID == nil || *task.CoverRandomFolderID <= 0 {
+			return scheduleCoverImage{}, errors.New("schedule random cover folder missing")
+		}
+		row = w.pool.QueryRow(ctx, `
+			SELECT id, object_key
+			FROM image_assets
+			WHERE tenant_id = $1
+			  AND folder_id = $2
+			  AND status = 'active'
+			  AND deleted_at IS NULL
+			ORDER BY random()
+			LIMIT 1
+		`, task.TenantID, *task.CoverRandomFolderID)
+	} else {
+		row = w.pool.QueryRow(ctx, `
+			SELECT id, object_key
+			FROM image_assets
+			WHERE tenant_id = $1
+			  AND status = 'active'
+			  AND deleted_at IS NULL
+			ORDER BY random()
+			LIMIT 1
+		`, task.TenantID)
+	}
+
+	var image scheduleCoverImage
+	if err := row.Scan(&image.ID, &image.ObjectKey); err != nil {
+		return scheduleCoverImage{}, errors.New("schedule random cover image not found")
+	}
+	return image, nil
+}
+
+type pgxRow interface {
+	Scan(dest ...interface{}) error
+}
+
+func (w *ScheduleDispatchWorker) assetTokenSecret() string {
+	if w != nil && w.configProvider != nil {
+		if cfg := w.configProvider.Current(); cfg != nil {
+			return strings.TrimSpace(cfg.JWT.Secret)
+		}
+	}
+	return ""
+}
+
+func buildScheduleCoverAssetURL(objectKey string, secret string) string {
+	return "/api/public/assets/" + publicasset.SignObjectKey(objectKey, secret)
+}
+
 func (w *ScheduleDispatchWorker) recordDispatchResult(ctx context.Context, task dueScheduleTask, generateCount int, failures []error) {
 	if w == nil || w.pool == nil {
 		return

server/internal/tenant/app/schedule_task_policy.go

@@ -14,6 +14,10 @@ import (
 const (
 	ScheduleTargetPromptRule            = "prompt_rule"
 	ScheduleTargetKolSubscriptionPrompt = "kol_subscription_prompt"
+	ScheduleCoverModeSpecific           = "specific"
+	ScheduleCoverModeRandom             = "random"
+	ScheduleCoverRandomScopeAll         = "all"
+	ScheduleCoverRandomScopeFolder      = "folder"
 
 	scheduleKindDaily  = "daily"
 	scheduleKindWeekly = "weekly"

server/internal/tenant/app/schedule_task_service.go

@@ -58,6 +58,9 @@ type ScheduleTaskRequest struct {
 	PublishEnterpriseSiteTargets []ScheduleEnterpriseSiteTarget `json:"publish_enterprise_site_targets"`
 	CoverAssetURL                *string                        `json:"cover_asset_url"`
 	CoverImageAssetID            *int64                         `json:"cover_image_asset_id"`
+	CoverMode                    string                         `json:"cover_mode"`
+	CoverRandomScope             string                         `json:"cover_random_scope"`
+	CoverRandomFolderID          *int64                         `json:"cover_random_folder_id"`
 	EnableWebSearch              *bool                          `json:"enable_web_search"`
 	GenerateCount                *int                           `json:"generate_count"`
 	StartAt                      *string                        `json:"start_at"`
@@ -90,6 +93,9 @@ type ScheduleTaskResponse struct {
 	AutoPublishPlatforms         []string                       `json:"auto_publish_platforms"`
 	CoverAssetURL                *string                        `json:"cover_asset_url"`
 	CoverImageAssetID            *int64                         `json:"cover_image_asset_id"`
+	CoverMode                    string                         `json:"cover_mode"`
+	CoverRandomScope             string                         `json:"cover_random_scope"`
+	CoverRandomFolderID          *int64                         `json:"cover_random_folder_id"`
 	EnableWebSearch              bool                           `json:"enable_web_search"`
 	GenerateCount                int                            `json:"generate_count"`
 	StartAt                      *string                        `json:"start_at"`
@@ -212,21 +218,27 @@ func (s *ScheduleTaskService) Create(ctx context.Context, req ScheduleTaskReques
 			brand_id, name, cron_expr, schedule_kind, schedule_days, schedule_time_mode,
 			random_window_start, random_window_end, generation_input_json,
 			enable_web_search, generate_count, auto_publish, publish_account_ids,
-			publish_enterprise_site_targets, cover_asset_url, cover_image_asset_id, start_at, end_at
+			publish_enterprise_site_targets, cover_asset_url, cover_image_asset_id,
+			cover_mode, cover_random_scope, cover_random_folder_id,
+			start_at, end_at
 		)
 		VALUES (
 			$1, $2, $3, $4, $5, $6,
 			$7, $8, $9, $10, $11::jsonb, $12,
 			$13::time, $14::time, $15::jsonb,
 			$16, $17, $18, $19::jsonb,
-			$20::jsonb, $21, $22, $23::timestamptz, $24::timestamptz
+			$20::jsonb, $21, $22,
+			$23, $24, $25,
+			$26::timestamptz, $27::timestamptz
 		)
 		RETURNING id, created_at, start_at, end_at, status
 	`, actor.TenantID, actor.PrimaryWorkspaceID, actor.UserID, targetType, promptRuleID, subscriptionPromptID,
 		req.BrandID, req.Name, plan.CronExpr, plan.ScheduleKind, encodeScheduleDayKeys(plan.ScheduleDays), plan.ScheduleTimeMode,
 		plan.RandomWindowStart, plan.RandomWindowEnd, encodeScheduleGenerationInput(generationInput),
 		enableWebSearch, generateCount, publishConfig.AutoPublish, publishConfig.AccountIDsJSON,
-		publishConfig.EnterpriseTargetsJSON, publishConfig.CoverAssetURL, publishConfig.CoverImageAssetID, req.StartAt, req.EndAt).
+		publishConfig.EnterpriseTargetsJSON, publishConfig.CoverAssetURL, publishConfig.CoverImageAssetID,
+		publishConfig.CoverMode, publishConfig.CoverRandomScope, publishConfig.CoverRandomFolderID,
+		req.StartAt, req.EndAt).
 		Scan(&id, &createdAt, &startAt, &endAt, &status)
 	if err != nil {
 		return nil, response.ErrInternal(50010, "create_failed", "failed to create schedule task")
@@ -286,9 +298,11 @@ func (s *ScheduleTaskService) Create(ctx context.Context, req ScheduleTaskReques
 		RandomWindowEnd: plan.RandomWindowEnd, GenerationInput: generationInput, AutoPublish: publishConfig.AutoPublish,
 		PublishAccountIDs: publishConfig.AccountIDs, PublishEnterpriseSiteTargets: publishConfig.EnterpriseTargets,
 		AutoPublishPlatforms: publishConfig.PlatformIDs, CoverAssetURL: publishConfig.CoverAssetURL,
-		CoverImageAssetID: publishConfig.CoverImageAssetID, EnableWebSearch: enableWebSearch,
+		CoverImageAssetID: publishConfig.CoverImageAssetID, CoverMode: publishConfig.CoverMode,
-		GenerateCount: generateCount,
+		CoverRandomScope: publishConfig.CoverRandomScope, CoverRandomFolderID: publishConfig.CoverRandomFolderID,
-		Status:        status, CreatedAt: timeStringFromDBValue(createdAt),
+		EnableWebSearch: enableWebSearch,
+		GenerateCount:   generateCount,
+		Status:          status, CreatedAt: timeStringFromDBValue(createdAt),
 		NextRunAt: timeStringPtr(nextRunAt),
 	}, nil
 }
@@ -350,17 +364,19 @@ func (s *ScheduleTaskService) Update(ctx context.Context, id int64, req Schedule
 	       workspace_id = $15, auto_publish = $16, publish_account_ids = $17::jsonb,
 	       publish_enterprise_site_targets = $18::jsonb,
 	       cover_asset_url = $19, cover_image_asset_id = $20,
-	       start_at = $21::timestamptz, end_at = $22::timestamptz, operator_id = $23,
+	       cover_mode = $21, cover_random_scope = $22, cover_random_folder_id = $23,
+	       start_at = $24::timestamptz, end_at = $25::timestamptz, operator_id = $26,
 	       last_dispatch_status = NULL, last_dispatch_error = NULL,
 	       consecutive_failures = 0,
 	       updated_at = NOW()
-		WHERE id = $24 AND tenant_id = $25 AND brand_id = $26 AND deleted_at IS NULL
+		WHERE id = $27 AND tenant_id = $28 AND brand_id = $29 AND deleted_at IS NULL
 		RETURNING status, start_at, end_at
 	`, targetType, promptRuleID, subscriptionPromptID, req.BrandID, req.Name, plan.CronExpr,
 		plan.ScheduleKind, encodeScheduleDayKeys(plan.ScheduleDays), plan.ScheduleTimeMode,
 		plan.RandomWindowStart, plan.RandomWindowEnd, encodeScheduleGenerationInput(generationInput),
 		enableWebSearch, generateCount, actor.PrimaryWorkspaceID, publishConfig.AutoPublish,
 		publishConfig.AccountIDsJSON, publishConfig.EnterpriseTargetsJSON, publishConfig.CoverAssetURL, publishConfig.CoverImageAssetID,
+		publishConfig.CoverMode, publishConfig.CoverRandomScope, publishConfig.CoverRandomFolderID,
 		req.StartAt, req.EndAt, actor.UserID, id, actor.TenantID, brandID).
 		Scan(&status, &startAt, &endAt)
 	if err != nil {
@@ -503,7 +519,9 @@ func (s *ScheduleTaskService) loadScheduleTasks(ctx context.Context, tenantID, b
 		       st.cron_expr, st.schedule_kind, st.schedule_days, st.schedule_time_mode,
 		       st.random_window_start::text, st.random_window_end::text, st.generation_input_json,
 		       st.auto_publish, st.publish_account_ids, st.publish_enterprise_site_targets,
-		       st.cover_asset_url, st.cover_image_asset_id, st.enable_web_search, st.generate_count, st.start_at, st.end_at,
+		       st.cover_asset_url, st.cover_image_asset_id,
+		       st.cover_mode, st.cover_random_scope, st.cover_random_folder_id,
+		       st.enable_web_search, st.generate_count, st.start_at, st.end_at,
 		       st.next_run_at, st.status, st.last_run_at, st.last_dispatch_status,
 		       st.last_dispatch_error, st.consecutive_failures, st.created_at, st.updated_at,
 		       pr.name AS prompt_rule_name,
@@ -558,7 +576,9 @@ func (s *ScheduleTaskService) loadScheduleTaskDetail(ctx context.Context, tenant
 		       st.cron_expr, st.schedule_kind, st.schedule_days, st.schedule_time_mode,
 		       st.random_window_start::text, st.random_window_end::text, st.generation_input_json,
 		       st.auto_publish, st.publish_account_ids, st.publish_enterprise_site_targets,
-		       st.cover_asset_url, st.cover_image_asset_id, st.enable_web_search, st.generate_count, st.start_at, st.end_at,
+		       st.cover_asset_url, st.cover_image_asset_id,
+		       st.cover_mode, st.cover_random_scope, st.cover_random_folder_id,
+		       st.enable_web_search, st.generate_count, st.start_at, st.end_at,
 		       st.next_run_at, st.status, st.last_run_at, st.last_dispatch_status,
 		       st.last_dispatch_error, st.consecutive_failures, st.created_at, st.updated_at,
 		       pr.name AS prompt_rule_name,
@@ -936,7 +956,9 @@ func scanScheduleTaskResponse(scanner interface {
 		&item.CronExpr, &item.ScheduleKind, &scheduleDaysJSON, &item.ScheduleTimeMode,
 		&item.RandomWindowStart, &item.RandomWindowEnd, &generationInputJSON,
 		&item.AutoPublish, &publishAccountIDsJSON, &publishEnterpriseSiteTargetsJSON,
-		&item.CoverAssetURL, &item.CoverImageAssetID, &item.EnableWebSearch, &item.GenerateCount, &startAt, &endAt,
+		&item.CoverAssetURL, &item.CoverImageAssetID,
+		&item.CoverMode, &item.CoverRandomScope, &item.CoverRandomFolderID,
+		&item.EnableWebSearch, &item.GenerateCount, &startAt, &endAt,
 		&nextRunAt, &item.Status, &lastRunAt, &item.LastDispatchStatus,
 		&item.LastDispatchError, &item.ConsecutiveFailures, &createdAt, &updatedAt,
 		&item.PromptRuleName, &item.SubscriptionPromptName, &item.SubscriptionPackageName,
@@ -961,6 +983,12 @@ func scanScheduleTaskResponse(scanner interface {
 	if item.RandomWindowEnd == "" {
 		item.RandomWindowEnd = defaultRandomWindowEnd
 	}
+	if item.CoverMode == "" {
+		item.CoverMode = ScheduleCoverModeSpecific
+	}
+	if item.CoverRandomScope == "" {
+		item.CoverRandomScope = ScheduleCoverRandomScopeAll
+	}
 	item.ScheduleDays = decodeScheduleDayKeys(scheduleDaysJSON)
 	item.GenerationInput = decodeScheduleGenerationInput(generationInputJSON)
 	item.PublishAccountIDs = decodeSchedulePublishAccountIDs(publishAccountIDsJSON)
@@ -1075,6 +1103,9 @@ type scheduleAutoPublishConfig struct {
 	EnterpriseTargetsJSON []byte
 	CoverAssetURL         *string
 	CoverImageAssetID     *int64
+	CoverMode             string
+	CoverRandomScope      string
+	CoverRandomFolderID   *int64
 }
 
 func (s *ScheduleTaskService) normalizeAutoPublishConfig(ctx context.Context, actor auth.Actor, req ScheduleTaskRequest) (scheduleAutoPublishConfig, error) {
@@ -1086,6 +1117,8 @@ func (s *ScheduleTaskService) normalizeAutoPublishConfig(ctx context.Context, ac
 		AutoPublish:       autoPublish,
 		AccountIDs:        accountIDs,
 		EnterpriseTargets: enterpriseTargets,
+		CoverMode:         ScheduleCoverModeSpecific,
+		CoverRandomScope:  ScheduleCoverRandomScopeAll,
 	}
 
 	if !autoPublish {
@@ -1105,6 +1138,18 @@ func (s *ScheduleTaskService) normalizeAutoPublishConfig(ctx context.Context, ac
 	if err := validateOptionalPositiveInt64(req.CoverImageAssetID, "cover_image_asset_id"); err != nil {
 		return config, err
 	}
+	coverMode, err := normalizeScheduleCoverMode(req.CoverMode)
+	if err != nil {
+		return config, err
+	}
+	randomScope := ScheduleCoverRandomScopeAll
+	var randomFolderID *int64
+	if coverMode == ScheduleCoverModeRandom {
+		randomScope, randomFolderID, err = s.normalizeScheduleCoverRandomSource(ctx, actor.TenantID, req.CoverRandomScope, req.CoverRandomFolderID)
+		if err != nil {
+			return config, err
+		}
+	}
 	coverURL := strings.TrimSpace(stringPointerValue(req.CoverAssetURL))
 	if len(accountIDs) > 0 {
 		platformIDs, err := s.loadPublishAccountPlatformIDs(ctx, actor.TenantID, actor.PrimaryWorkspaceID, accountIDs)
@@ -1112,7 +1157,7 @@ func (s *ScheduleTaskService) normalizeAutoPublishConfig(ctx context.Context, ac
 			return config, err
 		}
 		config.PlatformIDs = normalizePlatformIDs(platformIDs)
-		if schedulePublishPlatformsRequireCover(platformIDs) && coverURL == "" {
+		if schedulePublishPlatformsRequireCover(platformIDs) && coverMode == ScheduleCoverModeSpecific && coverURL == "" {
 			return config, response.ErrBadRequest(40025, "cover_required", "已选媒体账号的平台要求封面图，请先设置封面")
 		}
 	}
@@ -1133,13 +1178,67 @@ func (s *ScheduleTaskService) normalizeAutoPublishConfig(ctx context.Context, ac
 
 	config.AccountIDsJSON = accountIDsJSON
 	config.EnterpriseTargetsJSON = enterpriseTargetsJSON
-	if coverURL != "" {
+	config.CoverMode = coverMode
+	config.CoverRandomScope = randomScope
+	config.CoverRandomFolderID = randomFolderID
+	if coverMode == ScheduleCoverModeSpecific && coverURL != "" {
 		config.CoverAssetURL = &coverURL
 		config.CoverImageAssetID = req.CoverImageAssetID
 	}
 	return config, nil
 }
 
+func normalizeScheduleCoverMode(value string) (string, error) {
+	switch strings.TrimSpace(value) {
+	case "", ScheduleCoverModeSpecific:
+		return ScheduleCoverModeSpecific, nil
+	case ScheduleCoverModeRandom:
+		return ScheduleCoverModeRandom, nil
+	default:
+		return "", response.ErrBadRequest(40076, "invalid_cover_mode", "封面图模式不正确")
+	}
+}
+
+func (s *ScheduleTaskService) normalizeScheduleCoverRandomSource(ctx context.Context, tenantID int64, scope string, folderID *int64) (string, *int64, error) {
+	normalizedScope := strings.TrimSpace(scope)
+	if normalizedScope == "" {
+		normalizedScope = ScheduleCoverRandomScopeAll
+	}
+	switch normalizedScope {
+	case ScheduleCoverRandomScopeAll:
+		return ScheduleCoverRandomScopeAll, nil, nil
+	case ScheduleCoverRandomScopeFolder:
+		if folderID == nil || *folderID <= 0 {
+			return "", nil, response.ErrBadRequest(40077, "cover_random_folder_required", "请选择随机封面图片文件夹")
+		}
+		if err := s.ensureImageFolderExists(ctx, tenantID, *folderID); err != nil {
+			return "", nil, err
+		}
+		return ScheduleCoverRandomScopeFolder, folderID, nil
+	default:
+		return "", nil, response.ErrBadRequest(40078, "invalid_cover_random_scope", "随机封面范围不正确")
+	}
+}
+
+func (s *ScheduleTaskService) ensureImageFolderExists(ctx context.Context, tenantID, folderID int64) error {
+	var exists bool
+	if err := s.pool.QueryRow(ctx, `
+		SELECT EXISTS (
+			SELECT 1
+			FROM image_folders
+			WHERE id = $1
+			  AND tenant_id = $2
+			  AND deleted_at IS NULL
+		)
+	`, folderID, tenantID).Scan(&exists); err != nil {
+		return response.ErrInternal(50010, "query_failed", "failed to validate image folder")
+	}
+	if !exists {
+		return response.ErrBadRequest(40079, "image_folder_not_found", "随机封面图片文件夹不存在")
+	}
+	return nil
+}
+
 func (s *ScheduleTaskService) validateScheduleEnterpriseSiteTargets(ctx context.Context, tenantID, workspaceID int64, targets []ScheduleEnterpriseSiteTarget) error {
 	for _, target := range targets {
 		var status string

server/internal/tenant/domain/schedule_task.go

@@ -23,6 +23,9 @@ type ScheduleTask struct {
 	PublishAccountIDs    []string
 	CoverAssetURL        *string
 	CoverImageAssetID    *int64
+	CoverMode            string
+	CoverRandomScope     string
+	CoverRandomFolderID  *int64
 	EnableWebSearch      bool
 	GenerateCount        int
 	StartAt              *time.Time

server/migrations/20260614100000_add_schedule_random_cover.down.sql

@@ -0,0 +1,9 @@
+ALTER TABLE schedule_tasks
+    DROP CONSTRAINT IF EXISTS chk_schedule_tasks_cover_random_folder_id,
+    DROP CONSTRAINT IF EXISTS chk_schedule_tasks_cover_random_scope,
+    DROP CONSTRAINT IF EXISTS chk_schedule_tasks_cover_mode;
+
+ALTER TABLE schedule_tasks
+    DROP COLUMN IF EXISTS cover_random_folder_id,
+    DROP COLUMN IF EXISTS cover_random_scope,
+    DROP COLUMN IF EXISTS cover_mode;

server/migrations/20260614100000_add_schedule_random_cover.up.sql

@@ -0,0 +1,19 @@
+ALTER TABLE schedule_tasks
+    ADD COLUMN cover_mode VARCHAR(20) NOT NULL DEFAULT 'specific',
+    ADD COLUMN cover_random_scope VARCHAR(20) NOT NULL DEFAULT 'all',
+    ADD COLUMN cover_random_folder_id BIGINT;
+
+ALTER TABLE schedule_tasks
+    ADD CONSTRAINT chk_schedule_tasks_cover_mode
+        CHECK (cover_mode IN ('specific', 'random'));
+
+ALTER TABLE schedule_tasks
+    ADD CONSTRAINT chk_schedule_tasks_cover_random_scope
+        CHECK (cover_random_scope IN ('all', 'folder'));
+
+ALTER TABLE schedule_tasks
+    ADD CONSTRAINT chk_schedule_tasks_cover_random_folder_id
+        CHECK (
+            cover_random_folder_id IS NULL
+            OR cover_random_folder_id > 0
+        );