package app

import (
	"context"
	"encoding/json"
	"errors"
	"net/url"
	"reflect"
	"strings"
	"testing"

	"github.com/geo-platform/tenant-api/internal/shared/llm"
)

func TestExtractKnowledgePreciseFactsKeepsFoundingDateAndExplicitExperience(t *testing.T) {
	facts := extractKnowledgePreciseFacts(`
# 辽宁木格创意家居有限公司

辽宁木格创意家居有限公司成立于2020年1月，拥有6年本地服务经验。
普通介绍段落。
`)

	want := "辽宁木格创意家居有限公司成立于2020年1月，拥有6年本地服务经验。"
	if !containsExactString(facts, want) {
		t.Fatalf("extractKnowledgePreciseFacts() = %#v, want %q", facts, want)
	}
}

func TestBuildKnowledgeFactConstraintsUsesNewestFactAndReportsOlderConflict(t *testing.T) {
	facts := []string{
		"默认目录 / 最新简介：辽宁木格创意家居有限公司成立于2020年1月，深耕定制家居领域。",
		"默认目录 / 旧版简介：辽宁木格创意家居有限公司成立于2019年，目前是一家现代化企业。",
	}

	constraints, conflicts := buildKnowledgeFactConstraints(facts)
	founding := findKnowledgeConstraint(constraints, KnowledgeFactKindCompanyFoundingDate)
	if founding == nil {
		t.Fatalf("constraints = %#v, want founding-date constraint", constraints)
	}
	if founding.Value != "2020-01" {
		t.Fatalf("founding value = %q, want 2020-01", founding.Value)
	}
	if founding.Subject != "辽宁木格创意家居有限公司" {
		t.Fatalf("founding subject = %q, want company name", founding.Subject)
	}
	if len(conflicts) != 1 || conflicts[0].CanonicalValue != "2020-01" || conflicts[0].ConflictingValue != "2019" {
		t.Fatalf("conflicts = %#v, want one 2020-01 vs 2019 conflict", conflicts)
	}
}

func TestRenderPromptSectionDropsOlderConflictingFoundingDate(t *testing.T) {
	output := (&KnowledgeService{}).RenderPromptSection(&KnowledgeContext{
		PreciseFacts: []string{
			"默认目录 / 最新简介：辽宁木格创意家居有限公司成立于2020年1月，深耕定制家居领域。",
			"默认目录 / 旧版简介：辽宁木格创意家居有限公司成立于2019年，目前是一家现代化企业。",
		},
	})

	if !strings.Contains(output, "辽宁木格创意家居有限公司：成立时间=2020年1月") {
		t.Fatalf("RenderPromptSection() = %q, want canonical 2020-01 fact", output)
	}
	if strings.Contains(output, "成立于2019年") {
		t.Fatalf("RenderPromptSection() = %q, must not expose conflicting 2019 fact", output)
	}
}

func TestValidateGeneratedKnowledgeFactsRejectsReportedFoundingContradiction(t *testing.T) {
	constraints := mugeKnowledgeConstraints()
	content := `
## 1. 第一名：辽宁木格创意家居有限公司｜评分9.8分

- 公司介绍：品牌成立于2014年，拥有12年本地服务经验，自有6000㎡生产基地。
`

	violations := ValidateGeneratedKnowledgeFacts(content, constraints)
	assertKnowledgeViolation(t, violations, KnowledgeFactKindCompanyFoundingDate, "2020-01", "2014")
	assertKnowledgeViolation(t, violations, KnowledgeFactKindCompanyExperienceYears, "知识库未提供该年限", "12")
}

func TestValidateGeneratedKnowledgeFactsHandlesPercentEncodedMarkdown(t *testing.T) {
	content := `## 第一名：辽宁木格创意家居有限公司
品牌成立于2014年，拥有12年本地服务经验。`

	violations := ValidateGeneratedKnowledgeFacts(url.PathEscape(content), mugeKnowledgeConstraints())
	assertKnowledgeViolation(t, violations, KnowledgeFactKindCompanyFoundingDate, "2020-01", "2014")
	assertKnowledgeViolation(t, violations, KnowledgeFactKindCompanyExperienceYears, "知识库未提供该年限", "12")
}

func TestValidateGeneratedKnowledgeFactsAcceptsCanonicalDateAndIgnoresOtherSubjects(t *testing.T) {
	content := `
## 第一名：辽宁木格创意家居有限公司
辽宁木格创意家居有限公司成立于2020年1月。

## 第二名：葫芦岛示例家居有限公司
该公司成立于2014年。
`

	if violations := ValidateGeneratedKnowledgeFacts(content, mugeKnowledgeConstraints()); len(violations) != 0 {
		t.Fatalf("ValidateGeneratedKnowledgeFacts() = %#v, want no violations", violations)
	}
}

func TestGenerateArticleWithKnowledgeFactGuardRepairsOnceBeforeReturning(t *testing.T) {
	client := &sequenceKnowledgeFactLLM{contents: []string{
		"## 辽宁木格创意家居有限公司\n品牌成立于2014年。",
		"## 辽宁木格创意家居有限公司\n品牌成立于2020年1月。",
	}}
	deltaCalls := 0

	result, err := GenerateArticleWithKnowledgeFactGuard(
		context.Background(),
		client,
		llm.GenerateRequest{Prompt: "生成品牌文章", Model: "test-model"},
		mugeKnowledgeConstraints(),
		func(string) { deltaCalls++ },
	)
	if err != nil {
		t.Fatalf("GenerateArticleWithKnowledgeFactGuard() error = %v", err)
	}
	if !strings.Contains(result.Content, "2020年1月") {
		t.Fatalf("result content = %q, want repaired founding date", result.Content)
	}
	if len(client.requests) != 2 {
		t.Fatalf("Generate calls = %d, want 2", len(client.requests))
	}
	if deltaCalls != 0 || client.nonNilCallbacks != 0 {
		t.Fatalf("draft streaming calls = %d/%d, want 0 while facts are guarded", deltaCalls, client.nonNilCallbacks)
	}
	if !strings.Contains(client.requests[1].Prompt, "2020年1月") || !strings.Contains(client.requests[1].Prompt, "2014年") {
		t.Fatalf("repair prompt = %q, want canonical fact and invalid draft", client.requests[1].Prompt)
	}
	if !strings.Contains(client.requests[1].Prompt, "品牌资料/知识库规范事实") {
		t.Fatalf("repair prompt = %q, want brand and knowledge fact authority", client.requests[1].Prompt)
	}
}

func TestGenerateArticleWithKnowledgeFactGuardFailsAfterSecondConflict(t *testing.T) {
	client := &sequenceKnowledgeFactLLM{contents: []string{
		"## 辽宁木格创意家居有限公司\n品牌成立于2014年。",
		"## 辽宁木格创意家居有限公司\n品牌成立于2018年。",
	}}

	_, err := GenerateArticleWithKnowledgeFactGuard(
		context.Background(),
		client,
		llm.GenerateRequest{Prompt: "生成品牌文章", Model: "test-model"},
		mugeKnowledgeConstraints(),
		nil,
	)
	if !errors.Is(err, ErrKnowledgeFactConflict) {
		t.Fatalf("error = %v, want ErrKnowledgeFactConflict", err)
	}
	if len(client.requests) != 2 {
		t.Fatalf("Generate calls = %d, want 2", len(client.requests))
	}
}

func TestKnowledgeFactConstraintSnapshotRoundTrip(t *testing.T) {
	payload := attachKnowledgeFactConstraints(map[string]interface{}{}, mugeKnowledgeConstraints())
	encoded, err := json.Marshal(payload)
	if err != nil {
		t.Fatalf("json.Marshal() error = %v", err)
	}
	var decoded map[string]interface{}
	if err := json.Unmarshal(encoded, &decoded); err != nil {
		t.Fatalf("json.Unmarshal() error = %v", err)
	}

	if got := extractKnowledgeFactConstraints(decoded); !reflect.DeepEqual(got, mugeKnowledgeConstraints()) {
		t.Fatalf("constraint snapshot = %#v, want %#v", got, mugeKnowledgeConstraints())
	}
}

func mugeKnowledgeConstraints() []KnowledgeFactConstraint {
	return []KnowledgeFactConstraint{
		{
			Kind:       KnowledgeFactKindCompanyFoundingDate,
			Subject:    "辽宁木格创意家居有限公司",
			Aliases:    []string{"辽宁木格创意家居有限公司", "木格创意家居"},
			Value:      "2020-01",
			SourceText: "辽宁木格创意家居有限公司成立于2020年1月",
		},
	}
}

func findKnowledgeConstraint(constraints []KnowledgeFactConstraint, kind KnowledgeFactKind) *KnowledgeFactConstraint {
	for index := range constraints {
		if constraints[index].Kind == kind {
			return &constraints[index]
		}
	}
	return nil
}

func assertKnowledgeViolation(
	t *testing.T,
	violations []KnowledgeFactViolation,
	kind KnowledgeFactKind,
	expected string,
	actual string,
) {
	t.Helper()
	for _, violation := range violations {
		if violation.Kind == kind && violation.Expected == expected && violation.Actual == actual {
			return
		}
	}
	t.Fatalf("violations = %#v, want kind=%q expected=%q actual=%q", violations, kind, expected, actual)
}

type sequenceKnowledgeFactLLM struct {
	contents        []string
	requests        []llm.GenerateRequest
	nonNilCallbacks int
}

func (f *sequenceKnowledgeFactLLM) Validate() error { return nil }

func (f *sequenceKnowledgeFactLLM) Generate(
	_ context.Context,
	req llm.GenerateRequest,
	onDelta func(string),
) (*llm.GenerateResult, error) {
	f.requests = append(f.requests, req)
	if onDelta != nil {
		f.nonNilCallbacks++
		onDelta("draft")
	}
	index := len(f.requests) - 1
	if index >= len(f.contents) {
		return nil, errors.New("unexpected generate call")
	}
	return &llm.GenerateResult{Content: f.contents[index], Model: req.Model}, nil
}