package transport

import (
	"io"
	"net/http"
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"

	"github.com/geo-platform/tenant-api/internal/bootstrap"
	"github.com/geo-platform/tenant-api/internal/shared/response"
	"github.com/geo-platform/tenant-api/internal/tenant/app"
)

type ImageHandler struct {
	imageSvc  *app.ImageService
	folderSvc *app.ImageFolderService
	assets    *AssetHandler
}

func NewImageHandler(a *bootstrap.App) *ImageHandler {
	return &ImageHandler{
		imageSvc:  app.NewImageService(a.DB, a.ObjectStorage, a.RabbitMQ, a.Logger),
		folderSvc: app.NewImageFolderService(a.DB, a.ObjectStorage, a.RabbitMQ, a.Logger),
		assets:    NewAssetHandler(a),
	}
}

func (h *ImageHandler) ListFolders(c *gin.Context) {
	folders, err := h.folderSvc.List(c.Request.Context())
	if err != nil {
		response.Error(c, err)
		return
	}
	response.Success(c, folders)
}

func (h *ImageHandler) CreateFolder(c *gin.Context) {
	var body struct {
		Name string `json:"name"`
	}
	if err := c.ShouldBindJSON(&body); err != nil {
		response.Error(c, response.ErrBadRequest(40000, "invalid_request", "invalid request body"))
		return
	}

	id, err := h.folderSvc.Create(c.Request.Context(), body.Name)
	if err != nil {
		response.Error(c, err)
		return
	}
	response.SuccessWithStatus(c, http.StatusCreated, gin.H{"id": id})
}

func (h *ImageHandler) UpdateFolder(c *gin.Context) {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.Error(c, response.ErrBadRequest(40000, "invalid_id", "invalid folder id"))
		return
	}

	var body struct {
		Name string `json:"name"`
	}
	if err := c.ShouldBindJSON(&body); err != nil {
		response.Error(c, response.ErrBadRequest(40000, "invalid_request", "invalid request body"))
		return
	}

	if err := h.folderSvc.Update(c.Request.Context(), id, body.Name); err != nil {
		response.Error(c, err)
		return
	}
	response.Success(c, nil)
}

func (h *ImageHandler) FolderDeletePreview(c *gin.Context) {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.Error(c, response.ErrBadRequest(40000, "invalid_id", "invalid folder id"))
		return
	}

	preview, err := h.folderSvc.DeletePreview(c.Request.Context(), id)
	if err != nil {
		response.Error(c, err)
		return
	}
	response.Success(c, preview)
}

func (h *ImageHandler) DeleteFolder(c *gin.Context) {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.Error(c, response.ErrBadRequest(40000, "invalid_id", "invalid folder id"))
		return
	}

	if err := h.folderSvc.Delete(c.Request.Context(), id, c.Query("force") == "1"); err != nil {
		response.Error(c, err)
		return
	}
	response.Success(c, nil)
}

func (h *ImageHandler) ListImages(c *gin.Context) {
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))

	folderID, err := parseImageFolderFilter(c.Query("folder_id"))
	if err != nil {
		response.Error(c, err)
		return
	}

	var query *string
	if q := strings.TrimSpace(c.Query("q")); q != "" {
		query = &q
	}

	result, err := h.imageSvc.List(c.Request.Context(), folderID, query, page, pageSize, h.assets.BuildArticleImageURL)
	if err != nil {
		response.Error(c, err)
		return
	}
	response.Success(c, result)
}

func (h *ImageHandler) UploadImage(c *gin.Context) {
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, 11*1024*1024)
	file, header, err := c.Request.FormFile("file")
	if err != nil {
		if strings.Contains(err.Error(), "too large") {
			response.Error(c, response.ErrBadRequest(40011, "image_too_large", "image size cannot exceed 10 MB"))
			return
		}
		response.Error(c, response.ErrBadRequest(40000, "missing_file", "file is required"))
		return
	}
	defer file.Close()

	content, err := io.ReadAll(file)
	if err != nil {
		response.Error(c, response.ErrBadRequest(40000, "read_file_failed", "failed to read file"))
		return
	}

	folderID, err := parseAssignableFolderID(c.PostForm("folder_id"))
	if err != nil {
		response.Error(c, err)
		return
	}

	result, err := h.imageSvc.Upload(c.Request.Context(), header.Filename, content, folderID, h.assets.BuildArticleImageURL)
	if err != nil {
		response.Error(c, err)
		return
	}
	response.SuccessWithStatus(c, http.StatusCreated, result)
}

func (h *ImageHandler) UpdateImage(c *gin.Context) {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.Error(c, response.ErrBadRequest(40000, "invalid_id", "invalid image id"))
		return
	}

	var body app.ImageUpdateRequest
	if err := c.ShouldBindJSON(&body); err != nil {
		response.Error(c, response.ErrBadRequest(40000, "invalid_request", "invalid request body"))
		return
	}

	if err := h.imageSvc.Update(c.Request.Context(), id, body); err != nil {
		response.Error(c, err)
		return
	}
	response.Success(c, nil)
}

func (h *ImageHandler) GetImageReferences(c *gin.Context) {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.Error(c, response.ErrBadRequest(40000, "invalid_id", "invalid image id"))
		return
	}

	refs, err := h.imageSvc.GetReferences(c.Request.Context(), id)
	if err != nil {
		response.Error(c, err)
		return
	}
	response.Success(c, refs)
}

func (h *ImageHandler) DeleteImage(c *gin.Context) {
	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.Error(c, response.ErrBadRequest(40000, "invalid_id", "invalid image id"))
		return
	}

	if err := h.imageSvc.Delete(c.Request.Context(), id, c.Query("force") == "1"); err != nil {
		response.Error(c, err)
		return
	}
	response.Success(c, nil)
}

func (h *ImageHandler) StorageUsage(c *gin.Context) {
	usage, err := h.imageSvc.GetStorageUsage(c.Request.Context())
	if err != nil {
		response.Error(c, err)
		return
	}
	response.Success(c, usage)
}

func parseImageFolderFilter(raw string) (*int64, error) {
	raw = strings.TrimSpace(raw)
	if raw == "" {
		return nil, nil
	}
	if raw == "null" || raw == "uncategorized" {
		uncategorized := int64(0)
		return &uncategorized, nil
	}

	value, err := strconv.ParseInt(raw, 10, 64)
	if err != nil || value <= 0 {
		return nil, response.ErrBadRequest(40003, "invalid_folder_id", "folder_id must be a positive integer")
	}
	return &value, nil
}

func parseAssignableFolderID(raw string) (*int64, error) {
	raw = strings.TrimSpace(raw)
	if raw == "" || raw == "null" || raw == "uncategorized" {
		return nil, nil
	}

	value, err := strconv.ParseInt(raw, 10, 64)
	if err != nil || value <= 0 {
		return nil, response.ErrBadRequest(40003, "invalid_folder_id", "folder_id must be a positive integer")
	}
	return &value, nil
}