// 上传文件到cloudflare R2
package handler

import (
	"encoding/base64"
	"io"
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
	"tencent_ocr/pkg/service"
)

type UploadHandler struct {
	uploadService  *service.UploadService
	ocrService    *service.OCRService
	geminiService *service.GeminiService
}

func NewUploadHandler(
	uploadService *service.UploadService,
	ocrService *service.OCRService,
	geminiService *service.GeminiService,
) *UploadHandler {
	return &UploadHandler{
		uploadService:  uploadService,
		ocrService:    ocrService,
		geminiService: geminiService,
	}
}

type MultiUploadResponse struct {
	ImageURLs []string `json:"image_urls"`
	Text     string   `json:"text"`
	Success  bool     `json:"success"`
	Error    string   `json:"error,omitempty"`
}

func (h *UploadHandler) HandleUpload(c *gin.Context) {
	form, err := c.MultipartForm()
	if err != nil {
		c.JSON(http.StatusBadRequest, MultiUploadResponse{
			Success: false,
			Error:   "Failed to parse form",
		})
		return
	}

	files := form.File["files"]
	if len(files) == 0 {
		c.JSON(http.StatusBadRequest, MultiUploadResponse{
			Success: false,
			Error:   "No files uploaded",
		})
		return
	}

	if len(files) > 5 {
		c.JSON(http.StatusBadRequest, MultiUploadResponse{
			Success: false,
			Error:   "Maximum 5 files allowed",
		})
		return
	}

	var imageURLs []string
	var ocrTexts []string

	for _, fileHeader := range files {
		if fileHeader.Size > 10<<20 { // 10MB
			c.JSON(http.StatusBadRequest, MultiUploadResponse{
				Success: false,
				Error:   "File size exceeds the limit of 10MB",
			})
			return
		}

		file, err := fileHeader.Open()
		if err != nil {
			c.JSON(http.StatusInternalServerError, MultiUploadResponse{
				Success: false,
				Error:   "Failed to open file",
			})
			return
		}
		defer file.Close()

		// Read file content for content type detection
		fileBytes, err := io.ReadAll(file)
		if err != nil {
			c.JSON(http.StatusInternalServerError, MultiUploadResponse{
				Success: false,
				Error:   "Failed to read file",
			})
			return
		}

		// Verify file type
		contentType := http.DetectContentType(fileBytes)
		if !h.uploadService.IsValidFileType(contentType) {
			c.JSON(http.StatusBadRequest, MultiUploadResponse{
				Success: false,
				Error:   "Invalid file type. Only images are allowed",
			})
			return
		}

		// Convert to base64 for OCR
		base64Str := base64.StdEncoding.EncodeToString(fileBytes)

		// Process OCR
		ocrText, err := h.ocrService.ProcessImage(c.Request.Context(), base64Str)
		if err != nil {
			c.JSON(http.StatusInternalServerError, MultiUploadResponse{
				Success: false,
				Error:   "OCR processing failed",
			})
			return
		}
		ocrTexts = append(ocrTexts, ocrText)

		// Upload to R2
		imageURL, err := h.uploadService.UploadFile(file, fileHeader.Filename, contentType)
		if err != nil {
			c.JSON(http.StatusInternalServerError, MultiUploadResponse{
				Success: false,
				Error:   "Failed to upload file",
			})
			return
		}
		imageURLs = append(imageURLs, imageURL)
	}

	// Process combined text with Gemini if multiple images
	finalText := strings.Join(ocrTexts, "\n")
	if len(ocrTexts) > 1 {
		for _, ocrText := range ocrTexts {
		prompt := "根据以下多段文字的语意，重新拼接成一段通顺的文字，保持原来的所有文字不改变同时，确保拼接的正确：\n\n" 
			+ "第" +  + "段："
		processedText, err := h.geminiService.ProcessText(c.Request.Context(), prompt)
		if err != nil {
			c.JSON(http.StatusInternalServerError, MultiUploadResponse{
				Success: false,
				Error:   "Text processing failed",
			})
			return
		}
		finalText = processedText
	}

	c.JSON(http.StatusOK, MultiUploadResponse{
		ImageURLs: imageURLs,
		Text:      finalText,
		Success:   true,
	})
}