package image

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"os"
	"path/filepath"
)

// PddUploadResult 用于解析 PDD 上传返回的 result JSON
type PddUploadResult struct {
	URL string `json:"url"`
}

// UploadResponse 用于解析上传接口完整响应
type UploadResponse struct {
	Data struct {
		PddUpload struct {
			Result  string `json:"result"`
			Success bool   `json:"success"`
		} `json:"pddUpload"`
	} `json:"data"`
	Success bool   `json:"success"`
	Message string `json:"message"`
}

// DownloadFile 下载图片到临时文件
func DownloadFile(url string) (string, error) {
	resp, err := http.Get(url)
	if err != nil {
		return "", fmt.Errorf("下载文件失败: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("下载失败, 状态码: %d", resp.StatusCode)
	}

	tmpFile, err := os.CreateTemp("", "book_image_*.png")
	if err != nil {
		return "", fmt.Errorf("创建临时文件失败: %w", err)
	}
	defer tmpFile.Close()

	_, err = io.Copy(tmpFile, resp.Body)
	if err != nil {
		return "", fmt.Errorf("写入临时文件失败: %w", err)
	}

	return tmpFile.Name(), nil
}

// UploadBookImage 上传图片并返回 PDD URL
func UploadBookImage(filePath, isbn, isKW, goodsName, autoUpload string) (string, error) {
	file, err := os.Open(filePath)
	if err != nil {
		return "", fmt.Errorf("打开文件失败: %w", err)
	}
	defer file.Close()

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)

	part, err := writer.CreateFormFile("filepath", filepath.Base(file.Name()))
	if err != nil {
		return "", fmt.Errorf("创建文件字段失败: %w", err)
	}
	if _, err := io.Copy(part, file); err != nil {
		return "", fmt.Errorf("复制文件内容失败: %w", err)
	}

	fields := map[string]string{
		"isbn":       isbn,
		"isKW":       isKW,
		"goodsName":  goodsName,
		"autoUpload": autoUpload,
	}

	for k, v := range fields {
		if err := writer.WriteField(k, v); err != nil {
			return "", fmt.Errorf("写入字段 %s 失败: %w", k, err)
		}
	}

	if err := writer.Close(); err != nil {
		return "", fmt.Errorf("关闭 writer 失败: %w", err)
	}

	req, err := http.NewRequest("POST", "http://103.236.81.185:9000/processImage", &body)
	if err != nil {
		return "", fmt.Errorf("创建请求失败: %w", err)
	}

	req.Header.Set("Content-Type", writer.FormDataContentType())

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return "", fmt.Errorf("发送请求失败: %w", err)
	}
	defer resp.Body.Close()

	respBody, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", fmt.Errorf("读取响应失败: %w", err)
	}

	var uploadResp UploadResponse
	if err := json.Unmarshal(respBody, &uploadResp); err != nil {
		return "", fmt.Errorf("解析响应失败: %w", err)
	}

	if !uploadResp.Data.PddUpload.Success {
		return "", fmt.Errorf("上传失败: %s", uploadResp.Message)
	}

	// 解析 result 字段中的 JSON
	var result PddUploadResult
	if err := json.Unmarshal([]byte(uploadResp.Data.PddUpload.Result), &result); err != nil {
		return "", fmt.Errorf("解析 PDD result 失败: %w", err)
	}

	return result.URL, nil
}

// DownloadAndUploadBookImage 下载图片并上传，返回 PDD URL
func DownloadAndUploadBookImage(imageURL, isbn, isKW, goodsName, autoUpload string) (string, error) {
	tmpFile, err := DownloadFile(imageURL)
	if err != nil {
		return "", err
	}
	defer os.Remove(tmpFile) // 使用完删除临时文件

	return UploadBookImage(tmpFile, isbn, isKW, goodsName, autoUpload)
}