package handler

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"time"
)

// ConvertResponse 定义接口响应结构
type ConvertResponse struct {
	Filename string  `json:"filename"`
	LlmUsed  bool    `json:"llm_used"`
	Markdown string  `json:"markdown"`
	Size     int     `json:"size"`
	Success  bool    `json:"success"`
	Title    *string `json:"title"`
}

// ConvertRequest 定义请求参数结构
type ConvertRequest struct {
	File       multipart.File
	FileName   string
	LlmModel   string
	LlmApiKey  string
	LlmBaseUrl string
	LlmPrompt  string
}

const url = "http://121.199.38.107:5001/convert"

// ConvertFile 调用 /convert 接口识别本地文件内容
func ConvertFile(req ConvertRequest) (*ConvertResponse, error) {
	defer req.File.Close()
	// 创建 multipart 表单
	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	// 添加文件字段
	part, err := writer.CreateFormFile("file", req.FileName)
	if err != nil {
		return nil, fmt.Errorf("创建文件表单字段失败: %w", err)
	}
	if _, err := io.Copy(part, req.File); err != nil {
		return nil, fmt.Errorf("复制文件内容失败: %w", err)
	}
	// 添加可选参数（如果提供）
	if req.LlmModel != "" {
		_ = writer.WriteField("llm_model", req.LlmModel)
	}
	if req.LlmApiKey != "" {
		_ = writer.WriteField("llm_api_key", req.LlmApiKey)
	}
	if req.LlmBaseUrl != "" {
		_ = writer.WriteField("llm_base_url", req.LlmBaseUrl)
	}
	if req.LlmPrompt != "" {
		_ = writer.WriteField("llm_prompt", req.LlmPrompt)
	}

	// 关闭 multipart writer
	if err = writer.Close(); err != nil {
		return nil, fmt.Errorf("关闭表单写入器失败: %w", err)
	}

	// 创建 HTTP 请求

	httpReq, err := http.NewRequest("POST", url, body)
	if err != nil {
		return nil, fmt.Errorf("创建HTTP请求失败: %w", err)
	}
	httpReq.Header.Set("Content-Type", writer.FormDataContentType())

	// 发送请求
	client := &http.Client{Timeout: 60 * time.Second}
	resp, err := client.Do(httpReq)
	if err != nil {
		return nil, fmt.Errorf("发送请求失败: %w", err)
	}
	defer resp.Body.Close()

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

	// 检查 HTTP 状态码
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("请求返回非200状态码: %d, 响应: %s", resp.StatusCode, string(respBody))
	}

	// 解析响应 JSON
	var result ConvertResponse
	if err := json.Unmarshal(respBody, &result); err != nil {
		return nil, fmt.Errorf("解析响应JSON失败: %w, 原始响应: %s", err, string(respBody))
	}

	return &result, nil
}