package cpdaily

import (
	"bytes"
	"crypto/tls"
	"encoding/json"
	"fmt"
	"io"
	"mime/multipart"
	"time"

	"github.com/go-resty/resty/v2"
)

// CpImageUploadPolicy 今日校园 OBS 上传策略
type CpImageUploadPolicy struct {
	AccessId  string `json:"accessid"`
	FileName  string `json:"fileName"`
	Policy    string `json:"policy"`
	Host      string `json:"host"`
	Signature string `json:"signature"`
}

// getImageUrlPrefix 根据任务类型返回图片上传的 URL 前缀
func getImageUrlPrefix(taskType TaskType) string {
	switch taskType {
	case TaskTypeSleepCheck:
		return "/wec-counselor-attendance-apps/student/attendance"
	case TaskTypeSign:
		return "/wec-counselor-sign-apps/stu"
	default:
		return "/wec-counselor-sign-apps/stu"
	}
}

// GetUploadPolicy 从今日校园获取 OBS 上传策略（前端用，浏览器直传到 OBS）
func GetUploadPolicy(cookieMap map[string]string, host string, taskType TaskType) (*CpImageUploadPolicy, error) {
	client := newImgClient()
	cookieStr := cookiesToStr(cookieMap)
	urlPrefix := getImageUrlPrefix(taskType)

	var apiPath string
	if taskType == TaskTypeSleepCheck {
		apiPath = "/getUploadPolicy"
	} else {
		apiPath = "/obs/getUploadPolicy"
	}
	fullUrl := host + urlPrefix + apiPath

	resp, err := client.R().
		SetHeader("User-Agent", "Mozilla/5.0 (Linux; Android 15; Redmi Note 8 Pro) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/131.0.6778.81 Mobile Safari/537.36 cpdaily/9.9.6 wisedu/9.9.6").
		SetHeader("CpdailyClientType", "CPDAILY").
		SetHeader("Content-Type", "application/json; charset=UTF-8").
		SetHeader("Cookie", cookieStr).
		SetBody(map[string]interface{}{"fileType": 1}).
		Post(fullUrl)
	if err != nil {
		return nil, fmt.Errorf("获取上传策略失败: %w", err)
	}
	defer resp.RawBody().Close()

	body, _ := io.ReadAll(resp.RawBody())
	var result struct {
		ErrCode int                  `json:"errCode"`
		ErrMsg  string               `json:"errMsg"`
		Datas   *CpImageUploadPolicy `json:"datas"`
	}
	if err := json.Unmarshal(body, &result); err != nil {
		return nil, fmt.Errorf("解析上传策略失败: %w", err)
	}
	if result.ErrCode != 0 || result.Datas == nil {
		return nil, fmt.Errorf("获取上传策略错误(%d): %s", result.ErrCode, result.ErrMsg)
	}

	return result.Datas, nil
}

// uploadToOBS 将文件上传到今日校园的 OBS
func uploadToOBS(policy *CpImageUploadPolicy, fileData []byte, contentType string) error {
	client := resty.New().SetTimeout(30 * time.Second).SetTLSClientConfig(&tls.Config{InsecureSkipVerify: true})

	if contentType == "" {
		contentType = "image/jpeg"
	}

	// 手动构造 multipart form
	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)

	writer.WriteField("x-obs-acl", "public-read")
	writer.WriteField("AccessKeyId", policy.AccessId)
	writer.WriteField("key", policy.FileName)
	writer.WriteField("signature", policy.Signature)
	writer.WriteField("policy", policy.Policy)
	writer.WriteField("content-type", contentType)

	part, _ := writer.CreateFormFile("file", "file")
	part.Write(fileData)
	writer.Close()

	resp, err := client.R().
		SetHeader("Content-Type", writer.FormDataContentType()).
		SetBody(body.Bytes()).
		Post(policy.Host)
	if err != nil {
		return fmt.Errorf("上传文件到 OBS 失败: %w", err)
	}

	if resp.StatusCode() > 299 {
		return fmt.Errorf("上传文件到 OBS 返回错误(%d): %s", resp.StatusCode(), string(resp.Body()))
	}

	return nil
}

// GetPreviewUrl 从今日校园获取图片预览 URL
func GetPreviewUrl(cookieMap map[string]string, host string, taskType TaskType, fileKey string) (string, error) {
	client := newImgClient()
	cookieStr := cookiesToStr(cookieMap)
	urlPrefix := getImageUrlPrefix(taskType)

	var apiPath string
	switch taskType {
	case TaskTypeSleepCheck:
		apiPath = "/previewAttachment"
	case TaskTypeSign:
		apiPath = "/sign/previewAttachment"
	default:
		apiPath = "/sign/previewAttachment"
	}
	fullUrl := host + urlPrefix + apiPath

	resp, err := client.R().
		SetHeader("User-Agent", "Mozilla/5.0 (Linux; Android 15; Redmi Note 8 Pro) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/131.0.6778.81 Mobile Safari/537.36 cpdaily/9.9.6 wisedu/9.9.6").
		SetHeader("CpdailyClientType", "CPDAILY").
		SetHeader("Content-Type", "application/json; charset=UTF-8").
		SetHeader("Cookie", cookieStr).
		SetBody(map[string]interface{}{"ossKey": fileKey}).
		Post(fullUrl)
	if err != nil {
		return "", fmt.Errorf("获取预览 URL 失败: %w", err)
	}
	defer resp.RawBody().Close()

	body, _ := io.ReadAll(resp.RawBody())
	var result struct {
		ErrCode int             `json:"errCode"`
		ErrMsg  string          `json:"errMsg"`
		Datas   json.RawMessage `json:"datas"`
	}
	if err := json.Unmarshal(body, &result); err != nil {
		return "", fmt.Errorf("解析预览 URL 响应失败: %w", err)
	}
	if result.ErrCode != 0 {
		return "", fmt.Errorf("获取预览 URL 错误(%d): %s", result.ErrCode, result.ErrMsg)
	}

	var previewUrl string
	if err := json.Unmarshal(result.Datas, &previewUrl); err != nil {
		return "", fmt.Errorf("解析预览 URL 数据失败: %w", err)
	}

	return previewUrl, nil
}

// UploadImage 完整的图片上传流程：获取策略 → 上传 OBS → 获取预览 URL
func UploadImage(cookieMap map[string]string, host string, taskType TaskType, fileData []byte, contentType string) (string, error) {
	policy, err := GetUploadPolicy(cookieMap, host, taskType)
	if err != nil {
		return "", err
	}

	if err := uploadToOBS(policy, fileData, contentType); err != nil {
		return "", err
	}

	previewUrl, err := GetPreviewUrl(cookieMap, host, taskType, policy.FileName)
	if err != nil {
		return "", err
	}

	return previewUrl, nil
}

func newImgClient() *resty.Client {
	return resty.New().
		SetTimeout(30*time.Second).
		SetDoNotParseResponse(true).
		SetTLSClientConfig(&tls.Config{InsecureSkipVerify: true})
}