package user

import (
	"crypto/aes"
	"crypto/cipher"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"github.com/gin-gonic/gin"
	"math/rand"
	"net/http"
	"net/url"
	"strconv"
	"time"
	"toutoukan/config"
	"toutoukan/init/databaseInit"
	"toutoukan/model/usermodel"
	"toutoukan/utill"
)

const wxLoginURL = "https://api.weixin.qq.com/sns/jscode2session"

func UserLogin(c *gin.Context) {
	fmt.Println("Request Body:", c.Request.Body)
	var req usermodel.WxLoginM
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
	}
	fmt.Println("req:123")
	fmt.Println(req.EncryptedData)
	fmt.Println(req.Code)
	fmt.Println(req.Iv)
	fmt.Println("使用的appid:", config.Conf.WxID)
	fmt.Println("使用的secret:", config.Conf.Wxsecret)
	//----------------发送验证请求
	params := url.Values{}
	params.Add("appid", config.Conf.WxID)
	params.Add("secret", config.Conf.Wxsecret)
	params.Add("js_code", req.Code)
	params.Add("grant_type", "authorization_code")
	requestURL := fmt.Sprintf("%s?%s", wxLoginURL, params.Encode())
	fmt.Println("微信接口请求URL:", requestURL)

	resp, err := http.Get(fmt.Sprintf("%s?%s", wxLoginURL, params.Encode()))
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "调用微信登录接口失败: " + err.Error()})
		return
	}
	fmt.Println("微信登录返回结果：", resp.Body)
	defer resp.Body.Close()

	// 解析微信返回结果
	var wxResp usermodel.WxLoginResponse
	if err := json.NewDecoder(resp.Body).Decode(&wxResp); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "解析微信登录响应失败: " + err.Error(), "code": "10026"})
		return
	}

	// 检查微信返回的错误
	if wxResp.ErrCode != 0 {
		c.JSON(http.StatusBadRequest, gin.H{ // http.StatusBadRequest 对应 400
			"error": fmt.Sprintf("微信登录失败: %s (错误码: %d)", wxResp.ErrCode, wxResp.ErrMsg),
			"code":  "10027",
		})
		return
	}

	//可选）使用session_key、encryptedData和iv解密用户信息
	// 步骤2：解密手机号（复用AES解密函数）
	phoneData, err := decryptWxData(wxResp.SessionKey, req.EncryptedData, req.Iv)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "解密失败: " + err.Error()})
		return
	}

	// 步骤3：解析为手机号结构体
	var phoneInfo usermodel.WxPhoneInfo
	if err := json.Unmarshal(phoneData, &phoneInfo); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "解析手机号失败"})
		return
	}

	// 验证水印（确保数据有效性）
	if phoneInfo.Watermark.AppID != config.Conf.WxID {
		c.JSON(http.StatusForbidden, gin.H{"error": "数据水印验证失败"})
		return
	}

	fmt.Println("用户手机号为：", phoneInfo.PhoneNumber)

	openid := wxResp.OpenID
	ctx := c.Request.Context() // 获取请求上下文，用于控制数据库操作超时

	var username string

	// 1. 查询用户是否存在
	var exists bool
	query := "SELECT EXISTS(SELECT 1 FROM user_info WHERE uid = ? LIMIT 1)"
	err = databaseInit.UserDB.QueryRowContext(ctx, query, openid).Scan(&exists)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{
			"error": "查询用户存在性失败: " + err.Error(),
			"code":  "10029",
		})
		return
	}

	// 2. 如果用户不存在，插入新用户
	if !exists {
		username = generateUsername()
		now := time.Now()
		insertSQL := `
            INSERT INTO user_info (
                uid, gender,createdtime, updatedtime,username,telephone
            ) VALUES (?, ?, ?,?,?,?)
        `
		_, err := databaseInit.UserDB.ExecContext(
			ctx,
			insertSQL,
			openid, // uid（使用微信 openid）
			2,
			now, // createdtime
			now, // updatedtime
			username,
			phoneInfo.PhoneNumber,
		)
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{
				"error": "插入新用户失败: " + err.Error(),
				"code":  "10029",
			})
			return
		}
	} else {
		queryUser := "SELECT username FROM user_info WHERE uid = ? LIMIT 1"
		err = databaseInit.UserDB.QueryRowContext(ctx, queryUser, openid).Scan(&username)
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{
				"error": "查询用户信息失败: " + err.Error(),
				"code":  "10030",
			})
			return
		}
	}

	token, err := utill.GenerateJWTAndStore(openid)
	if err != nil {
		c.JSON(500, gin.H{"error": "生成令牌失败", "code": "10036"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"result": "success", "error": nil, "code": "20001", "token": token,
		"userinfo": map[string]string{
			"username":  username,
			"uid":       openid,
			"telephone": phoneInfo.PhoneNumber,
		},
	})
}

func generateUsername() string {
	// 初始化随机数种子（确保每次运行生成不同随机数）
	rand.Seed(time.Now().UnixNano())
	// 生成8位随机数字（范围：10000000-99999999）
	randomNum := 10000000 + rand.Intn(90000000) // 8位随机数
	return "用户" + strconv.Itoa(randomNum)
}

func decryptWxData(sessionKey, encryptedData, iv string) ([]byte, error) {
	key, _ := base64.StdEncoding.DecodeString(sessionKey)
	data, _ := base64.StdEncoding.DecodeString(encryptedData)
	ivBytes, _ := base64.StdEncoding.DecodeString(iv)

	block, err := aes.NewCipher(key)
	if err != nil {
		return nil, err
	}

	mode := cipher.NewCBCDecrypter(block, ivBytes)
	mode.CryptBlocks(data, data)

	return pkcs7Unpad(data), nil // 返回去除填充后的原始数据
}

// 去除PKCS#7填充（微信加密数据使用PKCS#7填充）
func pkcs7Unpad(data []byte) []byte {
	if len(data) == 0 {
		return nil
	}
	padding := int(data[len(data)-1])
	if padding > len(data) {
		return nil
	}
	return data[:len(data)-padding]
}