package utils

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

// TokenUserInfo 从token验证API返回的用户信息
type TokenUserInfo struct {
	AccountID     string `json:"accountID"`
	ID            int64  `json:"id"`
	Name          string `json:"name"`
	UserCode      string `json:"userCode"`
	ContactNumber string `json:"contactNumber"`
	TokenType     string `json:"token_type"`
	Exp           int64  `json:"exp"`
	Iat           int64  `json:"iat"`
}

// VerifyToken 验证token并返回用户信息
func VerifyToken(token string) (*TokenUserInfo, error) {
	if token == "" {
		return nil, fmt.Errorf("token不能为空")
	}

	authAPIURL := GetConfigString("auth_api_url", "")

	jsonData, _ := json.Marshal(map[string]string{"token": token})

	req, err := http.NewRequest("POST", authAPIURL, bytes.NewBuffer(jsonData))
	if err != nil {
		return nil, fmt.Errorf("创建请求失败: %v", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+token)

	client := &http.Client{Timeout: 10 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("请求token验证API失败: %v", err)
	}
	defer resp.Body.Close()

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

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("token验证失败，状态码: %d", resp.StatusCode)
	}

	var userInfo TokenUserInfo
	if err := json.Unmarshal(body, &userInfo); err != nil {
		return nil, fmt.Errorf("解析响应失败: %v", err)
	}

	if userInfo.Exp > 0 && time.Now().Unix() > userInfo.Exp {
		return nil, fmt.Errorf("token已过期")
	}

	return &userInfo, nil
}

// GetUserInfoFromToken 从请求头中获取token并验证
func GetUserInfoFromToken(headerFunc func(string) string) (*TokenUserInfo, error) {
	token := headerFunc("token")
	if token == "" {
		token = headerFunc("Token")
	}
	if token == "" {
		token = headerFunc("Authorization")
		if strings.HasPrefix(token, "Bearer ") {
			token = token[7:]
		}
	}

	if token == "" {
		return nil, fmt.Errorf("请求头中未找到token")
	}

	return VerifyToken(token)
}

// GetUserInfoFromContext 从Context中获取已验证的用户信息
func GetUserInfoFromContext(input interface{}) (*TokenUserInfo, error) {
	if input == nil {
		return nil, fmt.Errorf("未找到用户信息")
	}

	userInfo, ok := input.(*TokenUserInfo)
	if !ok {
		return nil, fmt.Errorf("用户信息类型错误")
	}

	if userInfo == nil {
		return nil, fmt.Errorf("用户信息为空")
	}

	return userInfo, nil
}