package services

import (
	"context"
	"encoding/json"
	"fmt"
	"go-policy-service/models"
	"go-policy-service/structs"
	"go-policy-service/utils"
	"log"
	"time"

	"github.com/go-redis/redis/v8"
)

type TokenManager struct {
	rdb        *redis.Client
	hgConfig   *models.HgConfig
	httpClient utils.HTTPClient // 自己请求 token
	apiUrl     string           // 自己请求 token 的接口
}

// 修复构造函数参数声明
func NewTokenManager(
	rdb *redis.Client,
	hgConfig *models.HgConfig,
	httpClient utils.HTTPClient, // 明确参数类型
	apiUrl string, // 添加类型声明
) *TokenManager {
	return &TokenManager{
		rdb:        rdb,
		hgConfig:   hgConfig,
		httpClient: httpClient,
		apiUrl:     apiUrl,
	}
}

func (t *TokenManager) GetAccessToken() (string, error) {
	tokenKey := fmt.Sprintf("60s-hgapi-%s", t.hgConfig.Account)
	ctx := context.Background()

	// 尝试从 Redis 获取现有 token
	token, err := t.rdb.Get(ctx, tokenKey).Result()
	if err == nil {
		return token, nil
	}

	// 重试机制
	const maxRetries = 3
	for i := 0; i < maxRetries; i++ {
		tokenData, err := t.requestToken()
		if err == nil {
			expireTimestamp := utils.StringToTimestamp(tokenData.ExpireTime, "2006-01-02 15:04:05")
			// 提前半小时失效
			durationSeconds := expireTimestamp - time.Now().Unix()
			// 确保最小有效期为0秒
			if durationSeconds < 0 {
				durationSeconds = 0
			}
			// 成功获取 token 后存入 Redis
			if setErr := t.rdb.SetEX(ctx, tokenKey, tokenData.AccessToken, time.Duration(durationSeconds)*time.Second).Err(); setErr != nil {
				log.Printf("Failed to set token in Redis: %v", setErr)
			}
			return tokenData.AccessToken, nil
		}

		log.Printf("获取hgApi token失败，剩余重试次数: %d, 错误: %v", maxRetries-i-1, err)

		if i < maxRetries-1 {
			time.Sleep(1 * time.Second)
		}
	}
	log.Println("hgApi token获取彻底失败，请检查接口状态")
	return "", fmt.Errorf("failed to get token after %d attempts", maxRetries)
}

func (t *TokenManager) requestToken() (structs.TokenData, error) {
	url := fmt.Sprintf("%s/gateway/oauth/token?grant_type=client_credentials&client_id=%s&client_secret=%s",
		t.apiUrl, t.hgConfig.Account, t.hgConfig.Password)

	respBytes, err := t.httpClient.RequestJSON(context.Background(), "GET", url, nil)
	if err != nil {
		return structs.TokenData{}, fmt.Errorf("HTTP请求失败: %w", err)
	}

	var tokenResp structs.TokenResponse
	if err := json.Unmarshal(respBytes, &tokenResp); err != nil {
		return structs.TokenData{}, fmt.Errorf("JSON解析失败: %w", err)
	}

	if !tokenResp.Success || tokenResp.Data.AccessToken == "" {
		return structs.TokenData{}, fmt.Errorf("接口返回无效响应")
	}

	return tokenResp.Data, nil
}