package htfutures

import (
	"context"
	"encoding/json"
	"errors"
	"eta/eta_bridge/global"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"
	"time"
)

const (
	get  = "GET"
	post = "POST"
)

type HttpClient[T any] interface {
	Get(url string, head http.Header, params map[string]interface{}) (Response[T], error)
	Post(url string, head http.Header, data interface{}) (Response[T], error)
	PostFromData(url string, fromData url.Values) (Response[T], error)
	doRequest(req *http.Request) (Response[T], error)
}

type Response[T any] struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
	Data    T      `json:"data"`
	TraceId string `json:"traceId"`
}

// DefaultHttpClient 结构体实现 SSOClient 接口
type DefaultHttpClient[T any] struct {
	client        *http.Client
	retryStrategy RetryStrategy
}

func (c *DefaultHttpClient[T]) PostFromData(urlStr string, fromData url.Values) (Response[T], error) {
	dataStr, err := json.Marshal(fromData)
	if err != nil {
		global.FILE_LOG.Error("formData参数json序列化失败，err:" + err.Error())
	}
	global.FILE_LOG.Info("post请求:" + urlStr + ",formData:" + string(dataStr))
	return c.doPostForm(urlStr, fromData)
}
func (c *DefaultHttpClient[T]) Post(urlStr string, head http.Header, data interface{}) (response Response[T], err error) {
	dataStr, err := json.Marshal(data)
	if err != nil {
		global.FILE_LOG.Error("请求data json序列化失败，err:" + err.Error())
	}
	global.FILE_LOG.Info("post请求:" + urlStr + ",data:" + string(dataStr))
	body := io.NopCloser(strings.NewReader(string(dataStr)))
	req, err := http.NewRequest(post, urlStr, body)
	if err != nil {
		global.FILE_LOG.Error("创建http求求失败:" + err.Error())
		return
	}
	if head != nil {
		req.Header = head
		var headStr []byte
		headStr, err = json.Marshal(head)
		if err != nil {
			global.FILE_LOG.Error("请求头json序列化失败，err:" + err.Error())
		}
		global.FILE_LOG.Info("自定义请求头:" + string(headStr))
	}
	return c.doRequest(req)
}

func (c *DefaultHttpClient[T]) Get(urlStr string, head http.Header, params map[string]interface{}) (response Response[T], err error) {
	if len(params) > 0 {
		queryParams := url.Values{}
		for key, value := range params {
			queryParams.Add(key, fmt.Sprintf("%v", value))
		}
		urlStr = urlStr + "?" + queryParams.Encode()
		global.FILE_LOG.Info("带参get请求:" + urlStr)
	}
	req, err := http.NewRequest(get, urlStr, nil)
	if err != nil {
		global.FILE_LOG.Error("创建http求求失败:" + err.Error())
		return
	}
	if head != nil {
		req.Header = head
		headStr, _ := json.Marshal(head)
		global.FILE_LOG.Info("自定义请求头:" + string(headStr))
	}
	return c.doRequest(req)
}

func (c *DefaultHttpClient[T]) RetryStrategy(retryStrategy RetryStrategy) *DefaultHttpClient[T] {
	c.retryStrategy = retryStrategy
	return c
}

// retryRequest 尝试执行请求并根据重试策略重试
// retryRequest 尝试执行请求并根据重试策略重试
func (c *DefaultHttpClient[T]) retryRequest(requestFunc func() (*http.Response, error)) (result *http.Response, err error) {
	for i := 0; ; i++ {
		result, err = requestFunc()
		if err == nil || !c.retryStrategy.ShouldRetry(i, err) {
			return
		}
		global.FILE_LOG.Error("http请求失败，开始第" + string(rune(i+1)) + "次重试,最近一次错误:[" + err.Error() + "]")
		time.Sleep(c.retryStrategy.RetryDelay(i))
	}
}

func (c *DefaultHttpClient[T]) doPostForm(urlStr string, values url.Values) (response Response[T], err error) {
	global.FILE_LOG.Info("发送请求:" + urlStr)
	//ctx 用Background
	resp, err := c.retryRequest(func() (*http.Response, error) {
		return c.client.PostForm(urlStr, values)
	})
	if err != nil {
		global.FILE_LOG.Error("http请求失败:" + err.Error())
		return
	}
	defer resp.Body.Close()
	repBody, err := io.ReadAll(resp.Body)
	if err != nil {
		global.FILE_LOG.Error("http请求失败，读取body失败:" + err.Error())
		return
	}
	if resp.StatusCode != http.StatusOK {
		global.FILE_LOG.Error("http请求异常，请求状态为:" + resp.Status)
	}
	global.FILE_LOG.Info("http应答为:" + string(repBody))
	err = json.Unmarshal(repBody, &response)
	if err != nil {
		global.FILE_LOG.Error("解析应答失败，反序列化失败:" + err.Error())
	}
	return
}

// DoRequest 执行 HTTP 请求
func (c *DefaultHttpClient[T]) doRequest(req *http.Request) (response Response[T], err error) {
	global.FILE_LOG.Info("发送请求:")
	//ctx 用Background
	resp, err := c.retryRequest(func() (*http.Response, error) {
		return c.client.Do(req)
	})
	if err != nil {
		global.FILE_LOG.Error("http请求失败:" + err.Error())
		return
	}
	defer resp.Body.Close()
	repBody, err := io.ReadAll(resp.Body)
	if err != nil {
		global.FILE_LOG.Error("http请求失败，读取body失败:" + err.Error())
		return
	}
	if resp.StatusCode != http.StatusOK {
		global.FILE_LOG.Error("http请求异常，请求状态为:" + resp.Status)
		return
	}
	global.FILE_LOG.Info("htt请求成功，body:" + string(repBody))
	return
}

// RetryStrategy 接口定义
type RetryStrategy interface {
	ShouldRetry(attempt int, err error) bool
	RetryDelay(attempt int) time.Duration
}

// FixedRetryStrategy 实现 RetryStrategy 接口
type FixedRetryStrategy struct {
	maxAttempts int
	delay       time.Duration
}

// NewFixedRetryStrategy 创建 FixedRetryStrategy 实例
func newFixedRetryStrategy(maxAttempts int, delay time.Duration) *FixedRetryStrategy {
	return &FixedRetryStrategy{
		maxAttempts: maxAttempts,
		delay:       delay,
	}
}

// ShouldRetry 判断是否应该重试
func (s *FixedRetryStrategy) ShouldRetry(attempt int, err error) bool {
	return attempt < s.maxAttempts && retryErr(err)
}
func (s *FixedRetryStrategy) Header() {

}
func retryErr(err error) bool {
	return errors.Is(err, context.DeadlineExceeded) || errors.Is(err, context.Canceled)
}

// RetryDelay 返回重试延迟时间
func (s *FixedRetryStrategy) RetryDelay(attempt int) time.Duration {
	return time.Duration(attempt) * s.delay
}

func CreateDefault[T any]() *DefaultHttpClient[T] {
	return &DefaultHttpClient[T]{
		client:        &http.Client{Timeout: 10 * time.Second},
		retryStrategy: newFixedRetryStrategy(3, 3*time.Second),
	}
}