package httpclent

import (
	"context"
	"io"
	"net/http"
	"net/url"
	"sync"
	"time"
)

const (
	SchemeHttp  Scheme = "http"
	SchemeHttps Scheme = "https"
	SchemeFtp   Scheme = "ftp"
	SchemeWs    Scheme = "ws"
	SchemeWss   Scheme = "wss"
)

/**
header or const
*/
const (
	_ServerName = "server-name"
)

// http 协议方式
type Scheme string
type HttpMethod string

func (s Scheme) NewUrl(host string) string {
	return string(s) + host
}

const (
	MethodGet     HttpMethod = "GET"
	MethodHead    HttpMethod = "HEAD"
	MethodPost    HttpMethod = "POST"
	MethodPut     HttpMethod = "PUT"
	MethodPatch   HttpMethod = "PATCH" // RFC 5789
	MethodDelete  HttpMethod = "DELETE"
	MethodConnect HttpMethod = "CONNECT"
	MethodOptions HttpMethod = "OPTIONS"
	MethodTrace   HttpMethod = "TRACE"
)

// 请求参数
type RequestParams map[string]interface{}

// 创建http request
type NewHttpRequestFunc func() (*http.Request, error)

// 设置请求header，在请求之前设置
type HandlerRequestHeader func(ctx context.Context, header http.Header)

// 添加request-cookie,requestCookie是请求中已经带有的Cookie，不能返回requestCookie
type AddRequestCookies func(ctx context.Context, requestCookie []*http.Cookie) []*http.Cookie

// 设置请求体，在请求之前设置，oldReq传入的req，newReq传出的
type HandlerRequestParams func(ctx context.Context, oldReq interface{}) (newReq interface{})

// 获取server_name 对应的uri
type ServerHostUrl func(ctx context.Context, serverName string) (string, error)

type HandlerResponse func(ctx context.Context, response *http.Response) error

type HandlerRequestUrl func(ctx context.Context, _url *url.URL) error

type EncodeRequestBody func(ctx context.Context, params interface{}) (io.Reader, error)

var (
	// 降低内存开销，切记使用pool记得用指针类型，不然会有额外的内存开销！
	optionsPool = sync.Pool{
		New: func() interface{} {
			return new(Options)
		},
	}
)

type Option func(*Options)
type Options struct {
	// Client客户端配置
	TimeOut       time.Duration // 超时时间,默认1s
	RetryMaxNum   int           // 重试次数，默认重试2次,如果值设置为0则不重试
	RetryIdleTime time.Duration // 再次重试的等待时间，默认1ms

	HandlerRequestHeader HandlerRequestHeader // 处理请求头，默认添加 content-type:application/json
	// Deprecated
	HandlerRequestParams HandlerRequestParams // 处理请求参数，默认添加 params，不推荐使用，推荐直接使用 EncodeRequestBody
	ServerHostUrl        ServerHostUrl        // 获取请求IP:PORT,可以为空
	Scheme               Scheme               // http协议方式，默认http
	AddRequestCookies    AddRequestCookies    // 处理http-request
	HttpMethod           HttpMethod           // Http请求方式，默认POST
	HandlerRequestUrl    HandlerRequestUrl    // 处理请求url，可以添加url的请求参数
	EncodeRequestBody    EncodeRequestBody    // 解析请求参数，默认是Json

	HandlerResponse HandlerResponse // 处理响应
}

// 加载OP-CONFIG，使用 sync.Pool 可以降低内存开销！记得用完调用FreeOp
func LoadDefaultOp(option ...Option) *Options {
	op := optionsPool.Get().(*Options)
	// init
	op.TimeOut = 0
	op.RetryMaxNum = 0
	op.RetryIdleTime = 0

	op.HandlerRequestHeader = nil
	op.HandlerRequestParams = nil
	op.ServerHostUrl = nil
	op.Scheme = ""
	op.AddRequestCookies = nil
	op.HttpMethod = ""
	op.HandlerRequestUrl = nil
	op.EncodeRequestBody = nil

	op.HandlerResponse = nil

	for _, elem := range option {
		if elem != nil {
			elem(op)
		}
	}
	return op
}

func FreeOp(options *Options) {
	if options != nil {
		optionsPool.Put(options)
	}
}