// Copyright 2017 gf Author(https://github.com/gogf/gf). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.

// HTTP客户端请求.

package ghttp

import (
	"bytes"
	"crypto/tls"
	"encoding/json"
	"errors"
	"fmt"
	"github.com/gogf/gf/g/os/gfile"
	"io"
	"mime/multipart"
	"net/http"
	"os"
	"strings"
	"time"
)

// http客户端
type Client struct {
	http.Client                     // 底层http client对象
	header        map[string]string // HEADER信息Map
	cookies       map[string]string // 自定义COOKIE
	prefix        string            // 设置请求的URL前缀
	authUser      string            // HTTP基本权限设置：名称
	authPass      string            // HTTP基本权限设置：密码
	browserMode   bool              // 是否模拟浏览器模式(自动保存提交COOKIE)
	retryCount    int               // 失败重试次数(网络失败情况下)
	retryInterval int               // 失败重试间隔
}

// http客户端对象指针
func NewClient() *Client {
	return &Client{
		Client: http.Client{
			Transport: &http.Transport{
				// 默认不校验HTTPS证书有效性
				TLSClientConfig: &tls.Config{
					InsecureSkipVerify: true,
				},
				// 默认关闭KeepAlive功能
				DisableKeepAlives: true,
			},
		},
		header:  make(map[string]string),
		cookies: make(map[string]string),
	}
}

// 克隆当前客户端对象，复制属性。
func (c *Client) Clone() *Client {
	newClient := NewClient()
	*newClient = *c
	newClient.header = make(map[string]string)
	newClient.cookies = make(map[string]string)
	for k, v := range c.header {
		newClient.header[k] = v
	}
	for k, v := range c.cookies {
		newClient.cookies[k] = v
	}
	return newClient
}

// GET请求
func (c *Client) Get(url string) (*ClientResponse, error) {
	return c.DoRequest("GET", url)
}

// PUT请求
func (c *Client) Put(url string, data ...interface{}) (*ClientResponse, error) {
	return c.DoRequest("PUT", url, data...)
}

// POST请求提交数据，默认使用表单方式提交数据(绝大部分场景下也是如此)。
// 如果服务端对Content-Type有要求，可使用Client对象进行请求，单独设置相关属性。
// 支持文件上传，需要字段格式为：FieldName=@file:
func (c *Client) Post(url string, data ...interface{}) (*ClientResponse, error) {
	if len(c.prefix) > 0 {
		url = c.prefix + url
	}
	param := ""
	if len(data) > 0 {
		param = BuildParams(data[0])
	}
	req := (*http.Request)(nil)
	if strings.Contains(param, "@file:") {
		// 文件上传
		buffer := new(bytes.Buffer)
		writer := multipart.NewWriter(buffer)
		for _, item := range strings.Split(param, "&") {
			array := strings.Split(item, "=")
			if len(array[1]) > 6 && strings.Compare(array[1][0:6], "@file:") == 0 {
				path := array[1][6:]
				if !gfile.Exists(path) {
					return nil, errors.New(fmt.Sprintf(`"%s" does not exist`, path))
				}
				if file, err := writer.CreateFormFile(array[0], path); err == nil {
					if f, err := os.Open(path); err == nil {
						defer f.Close()
						if _, err = io.Copy(file, f); err != nil {
							return nil, err
						}
					} else {
						return nil, err
					}
				} else {
					return nil, err
				}
			} else {
				writer.WriteField(array[0], array[1])
			}
		}
		writer.Close()
		if r, err := http.NewRequest("POST", url, buffer); err != nil {
			return nil, err
		} else {
			req = r
			req.Header.Set("Content-Type", writer.FormDataContentType())
		}
	} else {
		// 识别提交数据格式
		paramBytes := []byte(param)
		if r, err := http.NewRequest("POST", url, bytes.NewReader(paramBytes)); err != nil {
			return nil, err
		} else {
			req = r
			if json.Valid(paramBytes) {
				req.Header.Set("Content-Type", "application/json")
			} else {
				req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
			}
		}
	}
	// 自定义header
	if len(c.header) > 0 {
		for k, v := range c.header {
			req.Header.Set(k, v)
		}
	}
	// COOKIE
	if len(c.cookies) > 0 {
		headerCookie := ""
		for k, v := range c.cookies {
			if len(headerCookie) > 0 {
				headerCookie += ";"
			}
			headerCookie += k + "=" + v
		}
		if len(headerCookie) > 0 {
			req.Header.Set("Cookie", headerCookie)
		}
	}
	// HTTP账号密码
	if len(c.authUser) > 0 {
		req.SetBasicAuth(c.authUser, c.authPass)
	}
	// 执行请求
	resp := (*http.Response)(nil)
	for {
		if r, err := c.Do(req); err != nil {
			if c.retryCount > 0 {
				c.retryCount--
			} else {
				return nil, err
			}
		} else {
			resp = r
			break
		}
	}
	r := &ClientResponse{
		cookies: make(map[string]string),
	}
	r.Response = resp
	// 浏览器模式
	if c.browserMode {
		now := time.Now()
		for _, v := range r.Cookies() {
			if v.Expires.UnixNano() < now.UnixNano() {
				delete(c.cookies, v.Name)
			} else {
				c.cookies[v.Name] = v.Value
			}
		}
	}
	return r, nil
}

// DELETE请求
func (c *Client) Delete(url string, data ...interface{}) (*ClientResponse, error) {
	return c.DoRequest("DELETE", url, data...)
}

func (c *Client) Head(url string, data ...interface{}) (*ClientResponse, error) {
	return c.DoRequest("HEAD", url, data...)
}

func (c *Client) Patch(url string, data ...interface{}) (*ClientResponse, error) {
	return c.DoRequest("PATCH", url, data...)
}

func (c *Client) Connect(url string, data ...interface{}) (*ClientResponse, error) {
	return c.DoRequest("CONNECT", url, data...)
}

func (c *Client) Options(url string, data ...interface{}) (*ClientResponse, error) {
	return c.DoRequest("OPTIONS", url, data...)
}

func (c *Client) Trace(url string, data ...interface{}) (*ClientResponse, error) {
	return c.DoRequest("TRACE", url, data...)
}

// GET请求并返回服务端结果(内部会自动读取服务端返回结果并关闭缓冲区指针)
func (c *Client) GetContent(url string, data ...interface{}) string {
	return c.DoRequestContent("GET", url, data...)
}

// PUT请求并返回服务端结果(内部会自动读取服务端返回结果并关闭缓冲区指针)
func (c *Client) PutContent(url string, data ...interface{}) string {
	return c.DoRequestContent("PUT", url, data...)
}

// POST请求并返回服务端结果(内部会自动读取服务端返回结果并关闭缓冲区指针)
func (c *Client) PostContent(url string, data ...interface{}) string {
	return c.DoRequestContent("POST", url, data...)
}

// DELETE请求并返回服务端结果(内部会自动读取服务端返回结果并关闭缓冲区指针)
func (c *Client) DeleteContent(url string, data ...interface{}) string {
	return c.DoRequestContent("DELETE", url, data...)
}

func (c *Client) HeadContent(url string, data ...interface{}) string {
	return c.DoRequestContent("HEAD", url, data...)
}

func (c *Client) PatchContent(url string, data ...interface{}) string {
	return c.DoRequestContent("PATCH", url, data...)
}

func (c *Client) ConnectContent(url string, data ...interface{}) string {
	return c.DoRequestContent("CONNECT", url, data...)
}

func (c *Client) OptionsContent(url string, data ...interface{}) string {
	return c.DoRequestContent("OPTIONS", url, data...)
}

func (c *Client) TraceContent(url string, data ...interface{}) string {
	return c.DoRequestContent("TRACE", url, data...)
}

// 请求并返回服务端结果(内部会自动读取服务端返回结果并关闭缓冲区指针)
func (c *Client) DoRequestContent(method string, url string, data ...interface{}) string {
	response, err := c.DoRequest(method, url, data...)
	if err != nil {
		return ""
	}
	defer response.Close()
	return string(response.ReadAll())
}

// 请求并返回response对象
func (c *Client) DoRequest(method, url string, data ...interface{}) (*ClientResponse, error) {
	if strings.EqualFold("POST", method) {
		return c.Post(url, data...)
	}
	if len(c.prefix) > 0 {
		url = c.prefix + url
	}
	param := ""
	if len(data) > 0 {
		param = BuildParams(data[0])
	}
	req, err := http.NewRequest(strings.ToUpper(method), url, bytes.NewReader([]byte(param)))
	if err != nil {
		return nil, err
	}
	// 自定义header
	if len(c.header) > 0 {
		for k, v := range c.header {
			req.Header.Set(k, v)
		}
	}
	// COOKIE
	if len(c.cookies) > 0 {
		headerCookie := ""
		for k, v := range c.cookies {
			if len(headerCookie) > 0 {
				headerCookie += ";"
			}
			headerCookie += k + "=" + v
		}
		if len(headerCookie) > 0 {
			req.Header.Set("Cookie", headerCookie)
		}
	}
	// 执行请求
	resp := (*http.Response)(nil)
	for {
		if r, err := c.Do(req); err != nil {
			if c.retryCount > 0 {
				c.retryCount--
			} else {
				return nil, err
			}
		} else {
			resp = r
			break
		}
	}
	r := &ClientResponse{
		cookies: make(map[string]string),
	}
	r.Response = resp
	// 浏览器模式
	if c.browserMode {
		now := time.Now()
		for _, v := range r.Cookies() {
			if v.Expires.UnixNano() < now.UnixNano() {
				delete(c.cookies, v.Name)
			} else {
				c.cookies[v.Name] = v.Value
			}
		}
	}
	//fmt.Println(url, c.cookies)
	return r, nil
}