// Copyright (c) 2015 qianqiusoft.com
// Licensed to You under the GNU Affero GPL v3
// See the LICENSE file at git.qianqiusoft.com/qianqiusoft/light-vocation/LICENSE
// http://www.gnu.org/licenses/why-affero-gpl.en.html

package utils

import (
	"bytes"
	"errors"
	"io"
	"io/ioutil"
	"mime/multipart"
	"net/http"
	"os"
	"strings"
	"crypto/tls"
	"time"
)

type HttpUtil struct {
}

func NewHttpUtil() *HttpUtil {
	return &HttpUtil{}
}

// 使用body post提交数据
func (this *HttpUtil) PostBytes(url string, data []byte) ([]byte, error) {

	body := bytes.NewReader(data)
	request, err := http.NewRequest("POST", url, body)
	if err != nil {
		//log.Println("http.NewRequest,[err=%s][url=%s]", err, url)
		return []byte(""), err
	}
	request.Header.Set("Connection", "Keep-Alive")

	return this.getResponse(request)
}

// 模拟form提交数据，包含，上传文件
func (this *HttpUtil)PostFormWithReader(url string, params map[string]string, fileField, fileName string, r io.Reader) ([]byte, error) {
	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	part, err := writer.CreateFormFile(fileField, fileName)
	if err != nil {
		return nil, err
	}
	_, err = io.Copy(part, r)

	for key, val := range params {
		_ = writer.WriteField(key, val)
	}
	err = writer.Close()
	if err != nil {
		return nil, err
	}
	request, err := http.NewRequest("POST", url, body)
	request.Header.Set("Content-Type", writer.FormDataContentType())

	return this.getResponse(request)
}

// 模拟form提交数据，包含，上传文件
func (this *HttpUtil) PostFormWithFile(url string, params map[string]string, paramName, path string) ([]byte, error) {
	file, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	return this.PostFormWithReader(url, params, paramName, path, file)
}

// post
func (this *HttpUtil) Post(url string, params map[string]string, headers map[string]string) ([]byte, error) {
	return this.doRequest("POST", url, params, headers)
}

// get
func (this *HttpUtil) Get(url string, params map[string]string, headers map[string]string) ([]byte, error) {
	return this.doRequest("GET", url, params, headers)
}

// 一般数据提交
func (this *HttpUtil) doRequest(method string, url string, params map[string]string, headers map[string]string) ([]byte, error) {
	var r http.Request
	r.ParseForm()
	if params != nil {
		for k, v := range params {
			r.Form.Add(k, v)
		}
	}
	bodystr := strings.TrimSpace(r.Form.Encode())
	request, err := http.NewRequest(method, url, strings.NewReader(bodystr))
	if err != nil {
		return []byte(""), err
	}

	if headers == nil || len(headers) <= 0 {
		request.Header.Set("Content-Type", "application/x-www-form-urlencoded")
		request.Header.Set("Connection", "Keep-Alive")
	} else {
		for k, v := range headers {
			request.Header.Set(k, v)
		}
	}

	return this.getResponse(request)
}

func (this *HttpUtil) getResponse(request *http.Request) ([]byte, error) {
	if request == nil {
		return []byte(""), errors.New("request is nil")
	}

	tr := &http.Transport{
		TLSClientConfig:       &tls.Config{InsecureSkipVerify: true},
		ResponseHeaderTimeout: time.Second * 60,
		DisableKeepAlives:     true,
	}

	client := http.Client{Transport: tr}

	var resp *http.Response
	var err error
	resp, err = client.Do(request)
	if err != nil {
		//log.Println("http.Do failed,[err=%s][url=%s]", err, url)
		return []byte(""), err
	}
	defer resp.Body.Close()
	b, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return []byte(""), err
	}
	return b, err
}