package myth

import (
	"bytes"
	"compress/gzip"
	"crypto/tls"
	"crypto/x509"
	"encoding/json"
	"encoding/xml"
	"errors"
	"io"
	"net"
	"net/http"
	"time"
)

const (
	// ReqContentTypeURL application/x-www-form-urlencoded
	ReqContentTypeURL = `application/x-www-form-urlencoded; charset=utf-8`
	// ReqContentTypeJSON application/json
	ReqContentTypeJSON = `application/json; charset=utf-8`
	// ReqContentTypeXML application/xml
	ReqContentTypeXML = `application/xml; charset=utf-8`
	// ReqContentTypeMultipart multipart/form-data
	ReqContentTypeMultipart = `multipart/form-data`

	// HTTP header Accept
	Accept = `Accept`
	// HTTP header Accept-Encoding
	AcceptEncoding = `Accept-Encoding`
	// HTTP header Content-Type
	ContentType = `Content-Type`

	// Default Accept-Encoding
	DefaultAcceptEncoding = `gzip, deflate, br`

	// ContentTypeJSON application/json
	ContentTypeJSON = `application/json; charset=utf-8`
	// ContentTypeURL application/x-www-form-urlencoded
	ContentTypeURL = `application/x-www-form-urlencoded; charset=utf-8`
	// ContentTypeURL application/xml
	ContentTypeXML = `application/xml; charset=utf-8`

	// RequestTimeOut http request timeout (second)
	RequestTimeOut = 30
)

const (
	// response header Content-Encoding
	ResContentEncoding = `Content-Encoding`

	// encoding gzip
	EncodingGZIP = `gzip`
)

var (
	reqTimeOut = time.Duration(RequestTimeOut)

	ErrStausCodeNotOk = errors.New(`StatusCode not 200`)
)

// GetRealIP get real IP from Request
func GetRealIP(req *http.Request) (ip string) {
	if ips := req.Header["X-Real-Ip"]; ips != nil {
		ip = ips[0]
	}
	return
}

// SetHTTPRequestTimeout set request timeout
func SetHTTPRequestTimeout(seconds int) {
	reqTimeOut = time.Duration(seconds)
}

// HTTPHeader HTTP header
type HTTPHeader struct {
	header map[string]string
}

// DefaultTTPHeader default HTTP header
var DefaultTTPHeader = NewDefaultHTTPHeader()

// NewHTTPHeader new HTTPHeader
func NewHTTPHeader() (h *HTTPHeader) {
	return &HTTPHeader{header: map[string]string{}}
}

// NewDefaultHTTPHeader new HTTPHeader
func NewDefaultHTTPHeader() (h *HTTPHeader) {
	h = NewHTTPHeader()
	//h.Add(ContentType, ContentTypeJSON)
	h.Add(AcceptEncoding, DefaultAcceptEncoding)
	return
}

// Headers return header
func (h *HTTPHeader) Headers() map[string]string {
	return h.header
}

// Add add new k-v
func (h *HTTPHeader) Add(k, v string) {
	h.header[k] = v
}

// Del del k
func (h *HTTPHeader) Del(k string) {
	delete(h.header, k)
}

// SetContentType set Content-Type
func (h *HTTPHeader) SetContentType(v string) {
	h.header[ContentType] = v
}

// SetContentTypeJSON set Content-Type application/json
func (h *HTTPHeader) SetContentTypeJSON() {
	h.header[ContentType] = ContentTypeJSON
}

// SetContentTypeURL set Content-Type application/x-www-form-urlencoded
func (h *HTTPHeader) SetContentTypeURL() {
	h.header[ContentType] = ContentTypeURL
}

// SetContentTypeXML set Content-Type application/xml
func (h *HTTPHeader) SetContentTypeXML() {
	h.header[ContentType] = ContentTypeXML
}

// HTTPReqOption request option
type HTTPReqOption struct {
}

// HTTPMessage HTTP response
type HTTPMessage struct {
	StatusCode int
	Body       []byte
	Header     http.Header

	Req *http.Request
	Res *http.Response
}

// Headerx return response http.Header
func (m HTTPMessage) Headerx() http.Header {
	return m.Header
}

// Request return raw *http.Request
func (m HTTPMessage) Request() *http.Request {
	return m.Req
}

// Response return raw *http.Response
func (m HTTPMessage) Response() *http.Response {
	return m.Res
}

// ResponseBytes return Response bytes
func (m HTTPMessage) ResponseBytes() []byte {
	return m.Body
}

// JSON Body to JSON
func (m HTTPMessage) JSON(dest interface{}) (err error) {
	if m.StatusCode != http.StatusOK {
		err = ErrStausCodeNotOk
		return
	}
	err = json.Unmarshal(m.Body, &dest)
	return
}

// XML Body to XML
func (m HTTPMessage) XML(dest interface{}) (err error) {
	if m.StatusCode != http.StatusOK {
		err = ErrStausCodeNotOk
		return
	}
	err = xml.Unmarshal(m.Body, &dest)
	return
}

// JSONQuery Body to JSONQuery
func (m HTTPMessage) JSONQuery() (jq *JSONQuery, err error) {
	if m.StatusCode != http.StatusOK {
		err = ErrStausCodeNotOk
		return
	}
	jq, err = NewJSONQuery(m.Body)
	return
}

func newRequest(method, uri, certPath, keyPath string, header map[string]string, body io.Reader) (req *http.Request, res *http.Response, err error) {
	t := &http.Transport{
		Dial: func(netw, addr string) (net.Conn, error) {
			var c net.Conn
			c, err = net.DialTimeout(netw, addr, time.Second*RequestTimeOut)
			if err != nil {
				return nil, err
			}
			c.SetDeadline(time.Now().Add(time.Second * reqTimeOut))
			return c, nil
		},
		MaxIdleConnsPerHost:   50,
		ResponseHeaderTimeout: time.Second * reqTimeOut,
	}

	if certPath != "" {
		cert, e := tls.LoadX509KeyPair(certPath, keyPath)
		if e != nil {
			t.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
		} else {
			pool := x509.NewCertPool()
			t.TLSClientConfig = &tls.Config{InsecureSkipVerify: true, Certificates: []tls.Certificate{cert}, RootCAs: pool}
		}
	}

	req, err = http.NewRequest(method, uri, body)
	if err != nil {
		return
	}

	for k := range header {
		req.Header.Add(k, header[k])
	}

	client := &http.Client{Transport: t}
	res, err = client.Do(req)
	return
}

func readBody(msg *HTTPMessage, res *http.Response) (err error) {
	var (
		body   []byte
		reader io.Reader
	)
	encoding := res.Header.Get(ResContentEncoding)
	switch encoding {
	case EncodingGZIP:
		reader, err = gzip.NewReader(res.Body)
		if err == nil {
			body, err = io.ReadAll(reader)
		}
	default:
		body, err = io.ReadAll(res.Body)
	}
	if err != nil {
		return
	}

	msg.StatusCode = res.StatusCode
	msg.Header = res.Header
	msg.Body = body
	return
}

// Postx request with Content-Type
func Postx(contentType, uri string, headers map[string]string, data []byte) (msg HTTPMessage, err error) {
	headers[ContentType] = contentType
	if msg.Req, msg.Res, err = newRequest(http.MethodPost, uri, ``, ``, headers, bytes.NewReader(data)); err != nil {
		return
	}
	defer msg.Res.Body.Close()
	err = readBody(&msg, msg.Res)
	return
}

// Post HTTP request POST
func Post(uri, certPath, keyPath string, header map[string]string, data io.Reader) (msg HTTPMessage, err error) {
	if msg.Req, msg.Res, err = newRequest(http.MethodPost, uri, certPath, keyPath, header, data); err != nil {
		return
	}
	defer msg.Res.Body.Close()
	err = readBody(&msg, msg.Res)
	return
}

// Get HTTP request GET
func Get(uri, certPath, keyPath string, header map[string]string) (msg HTTPMessage, err error) {
	//var res *http.Response
	if msg.Req, msg.Res, err = newRequest(http.MethodGet, uri, certPath, keyPath, header, nil); err != nil {
		return
	}

	defer msg.Res.Body.Close()
	err = readBody(&msg, msg.Res)
	return
}