package http

import (
	"context"
	"encoding/json"
	"encoding/xml"
	"io/ioutil"
	"net/http"
	"net/url"
	"strings"

	"git.chuangxin1.com/csacred/toolkit"
)

// DecodeRequestFunc extracts a user-domain request object from an HTTP
// request object. It's designed to be used in HTTP servers, for server-side
// endpoints. One straightforward DecodeRequestFunc could be something that
// JSON decodes from the request body to the concrete response type.
type DecodeRequestFunc func(context.Context, *http.Request) (request interface{}, err error)

func header(w http.ResponseWriter, contentType string) {
	w.Header().Set(`Content-Type`, contentType)
	w.Header().Set(`X-Power`, toolkit.LibName+`/`+toolkit.LibVersion)
	w.WriteHeader(http.StatusOK)
}

// WriteJSON response JSON data.
func WriteJSON(w http.ResponseWriter, response interface{}) error {
	header(w, `application/json; charset=utf-8`)
	return json.NewEncoder(w).Encode(response)
}

// WriteXML response XML data.
func WriteXML(w http.ResponseWriter, response interface{}) error {
	header(w, `application/xml; charset=utf-8`)
	return xml.NewEncoder(w).Encode(response)
}

// WriteBytes response bytes
func WriteBytes(w http.ResponseWriter, response interface{}) error {
	header(w, `text/html; charset=utf-8`)
	w.Write(response.([]byte))
	return nil
}

// WriteCtxJSON response JSON data.
func WriteCtxJSON(ctx context.Context, w http.ResponseWriter, response interface{}) error {
	return WriteJSON(w, response)
}

// WriteCtxXML response XML data.
func WriteCtxXML(ctx context.Context, w http.ResponseWriter, response interface{}) error {
	return WriteXML(w, response)
}

// WriteCtxBytes response text data.
func WriteCtxBytes(ctx context.Context, w http.ResponseWriter, response interface{}) error {
	return WriteBytes(w, response)
}

// EncodeError request encode error response
func EncodeError(_ context.Context, err error, w http.ResponseWriter) {
	WriteJSON(w, toolkit.ErrReplyData(toolkit.ErrParamsError, err.Error()))
}

// EncodeXMLError request encode error response
func EncodeXMLError(_ context.Context, err error, w http.ResponseWriter) {
	WriteXML(w, toolkit.ErrReplyData(toolkit.ErrParamsError, err.Error()))
}

// DecodeJSONResponse decode client
func DecodeJSONResponse(ctx context.Context, r *http.Response) (interface{}, error) {
	var res toolkit.ReplyData
	if err := json.NewDecoder(r.Body).Decode(&res); err != nil {
		return toolkit.ErrReplyData(toolkit.ErrException, `data format error`), err
	}
	return res, nil
}

// DecodeXMLResponse decode client
func DecodeXMLResponse(ctx context.Context, r *http.Response) (interface{}, error) {
	var res toolkit.ReplyData
	if err := xml.NewDecoder(r.Body).Decode(&res); err != nil {
		return toolkit.ErrReplyData(toolkit.ErrException, `data format error`), err
	}
	return res, nil
}

// DecodeBytesResponse decode client
func DecodeBytesResponse(ctx context.Context, r *http.Response) (interface{}, error) {
	return ioutil.ReadAll(r.Body)
}

// PopulateRequestContext is a RequestFunc that populates several values into
// the context from the HTTP request. Those values may be extracted using the
// corresponding ContextKey type in this package.
func PopulateRequestContext(ctx context.Context, r *http.Request) context.Context {
	var accessToken string
	accessToken = r.URL.Query().Get(toolkit.VarUserAuthorization)
	if accessToken == "" {
		if cookie, err := r.Cookie(toolkit.VarUserAuthorization); err == nil {
			accessToken, _ = url.QueryUnescape(cookie.Value)
		}
	}

	token := r.Header.Get(toolkit.HTTPHeaderAuthorization)
	if accessToken == "" {
		if len(token) > 6 && strings.ToUpper(token[0:7]) == "BEARER " {
			accessToken = token[7:]
		}
	}

	for k, v := range map[toolkit.ContextKey]string{
		toolkit.ContextKeyRequestMethod:          r.Method,
		toolkit.ContextKeyRequestURI:             r.RequestURI,
		toolkit.ContextKeyRequestPath:            r.URL.Path,
		toolkit.ContextKeyRequestProto:           r.Proto,
		toolkit.ContextKeyRequestHost:            r.Host,
		toolkit.ContextKeyRequestRemoteAddr:      r.RemoteAddr,
		toolkit.ContextKeyRequestXForwardedFor:   r.Header.Get("X-Forwarded-For"),
		toolkit.ContextKeyRequestXForwardedProto: r.Header.Get("X-Forwarded-Proto"),
		toolkit.ContextKeyRequestAuthorization:   token,
		toolkit.ContextKeyRequestReferer:         r.Header.Get("Referer"),
		toolkit.ContextKeyRequestUserAgent:       r.Header.Get("User-Agent"),
		toolkit.ContextKeyRequestXRequestID:      r.Header.Get("X-Request-Id"),
		toolkit.ContextKeyRequestAccept:          r.Header.Get("Accept"),
		toolkit.ContextKeyAccessToken:            accessToken,
	} {
		//fmt.Println(k, v)
		ctx = context.WithValue(ctx, k, v)
	}
	return ctx
}