package http

import (
	"fmt"
	"net/http"
	"strings"

	"git.loafle.net/commons_go/rpc/server"
)

type HTTPAdapter struct {
	http.Handler
	RPCServerHandler server.ServerHandler
}

func New(rpcServerHandler server.ServerHandler) *HTTPAdapter {
	return &HTTPAdapter{
		RPCServerHandler: rpcServerHandler,
	}
}

// ServeHTTP
func (a *HTTPAdapter) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	if r.Method != "POST" {
		writeError(w, 405, "rpc: POST method required, received "+r.Method)
		return
	}

	contentType := r.Header.Get("Content-Type")
	idx := strings.Index(contentType, ";")
	if idx != -1 {
		contentType = contentType[:idx]
	}

	codec, err := a.RPCServerHandler.GetCodec(contentType)
	if nil != err {
		writeError(w, 415, "rpc: Unsupported Media Type "+contentType)
		return
	}

	if err := server.Handle(a.RPCServerHandler, codec, r.Body, w); nil != err {
		writeError(w, 500, err.Error())
		return
	}

}

func writeError(w http.ResponseWriter, status int, msg string) {
	w.WriteHeader(status)
	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
	fmt.Fprint(w, msg)
}