package main

import (
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"

	_ "git.euclide.org/euclide/openvpn-mgt/statik"
	"github.com/rakyll/statik/fs"
)

type jsonInput struct {
	Action string          `json:"action"`
	Params jsonInputParams `json:"params"`
}

type jsonInputParams struct {
	Server  string `json:"server"`
	Session int    `json:"session"`
}

type HttpServer struct {
	Port string
	ovpn *OpenVpnMgt
}

func parseJsonQuery(r *http.Request) (*jsonInput, error) {
	var in jsonInput
	body, err := ioutil.ReadAll(r.Body)
	if err != nil {
		return nil, err
	}
	if err = json.Unmarshal(body, &in); err !=
		nil {
		return nil, err
	}
	return &in, nil
}

func (h *HttpServer) handler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-type", "application/javascript")
	fmt.Fprintf(w, "\n")
}

func (h *HttpServer) ajaxHandler(w http.ResponseWriter, r *http.Request) {
	var err error
	var jsonStr []byte

	w.Header().Set("Content-type", "application/json")

	// add CORS headers
	w.Header().Set("Access-Control-Allow-Origin", r.Header.Get("Origin"))
	w.Header().Set("Access-Control-Allow-Methods", "POST")
	w.Header().Set("Access-Control-Allow-Credentials", "true")
	w.Header().Set("Access-Control-Allow-Headers", "content-type, accept, origin, user-agent, Accept-Encoding")

	// stop here if the method is OPTIONS, to allow CORS to work
	if r.Method == "OPTIONS" {
		return
	}

	// stop here if the method is OPTIONS, to allow CORS to work
	if r.Method != "POST" {
		http.Error(w, "post only", 405)
		return
	}

	req, err := parseJsonQuery(r)
	if err != nil {
		log.Println(err)
		http.Error(w, "Invalid request", 500)
		return
	}
	h.ovpn.Debug(req)

	switch req.Action {
	case "get-remotes":
		jsonStr, err = json.Marshal(h.ovpn)
	case "set-remote":
		err = h.ovpn.SetRemote(req.Params.Server, req.Params.Session)
		jsonStr = []byte("{\"status\": \"ok\"}")
	case "get-sessions":
		jsonStr, err = json.Marshal(h.ovpn)
	case "version":
		err, version := h.ovpn.Version()
		if err != nil {
			break
		}
		jsonStr, err = json.Marshal(version)
	case "stats":
	case "restart":
		err = h.ovpn.Restart(req.Params.Session)
		jsonStr = []byte("{\"status\": \"ok\"}")
	case "kill":
		err = h.ovpn.Kill(req.Params.Session)
		jsonStr = []byte("{\"status\": \"ok\"}")
	default:
		err = errors.New("Invalid request")
	}

	if err != nil {
		http.Error(w, fmt.Sprintf("Error : %s", err), 500)
		return
	}
	fmt.Fprintf(w, "%s", jsonStr)

	return
}

func NewHTTPServer(port string, s *OpenVpnMgt) {
	h := &HttpServer{
		Port: port,
		ovpn: s,
	}

	statikFS, err := fs.New()
	if err != nil {
		log.Fatal(err)
	}

	http.HandleFunc("/ajax", h.ajaxHandler)
	http.Handle("/", http.FileServer(statikFS))

	log.Fatal(http.ListenAndServe(port, nil))
}