package api

import (
	"encoding/json"
	"net/http"

	"github.com/astaxie/session"
	"github.com/julienschmidt/httprouter"
)

// Handle for session
type Handle func(w http.ResponseWriter, r *http.Request, ps httprouter.Params, sess session.Session) (interface{}, *ErrorResult)

// ErrorResult struct for api error answer
type ErrorResult struct {
	Fields  []string `json:"fields"`
	Message string   `json:"msg"`
}

// JSONResult struct for api answer
type JSONResult struct {
	Data    interface{}  `json:"data"`
	Error   *ErrorResult `json:"error,omitempty"`
	Session struct {
		Login  interface{}            `json:"login,omitempty"`
		Profil map[string]interface{} `json:"profil,omitempty"`
	} `json:"session,omitempty"`
}

// JSONOutput generate default json answer
func JSONOutput(w http.ResponseWriter, r *http.Request, sess session.Session, data interface{}, errorresult *ErrorResult) {
	result := JSONResult{Data: data, Error: errorresult}
	result.Session.Login = sess.Get("login")
	js, err := json.Marshal(result)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	if origin := r.Header.Get("Origin"); origin != "" {
		w.Header().Set("Access-Control-Allow-Origin", origin)
	}
	w.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
	w.Header().Set("Access-Control-Allow-Headers", "Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization")
	w.Header().Set("Access-Control-Allow-Credentials", "true")
	w.Write(js)
}

// SessionHandler Handler to manage session of api request
func SessionHandler(h Handle, sessions *session.Manager) httprouter.Handle {
	return func(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
		sess := sessions.SessionStart(w, r)
		data, err := h(w, r, ps, sess)
		JSONOutput(w, r, sess, data, err)
	}
}