package api

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

	log "github.com/Sirupsen/logrus" // TODO-Bad
	"goji.io"
	"golang.org/x/net/context"

	libsession "dev.sum7.eu/sum7/warehost/lib/session"
)

// Handle with response
type Handle func(ctx context.Context, w http.ResponseWriter, r *http.Request) (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(ctx context.Context, w http.ResponseWriter, r *http.Request, data interface{}, errorresult *ErrorResult) {
	sess := ctx.Value("session").(libsession.Session)
	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) goji.HandlerFunc {
	return func(ctx context.Context, w http.ResponseWriter, r *http.Request) {
		sess := libsession.SessionStart(w, r)
		ctx = context.WithValue(ctx, "session", sess)
		data, err := h(ctx, w, r)
		JSONOutput(ctx, w, r, data, err)
	}
}

//JSONDecoder handle complete request of JSON
func JSONDecoder(r io.Reader, data interface{}, w http.ResponseWriter, logger *log.Entry) (returnerr *ErrorResult) {
	err := json.NewDecoder(r).Decode(data)
	if err != nil {
		logger.Error("fetch request")
		returnerr = &ErrorResult{
			Message: "Internal Request Error",
		}
		w.WriteHeader(http.StatusBadRequest)
		return
	}
	return nil
}