package handler

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

	"github.com/dalu/voce/model"

	"gopkg.in/mgo.v2"
	"gopkg.in/mgo.v2/bson"
)

type PostHandler struct {
	MS *mgo.Session
	DB string
	C  string
}

func (h *PostHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	switch r.Method {
	case "GET":
		h.GET(w, r)
	case "POST":
		h.POST(w, r)
	case "PUT":
		h.PUT(w, r)
	case "DELETE":
		h.DELETE(w, r)
	default:
		http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
	}
}

func (h *PostHandler) GET(w http.ResponseWriter, r *http.Request) {
	ms := h.MS.Copy()
	defer ms.Close()

	c := ms.DB(h.DB).C(h.C)

	if !bsonRE.MatchString(r.URL.Path) {
		//all
		dv := []model.Post{}
		if e := c.Find(nil).All(&dv); e != nil {
			http.Error(w, e.Error(), 500)
			return
		}
		enc := json.NewEncoder(w)
		if e := enc.Encode(dv); e != nil {
			http.Error(w, e.Error(), 500)
			return
		}
	} else {
		//one
		dv := model.Post{}
		if e := c.FindId(bson.ObjectIdHex(r.URL.Path)).One(&dv); e != nil {
			http.Error(w, e.Error(), 500)
			return
		}
		enc := json.NewEncoder(w)
		if e := enc.Encode(dv); e != nil {
			http.Error(w, e.Error(), 500)
			return
		}
	}
}

func (h *PostHandler) POST(w http.ResponseWriter, r *http.Request) {
	ms := h.MS.Copy()
	defer ms.Close()

	c := ms.DB(h.DB).C(h.C)

	dv := new(model.Post)
	dec := json.NewDecoder(r.Body)
	if e := dec.Decode(dv); e != nil {
		http.Error(w, e.Error(), 400)
		return
	}
	if e := c.UpdateId(dv.Id, dv); e != nil {
		http.Error(w, e.Error(), 400)
		return
	}
	w.WriteHeader(200)
}

func (h *PostHandler) PUT(w http.ResponseWriter, r *http.Request) {
	ms := h.MS.Copy()
	defer ms.Close()

	c := ms.DB(h.DB).C(h.C)

	dv := new(model.Post)
	dec := json.NewDecoder(r.Body)
	if e := dec.Decode(dv); e != nil {
		http.Error(w, e.Error(), 400)
		return
	}
	dv.Date = time.Now()
	if e := c.Insert(dv); e != nil {
		http.Error(w, e.Error(), 400)
		return
	}
	w.WriteHeader(201)
}

func (h *PostHandler) DELETE(w http.ResponseWriter, r *http.Request) {
	if !bsonRE.MatchString(r.URL.Path) {
		http.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
		return
	}
	ms := h.MS.Copy()
	defer ms.Close()

	c := ms.DB(h.DB).C(h.C)
	if e := c.RemoveId(bson.ObjectIdHex(r.URL.Path)); e != nil {
		http.Error(w, e.Error(), 500)
	}
	w.WriteHeader(200)
}