package v1

import (
	"encoding/json"
	"github.com/gorilla/mux"
	"net/http"
	"strconv"
)

func RegisterNewsRoutes(r *mux.Router) {
	r.HandleFunc("/news", resolveNews).Methods("GET", "OPTIONS", "POST")
	r.HandleFunc("/news/{id:[0-9]+}", resolvePost).Methods("GET", "OPTIONS", "PUT", "DELETE")
}

func resolveNews(w http.ResponseWriter, r *http.Request) {
	if r.Method == http.MethodGet {
		q := r.URL.Query()

		offset, _ := strconv.Atoi(q.Get("offset"))
		limit, _ := strconv.Atoi(q.Get("limit"))
		if limit == 0 {
			limit = 20
		}

		total, err := FetchTotalNews()
		if err != nil {
			Error(w, err)
			return
		}

		pagination := map[string]interface{}{
			"offset": offset,
			"limit": limit,
			"total": total,
		}

		news, err := FetchNews(offset, limit)
		ResponsePagination(w, err, news, pagination)
	} else if r.Method == http.MethodPost {
		body, err := ReadBody(r)
		if err != nil {
			Error(w, err)
			return
		}

		post := new(Post)
		err = json.Unmarshal(body, post)
		if err != nil {
			Error(w, err)
			return
		}

		uid, err := GetCurrentUserID(r)
		if err != nil {
			Error(w, err)
			return
		}

		post.AuthorID = uid

		createdPost, err := CreatePost(post)
		Response(w, err, createdPost)
	}
}

func resolvePost(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	id, _ := strconv.Atoi(vars["id"])

	if r.Method == http.MethodGet {
		post, err := FetchPost(id)
		Response(w, err, post)
	} else if r.Method == http.MethodPut {
		body, err := ReadBody(r)
		if err != nil {
			Error(w, err)
			return
		}

		post, err := FetchPost(id)
		if err != nil {
			Error(w, err)
			return
		}

		err = json.Unmarshal(body, post)
		if err != nil {
			Error(w, err)
			return
		}

		err = UpdatePost(post)
		if err != nil {
			Error(w, err)
			return
		}

		w.WriteHeader(http.StatusNoContent)
	} else if r.Method == http.MethodDelete {
		err := DeletePost(id)
		if err != nil {
			Error(w, err)
			return
		}
		w.WriteHeader(http.StatusNoContent)
	}
}