package v1

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/gorilla/mux"
)

func RegisterNovelsRoutes(r *mux.Router) {
	r.HandleFunc("/novels", resolveNovels).Methods("GET", "OPTIONS", "POST")
	r.HandleFunc("/novels/{novelId:[0-9]+}", resolveNovel).Methods("GET", "OPTIONS", "PUT", "DELETE")
	r.HandleFunc("/novels/{novelId:[0-9]+}/cover", uploadNovelCover).Methods("POST", "OPTIONS")
	r.HandleFunc("/novels/{novelId:[0-9]+}/comments", resolveNovelComments).Methods("GET", "OPTIONS", "POST")
	r.HandleFunc("/novels/{novelId:[0-9]+}/characters", resolveNovelCharacters).Methods("GET", "OPTIONS")
	r.HandleFunc("/novels/{novelId:[0-9]+}/genres", resolveNovelGenres).Methods("GET", "OPTIONS")
}

func resolveNovels(w http.ResponseWriter, r *http.Request) {
	if r.Method == http.MethodGet {
		sortBy, ok := r.URL.Query()["sort"]

		if !ok || len(sortBy) <= 0 {
			sortBy = append(sortBy, "rating")
		}

		query, ok := r.URL.Query()["q"]
		if ok {
			novels, err := SearchNovels(query[0])
			Response(w, err, novels)
			return
		}

		novels, err := FetchNovels(sortBy[0])
		Response(w, err, &novels)
	} else if r.Method == http.MethodPost {
		body, err := ReadBody(r)
		if err != nil {
			Error(w, err)
			return
		}

		var novel Novel
		err = json.Unmarshal(body, &novel)
		if err != nil {
			Error(w, err)
			return
		}

		novel, err = CreateNovel(&novel)
		if err == nil {
			w.WriteHeader(http.StatusCreated)
			w.Header().Add("Location", fmt.Sprintf("https://%v%v/%v", r.Host, r.URL, novel.ID))
		}
		Response(w, err, &novel)
	}
}

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

	genres, err := FetchNovelGenres(int32(id))
	Response(w, err, genres)
}

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

	characters, err := FetchNovelCharacters(novelId)
	Response(w, err, characters)
}

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

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

		novel, err := FetchNovel(novelId)
		if err != nil {
			Response(w, err, nil)
			return
		}
		err = json.Unmarshal(body, novel)
		if err != nil {
			Error(w, err)
			return
		}

		novel, err = UpdateNovel(novel)
		Response(w, err, novel)
	} else if r.Method == http.MethodDelete {
		_, err := FetchNovel(novelId)
		if err == sql.ErrNoRows {
			NotFound.Ferror(w)
			return
		}

		err = DeleteNovel(novelId)
		if err != nil {
			w.WriteHeader(500)
			Error(w, err)
			return
		}
		w.WriteHeader(http.StatusNoContent)
		JSON(w, "")
	}
}

func uploadNovelCover(w http.ResponseWriter, r *http.Request) {
	user, err := FetchCurrentUser(r)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		Error(w, err)
		return
	}

	if !hasPermission(user, "novel") {
		NoAccess.Ferror(w)
		return
	}

	vars := mux.Vars(r)
	novelId, _ := strconv.Atoi(vars["novelId"])

	err = r.ParseMultipartForm(1024 * 1024 * 2)
	if err != nil {
		w.WriteHeader(http.StatusBadRequest)
		Error(w, err)
		return
	}

	file, handler, err := r.FormFile("cover")
	if err != nil {
		w.WriteHeader(http.StatusBadRequest)
		Error(w, err)
		return
	}

	if !strings.HasPrefix(handler.Header["Content-Type"][0], "image") {
		w.WriteHeader(http.StatusBadRequest)
		RawError(w, "Wrong document type!")
		return
	}

	fileBytes, err := ioutil.ReadAll(file)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		Error(w, err)
		return
	}
	err = file.Close()
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		Error(w, err)
		return
	}

	ext := strings.Split(handler.Header["Content-Type"][0], "/")[1]
	path := filepath.Join(config.CDNPath, "novels", "logo", fmt.Sprintf("%v.%v", novelId, ext))

	err = ioutil.WriteFile(path, fileBytes, 0644)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		Error(w, err)
		return
	}
	coverPath := fmt.Sprintf("%v/novels/logo/%v.%v", config.CDNUrl, novelId, ext)
	err = UpdateNovelCover(novelId, coverPath)
	Response(w, err, coverPath)
}

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

	if r.Method == http.MethodGet {
		offsetParam, ok := r.URL.Query()["offset"]
		if !ok || len(offsetParam) <= 0 {
			offsetParam = append(offsetParam, "0")
		}

		countParam, ok := r.URL.Query()["count"]
		if !ok || len(countParam) <= 0 {
			countParam = append(countParam, "5")
		}

		offset, _ := strconv.Atoi(offsetParam[0])
		count, _ := strconv.Atoi(countParam[0])

		var response = make(map[string]interface{}, 2)
		comments, err := FetchNovelComments(novelId)
		response["count"] = len(comments)

		if offset+count > len(comments) {
			comments = comments[offset:]
		} else {
			comments = comments[offset : offset+count]
		}
		response["comments"] = comments
		Response(w, err, response)
	} else if r.Method == http.MethodPost {
		user, err := FetchCurrentUser(r)
		if err != nil {
			Error(w, err)
			return
		}
		body, err := ReadBody(r)
		if err != nil {
			Error(w, err)
			return
		}
		commentData := CommentNovel{NovelID: int16(novelId), UserID: user.ID}
		err = json.Unmarshal(body, &commentData)
		if err != nil {
			Error(w, err)
			return
		}

		comment, err := AddNovelComment(commentData)
		Response(w, err, comment)
	}
}