package main

import (
	"encoding/json"
	"fmt"
	"log"
	"strconv"
	"strings"

	"github.com/fasthttp/router"
	"github.com/valyala/fasthttp"
	"github.com/xujiajun/nutsdb"
)

func RunWebserv() {
	r := router.New()
	r.GET("/", Headers(Start))
	r.GET("/api/season", Headers(Season))
	r.GET("/api/anime/{id}", Headers(AnimeGet))
	r.GET("/api/user/{user?}", Headers(UserGet))
	r.GET("/api/watch/{user?}", Headers(WatchGet))
	r.GET("/api/watchext/{user?}", Headers(WatchExtendedGet))
	r.POST("/api/register", Headers(Register))
	r.POST("/api/watch/{user}", Headers(WatchPost))
	r.DELETE("/api/register", Headers(UnRegister))
	r.DELETE("/api/watch/{user}", Headers(WatchDelete))
	log.Fatal(fasthttp.ListenAndServe(":"+strconv.Itoa(*webServerPort), r.Handler))
}

func Start(ctx *fasthttp.RequestCtx) {
	season, err := GetSeasonCache()
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}

	WriteIndex(ctx, season)

	ctx.SetContentType("text/html; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
}

func Season(ctx *fasthttp.RequestCtx) {
	data, err := seasoncache.Get(seasonApiJikan)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}

	err = writeResponseBody(ctx, data)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}

	ctx.SetContentType("application/json; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
}

func AnimeGet(ctx *fasthttp.RequestCtx) {
	idVal := ctx.UserValue("id")
	if idVal == nil {
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	// check user exists
	malId, err := strconv.ParseInt(fmt.Sprintf("%s", idVal), 10, 64)
	if err != nil {
		ctx.WriteString(err.Error())
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	// search season first
	anime, err := SearchSeason(malId)
	var bytes []byte
	if err != nil {
		_, bytes, err = GetAnimeDetailData(malId)
		if err != nil {
			addErrorToCtx(ctx, err)
			return
		}
	} else {
		bytes, err = json.Marshal(&anime)
		if err != nil {
			addErrorToCtx(ctx, err)
			return
		}
	}
	_, err = ctx.Write(bytes)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}

	ctx.SetContentType("application/json; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
}

func UserGet(ctx *fasthttp.RequestCtx) {
	usrVal := ctx.UserValue("user")
	users := make([]User, 0)
	if usrVal != nil {
		// get specific user
		user, _, err := GetUserData(fmt.Sprintf("%s", usrVal))
		if err != nil {
			ctx.WriteString(err.Error())
			ctx.SetStatusCode(fasthttp.StatusNotFound)
			return
		}
		users = append(users, *user)
	} else {
		regUsers, err := ReadRegisteredUsers()
		if err != nil {
			// check if no users registered
			if err != nutsdb.ErrBucketEmpty {
				addErrorToCtx(ctx, err)
				return
			}
			regUsers = make([]UserData, 0)
		}
		for _, u := range regUsers {
			user, _, err := GetUserData(u.Username)
			if err != nil {
				addErrorToCtx(ctx, err)
				return
			}
			users = append(users, *user)
		}
	}

	bytes, err := json.Marshal(users)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}
	_, err = ctx.Write(bytes)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}

	ctx.SetContentType("application/json; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
}

func WatchGet(ctx *fasthttp.RequestCtx) {
	animeUsers, err := watchGetLogic(ctx)
	if err != nil {
		return
	}

	bytes, err := json.Marshal(animeUsers)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}
	_, err = ctx.Write(bytes)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}

	ctx.SetContentType("application/json; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
}

func WatchExtendedGet(ctx *fasthttp.RequestCtx) {
	animeUsers, err := watchGetLogic(ctx)
	if err != nil {
		return
	}

	animeUsersExtended := make([]AnimeUserExtended, 0)
	// make list advanced
	for _, a := range animeUsers {
		data, _, err := GetAnimeDetailData(a.Anime)
		if err != nil {
			addErrorToCtx(ctx, err)
			return
		}
		animeUsersExtended = append(animeUsersExtended, AnimeUserExtended{
			Anime: a.Anime,
			Users: a.Users,
			Data:  *data,
		})
	}

	bytes, err := json.Marshal(animeUsersExtended)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}
	_, err = ctx.Write(bytes)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}

	ctx.SetContentType("application/json; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
}

func Register(ctx *fasthttp.RequestCtx) {
	if string(ctx.Request.Header.ContentType()) != "application/json" {
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	body := ctx.PostBody()
	var register RegisterData
	err := json.Unmarshal(body, &register)
	if err != nil {
		ctx.WriteString(err.Error())
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	if register.MalID == 0 || register.Username == "" || register.Secret == "" || register.Sauce == "" {
		ctx.WriteString("Sprich JSON du Hurensohn")
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	calcSauce := Sauce(register.MalID, register.Username)
	if calcSauce != strings.ToLower(register.Sauce) {
		ctx.WriteString("Möge die Sauce mit dir sein")
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	// check user exists
	_, err = ReadUser(register.Username)
	if err == nil {
		ctx.WriteString("Nicht drängeln")
		ctx.SetStatusCode(fasthttp.StatusConflict)
		return
	}
	// check user legit
	userData, _, err := GetUserData(register.Username)
	if err != nil {
		ctx.WriteString(err.Error())
		ctx.SetStatusCode(fasthttp.StatusExpectationFailed)
		return
	}
	if userData.MalID != register.MalID {
		ctx.WriteString("Dich gibts nicht auf MAL")
		ctx.SetStatusCode(fasthttp.StatusExpectationFailed)
		return
	}
	// REGISTER
	user := UserData{
		Username: register.Username,
		MalID:    register.MalID,
		Secret:   register.Secret,
	}
	err = SaveUser(&user)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}

	ctx.SetBody(body)
	ctx.SetContentType("application/json; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
}

func WatchPost(ctx *fasthttp.RequestCtx) {
	processUpdateReq(ctx, true)
}

func UnRegister(ctx *fasthttp.RequestCtx) {
	if string(ctx.Request.Header.ContentType()) != "application/json" {
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	body := ctx.PostBody()
	var register RegisterData
	err := json.Unmarshal(body, &register)
	if err != nil {
		ctx.WriteString(err.Error())
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	if register.MalID == 0 || register.Username == "" || register.Secret == "" || register.Sauce == "" {
		ctx.WriteString("Sprich JSON du Hurensohn")
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	calcSauce := Sauce(register.MalID, register.Username)
	if calcSauce != strings.ToLower(register.Sauce) {
		ctx.WriteString("Möge die Sauce mit dir sein")
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	// DELETE
	err = DeleteUserFromAnimes(register.MalID)
	if err != nil {
		ctx.WriteString(err.Error())
		ctx.SetStatusCode(fasthttp.StatusNotFound)
		return
	}
	err = DbDelete(bucketUsers, register.Username)
	if err != nil {
		ctx.WriteString(err.Error())
		ctx.SetStatusCode(fasthttp.StatusNotFound)
		return
	}

	ctx.SetBody(body)
	ctx.SetContentType("application/json; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
}

func WatchDelete(ctx *fasthttp.RequestCtx) {
	processUpdateReq(ctx, false)
}

func GheddoAuth(username, auth string) (bool, int64) {
	user, err := ReadUser(username)
	if err != nil {
		return false, 0
	}
	return user.Secret == auth, user.MalID
}

func Headers(h fasthttp.RequestHandler) fasthttp.RequestHandler {
	return fasthttp.RequestHandler(func(ctx *fasthttp.RequestCtx) {
		if *localServer {
			ctx.Response.Header.Set("Access-Control-Allow-Origin", "*")
			ctx.Response.Header.Set("Access-Control-Allow-Headers", "*")
			ctx.Response.Header.Set("Access-Control-Allow-Methods", "*")
		}
		h(ctx)
	})
}

func watchGetLogic(ctx *fasthttp.RequestCtx) ([]AnimeUser, error) {
	usrVal := ctx.UserValue("user")
	var userId int64
	if usrVal != nil {
		// check user exists
		user, err := ReadUser(fmt.Sprintf("%s", usrVal))
		if err != nil {
			ctx.WriteString("Dich gibts nicht")
			ctx.SetStatusCode(fasthttp.StatusNotFound)
			return nil, err
		}
		userId = user.MalID
	}
	animesUsers, err := ReadAnimeUsers()
	if err != nil {
		// check if no anime were inserted
		if err != nutsdb.ErrBucketEmpty {
			addErrorToCtx(ctx, err)
			return nil, err
		}
		animesUsers = make([]AnimeUser, 0)
	}

	// apply single user logic
	if usrVal != nil {
		filteredAnimes := make([]AnimeUser, 0)
		for _, a := range animesUsers {
			for _, u := range a.Users {
				if u.MalID == userId {
					filteredAnimes = append(filteredAnimes, a)
					break
				}
			}
		}
		animesUsers = filteredAnimes
	}
	return animesUsers, err
}

func processUpdateReq(ctx *fasthttp.RequestCtx, update bool) {
	auth := ctx.Request.Header.Peek("X-HUSO-AUTH")
	if ctx.UserValue("user") == nil || auth == nil || string(auth) == "" || string(ctx.Request.Header.ContentType()) != "application/json" {
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}
	username := fmt.Sprintf("%s", ctx.UserValue("user"))
	legit, userId := GheddoAuth(username, string(auth))
	if !legit {
		ctx.SetStatusCode(fasthttp.StatusUnauthorized)
		return
	}

	body := ctx.PostBody()
	var animes []AnimeUser
	err := json.Unmarshal(body, &animes)
	if err != nil || len(animes) == 0 {
		ctx.WriteString(err.Error())
		ctx.SetStatusCode(fasthttp.StatusBadRequest)
		return
	}

	// iterate sent animes
	for i, anime := range animes {
		// check if anime is in season
		_, err = SearchSeason(anime.Anime)
		if err != nil {
			// anime not in season => holen sie diese
			_, _, err := GetAnimeDetailData(anime.Anime)
			if err != nil {
				ctx.WriteString(err.Error())
				ctx.SetStatusCode(fasthttp.StatusNotFound)
				return
			}
		}

		var animeData *AnimeUser
		// update or delete request
		if update {
			// anime exitsts => save
			animeData, err = AddUserToAnime(username, userId, anime.Anime)
		} else {
			// anime exitsts => delete
			animeData, err = DeleteUserFromAnime(username, userId, anime.Anime)
		}
		if err != nil {
			addErrorToCtx(ctx, err)
			return
		}
		animes[i].Users = animeData.Users
	}

	data, err := json.Marshal(animes)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}
	err = writeResponseBody(ctx, data)
	if err != nil {
		addErrorToCtx(ctx, err)
		return
	}
	ctx.SetContentType("application/json; charset=utf-8")
}

func writeResponseBody(ctx *fasthttp.RequestCtx, bytes []byte) error {
	_, err := ctx.Write(bytes)
	if err != nil {
		return err
	}
	ctx.SetContentType("application/json; charset=utf-8")
	ctx.SetStatusCode(fasthttp.StatusOK)
	return err
}

func addErrorToCtx(ctx *fasthttp.RequestCtx, err error) {
	ctx.WriteString(err.Error())
	ctx.SetStatusCode(fasthttp.StatusInternalServerError)
}