package bot

import (
	"bytes"
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"log"
	"os"
	"strings"
	"time"

	"git.lalonde.me/matth/AltVRBot/pkg/altvr"
	"git.lalonde.me/matth/AltVRBot/pkg/discord"
)

const (
	tickerIntervalFriendshipOnline               = 2
	tickerIntervalCheckIncomingConversations     = 1
	tickerIntervalCheckIncomingFriendshipRequest = 5
	tickerIntervalUpdateGuildEmojis              = 24 * 60
)

// UserEmoji holds a guild emoji information for a user
type UserEmoji struct {
	ID   string
	Name string
}

type userPrivacy uint8

const (
	userPrivacyNone   userPrivacy = 0
	userPrivacyPart   userPrivacy = 1 << iota
	userPrivacyJoin   userPrivacy = 1 << iota
	userPrivacyStatus userPrivacy = 1 << iota
	userPrivacyAll    userPrivacy = 0xFF
)

func upSet(b, flag userPrivacy) userPrivacy    { return b | flag }
func upClear(b, flag userPrivacy) userPrivacy  { return b &^ flag }
func upToggle(b, flag userPrivacy) userPrivacy { return b ^ flag }
func upHas(b, flag userPrivacy) bool           { return b&flag != 0 }

func (up userPrivacy) String() string {
	switch up {
	case userPrivacyPart:
		return "part"
	case userPrivacyJoin:
		return "join"
	case userPrivacyStatus:
		return "status"
	case userPrivacyAll:
		return "all"
	case userPrivacyNone:
		return "none"
	}
	return "none"
}

func userPrivacyFromString(up string) userPrivacy {
	switch up {
	case userPrivacyPart.String():
		return userPrivacyPart
	case userPrivacyJoin.String():
		return userPrivacyJoin
	case userPrivacyStatus.String():
		return userPrivacyStatus
	case userPrivacyAll.String():
		return userPrivacyAll
	case userPrivacyNone.String():
		return userPrivacyNone
	}
	return userPrivacyNone
}

const userPrivacyDefault = userPrivacyNone

// User is the structure for a single bot user
type User struct {
	AltVRUserID  string
	DiscordID    string
	DiscordName  string
	DiscordEmoji UserEmoji
	Role         Roles
	MsgMode      msgMode
	Privacy      userPrivacy
}

// GetDiscordEmoji If it exists, builds a discord emoji for the user
func (u *User) GetDiscordEmoji() string {
	if u.DiscordEmoji.ID != "" {
		return fmt.Sprintf("<:%s:%s> ", u.DiscordEmoji.Name, u.DiscordEmoji.ID)
	}
	return ""
}

// Roles determines the bot user roles
type Roles uint

// Bot user roles
const (
	RoleUser Roles = iota
	RoleModerator
	RoleAdmin
)

// FriendshipRequestPending data for a pending friendship request
type FriendshipRequestPending struct {
	Friendship altvr.Friendship
	MessageID  string
}

// Type the AltVR bot type
type Type struct {
	DGToken       string
	DGsID         string
	DGcID         string
	AltVRUsername string
	AltVRPassword string
	dg            *discord.Discord
	avr           altvr.AltVR
	users         []User
	msgMode       msgMode
	isQuiet       bool
	frPending     []FriendshipRequestPending
	convos        map[string]string
}

func (b *Type) setFlags() {
	b.DGToken = os.Getenv("DG_TOKEN")
	if b.DGToken == "" {
		flag.StringVar(&b.DGToken, "t", "", "Discord Authentication Token")
	}
	b.DGsID = os.Getenv("DG_SERVER_ID")
	if b.DGsID == "" {
		flag.StringVar(&b.DGsID, "s", "", "Discord Server ID")
	}
	b.DGcID = os.Getenv("DG_CHANNEL_ID")
	if b.DGcID == "" {
		flag.StringVar(&b.DGcID, "c", "", "Discord Channel ID")
	}
	b.AltVRUsername = os.Getenv("ALTVR_USERNAME")
	if b.AltVRUsername == "" {
		flag.StringVar(&b.AltVRUsername, "u", "", "AltVR Username")
	}
	b.AltVRPassword = os.Getenv("ALTVR_PASSWORD")
	if b.AltVRPassword == "" {
		flag.StringVar(&b.AltVRPassword, "p", "", "AltVR Password")
	}
	var mode string
	ms := fmt.Sprintf("%s|%s|%s|%s", msgModeNormal, msgModeRude, msgModeFlirty, msgModeRandom)
	flag.StringVar(&mode, "m", "", "Select the reply message mode <"+ms+">")
	if mode == "" {
		if value, ok := os.LookupEnv("DG_MSG_MODE"); ok {
			mode = value
		}
	}
	switch strings.ToLower(mode) {
	case msgModeRandom.String():
		b.msgMode = msgModeRandom
	case msgModeFlirty.String():
		b.msgMode = msgModeFlirty
	case msgModeRude.String():
		b.msgMode = msgModeRude
	case msgModeNormal.String():
		b.msgMode = msgModeNormal
	default:
		if mode != "" {
			fmt.Printf("Unknown message mode `%s` defaulting to normal\n", mode)
		}
		b.msgMode = msgModeNormal
	}
	flag.BoolVar(&b.isQuiet, "q", false, "Turn on quiet mode (don't be verbose on the discord chat)")
	flag.Parse()
}

// Start launches the bot
func (b *Type) Start() {
	b.setFlags()

	var err error
	b.avr = altvr.New(b.AltVRUsername, b.AltVRPassword)
	b.dg, err = discord.New(b.DGToken, b.DGsID, b.DGcID)
	if err != nil {
		log.Fatal(err)
	}

	b.dg.UpdateAvatar(b.avr.GetAvatarURL())
	b.convos = make(map[string]string)
	b.loadUserFile()
	b.loadDiscordHandlers()

	if !b.isQuiet {
		s := b.getMessageString("online_welcome")
		if _, err := b.dg.Session.ChannelMessageSend(b.DGcID, s); err != nil {
			log.Printf("Error sending welcome message: %+v\n", err)
		}
	}
	//b.avr.FetchOnlineFriendships(b.userConnected, b.userDisconnected)
	go b.periodicTicker()
}

// Close closes any open session
func (b *Type) Close() {
	b.dg.Close()
}

func (b *Type) periodicTicker() {
	onlineFriendships := time.NewTimer(tickerIntervalFriendshipOnline * time.Minute)
	checkConversations := time.NewTimer(tickerIntervalCheckIncomingConversations * time.Minute)
	checkIncomingFriendshipRequests := time.NewTimer(tickerIntervalCheckIncomingFriendshipRequest * time.Minute)
	updateGuildEmojis := time.NewTimer(tickerIntervalUpdateGuildEmojis * time.Minute)
	for {
		select {
		case <-onlineFriendships.C:
			b.avr.FetchOnlineFriendships(b.userConnected, b.userDisconnected)
			onlineFriendships.Reset(tickerIntervalFriendshipOnline * time.Minute)
		case <-checkConversations.C:
			log.Println("Checking for conversations")
			pm, _ := b.avr.FetchPendingConversations()
			if len(pm) > 0 {
				b.handleNewPendingConversation(pm)
			}
			checkConversations.Reset(tickerIntervalCheckIncomingConversations * time.Minute)
		case <-checkIncomingFriendshipRequests.C:
			log.Println("Checking for incoming friendship request")
			fr, _ := b.avr.FetchPendingFriendshipRequests()
			if len(fr) > 0 {
				b.handleNewFriendshipRequests(fr)
			}
			checkIncomingFriendshipRequests.Reset(tickerIntervalCheckIncomingFriendshipRequest * time.Minute)
		case <-updateGuildEmojis.C:
			log.Println("Updating guild emojis")
			b.dg.Emojis, _ = b.dg.Session.GuildEmojis(b.DGsID)
			updateGuildEmojis.Reset(tickerIntervalUpdateGuildEmojis * time.Minute)
		}
	}
}

func (b *Type) userConnected(u altvr.User) {
	uu, err := b.getUserByAltVRUserID(u.UserID)
	if err != nil {
		return
	}
	s := fmt.Sprintf("%s**%s is now online in %s!**", b.getUserEmojiByAltVRUser(u), u.GetDisplayName(), u.CurrentSpace.Name)
	if !b.isQuiet && !upHas(uu.Privacy, userPrivacyJoin) {
		b.dg.Session.ChannelMessageSend(b.DGcID, s)
	}
}

func (b *Type) userDisconnected(u altvr.User) {
	uu, err := b.getUserByAltVRUserID(u.UserID)
	if err != nil {
		return
	}
	s := fmt.Sprintf("%s_%s is now offline!_", b.getUserEmojiByAltVRUser(u), u.GetDisplayName())
	if !b.isQuiet && !upHas(uu.Privacy, userPrivacyPart) {
		b.dg.Session.ChannelMessageSend(b.DGcID, s)
	}
}

func (b *Type) loadUserFile() error {
	var err error
	file, err := os.Open("users.json")
	if err != nil {
		return err
	}
	defer file.Close()
	decoder := json.NewDecoder(file)
	err = decoder.Decode(&b.users)
	if err != nil {
		return err
	}
	return nil
}

func (b *Type) saveUserFile() error {
	var err error
	file, err := os.OpenFile("users.json", os.O_RDWR|os.O_CREATE, 0644)
	if err != nil {
		return err
	}
	defer file.Close()

	buffer := new(bytes.Buffer)
	encoder := json.NewEncoder(file)
	err = encoder.Encode(b.users)
	if err != nil {
		return err
	}
	_, err = file.Write(buffer.Bytes())
	if err != nil {
		return err
	}
	return nil
}

func (b *Type) handleNewFriendshipRequests(fr []altvr.Friendship) {
	for _, rr := range fr {
		found := false
		for _, rrr := range b.frPending {
			if rr.FriendshipID == rrr.Friendship.FriendshipID {
				found = true
				break
			}
		}
		if !found {
			u := b.avr.GetFriend(rr.UserID)
			s := b.getMessageString("new_friendship_requested", u.GetDisplayName())
			if msg, err := b.dg.Session.ChannelMessageSend(b.DGcID, s); err == nil {
				b.frPending = append(b.frPending, FriendshipRequestPending{
					Friendship: rr,
					MessageID:  msg.ID,
				})
			}
		}
	}
	// XXX: Remove withdrawn requests
}

func (b *Type) handleNewPendingConversation(pm []altvr.Conversation) {
	for _, mm := range pm {
		au := b.avr.GetFriend(mm.SenderID)
		uu, _ := b.getUserByAltVRUserID(mm.SenderID)
		at := au.GetDisplayName()
		if uu.DiscordID != "" {
			at = b.buildMention(uu)
		}
		s := at + ": " + mm.Subject
		if msg, err := b.dg.Session.ChannelMessageSend(b.DGcID, s); err == nil {
			b.convos[msg.ID] = mm.ID
			if err := b.avr.AcknowkledgeConversation(mm.ID); err != nil {
				log.Printf("Error acknownledging conversation: %+v\n", err)
			}
		}
	}
}

func (b *Type) getUserEmojiByAltVRUser(au altvr.User) string {
	for _, u := range b.users {
		if u.AltVRUserID == au.UserID {
			for k, e := range b.dg.Emojis {
				if e.Name == u.DiscordEmoji.Name {
					return fmt.Sprintf("<:%s:%s> ", b.dg.Emojis[k].Name, b.dg.Emojis[k].ID)
				}
			}
		}
	}

	return ""
}

func (b *Type) getUserByAltVRUserID(avrID string) (*User, error) {
	for k, u := range b.users {
		if u.AltVRUserID == avrID {
			return &b.users[k], nil
		}
	}
	return &User{}, errors.New("User not found")
}

func (b *Type) getUserByDiscordID(discordID string) (*User, error) {
	for k, u := range b.users {
		if u.DiscordID == discordID {
			return &b.users[k], nil
		}
	}
	return &User{}, errors.New("User not found")
}

func (b *Type) getUserByDiscordName(discordName string) (*User, error) {
	for k, u := range b.users {
		if u.DiscordName == discordName {
			return &b.users[k], nil
		}
	}
	return &User{}, errors.New("User not found")
}

func (b *Type) buildMention(uu *User) string {
	var msg string
	if uu.DiscordEmoji.Name != "" {
		msg = fmt.Sprintf("<:%s:%s> ", uu.DiscordEmoji.Name, uu.DiscordEmoji.ID)
	}
	du, err := b.dg.Session.User(uu.DiscordID)
	if err == nil {
		msg = msg + du.Mention()
	}
	return msg
}