package plugins

import (
	"bufio"
	"errors"
	"fmt"
	"os"
	"sort"
	"strconv"
	"strings"
	"time"

	aoc "git.bullercodeworks.com/brian/go-adventofcode"
	"git.bullercodeworks.com/brian/helperbot/models"
	"github.com/slack-go/slack"
)

/* Plugin State */
type AoCState struct {
	model              *models.BotModel
	boardId            string
	sessionCookie      string
	sessionNeedsUpdate bool
	lastUpdate         time.Time

	aoc      *aoc.AoC
	lastYear int
}

/* Plugin Interface Functions */
func (s *AoCState) Name() string { return "advent-of-code" }
func (s *AoCState) Initialize(m *models.BotModel) error {
	// Initialize AoC stuff
	var err error
	var boardId, aocSession, aocChannelId string
	s.model = m

	boardId, err = s.getAoCBoardId()
	boardId = strings.TrimSpace(boardId)
	if err != nil || boardId == "" {
		s.RequestBoardId()
	}

	aocSession, err = s.getAoCSessionCookie()
	aocSession = strings.TrimSpace(aocSession)
	if err != nil || aocSession == "" {
		s.RequestSessionCookie()
	} else {
		s.sessionCookie = aocSession
	}

	aocChannelId, err = s.getChannelId()
	aocChannelId = strings.TrimSpace(aocChannelId)
	if err != nil || aocChannelId == "" {
		s.RequestChannelId()
	}

	if err = s.NewAoC(); err != nil {
		return err
	}
	return nil
}

func (s *AoCState) ProcessMessage(m models.BotMessage) bool {
	if m.Source == models.MsgSrcSlack {
		if len(m.Target) == 0 {
			return false
		}
		switch m.Target[0] {
		case 'C', 'G':
			return s.ProcessChannelMessage(m)
		case 'D':
			admin := s.model.GetSlackAdminDMId()
			if m.Target == admin {
				return s.ProcessAdminDirectMessage(m)
			} else {
				return s.ProcessDirectMessage(m)
			}
		}
	}
	return false
}

func (s *AoCState) ProcessRTMEvent(msg *slack.RTMEvent) bool {
	return false
}

func (s *AoCState) Run() {
	go s.runLoop()
}

func (s *AoCState) Exit() {}

/* Other Functions */
func (s *AoCState) NewAoC() error {
	board, err := s.getAoCBoardId()
	if err != nil {
		return err
	}
	sess, err := s.getAoCSessionCookie()
	if err != nil {
		return err
	}
	if s.aoc, err = aoc.NewAoC(board, sess); err != nil {
		return err
	}
	return nil
}

func (s *AoCState) runLoop() {
	_, err := s.getChannelId()
	// This plugin fails without a channel id
	if err != nil {
		return
	}
	for s.model.Running {
		_, err := s.getChannelId()
		// This plugin fails without a channel id
		if err != nil {
			return
		}

		if !s.sessionNeedsUpdate {
			if s.GetLatestYear() != s.lastYear {
				// Latest year changed. Update it.
				s.lastYear = s.GetLatestYear()
				admin := s.model.GetSlackAdminDMId()
				if admin == "" {
					s.SendAdminIdError()
					return
				}
				s.SendSlackMessage(fmt.Sprintf(":christmas_tree: AoC Set latest leaderboard to %d", s.lastYear), admin)
			}
			s.AoCBoardCheckAndUpdate(s.lastYear)
			s.lastUpdate = time.Now()
		}
		time.Sleep(time.Minute * 15)
	}

	s.model.SendMessage(models.NewBotMessage(s.Name(), models.MsgSrcApp, "status", "done", ""))
}

func (s *AoCState) ProcessDirectMessage(m models.BotMessage) bool {
	msgPts := strings.Fields(m.Text)
	if len(msgPts) < 2 || msgPts[0] != "!aoc" {
		return false
	}
	switch msgPts[1] {
	case "help":
		return s.DoHelpCmd(m)
	case "ping":
		return s.DoPingCmd(m)
	case "top":
		return s.DoTopCmd(m)
	}
	return false
}

func (s *AoCState) ProcessAdminDirectMessage(m models.BotMessage) bool {
	msgPts := strings.Fields(m.Text)
	if len(msgPts) < 2 || msgPts[0] != "!aoc" {
		return false
	}
	switch msgPts[1] {
	case "help":
		s.DoHelpAdminCmd(m)
		return true
	case "ping":
		s.DoPingCmd(m)
		return true
	case "top":
		s.DoTopCmd(m)
		return true
	case "session":
		s.DoSessionCmd(m)
		return true
	case "status":
		s.DoStatusCmd(m)
		return true
	}
	return false
}

func (s *AoCState) ProcessChannelMessage(m models.BotMessage) bool {
	msgPts := strings.Fields(m.Text)
	if len(msgPts) < 2 || msgPts[0] != "!aoc" {
		return false
	}
	switch msgPts[1] {
	case "top":
		return s.DoTopCmd(m)
	}
	return false
}

func (s *AoCState) DoHelpCmd(m models.BotMessage) bool {
	txt := fmt.Sprint(":christmas_tree: AoC Help :christmas_tree:\n",
		"• help            - Print this message\n",
		"• ping            - PONG! Check if the service is running\n",
		"• top [year]      - Print the top 5 users for the passed year\n",
		"                    If no year is passed, the current year is used\n",
		"                    Passing 'all' considers all years\n",
	)
	s.SendSlackMessage(txt, m.Target)
	return true
}

func (s *AoCState) DoHelpAdminCmd(m models.BotMessage) bool {
	txt := fmt.Sprint(":christmas_tree: AoC Help :christmas_tree:\n",
		"• help            - Print this message\n",
		"• ping            - PONG! Check if the service is running\n",
		"• top [year]      - Print the top 5 users for the passed year\n",
		"                    If no year is passed, the current year is used\n",
		"                    Passing 'all' considers all years\n",
		"• session [token] - Print or set the session cookie\n",
		"• status          - Print the status of the service\n",
	)
	s.SendSlackMessage(txt, m.Target)
	return true
}

func (s *AoCState) DoPingCmd(m models.BotMessage) bool {
	s.SendSlackMessage(":christmas_tree: PONG :christmas_tree:", m.Target)
	return true
}

func (s *AoCState) DoSessionCmd(m models.BotMessage) bool {
	msgPts := strings.Fields(m.Text)
	if len(msgPts) == 3 && msgPts[1] == "session" {
		// Set the session cookie
		admin := s.model.GetSlackAdminDMId()
		if admin == "" {
			s.SendAdminIdError()
			return true
		}
		aocSession := msgPts[2]
		s.setAoCSessionCookie(strings.TrimSpace(aocSession))
		s.sessionCookie = aocSession
		s.sessionNeedsUpdate = false
		s.SendSlackMessage(":christmas_tree: New Session: "+s.sessionCookie, admin)
	} else if len(msgPts) == 2 && msgPts[1] == "session" {
		// Print the session cookie
		admin := s.model.GetSlackAdminDMId()
		if admin == "" {
			s.SendAdminIdError()
			return true
		}
		// We only send the session cookie to the admin
		s.SendSlackMessage(":christmas_tree: session: "+s.sessionCookie, admin)
	}
	return true
}

func (s *AoCState) DoStatusCmd(m models.BotMessage) bool {
	admin := s.model.GetSlackAdminDMId()
	if admin == "" {
		s.SendAdminIdError()
		return true
	}
	txt := ":christmas_tree: Advent of Code Status :christmas_tree:"
	txt = fmt.Sprintf(
		"%s\nLast Update: %s\nNext Update In: %s", txt,
		s.lastUpdate.Format(time.RFC3339),
		s.lastUpdate.Add(time.Minute*15).Sub(time.Now()).Round(time.Second),
	)

	s.SendSlackMessage(txt, m.Target)
	return false
}

func (s *AoCState) DoTopCmd(m models.BotMessage) bool {
	msgPts := strings.Fields(m.Text)
	var err error
	var yr int
	if len(msgPts) > 2 {
		yr, err = strconv.Atoi(msgPts[2])
		if err != nil {
			if msgPts[2] == "all" {
				yr = -1
			}
		}
	} else {
		yr = s.GetLatestYear()
	}
	var txt string
	if yr == -1 {
		var err error
		txt, err = s.DoTopForAll()
		if err != nil {
			txt = "Error calculating all-time tops"
		}
	} else {
		txt = s.DoTopForYear(yr)
	}
	s.SendSlackMessage(txt, m.Target)
	return true
}

func (s *AoCState) DoTopForAll() (string, error) {
	mbrMap := make(map[string]aoc.Member)
	for _, yr := range s.GetListOfAoCYears() {
		l, err := s.aoc.GetLeaderboard(yr)
		if err != nil {
			return "", err
		}
		for k, v := range l.Members {
			if m, ok := mbrMap[k]; ok {
				m.Stars = m.Stars + v.Stars
				m.LocalScore = m.LocalScore + v.LocalScore
				mbrMap[k] = m
			} else {
				mbrMap[k] = v
			}
		}
	}
	var mbrs []aoc.Member
	for _, v := range mbrMap {
		mbrs = append(mbrs, v)
	}

	if len(mbrs) == 0 {
		return "", errors.New("No member data")
	}
	sort.Sort(aoc.ByStarsThenScore(mbrs))
	txt := ":christmas_tree: AoC All-Time Top Five! :christmas_tree:"
	var num int
	for k := 0; k < len(mbrs); k++ {
		v := mbrs[len(mbrs)-k-1]
		txt = fmt.Sprintf("%s\n%s (%d :star:, %d)", txt, v.Name, v.Stars, v.LocalScore)
		num++
		if num >= 5 {
			break
		}
	}
	return txt, nil
}

func (s *AoCState) DoTopForYear(yr int) string {
	mbrs := s.GetMembers(yr)
	if len(mbrs) == 0 {
		return "No data for that year"
	}
	sort.Sort(aoc.ByStarsThenScore(mbrs))
	txt := fmt.Sprintf(":christmas_tree: AoC Top Five for %d! :christmas_tree:", yr)
	var num int
	for k := 0; k < len(mbrs); k++ {
		v := mbrs[len(mbrs)-k-1]
		txt = fmt.Sprintf("%s\n%s (%d :star:, %d)", txt, v.Name, v.Stars, v.LocalScore)
		num++
		if num >= 5 {
			break
		}
	}
	return txt
}

func (s *AoCState) GetMembers(yr int) []aoc.Member {
	var ret []aoc.Member
	l, err := s.aoc.GetLeaderboard(yr)
	if err != nil {
		return ret
	}
	for _, v := range l.Members {
		ret = append(ret, v)
	}
	return ret
}

func (s *AoCState) GetLatestYear() int {
	latestYear := time.Now().Year()
	if time.Now().Month() < 12 {
		latestYear--
	}
	return latestYear
}

func (s *AoCState) GetListOfAoCYears() []int {
	var ret []int
	for k := s.GetLatestYear(); k > 2014; k-- {
		ret = append(ret, k)
	}
	return ret
}

func (s *AoCState) GetAoCBoard(yr int) (*aoc.Leaderboard, error) {
	return s.aoc.GetLeaderboard(yr)
}

func (s *AoCState) AoCSilentBoardCheckAndUpdate(yr int) {
	if s.AoCBoardNeedsUpdate(yr) {
		l, err := s.aoc.GetLeaderboard(yr)
		if err != nil {
			admin := s.model.GetSlackAdminDMId()
			if admin == "" {
				s.SendAdminIdError()
				return
			}
			if err.Error() == "Invalid Session Cookie" {
				s.sessionNeedsUpdate = true
			}
			s.SendSlackMessage(fmt.Sprintf(":warning: AoC Error processing leaderboard (%d) - %s", yr, err.Error()), admin)
			return
		}

		s.model.SendMessage(models.NewBotMessage(s.Name(), models.MsgSrcApp, models.MsgTpStatus, "", fmt.Sprintf("Received leaderboard (%d)", yr)))
		// Save the leaderboard to the db
		s.saveLeaderboard(l)
	}
}

func (s *AoCState) AoCBoardCheckAndUpdate(yr int) {
	stYr := strconv.Itoa(yr)
	channelId, _ := s.getChannelId()
	if s.AoCBoardNeedsUpdate(yr) {
		l, err := s.aoc.GetLeaderboard(yr)
		if err != nil {
			admin := s.model.GetSlackAdminDMId()
			if admin == "" {
				s.SendAdminIdError()
				return
			}
			if err.Error() == "Invalid Session Cookie" {
				s.sessionNeedsUpdate = true
			}
			s.SendSlackMessage(fmt.Sprintf(":warning: AoC Error processing leaderboard (%d) - %s", yr, err.Error()), admin)
			return
		}

		s.model.SendMessage(models.NewBotMessage(s.Name(), models.MsgSrcApp, models.MsgTpStatus, "", fmt.Sprintf("Received leaderboard (%d)", yr)))
		// Compare the new leaderboard to the saved one
		for _, v := range l.Members {
			mbr, err := s.getMember(l.Event, v.ID)
			if err != nil {
				continue
			}
			if mbr.Stars != v.Stars {
				plural := "star"
				if v.Stars > 1 {
					plural = "stars"
				}
				mbrAll := s.getMemberAllYears(v.ID)
				// Gather all stars from all leaderboards
				var totalStars int
				for k, m := range mbrAll {
					if k != stYr {
						totalStars += m.Stars
					}
				}
				// Add this new one into the total
				allYearsText := fmt.Sprintf(" (%d for all years)", totalStars+v.Stars)
				if yr == s.GetLatestYear() {
					s.SendSlackMessage(fmt.Sprintf(":christmas_tree: %s now has %d %s! :christmas_tree:%s", v.Name, v.Stars, plural, allYearsText), channelId)
				} else {
					s.SendSlackMessage(fmt.Sprintf(":christmas_tree: %s now has %d %s! (%d) :christmas_tree:%s", v.Name, v.Stars, plural, yr, allYearsText), channelId)
				}
			}
		}
		// Save the leaderboard to the db
		s.saveLeaderboard(l)
	}
}

func (s *AoCState) AoCBoardNeedsUpdate(yr int) bool {
	var freshDt time.Duration
	if yr == s.GetLatestYear() {
		freshDt, _ = time.ParseDuration("15m") // AoC asks that we not update more than once every 15 minutes
	} else {
		freshDt, _ = time.ParseDuration("1h")
	}
	l, err := s.aoc.GetCachedLeaderboard(yr)
	if err != nil {
		if err.Error() == "Invalid Year" {
			return false
		}
		// This board is not cached, we need to pull it
		return true
	}
	return time.Since(l.LastFetch) > freshDt
}

func (s *AoCState) AoCBoardIsNew(yr int) bool {
	l, err := s.aoc.GetCachedLeaderboard(yr)
	if err != nil || l == nil {
		if err.Error() == "Invalid Year" {
			return false
		}
		return true
	}
	return false
}

func (s *AoCState) RequestBoardId() {
	reader := bufio.NewReader(os.Stdin)
	fmt.Print("Advent of Code Board ID: ")
	boardId, _ := reader.ReadString('\n')
	s.setAoCBoardId(strings.TrimSpace(boardId))
}

func (s *AoCState) RequestSessionCookie() {
	reader := bufio.NewReader(os.Stdin)
	fmt.Print("Advent of Code Session Cookie: ")
	aocSession, _ := reader.ReadString('\n')
	s.setAoCSessionCookie(strings.TrimSpace(aocSession))
	s.sessionCookie = aocSession
}

// The channel that we post updates to
func (s *AoCState) RequestChannelId() {
	reader := bufio.NewReader(os.Stdin)
	fmt.Print("Advent of Code Slack Channel ID: ")
	chn, _ := reader.ReadString('\n')
	s.setChannelId(strings.TrimSpace(chn))
}

// Returns true if we have all AoC years saved to the DB
func (s *AoCState) haveAllYearsCached() bool {
	for _, yr := range s.GetListOfAoCYears() {
		_, err := s.aoc.GetCachedLeaderboard(yr)
		if err != nil {
			return false
		}
	}
	return true
}

/* DB Functions */
func (s *AoCState) setAoCBoardId(brdId string) error {
	return s.model.SetString([]string{"aoc", "config", "board_id"}, brdId)
}

func (s *AoCState) getAoCBoardId() (string, error) {
	return s.model.GetString([]string{"aoc", "config", "board_id"})
}

func (s *AoCState) setAoCSessionCookie(sess string) error {
	return s.model.SetString([]string{"aoc", "config", "session"}, sess)
}

func (s *AoCState) getAoCSessionCookie() (string, error) {
	return s.model.GetString([]string{"aoc", "config", "session"})
}

func (s *AoCState) setChannelId(chn string) error {
	return s.model.SetString([]string{"aoc", "config", "channel_id"}, chn)
}

func (s *AoCState) getChannelId() (string, error) {
	return s.model.GetString([]string{"aoc", "config", "channel_id"})
}

func (s *AoCState) saveLeaderboard(l *aoc.Leaderboard) error {
	err := s.model.SetInt([]string{"aoc", "leaderboards", l.Event, "owner_id"}, l.OwnerID)
	if err != nil {
		return err
	}
	err = s.model.SetString([]string{"aoc", "leaderboards", l.Event, "last_fetch"}, l.LastFetch.Format(time.RFC3339))
	if err != nil {
		return err
	}
	for _, v := range l.Members {
		if err = s.saveMember(l.Event, &v); err != nil {
			s.model.SendMessage(models.NewErrorBotMessage(s.Name(), models.MsgSrcApp, fmt.Sprintf("Error Saving Member (%s)", v.Name)))
		}
	}
	return nil
}

func (s *AoCState) saveMember(event string, m *aoc.Member) error {
	strId := strconv.Itoa(m.ID)
	err := s.model.SetString([]string{"aoc", "leaderboards", event, "members", strId, "id"}, strId)
	if err != nil {
		return err
	}
	err = s.model.SetString([]string{"aoc", "leaderboards", event, "members", strId, "stars"}, strconv.Itoa(m.Stars))
	if err != nil {
		return err
	}
	err = s.model.SetString([]string{"aoc", "leaderboards", event, "members", strId, "last_star_ts"}, m.LastStarTs.Format(time.RFC3339))
	if err != nil {
		return err
	}
	err = s.model.SetString([]string{"aoc", "leaderboards", event, "members", strId, "name"}, m.Name)
	if err != nil {
		return err
	}
	err = s.model.SetString([]string{"aoc", "leaderboards", event, "members", strId, "local_score"}, strconv.Itoa(m.LocalScore))
	if err != nil {
		return err
	}
	err = s.model.SetString([]string{"aoc", "leaderboards", event, "members", strId, "global_score"}, strconv.Itoa(m.GlobalScore))
	if err != nil {
		return err
	}

	return nil
}

func (s *AoCState) getMemberAllYears(memberId int) map[string]*aoc.Member {
	ret := make(map[string]*aoc.Member)
	for _, yr := range s.GetListOfAoCYears() {
		stYr := strconv.Itoa(yr)
		m, err := s.getMember(stYr, memberId)
		if err == nil {
			ret[stYr] = m
		}
	}
	return ret
}

func (s *AoCState) getMember(event string, memberId int) (*aoc.Member, error) {
	var err error
	var wrk string
	mbr := new(aoc.Member)
	mbrPath := []string{"aoc", "leaderboards", event, "members", strconv.Itoa(memberId)}
	mbr.ID, err = s.model.GetInt(append(mbrPath, "id"))
	if err != nil {
		return nil, err
	}
	wrk, err = s.model.GetString(append(mbrPath, "stars"))
	if err != nil {
		return nil, err
	}
	mbr.Stars, err = strconv.Atoi(wrk)
	if err != nil {
		return nil, err
	}
	wrk, err = s.model.GetString(append(mbrPath, "last_star_ts"))
	if err != nil {
		return nil, err
	}
	mbr.LastStarTs, err = time.Parse(time.RFC3339, wrk)
	if err != nil {
		return nil, err
	}
	mbr.Name, err = s.model.GetString(append(mbrPath, "name"))
	if err != nil {
		return nil, err
	}
	wrk, err = s.model.GetString(append(mbrPath, "local_score"))
	if err != nil {
		return nil, err
	}
	mbr.LocalScore, err = strconv.Atoi(wrk)
	wrk, err = s.model.GetString(append(mbrPath, "global_score"))
	if err != nil {
		return nil, err
	}
	mbr.GlobalScore, err = strconv.Atoi(wrk)
	return mbr, nil
}

func (s *AoCState) SendAdminIdError() {
	s.model.SendMessage(models.NewBotMessage(s.Name(), models.MsgSrcApp, models.MsgTpError, models.MsgSrcApp, "No Admin ID Found"))
}

func (s *AoCState) SendSlackMessage(text, dest string) {
	s.model.SendMessage(models.NewBotMessage(s.Name(), models.MsgSrcSlack, models.MsgTpMessage, dest, text))
}