package app

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"time"

	"daily-timer/internal/models"
	"daily-timer/internal/services/updater"
	"daily-timer/internal/storage"
	"daily-timer/internal/timer"
	"daily-timer/internal/version"

	"github.com/wailsapp/wails/v2/pkg/runtime"
)

type App struct {
	ctx         context.Context
	store       *storage.Storage
	timer       *timer.Timer
	session     *models.MeetingSession
	currentLogs map[uint]*models.ParticipantLog
	updater     *updater.Updater
}

func New(store *storage.Storage) *App {
	return &App{
		store:       store,
		currentLogs: make(map[uint]*models.ParticipantLog),
		updater:     updater.New(),
	}
}

func (a *App) Startup(ctx context.Context) {
	a.ctx = ctx
}

func (a *App) OnDomReady(ctx context.Context) {
	runtime.WindowShow(ctx)
}

func (a *App) Shutdown(ctx context.Context) {
	if a.timer != nil {
		a.timer.Close()
	}
	if a.store != nil {
		_ = a.store.Close()
	}
}

// Participants

func (a *App) GetParticipants() ([]models.Participant, error) {
	return a.store.GetParticipants()
}

func (a *App) AddParticipant(name string, email string, timeLimit int) (*models.Participant, error) {
	participants, _ := a.store.GetAllParticipants()
	order := len(participants)

	p := &models.Participant{
		Name:      name,
		Email:     email,
		TimeLimit: timeLimit,
		Order:     order,
		Active:    true,
	}

	if err := a.store.CreateParticipant(p); err != nil {
		return nil, err
	}
	return p, nil
}

func (a *App) UpdateParticipant(id uint, name string, email string, timeLimit int) error {
	p := &models.Participant{
		ID:        id,
		Name:      name,
		Email:     email,
		TimeLimit: timeLimit,
	}
	return a.store.UpdateParticipant(p)
}

func (a *App) DeleteParticipant(id uint) error {
	return a.store.DeleteParticipant(id)
}

func (a *App) ReorderParticipants(ids []uint) error {
	return a.store.ReorderParticipants(ids)
}

// Meeting

func (a *App) GetMeeting() (*models.Meeting, error) {
	return a.store.GetMeeting()
}

func (a *App) UpdateMeeting(name string, timeLimit int) error {
	meeting, err := a.store.GetMeeting()
	if err != nil {
		return err
	}
	meeting.Name = name
	meeting.TimeLimit = timeLimit
	return a.store.UpdateMeeting(meeting)
}

// Timer Controls

func (a *App) StartMeeting(participantOrder []uint, attendance map[uint]bool) error {
	meeting, err := a.store.GetMeeting()
	if err != nil {
		return err
	}

	settings, _ := a.store.GetSettings()
	warningThreshold := 30
	if settings != nil {
		warningThreshold = settings.WarningThreshold
	}

	session, err := a.store.CreateSession(meeting.ID)
	if err != nil {
		return err
	}
	a.session = session

	for participantID, present := range attendance {
		_ = a.store.SetAttendance(session.ID, participantID, present, false)
	}

	participants, _ := a.store.GetParticipants()
	participantMap := make(map[uint]models.Participant)
	for _, p := range participants {
		participantMap[p.ID] = p
	}

	queue := make([]models.QueuedSpeaker, 0, len(participantOrder))
	for i, id := range participantOrder {
		if p, ok := participantMap[id]; ok {
			if present, ok := attendance[id]; ok && present {
				queue = append(queue, models.QueuedSpeaker{
					ID:        p.ID,
					Name:      p.Name,
					TimeLimit: p.TimeLimit,
					Order:     i,
				})
			}
		}
	}

	a.timer = timer.New(meeting.TimeLimit, warningThreshold)
	a.timer.SetQueue(queue)
	a.currentLogs = make(map[uint]*models.ParticipantLog)
	go a.handleTimerEvents()
	a.timer.Start()

	return nil
}

func (a *App) handleTimerEvents() {
	for event := range a.timer.Events() {
		switch event.Type {
		case timer.EventTick:
			runtime.EventsEmit(a.ctx, "timer:tick", event.State)
		case timer.EventSpeakerWarning:
			runtime.EventsEmit(a.ctx, "timer:speaker_warning", event.State)
		case timer.EventSpeakerTimeUp:
			runtime.EventsEmit(a.ctx, "timer:speaker_timeup", event.State)
		case timer.EventMeetingWarning:
			runtime.EventsEmit(a.ctx, "timer:meeting_warning", event.State)
		case timer.EventMeetingTimeUp:
			runtime.EventsEmit(a.ctx, "timer:meeting_timeup", event.State)
		case timer.EventSpeakerChanged:
			a.saveSpeakerLog(event.State)
			runtime.EventsEmit(a.ctx, "timer:speaker_changed", event.State)
		case timer.EventMeetingEnded:
			a.finalizeSpeakerLogs(event.State)
			a.endMeetingSession(event.State)
			runtime.EventsEmit(a.ctx, "timer:meeting_ended", event.State)
		}
	}
}

func (a *App) finalizeSpeakerLogs(state models.TimerState) {
	if a.session == nil {
		return
	}

	// Only finalize existing logs, don't create new ones
	for id, log := range a.currentLogs {
		if log.EndedAt == nil {
			now := time.Now()
			log.EndedAt = &now
			log.Duration = int(now.Sub(log.StartedAt).Seconds())

			participants, _ := a.store.GetParticipants()
			for _, p := range participants {
				if p.ID == id {
					log.Overtime = log.Duration > p.TimeLimit
					break
				}
			}
			_ = a.store.UpdateParticipantLog(log)
		}
	}
}

func (a *App) saveSpeakerLog(state models.TimerState) {
	if a.session == nil {
		return
	}

	for id, log := range a.currentLogs {
		if log.EndedAt == nil {
			now := time.Now()
			log.EndedAt = &now
			log.Duration = int(now.Sub(log.StartedAt).Seconds())

			participants, _ := a.store.GetParticipants()
			for _, p := range participants {
				if p.ID == id {
					log.Overtime = log.Duration > p.TimeLimit
					break
				}
			}
			_ = a.store.UpdateParticipantLog(log)
		}
	}

	if state.CurrentSpeakerID > 0 {
		log := &models.ParticipantLog{
			SessionID:     a.session.ID,
			ParticipantID: state.CurrentSpeakerID,
			StartedAt:     time.Now(),
			Order:         state.SpeakingOrder,
		}
		_ = a.store.CreateParticipantLog(log)
		a.currentLogs[state.CurrentSpeakerID] = log
	}
}

func (a *App) endMeetingSession(state models.TimerState) {
	if a.session == nil {
		return
	}
	_ = a.store.EndSession(a.session.ID, state.MeetingElapsed)
	a.session = nil
	a.currentLogs = make(map[uint]*models.ParticipantLog)
}

func (a *App) NextSpeaker() {
	if a.timer != nil {
		a.timer.NextSpeaker()
	}
}

func (a *App) SkipSpeaker() {
	if a.timer != nil {
		a.timer.SkipSpeaker()
	}
}

func (a *App) RemoveFromQueue(speakerID uint) {
	if a.timer != nil {
		a.timer.RemoveFromQueue(speakerID)
	}
}

func (a *App) SwitchToSpeaker(speakerID uint) {
	if a.timer != nil {
		a.timer.SwitchToSpeaker(speakerID)
	}
}

func (a *App) PauseMeeting() {
	if a.timer != nil {
		a.timer.Pause()
	}
}

func (a *App) ResumeMeeting() {
	if a.timer != nil {
		a.timer.Resume()
	}
}

func (a *App) StopMeeting() {
	if a.timer != nil {
		a.timer.Stop()
	}
}

func (a *App) GetTimerState() *models.TimerState {
	if a.timer == nil {
		return nil
	}
	state := a.timer.GetState()
	return &state
}

// Settings

func (a *App) GetSettings() (*models.Settings, error) {
	return a.store.GetSettings()
}

func (a *App) UpdateSettings(settings *models.Settings) error {
	return a.store.UpdateSettings(settings)
}

// History & Statistics

func (a *App) GetSessions(limit, offset int) ([]models.MeetingSession, error) {
	return a.store.GetSessions(limit, offset)
}

func (a *App) GetSession(id uint) (*models.MeetingSession, error) {
	return a.store.GetSession(id)
}

func (a *App) DeleteSession(id uint) error {
	return a.store.DeleteSession(id)
}

func (a *App) DeleteAllSessions() error {
	return a.store.DeleteAllSessions()
}

func (a *App) GetStatistics(fromStr, toStr string) (*models.AggregatedStats, error) {
	from, err := time.Parse("2006-01-02", fromStr)
	if err != nil {
		from = time.Now().AddDate(0, -1, 0)
	}

	to, err := time.Parse("2006-01-02", toStr)
	if err != nil {
		to = time.Now()
	}

	return a.store.GetAggregatedStats(from, to)
}

func (a *App) ExportData(fromStr, toStr string) (string, error) {
	from, _ := time.Parse("2006-01-02", fromStr)
	to, _ := time.Parse("2006-01-02", toStr)

	if from.IsZero() {
		from = time.Now().AddDate(-1, 0, 0)
	}
	if to.IsZero() {
		to = time.Now()
	}

	participants, err := a.store.GetAllParticipants()
	if err != nil {
		return "", err
	}

	sessions, err := a.store.GetSessions(1000, 0)
	if err != nil {
		return "", err
	}

	meeting, _ := a.store.GetMeeting()
	sessionStats := make([]models.SessionStats, 0, len(sessions))

	for _, s := range sessions {
		if s.StartedAt.Before(from) || s.StartedAt.After(to) {
			continue
		}

		stats := models.SessionStats{
			SessionID:     s.ID,
			Date:          s.StartedAt.Format("2006-01-02 15:04"),
			TotalDuration: s.TotalDuration,
			MeetingLimit:  meeting.TimeLimit,
			Overtime:      s.TotalDuration > meeting.TimeLimit,
		}

		for _, log := range s.ParticipantLogs {
			stats.ParticipantStats = append(stats.ParticipantStats, models.ParticipantStats{
				ParticipantID: log.ParticipantID,
				Name:          log.Participant.Name,
				Duration:      log.Duration,
				TimeLimit:     log.Participant.TimeLimit,
				Overtime:      log.Overtime,
				Skipped:       log.Skipped,
				SpeakingOrder: log.Order,
			})
			if log.Overtime {
				stats.OvertimeCount++
			}
			if log.Skipped {
				stats.SkippedCount++
			}
		}

		for _, att := range s.Attendance {
			if att.Present {
				stats.PresentCount++
			} else {
				stats.AbsentCount++
			}
		}
		stats.ParticipantCount = stats.PresentCount + stats.AbsentCount

		sessionStats = append(sessionStats, stats)
	}

	aggStats, _ := a.store.GetAggregatedStats(from, to)

	exportData := models.ExportData{
		ExportedAt:   time.Now().Format(time.RFC3339),
		Participants: participants,
		Sessions:     sessionStats,
		Statistics:   *aggStats,
	}

	data, err := json.MarshalIndent(exportData, "", "  ")
	if err != nil {
		return "", err
	}

	filename := fmt.Sprintf("daily-timer-export-%s.json", time.Now().Format("2006-01-02"))
	savePath, err := runtime.SaveFileDialog(a.ctx, runtime.SaveDialogOptions{
		DefaultFilename: filename,
		Filters: []runtime.FileFilter{
			{DisplayName: "JSON Files", Pattern: "*.json"},
		},
	})
	if err != nil {
		return "", err
	}
	if savePath == "" {
		return "", nil
	}

	if err := os.WriteFile(savePath, data, 0644); err != nil {
		return "", err
	}

	return savePath, nil
}

func (a *App) ExportCSV(fromStr, toStr string) (string, error) {
	from, _ := time.Parse("2006-01-02", fromStr)
	to, _ := time.Parse("2006-01-02", toStr)

	if from.IsZero() {
		from = time.Now().AddDate(-1, 0, 0)
	}
	if to.IsZero() {
		to = time.Now()
	}

	sessions, err := a.store.GetSessions(1000, 0)
	if err != nil {
		return "", err
	}

	csv := "Date,Participant,Duration (s),Time Limit (s),Overtime,Skipped,Speaking Order\n"

	for _, s := range sessions {
		if s.StartedAt.Before(from) || s.StartedAt.After(to) {
			continue
		}
		date := s.StartedAt.Format("2006-01-02")

		for _, log := range s.ParticipantLogs {
			csv += fmt.Sprintf("%s,%s,%d,%d,%t,%t,%d\n",
				date,
				log.Participant.Name,
				log.Duration,
				log.Participant.TimeLimit,
				log.Overtime,
				log.Skipped,
				log.Order,
			)
		}
	}

	filename := fmt.Sprintf("daily-timer-export-%s.csv", time.Now().Format("2006-01-02"))
	savePath, err := runtime.SaveFileDialog(a.ctx, runtime.SaveDialogOptions{
		DefaultFilename: filename,
		Filters: []runtime.FileFilter{
			{DisplayName: "CSV Files", Pattern: "*.csv"},
		},
	})
	if err != nil {
		return "", err
	}
	if savePath == "" {
		return "", nil
	}

	if err := os.WriteFile(savePath, []byte(csv), 0644); err != nil {
		return "", err
	}

	return savePath, nil
}

// Sound

func (a *App) GetSoundsDir() string {
	configDir, _ := os.UserConfigDir()
	soundsDir := filepath.Join(configDir, "DailyTimer", "sounds")
	_ = os.MkdirAll(soundsDir, 0755)
	return soundsDir
}

// Updates

func (a *App) GetVersion() string {
	return version.Version
}

func (a *App) CheckForUpdates() (*updater.UpdateInfo, error) {
	return a.updater.CheckForUpdates()
}

func (a *App) DownloadAndInstallUpdate() error {
	err := a.updater.DownloadAndInstall(func(progress float64) {
		runtime.EventsEmit(a.ctx, "update:progress", progress)
	})
	if err != nil {
		return err
	}
	runtime.EventsEmit(a.ctx, "update:complete", true)
	return nil
}

func (a *App) RestartApp() error {
	return a.updater.RestartApp()
}

// Sound Management

func (a *App) getSoundsDir() (string, error) {
	configDir, err := os.UserConfigDir()
	if err != nil {
		return "", err
	}
	soundsDir := filepath.Join(configDir, "DailyTimer", "sounds")
	if err := os.MkdirAll(soundsDir, 0755); err != nil {
		return "", err
	}
	return soundsDir, nil
}

func (a *App) SelectCustomSound(soundType string) (string, error) {
	// Validate sound type
	validTypes := map[string]bool{"warning": true, "timeup": true, "meeting_end": true}
	if !validTypes[soundType] {
		return "", fmt.Errorf("invalid sound type: %s", soundType)
	}

	// Open file dialog
	selection, err := runtime.OpenFileDialog(a.ctx, runtime.OpenDialogOptions{
		Title: "Select Sound File",
		Filters: []runtime.FileFilter{
			{DisplayName: "Audio Files", Pattern: "*.mp3;*.wav;*.m4a;*.ogg"},
		},
	})
	if err != nil {
		return "", err
	}
	if selection == "" {
		return "", nil // User cancelled
	}

	// Get sounds directory
	soundsDir, err := a.getSoundsDir()
	if err != nil {
		return "", err
	}

	// Determine destination filename
	ext := filepath.Ext(selection)
	destPath := filepath.Join(soundsDir, soundType+ext)

	// Copy file
	src, err := os.Open(selection)
	if err != nil {
		return "", err
	}
	defer func() { _ = src.Close() }()

	dst, err := os.Create(destPath)
	if err != nil {
		return "", err
	}
	defer func() { _ = dst.Close() }()

	if _, err := dst.ReadFrom(src); err != nil {
		return "", err
	}

	return destPath, nil
}

func (a *App) GetCustomSoundPath(soundType string) string {
	soundsDir, err := a.getSoundsDir()
	if err != nil {
		return ""
	}

	// Check for common audio extensions
	extensions := []string{".mp3", ".wav", ".m4a", ".ogg"}
	for _, ext := range extensions {
		path := filepath.Join(soundsDir, soundType+ext)
		if _, err := os.Stat(path); err == nil {
			return path
		}
	}

	return ""
}

func (a *App) ClearCustomSound(soundType string) error {
	soundsDir, err := a.getSoundsDir()
	if err != nil {
		return err
	}

	extensions := []string{".mp3", ".wav", ".m4a", ".ogg"}
	for _, ext := range extensions {
		path := filepath.Join(soundsDir, soundType+ext)
		if _, err := os.Stat(path); err == nil {
			if err := os.Remove(path); err != nil {
				return err
			}
		}
	}

	return nil
}