// Package tournament provides the tournament lifecycle management, multi-tournament
// coordination, and state aggregation for the Felt tournament engine. It wires
// together the clock engine, financial engine, player management, and seating
// engine to provide a complete tournament lifecycle: create, configure, start,
// run, pause, resume, and end.
package tournament

import (
	"context"
	"crypto/rand"
	"database/sql"
	"encoding/json"
	"fmt"
	"log"
	"time"

	"github.com/felt-app/felt/internal/audit"
	"github.com/felt-app/felt/internal/clock"
	"github.com/felt-app/felt/internal/financial"
	"github.com/felt-app/felt/internal/player"
	"github.com/felt-app/felt/internal/seating"
	"github.com/felt-app/felt/internal/server/middleware"
	"github.com/felt-app/felt/internal/server/ws"
	"github.com/felt-app/felt/internal/template"
)

// Tournament statuses.
const (
	StatusCreated     = "created"
	StatusRegistering = "registering"
	StatusRunning     = "running"
	StatusPaused      = "paused"
	StatusFinalTable  = "final_table"
	StatusCompleted   = "completed"
	StatusCancelled   = "cancelled"
)

// Errors returned by the tournament service.
var (
	ErrTournamentNotFound      = fmt.Errorf("tournament: not found")
	ErrInvalidStatus           = fmt.Errorf("tournament: invalid status transition")
	ErrMinPlayersNotMet        = fmt.Errorf("tournament: minimum players not met")
	ErrNoTablesConfigured      = fmt.Errorf("tournament: no tables configured")
	ErrTournamentAlreadyEnded  = fmt.Errorf("tournament: already ended or cancelled")
	ErrTemplateNotFound        = fmt.Errorf("tournament: template not found")
	ErrTournamentNotRunning    = fmt.Errorf("tournament: not running")
	ErrTournamentNotPaused     = fmt.Errorf("tournament: not paused")
)

// Tournament represents a tournament record as stored in the DB.
type Tournament struct {
	ID                    string  `json:"id"`
	Name                  string  `json:"name"`
	TemplateID            *int64  `json:"template_id,omitempty"`
	ChipSetID             int64   `json:"chip_set_id"`
	BlindStructureID      int64   `json:"blind_structure_id"`
	PayoutStructureID     int64   `json:"payout_structure_id"`
	BuyinConfigID         int64   `json:"buyin_config_id"`
	PointsFormulaID       *int64  `json:"points_formula_id,omitempty"`
	Status                string  `json:"status"`
	MinPlayers            int     `json:"min_players"`
	MaxPlayers            *int    `json:"max_players,omitempty"`
	EarlySignupBonusChips int64   `json:"early_signup_bonus_chips"`
	EarlySignupCutoff     *string `json:"early_signup_cutoff,omitempty"`
	PunctualityBonusChips int64   `json:"punctuality_bonus_chips"`
	IsPKO                 bool    `json:"is_pko"`
	CurrentLevel          int     `json:"current_level"`
	ClockState            string  `json:"clock_state"`
	StartedAt             *int64  `json:"started_at,omitempty"`
	EndedAt               *int64  `json:"ended_at,omitempty"`
	CreatedAt             int64   `json:"created_at"`
	UpdatedAt             int64   `json:"updated_at"`
}

// TournamentOverrides allows overriding template values when creating from template.
type TournamentOverrides struct {
	Name                  string  `json:"name,omitempty"`
	MinPlayers            *int    `json:"min_players,omitempty"`
	MaxPlayers            *int    `json:"max_players,omitempty"`
	IsPKO                 *bool   `json:"is_pko,omitempty"`
	EarlySignupBonusChips *int64  `json:"early_signup_bonus_chips,omitempty"`
	PunctualityBonusChips *int64  `json:"punctuality_bonus_chips,omitempty"`
}

// TournamentConfig for creating a tournament manually (without template).
type TournamentConfig struct {
	Name                  string  `json:"name"`
	ChipSetID             int64   `json:"chip_set_id"`
	BlindStructureID      int64   `json:"blind_structure_id"`
	PayoutStructureID     int64   `json:"payout_structure_id"`
	BuyinConfigID         int64   `json:"buyin_config_id"`
	PointsFormulaID       *int64  `json:"points_formula_id,omitempty"`
	MinPlayers            int     `json:"min_players"`
	MaxPlayers            *int    `json:"max_players,omitempty"`
	EarlySignupBonusChips int64   `json:"early_signup_bonus_chips"`
	PunctualityBonusChips int64   `json:"punctuality_bonus_chips"`
	IsPKO                 bool    `json:"is_pko"`
}

// TournamentDetail is the full tournament state for display.
type TournamentDetail struct {
	Tournament     Tournament                  `json:"tournament"`
	ClockSnapshot  *clock.ClockSnapshot        `json:"clock_snapshot,omitempty"`
	Tables         []seating.TableDetail       `json:"tables"`
	Players        PlayerSummary               `json:"players"`
	PrizePool      *financial.PrizePoolSummary `json:"prize_pool,omitempty"`
	Rankings       []player.PlayerRanking      `json:"rankings"`
	RecentActivity []audit.AuditEntry          `json:"recent_activity"`
	BalanceStatus  *seating.BalanceStatus       `json:"balance_status,omitempty"`
}

// PlayerSummary summarizes player counts.
type PlayerSummary struct {
	Registered int `json:"registered"`
	Active     int `json:"active"`
	Busted     int `json:"busted"`
	Deal       int `json:"deal"`
	Total      int `json:"total"`
}

// Service provides tournament lifecycle management.
type Service struct {
	db        *sql.DB
	registry  *clock.Registry
	financial *financial.Engine
	players   *player.Service
	ranking   *player.RankingEngine
	tables    *seating.TableService
	balance   *seating.BalanceEngine
	templates *template.TournamentTemplateService
	trail     *audit.Trail
	hub       *ws.Hub
}

// NewService creates a new tournament service.
func NewService(
	db *sql.DB,
	registry *clock.Registry,
	fin *financial.Engine,
	players *player.Service,
	ranking *player.RankingEngine,
	tables *seating.TableService,
	balance *seating.BalanceEngine,
	templates *template.TournamentTemplateService,
	trail *audit.Trail,
	hub *ws.Hub,
) *Service {
	return &Service{
		db:        db,
		registry:  registry,
		financial: fin,
		players:   players,
		ranking:   ranking,
		tables:    tables,
		balance:   balance,
		templates: templates,
		trail:     trail,
		hub:       hub,
	}
}

// CreateFromTemplate creates a tournament from a template with optional overrides.
// This is the template-first flow: pick template, everything pre-fills, tweak, start.
func (s *Service) CreateFromTemplate(ctx context.Context, templateID int64, overrides TournamentOverrides) (*Tournament, error) {
	// Load the expanded template
	expanded, err := s.templates.GetTemplateExpanded(ctx, templateID)
	if err != nil {
		return nil, ErrTemplateNotFound
	}

	tmpl := expanded.TournamentTemplate
	tournamentID := generateUUID()
	now := time.Now().Unix()

	name := tmpl.Name
	if overrides.Name != "" {
		name = overrides.Name
	}
	minPlayers := tmpl.MinPlayers
	if overrides.MinPlayers != nil {
		minPlayers = *overrides.MinPlayers
	}
	maxPlayers := tmpl.MaxPlayers
	if overrides.MaxPlayers != nil {
		maxPlayers = overrides.MaxPlayers
	}
	isPKO := tmpl.IsPKO
	if overrides.IsPKO != nil {
		isPKO = *overrides.IsPKO
	}
	earlyBonus := tmpl.EarlySignupBonusChips
	if overrides.EarlySignupBonusChips != nil {
		earlyBonus = *overrides.EarlySignupBonusChips
	}
	punctBonus := tmpl.PunctualityBonusChips
	if overrides.PunctualityBonusChips != nil {
		punctBonus = *overrides.PunctualityBonusChips
	}

	isPKOInt := 0
	if isPKO {
		isPKOInt = 1
	}

	var maxPlayersDB sql.NullInt64
	if maxPlayers != nil {
		maxPlayersDB = sql.NullInt64{Int64: int64(*maxPlayers), Valid: true}
	}

	var pointsFormulaDB sql.NullInt64
	if tmpl.PointsFormulaID != nil {
		pointsFormulaDB = sql.NullInt64{Int64: *tmpl.PointsFormulaID, Valid: true}
	}

	_, err = s.db.ExecContext(ctx,
		`INSERT INTO tournaments (
			id, name, template_id, chip_set_id, blind_structure_id,
			payout_structure_id, buyin_config_id, points_formula_id,
			status, min_players, max_players,
			early_signup_bonus_chips, early_signup_cutoff,
			punctuality_bonus_chips, is_pko,
			created_at, updated_at
		) VALUES (?, ?, ?, ?, ?, ?, ?, ?, 'created', ?, ?, ?, ?, ?, ?, ?, ?)`,
		tournamentID, name, templateID,
		tmpl.ChipSetID, tmpl.BlindStructureID,
		tmpl.PayoutStructureID, tmpl.BuyinConfigID, pointsFormulaDB,
		minPlayers, maxPlayersDB,
		earlyBonus, tmpl.EarlySignupCutoff,
		punctBonus, isPKOInt,
		now, now,
	)
	if err != nil {
		return nil, fmt.Errorf("tournament: create from template: %w", err)
	}

	tournament := &Tournament{
		ID:                    tournamentID,
		Name:                  name,
		TemplateID:            &templateID,
		ChipSetID:             tmpl.ChipSetID,
		BlindStructureID:      tmpl.BlindStructureID,
		PayoutStructureID:     tmpl.PayoutStructureID,
		BuyinConfigID:         tmpl.BuyinConfigID,
		PointsFormulaID:       tmpl.PointsFormulaID,
		Status:                StatusCreated,
		MinPlayers:            minPlayers,
		MaxPlayers:            maxPlayers,
		EarlySignupBonusChips: earlyBonus,
		EarlySignupCutoff:     tmpl.EarlySignupCutoff,
		PunctualityBonusChips: punctBonus,
		IsPKO:                 isPKO,
		ClockState:            "stopped",
		CreatedAt:             now,
		UpdatedAt:             now,
	}

	// Audit entry
	s.recordAudit(ctx, tournamentID, audit.ActionTournamentCreate, "tournament", tournamentID, tournament)
	s.broadcast(tournamentID, "tournament.created", tournament)

	return tournament, nil
}

// CreateManual creates a tournament without a template.
func (s *Service) CreateManual(ctx context.Context, config TournamentConfig) (*Tournament, error) {
	tournamentID := generateUUID()
	now := time.Now().Unix()

	if config.Name == "" {
		return nil, fmt.Errorf("tournament: name is required")
	}
	if config.MinPlayers < 2 {
		config.MinPlayers = 2
	}

	isPKOInt := 0
	if config.IsPKO {
		isPKOInt = 1
	}

	var maxPlayersDB sql.NullInt64
	if config.MaxPlayers != nil {
		maxPlayersDB = sql.NullInt64{Int64: int64(*config.MaxPlayers), Valid: true}
	}

	var pointsFormulaDB sql.NullInt64
	if config.PointsFormulaID != nil {
		pointsFormulaDB = sql.NullInt64{Int64: *config.PointsFormulaID, Valid: true}
	}

	_, err := s.db.ExecContext(ctx,
		`INSERT INTO tournaments (
			id, name, chip_set_id, blind_structure_id,
			payout_structure_id, buyin_config_id, points_formula_id,
			status, min_players, max_players,
			early_signup_bonus_chips, punctuality_bonus_chips, is_pko,
			created_at, updated_at
		) VALUES (?, ?, ?, ?, ?, ?, ?, 'created', ?, ?, ?, ?, ?, ?, ?)`,
		tournamentID, config.Name,
		config.ChipSetID, config.BlindStructureID,
		config.PayoutStructureID, config.BuyinConfigID, pointsFormulaDB,
		config.MinPlayers, maxPlayersDB,
		config.EarlySignupBonusChips, config.PunctualityBonusChips, isPKOInt,
		now, now,
	)
	if err != nil {
		return nil, fmt.Errorf("tournament: create manual: %w", err)
	}

	tournament := &Tournament{
		ID:                    tournamentID,
		Name:                  config.Name,
		ChipSetID:             config.ChipSetID,
		BlindStructureID:      config.BlindStructureID,
		PayoutStructureID:     config.PayoutStructureID,
		BuyinConfigID:         config.BuyinConfigID,
		PointsFormulaID:       config.PointsFormulaID,
		Status:                StatusCreated,
		MinPlayers:            config.MinPlayers,
		MaxPlayers:            config.MaxPlayers,
		EarlySignupBonusChips: config.EarlySignupBonusChips,
		PunctualityBonusChips: config.PunctualityBonusChips,
		IsPKO:                 config.IsPKO,
		ClockState:            "stopped",
		CreatedAt:             now,
		UpdatedAt:             now,
	}

	s.recordAudit(ctx, tournamentID, audit.ActionTournamentCreate, "tournament", tournamentID, tournament)
	s.broadcast(tournamentID, "tournament.created", tournament)

	return tournament, nil
}

// GetTournament returns the full tournament detail including state from all subsystems.
func (s *Service) GetTournament(ctx context.Context, id string) (*TournamentDetail, error) {
	t, err := s.loadTournament(ctx, id)
	if err != nil {
		return nil, err
	}

	detail := &TournamentDetail{
		Tournament: *t,
	}

	// Clock snapshot
	if engine := s.registry.Get(id); engine != nil {
		snap := engine.Snapshot()
		detail.ClockSnapshot = &snap
	}

	// Tables
	if s.tables != nil {
		tables, err := s.tables.GetTables(ctx, id)
		if err == nil {
			detail.Tables = tables
		}
	}

	// Player summary
	detail.Players = s.getPlayerSummary(ctx, id)

	// Prize pool
	if s.financial != nil {
		pool, err := s.financial.CalculatePrizePool(ctx, id)
		if err == nil {
			detail.PrizePool = pool
		}
	}

	// Rankings
	if s.ranking != nil {
		rankings, err := s.ranking.CalculateRankings(ctx, id)
		if err == nil {
			detail.Rankings = rankings
		}
	}

	// Recent activity (last 20 audit entries)
	detail.RecentActivity = s.getRecentActivity(ctx, id, 20)

	// Balance status
	if s.balance != nil {
		status, err := s.balance.CheckBalance(ctx, id)
		if err == nil {
			detail.BalanceStatus = status
		}
	}

	return detail, nil
}

// StartTournament transitions a tournament from created/registering to running.
func (s *Service) StartTournament(ctx context.Context, id string) error {
	t, err := s.loadTournament(ctx, id)
	if err != nil {
		return err
	}

	if t.Status != StatusCreated && t.Status != StatusRegistering {
		return ErrInvalidStatus
	}

	// Validate minimum players met
	playerCount := s.countActivePlayers(ctx, id)
	if playerCount < t.MinPlayers {
		return ErrMinPlayersNotMet
	}

	// Validate at least one table exists
	tableCount := s.countTables(ctx, id)
	if tableCount == 0 {
		return ErrNoTablesConfigured
	}

	now := time.Now().Unix()

	// Start the clock engine
	if s.registry != nil {
		engine := s.registry.GetOrCreate(id)
		levels, loadErr := s.loadLevelsFromDB(id)
		if loadErr == nil && len(levels) > 0 {
			engine.LoadLevels(levels)
			engine.SetOnStateChange(func(tid string, snap clock.ClockSnapshot) {
				s.persistClockState(tid, snap)
			})
			operatorID := middleware.OperatorIDFromCtx(ctx)
			if startErr := engine.Start(operatorID); startErr != nil {
				log.Printf("tournament: clock start error: %v", startErr)
			}
			_ = s.registry.StartTicker(ctx, id)
		}
	}

	// Update tournament status
	_, err = s.db.ExecContext(ctx,
		`UPDATE tournaments SET status = 'running', started_at = ?, updated_at = ? WHERE id = ?`,
		now, now, id,
	)
	if err != nil {
		return fmt.Errorf("tournament: start: %w", err)
	}

	s.recordAudit(ctx, id, audit.ActionTournamentStart, "tournament", id, map[string]interface{}{
		"player_count": playerCount,
		"table_count":  tableCount,
	})
	s.broadcast(id, "tournament.started", map[string]interface{}{
		"tournament_id": id,
		"started_at":    now,
	})

	return nil
}

// PauseTournament pauses a running tournament (pauses the clock).
func (s *Service) PauseTournament(ctx context.Context, id string) error {
	t, err := s.loadTournament(ctx, id)
	if err != nil {
		return err
	}

	if t.Status != StatusRunning && t.Status != StatusFinalTable {
		return ErrTournamentNotRunning
	}

	// Pause the clock
	if engine := s.registry.Get(id); engine != nil {
		operatorID := middleware.OperatorIDFromCtx(ctx)
		if pauseErr := engine.Pause(operatorID); pauseErr != nil {
			log.Printf("tournament: clock pause error: %v", pauseErr)
		}
	}

	now := time.Now().Unix()
	_, err = s.db.ExecContext(ctx,
		`UPDATE tournaments SET status = 'paused', updated_at = ? WHERE id = ?`,
		now, id,
	)
	if err != nil {
		return fmt.Errorf("tournament: pause: %w", err)
	}

	s.recordAudit(ctx, id, "tournament.pause", "tournament", id, nil)
	s.broadcast(id, "tournament.paused", map[string]string{"tournament_id": id})

	return nil
}

// ResumeTournament resumes a paused tournament (resumes the clock).
func (s *Service) ResumeTournament(ctx context.Context, id string) error {
	t, err := s.loadTournament(ctx, id)
	if err != nil {
		return err
	}

	if t.Status != StatusPaused {
		return ErrTournamentNotPaused
	}

	// Resume the clock
	if engine := s.registry.Get(id); engine != nil {
		operatorID := middleware.OperatorIDFromCtx(ctx)
		if resumeErr := engine.Resume(operatorID); resumeErr != nil {
			log.Printf("tournament: clock resume error: %v", resumeErr)
		}
	}

	now := time.Now().Unix()
	_, err = s.db.ExecContext(ctx,
		`UPDATE tournaments SET status = 'running', updated_at = ? WHERE id = ?`,
		now, id,
	)
	if err != nil {
		return fmt.Errorf("tournament: resume: %w", err)
	}

	s.recordAudit(ctx, id, "tournament.resume", "tournament", id, nil)
	s.broadcast(id, "tournament.resumed", map[string]string{"tournament_id": id})

	return nil
}

// EndTournament ends a tournament. Called when 1 player remains or manually for deals.
func (s *Service) EndTournament(ctx context.Context, id string) error {
	t, err := s.loadTournament(ctx, id)
	if err != nil {
		return err
	}

	if t.Status == StatusCompleted || t.Status == StatusCancelled {
		return ErrTournamentAlreadyEnded
	}

	// Stop the clock
	if engine := s.registry.Get(id); engine != nil {
		operatorID := middleware.OperatorIDFromCtx(ctx)
		_ = engine.Pause(operatorID) // Pause stops the ticker
	}

	// Assign finishing positions to remaining active players
	s.assignFinalPositions(ctx, id)

	// Calculate and apply payouts
	if s.financial != nil {
		payouts, payoutErr := s.financial.CalculatePayouts(ctx, id)
		if payoutErr == nil && len(payouts) > 0 {
			if applyErr := s.financial.ApplyPayouts(ctx, id, payouts); applyErr != nil {
				log.Printf("tournament: apply payouts error: %v", applyErr)
			}
		}
	}

	now := time.Now().Unix()
	_, err = s.db.ExecContext(ctx,
		`UPDATE tournaments SET status = 'completed', ended_at = ?, updated_at = ? WHERE id = ?`,
		now, now, id,
	)
	if err != nil {
		return fmt.Errorf("tournament: end: %w", err)
	}

	s.recordAudit(ctx, id, audit.ActionTournamentEnd, "tournament", id, map[string]interface{}{
		"ended_at": now,
	})
	s.broadcast(id, "tournament.ended", map[string]interface{}{
		"tournament_id": id,
		"ended_at":      now,
	})

	return nil
}

// CancelTournament cancels a tournament, voiding all pending transactions.
func (s *Service) CancelTournament(ctx context.Context, id string) error {
	t, err := s.loadTournament(ctx, id)
	if err != nil {
		return err
	}

	if t.Status == StatusCompleted || t.Status == StatusCancelled {
		return ErrTournamentAlreadyEnded
	}

	// Stop clock if running
	if engine := s.registry.Get(id); engine != nil {
		operatorID := middleware.OperatorIDFromCtx(ctx)
		_ = engine.Pause(operatorID)
	}

	// Mark all non-undone transactions as cancelled (via metadata flag, not deletion)
	_, _ = s.db.ExecContext(ctx,
		`UPDATE transactions SET metadata = json_set(COALESCE(metadata, '{}'), '$.cancelled', 1)
		 WHERE tournament_id = ? AND undone = 0`, id,
	)

	now := time.Now().Unix()
	_, err = s.db.ExecContext(ctx,
		`UPDATE tournaments SET status = 'cancelled', ended_at = ?, updated_at = ? WHERE id = ?`,
		now, now, id,
	)
	if err != nil {
		return fmt.Errorf("tournament: cancel: %w", err)
	}

	s.recordAudit(ctx, id, audit.ActionTournamentCancel, "tournament", id, nil)
	s.broadcast(id, "tournament.cancelled", map[string]string{"tournament_id": id})

	return nil
}

// CheckAutoClose checks if the tournament should auto-close (1 player remains).
// Called after every bust-out.
func (s *Service) CheckAutoClose(ctx context.Context, id string) error {
	activeCount := s.countActivePlayers(ctx, id)

	if activeCount <= 0 {
		// Edge case: 0 players remaining, cancel
		return s.CancelTournament(ctx, id)
	}
	if activeCount == 1 {
		// Auto-close: 1 player remaining = winner
		return s.EndTournament(ctx, id)
	}

	return nil
}

// ListTournaments returns all tournaments, optionally filtered by status.
func (s *Service) ListTournaments(ctx context.Context, statusFilter string) ([]Tournament, error) {
	var query string
	var args []interface{}

	if statusFilter != "" {
		query = `SELECT id, name, template_id, chip_set_id, blind_structure_id,
			payout_structure_id, buyin_config_id, points_formula_id,
			status, min_players, max_players,
			early_signup_bonus_chips, early_signup_cutoff,
			punctuality_bonus_chips, is_pko,
			current_level, clock_state, started_at, ended_at,
			created_at, updated_at
			FROM tournaments WHERE status = ?
			ORDER BY created_at DESC`
		args = []interface{}{statusFilter}
	} else {
		query = `SELECT id, name, template_id, chip_set_id, blind_structure_id,
			payout_structure_id, buyin_config_id, points_formula_id,
			status, min_players, max_players,
			early_signup_bonus_chips, early_signup_cutoff,
			punctuality_bonus_chips, is_pko,
			current_level, clock_state, started_at, ended_at,
			created_at, updated_at
			FROM tournaments ORDER BY created_at DESC`
	}

	rows, err := s.db.QueryContext(ctx, query, args...)
	if err != nil {
		return nil, fmt.Errorf("tournament: list: %w", err)
	}
	defer rows.Close()

	return s.scanTournaments(rows)
}

// --- Internal helpers ---

func (s *Service) loadTournament(ctx context.Context, id string) (*Tournament, error) {
	t := &Tournament{}
	var templateID, pointsFormulaID sql.NullInt64
	var maxPlayers sql.NullInt64
	var earlySignupCutoff sql.NullString
	var isPKO int
	var startedAt, endedAt sql.NullInt64

	err := s.db.QueryRowContext(ctx,
		`SELECT id, name, template_id, chip_set_id, blind_structure_id,
		 payout_structure_id, buyin_config_id, points_formula_id,
		 status, min_players, max_players,
		 early_signup_bonus_chips, early_signup_cutoff,
		 punctuality_bonus_chips, is_pko,
		 current_level, clock_state, started_at, ended_at,
		 created_at, updated_at
		 FROM tournaments WHERE id = ?`, id,
	).Scan(
		&t.ID, &t.Name, &templateID, &t.ChipSetID, &t.BlindStructureID,
		&t.PayoutStructureID, &t.BuyinConfigID, &pointsFormulaID,
		&t.Status, &t.MinPlayers, &maxPlayers,
		&t.EarlySignupBonusChips, &earlySignupCutoff,
		&t.PunctualityBonusChips, &isPKO,
		&t.CurrentLevel, &t.ClockState, &startedAt, &endedAt,
		&t.CreatedAt, &t.UpdatedAt,
	)
	if err == sql.ErrNoRows {
		return nil, ErrTournamentNotFound
	}
	if err != nil {
		return nil, fmt.Errorf("tournament: load: %w", err)
	}

	if templateID.Valid {
		t.TemplateID = &templateID.Int64
	}
	if pointsFormulaID.Valid {
		t.PointsFormulaID = &pointsFormulaID.Int64
	}
	if maxPlayers.Valid {
		v := int(maxPlayers.Int64)
		t.MaxPlayers = &v
	}
	if earlySignupCutoff.Valid {
		t.EarlySignupCutoff = &earlySignupCutoff.String
	}
	if startedAt.Valid {
		t.StartedAt = &startedAt.Int64
	}
	if endedAt.Valid {
		t.EndedAt = &endedAt.Int64
	}
	t.IsPKO = isPKO != 0

	return t, nil
}

func (s *Service) scanTournaments(rows *sql.Rows) ([]Tournament, error) {
	var tournaments []Tournament
	for rows.Next() {
		t := Tournament{}
		var templateID, pointsFormulaID sql.NullInt64
		var maxPlayers sql.NullInt64
		var earlySignupCutoff sql.NullString
		var isPKO int
		var startedAt, endedAt sql.NullInt64

		if err := rows.Scan(
			&t.ID, &t.Name, &templateID, &t.ChipSetID, &t.BlindStructureID,
			&t.PayoutStructureID, &t.BuyinConfigID, &pointsFormulaID,
			&t.Status, &t.MinPlayers, &maxPlayers,
			&t.EarlySignupBonusChips, &earlySignupCutoff,
			&t.PunctualityBonusChips, &isPKO,
			&t.CurrentLevel, &t.ClockState, &startedAt, &endedAt,
			&t.CreatedAt, &t.UpdatedAt,
		); err != nil {
			return nil, fmt.Errorf("tournament: scan: %w", err)
		}

		if templateID.Valid {
			t.TemplateID = &templateID.Int64
		}
		if pointsFormulaID.Valid {
			t.PointsFormulaID = &pointsFormulaID.Int64
		}
		if maxPlayers.Valid {
			v := int(maxPlayers.Int64)
			t.MaxPlayers = &v
		}
		if earlySignupCutoff.Valid {
			t.EarlySignupCutoff = &earlySignupCutoff.String
		}
		if startedAt.Valid {
			t.StartedAt = &startedAt.Int64
		}
		if endedAt.Valid {
			t.EndedAt = &endedAt.Int64
		}
		t.IsPKO = isPKO != 0

		tournaments = append(tournaments, t)
	}
	return tournaments, rows.Err()
}

func (s *Service) countActivePlayers(ctx context.Context, tournamentID string) int {
	var count int
	s.db.QueryRowContext(ctx,
		`SELECT COUNT(*) FROM tournament_players
		 WHERE tournament_id = ? AND status IN ('active', 'registered')`,
		tournamentID,
	).Scan(&count)
	return count
}

func (s *Service) countTables(ctx context.Context, tournamentID string) int {
	var count int
	s.db.QueryRowContext(ctx,
		`SELECT COUNT(*) FROM tables
		 WHERE tournament_id = ? AND is_active = 1`,
		tournamentID,
	).Scan(&count)
	return count
}

func (s *Service) getPlayerSummary(ctx context.Context, tournamentID string) PlayerSummary {
	ps := PlayerSummary{}
	rows, err := s.db.QueryContext(ctx,
		`SELECT status, COUNT(*) FROM tournament_players
		 WHERE tournament_id = ? GROUP BY status`,
		tournamentID,
	)
	if err != nil {
		return ps
	}
	defer rows.Close()

	for rows.Next() {
		var status string
		var count int
		if err := rows.Scan(&status, &count); err != nil {
			continue
		}
		switch status {
		case "registered":
			ps.Registered = count
		case "active":
			ps.Active = count
		case "busted":
			ps.Busted = count
		case "deal":
			ps.Deal = count
		}
		ps.Total += count
	}
	return ps
}

func (s *Service) getRecentActivity(ctx context.Context, tournamentID string, limit int) []audit.AuditEntry {
	rows, err := s.db.QueryContext(ctx,
		`SELECT id, tournament_id, timestamp, operator_id, action,
		 target_type, target_id, previous_state, new_state, metadata
		 FROM audit_entries
		 WHERE tournament_id = ?
		 ORDER BY timestamp DESC LIMIT ?`,
		tournamentID, limit,
	)
	if err != nil {
		return nil
	}
	defer rows.Close()

	var entries []audit.AuditEntry
	for rows.Next() {
		var e audit.AuditEntry
		var tournID sql.NullString
		var prevState, newState, meta sql.NullString

		if err := rows.Scan(
			&e.ID, &tournID, &e.Timestamp, &e.OperatorID, &e.Action,
			&e.TargetType, &e.TargetID, &prevState, &newState, &meta,
		); err != nil {
			continue
		}
		if tournID.Valid {
			e.TournamentID = &tournID.String
		}
		if prevState.Valid {
			e.PreviousState = json.RawMessage(prevState.String)
		}
		if newState.Valid {
			e.NewState = json.RawMessage(newState.String)
		}
		if meta.Valid {
			e.Metadata = json.RawMessage(meta.String)
		}
		entries = append(entries, e)
	}
	return entries
}

func (s *Service) assignFinalPositions(ctx context.Context, tournamentID string) {
	// Get remaining active players ordered by chip count (descending)
	rows, err := s.db.QueryContext(ctx,
		`SELECT player_id, current_chips FROM tournament_players
		 WHERE tournament_id = ? AND status = 'active'
		 ORDER BY current_chips DESC`,
		tournamentID,
	)
	if err != nil {
		return
	}
	defer rows.Close()

	// Count busted players to determine starting position
	var bustedCount int
	s.db.QueryRowContext(ctx,
		`SELECT COUNT(*) FROM tournament_players
		 WHERE tournament_id = ? AND status = 'busted'`,
		tournamentID,
	).Scan(&bustedCount)

	position := 1
	for rows.Next() {
		var playerID string
		var chips int64
		if err := rows.Scan(&playerID, &chips); err != nil {
			continue
		}

		// Assign position based on chip count order
		_, _ = s.db.ExecContext(ctx,
			`UPDATE tournament_players SET finishing_position = ?, updated_at = unixepoch()
			 WHERE tournament_id = ? AND player_id = ?`,
			position, tournamentID, playerID,
		)
		position++
	}
}

func (s *Service) loadLevelsFromDB(tournamentID string) ([]clock.Level, error) {
	var structureID int
	err := s.db.QueryRow(
		"SELECT blind_structure_id FROM tournaments WHERE id = ?",
		tournamentID,
	).Scan(&structureID)
	if err != nil {
		return nil, err
	}

	rows, err := s.db.Query(
		`SELECT position, level_type, game_type, small_blind, big_blind, ante, bb_ante,
		        duration_seconds, chip_up_denomination_value, notes
		 FROM blind_levels
		 WHERE structure_id = ?
		 ORDER BY position`,
		structureID,
	)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var levels []clock.Level
	for rows.Next() {
		var l clock.Level
		var chipUpDenom sql.NullInt64
		var notes sql.NullString
		err := rows.Scan(
			&l.Position, &l.LevelType, &l.GameType, &l.SmallBlind, &l.BigBlind,
			&l.Ante, &l.BBAnte, &l.DurationSeconds, &chipUpDenom, &notes,
		)
		if err != nil {
			return nil, err
		}
		if chipUpDenom.Valid {
			v := chipUpDenom.Int64
			l.ChipUpDenominationVal = &v
		}
		if notes.Valid {
			l.Notes = notes.String
		}
		levels = append(levels, l)
	}

	return levels, rows.Err()
}

func (s *Service) persistClockState(tournamentID string, snap clock.ClockSnapshot) {
	_, err := s.db.Exec(
		`UPDATE tournaments
		 SET current_level = ?, clock_state = ?, clock_remaining_ns = ?,
		     total_elapsed_ns = ?, updated_at = unixepoch()
		 WHERE id = ?`,
		snap.CurrentLevel,
		snap.State,
		snap.RemainingMs*int64(1000000),
		snap.TotalElapsedMs*int64(1000000),
		tournamentID,
	)
	if err != nil {
		log.Printf("tournament: persist clock state error: %v", err)
	}
}

func (s *Service) recordAudit(ctx context.Context, tournamentID, action, targetType, targetID string, data interface{}) {
	if s.trail == nil {
		return
	}
	var newState json.RawMessage
	if data != nil {
		newState, _ = json.Marshal(data)
	}
	tidPtr := &tournamentID
	_, err := s.trail.Record(ctx, audit.AuditEntry{
		TournamentID: tidPtr,
		Action:       action,
		TargetType:   targetType,
		TargetID:     targetID,
		NewState:     newState,
	})
	if err != nil {
		log.Printf("tournament: audit record failed: %v", err)
	}
}

func (s *Service) broadcast(tournamentID, eventType string, data interface{}) {
	if s.hub == nil {
		return
	}
	payload, err := json.Marshal(data)
	if err != nil {
		log.Printf("tournament: broadcast marshal error: %v", err)
		return
	}
	s.hub.Broadcast(tournamentID, eventType, payload)
}

// generateUUID generates a v4 UUID.
func generateUUID() string {
	b := make([]byte, 16)
	_, _ = rand.Read(b)
	b[6] = (b[6] & 0x0f) | 0x40 // Version 4
	b[8] = (b[8] & 0x3f) | 0x80 // Variant 1
	return fmt.Sprintf("%08x-%04x-%04x-%04x-%012x",
		b[0:4], b[4:6], b[6:8], b[8:10], b[10:16])
}