package seating

import (
	"context"
	"fmt"
	"testing"
)

func TestBreakTable_DistributesEvenly(t *testing.T) {
	db := testDB(t)
	ctx := context.Background()
	tournamentID := "t1"
	seedTournament(t, db, tournamentID)

	tbl1 := seedTable(t, db, tournamentID, "Table 1", 9)
	tbl2 := seedTable(t, db, tournamentID, "Table 2", 9)
	tbl3 := seedTable(t, db, tournamentID, "Table 3", 9)

	// Table 1: 6 players (will be broken)
	// Table 2: 5 players
	// Table 3: 5 players
	for i := 1; i <= 6; i++ {
		pid := fmt.Sprintf("p1_%d", i)
		seedPlayer(t, db, pid, fmt.Sprintf("Player 1-%d", i))
		seatPlayer(t, db, tournamentID, pid, tbl1, i)
	}
	for i := 1; i <= 5; i++ {
		pid := fmt.Sprintf("p2_%d", i)
		seedPlayer(t, db, pid, fmt.Sprintf("Player 2-%d", i))
		seatPlayer(t, db, tournamentID, pid, tbl2, i)
	}
	for i := 1; i <= 5; i++ {
		pid := fmt.Sprintf("p3_%d", i)
		seedPlayer(t, db, pid, fmt.Sprintf("Player 3-%d", i))
		seatPlayer(t, db, tournamentID, pid, tbl3, i)
	}

	svc := NewBreakTableService(db, nil, nil)
	result, err := svc.BreakTable(ctx, tournamentID, tbl1)
	if err != nil {
		t.Fatalf("break table: %v", err)
	}

	if result.BrokenTableID != tbl1 {
		t.Errorf("expected broken table id %d, got %d", tbl1, result.BrokenTableID)
	}
	if len(result.Moves) != 6 {
		t.Fatalf("expected 6 moves, got %d", len(result.Moves))
	}

	// Count how many went to each table: should be 3 each (5+3=8, 5+3=8)
	movesToTable := make(map[int]int)
	for _, m := range result.Moves {
		movesToTable[m.ToTableID]++
	}

	for tid, count := range movesToTable {
		if count < 2 || count > 4 {
			t.Errorf("table %d got %d players, expected roughly even distribution", tid, count)
		}
	}

	// Verify table 1 is deactivated
	var isActive int
	db.QueryRow(`SELECT is_active FROM tables WHERE id = ?`, tbl1).Scan(&isActive)
	if isActive != 0 {
		t.Error("broken table should be deactivated")
	}

	// Verify all players are seated at other tables
	var unseatedCount int
	db.QueryRow(
		`SELECT COUNT(*) FROM tournament_players
		 WHERE tournament_id = ? AND status = 'active' AND seat_table_id IS NULL`,
		tournamentID,
	).Scan(&unseatedCount)
	if unseatedCount != 0 {
		t.Errorf("expected 0 unseated players, got %d", unseatedCount)
	}
}

func TestBreakTable_OddPlayerCount(t *testing.T) {
	db := testDB(t)
	ctx := context.Background()
	tournamentID := "t1"
	seedTournament(t, db, tournamentID)

	tbl1 := seedTable(t, db, tournamentID, "Table 1", 9)
	tbl2 := seedTable(t, db, tournamentID, "Table 2", 9)
	tbl3 := seedTable(t, db, tournamentID, "Table 3", 9)

	// Table 1: 5 players (will be broken)
	// Table 2: 4 players
	// Table 3: 3 players
	for i := 1; i <= 5; i++ {
		pid := fmt.Sprintf("p1_%d", i)
		seedPlayer(t, db, pid, fmt.Sprintf("Player 1-%d", i))
		seatPlayer(t, db, tournamentID, pid, tbl1, i)
	}
	for i := 1; i <= 4; i++ {
		pid := fmt.Sprintf("p2_%d", i)
		seedPlayer(t, db, pid, fmt.Sprintf("Player 2-%d", i))
		seatPlayer(t, db, tournamentID, pid, tbl2, i)
	}
	for i := 1; i <= 3; i++ {
		pid := fmt.Sprintf("p3_%d", i)
		seedPlayer(t, db, pid, fmt.Sprintf("Player 3-%d", i))
		seatPlayer(t, db, tournamentID, pid, tbl3, i)
	}

	svc := NewBreakTableService(db, nil, nil)
	result, err := svc.BreakTable(ctx, tournamentID, tbl1)
	if err != nil {
		t.Fatalf("break table: %v", err)
	}

	if len(result.Moves) != 5 {
		t.Fatalf("expected 5 moves, got %d", len(result.Moves))
	}

	// Count final player counts at tbl2 and tbl3
	var count2, count3 int
	db.QueryRow(`SELECT COUNT(*) FROM tournament_players WHERE tournament_id = ? AND seat_table_id = ? AND status = 'active'`,
		tournamentID, tbl2).Scan(&count2)
	db.QueryRow(`SELECT COUNT(*) FROM tournament_players WHERE tournament_id = ? AND seat_table_id = ? AND status = 'active'`,
		tournamentID, tbl3).Scan(&count3)

	// 12 total players across 2 tables -> 6 each
	if count2+count3 != 12 {
		t.Errorf("expected 12 total, got %d", count2+count3)
	}
	// Difference should be at most 1
	diff := count2 - count3
	if diff < 0 {
		diff = -diff
	}
	if diff > 1 {
		t.Errorf("expected tables balanced to within 1, got diff=%d (table2=%d, table3=%d)", diff, count2, count3)
	}
}

func TestBreakTable_DeactivatesTable(t *testing.T) {
	db := testDB(t)
	ctx := context.Background()
	tournamentID := "t1"
	seedTournament(t, db, tournamentID)

	tbl1 := seedTable(t, db, tournamentID, "Table 1", 9)
	tbl2 := seedTable(t, db, tournamentID, "Table 2", 9)

	// 2 players at each table
	seedPlayer(t, db, "p1", "P1")
	seatPlayer(t, db, tournamentID, "p1", tbl1, 1)
	seedPlayer(t, db, "p2", "P2")
	seatPlayer(t, db, tournamentID, "p2", tbl1, 2)
	seedPlayer(t, db, "p3", "P3")
	seatPlayer(t, db, tournamentID, "p3", tbl2, 1)
	seedPlayer(t, db, "p4", "P4")
	seatPlayer(t, db, tournamentID, "p4", tbl2, 2)

	svc := NewBreakTableService(db, nil, nil)
	_, err := svc.BreakTable(ctx, tournamentID, tbl1)
	if err != nil {
		t.Fatalf("break table: %v", err)
	}

	var isActive int
	db.QueryRow(`SELECT is_active FROM tables WHERE id = ?`, tbl1).Scan(&isActive)
	if isActive != 0 {
		t.Error("broken table should be deactivated (is_active = 0)")
	}
}

func TestBreakTable_InactiveTableReturnsError(t *testing.T) {
	db := testDB(t)
	ctx := context.Background()
	tournamentID := "t1"
	seedTournament(t, db, tournamentID)

	tbl := seedTable(t, db, tournamentID, "Table 1", 9)
	_ = seedTable(t, db, tournamentID, "Table 2", 9)

	// Deactivate the table first
	db.Exec(`UPDATE tables SET is_active = 0 WHERE id = ?`, tbl)

	svc := NewBreakTableService(db, nil, nil)
	_, err := svc.BreakTable(ctx, tournamentID, tbl)
	if err == nil {
		t.Fatal("expected error for inactive table")
	}
}

func TestBreakTable_NoDestinationTablesReturnsError(t *testing.T) {
	db := testDB(t)
	ctx := context.Background()
	tournamentID := "t1"
	seedTournament(t, db, tournamentID)

	tbl := seedTable(t, db, tournamentID, "Table 1", 9)
	seedPlayer(t, db, "p1", "P1")
	seatPlayer(t, db, tournamentID, "p1", tbl, 1)

	svc := NewBreakTableService(db, nil, nil)
	_, err := svc.BreakTable(ctx, tournamentID, tbl)
	if err == nil {
		t.Fatal("expected error when no destination tables")
	}
}