//go:build test && dev

package payments

import (
	"context"
	"errors"
	"fmt"
	"testing"
	"time"

	"crussell/db"
	"crussell/internal/square"
	"crussell/testutils"
	"crussell/testutils/fixtures"
)

// TestSweepStalePendingPayments_ReconcileCompleted locks the F3 fix: a stale
// pending payment whose square_payment_id resolves to a COMPLETED charge at
// Square (the DB row was genuinely charged, the post-charge DB write failed)
// is rescued to 'completed' instead of being swept to 'failed' with no
// automatic resolution.
func TestSweepStalePendingPayments_ReconcileCompleted(t *testing.T) {
	ctx, tx := testutils.SetupTestTx(t)

	userID, err := fixtures.CreateTestUser(tx)
	if err != nil {
		t.Fatalf("failed to create user: %v", err)
	}
	serviceID, err := fixtures.CreateTestService(tx)
	if err != nil {
		t.Fatalf("failed to create service: %v", err)
	}
	bookingID, err := fixtures.CreateTestBookingAtTime(tx, userID, serviceID,
		time.Date(2099, 12, 31, 10, 0, 0, 0, time.UTC))
	if err != nil {
		t.Fatalf("failed to create booking: %v", err)
	}

	staleID, err := fixtures.CreateTestPayment(tx, bookingID, 2000.00, "online_square", "full", "pending")
	if err != nil {
		t.Fatalf("failed to create stale pending payment: %v", err)
	}
	if _, err := tx.Exec(ctx, "UPDATE payments SET created_at = NOW() - INTERVAL '25 hours' WHERE id = $1", staleID); err != nil {
		t.Fatalf("failed to age the stale payment: %v", err)
	}

	origClient := SquareClient
	mock := square.NewDevClient().(*square.MockClient)
	// Seed the completed charge at Square with the same idempotency semantics
	// the charge would have used in production.
	pay, err := mock.CreatePayment(context.Background(), square.CreatePaymentReq{
		Amount:         200000,
		Currency:       "GBP",
		SourceID:       "cnon:test-card",
		IdempotencyKey: "seed-stale-completed",
	})
	if err != nil {
		t.Fatalf("failed to seed completed Square payment: %v", err)
	}
	if _, err := tx.Exec(ctx, "UPDATE payments SET square_payment_id = $1 WHERE id = $2", pay.SquarePayID, staleID); err != nil {
		t.Fatalf("failed to set square_payment_id: %v", err)
	}
	SquareClient = mock
	defer func() { SquareClient = origClient }()

	pgxTx := db.TxFromContext(ctx)
	if pgxTx == nil {
		t.Fatal("no transaction in context")
	}
	if err := pgxTx.Commit(ctx); err != nil {
		t.Fatalf("failed to commit test tx: %v", err)
	}

	// The committed rows live in the SHARED test pool, so clean them up or
	// parallel tests that count whole tables see them (test isolation).
	t.Cleanup(func() {
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM payments WHERE id = $1`, staleID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM bookings WHERE id = $1`, bookingID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM services WHERE id = $1`, serviceID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM users WHERE id = $1`, userID)
	})

	freshCtx := context.Background()
	if _, err := SweepStalePendingPayments(freshCtx); err != nil {
		t.Fatalf("sweep failed: %v", err)
	}

	var status string
	if err := db.Conn.QueryRow(freshCtx, "SELECT status FROM payments WHERE id = $1", staleID).Scan(&status); err != nil {
		t.Fatalf("failed to query payment: %v", err)
	}
	if status != "completed" {
		t.Errorf("expected genuinely-charged stale pending payment rescued to 'completed', got %q", status)
	}
}

// TestSweepStalePendingPayments_ReconcileNotFound_Fails locks the F3 fallback:
// a stale pending payment whose square_payment_id does NOT resolve to a
// COMPLETED charge at Square (payment not found / not completed) is marked
// failed exactly as the legacy bulk sweep did — the double-charge window must
// stay closed.
func TestSweepStalePendingPayments_ReconcileNotFound_Fails(t *testing.T) {
	ctx, tx := testutils.SetupTestTx(t)

	userID, err := fixtures.CreateTestUser(tx)
	if err != nil {
		t.Fatalf("failed to create user: %v", err)
	}
	serviceID, err := fixtures.CreateTestService(tx)
	if err != nil {
		t.Fatalf("failed to create service: %v", err)
	}
	bookingID, err := fixtures.CreateTestBookingAtTime(tx, userID, serviceID,
		time.Date(2099, 12, 31, 10, 0, 0, 0, time.UTC))
	if err != nil {
		t.Fatalf("failed to create booking: %v", err)
	}

	staleID, err := fixtures.CreateTestPayment(tx, bookingID, 2000.00, "online_square", "full", "pending")
	if err != nil {
		t.Fatalf("failed to create stale pending payment: %v", err)
	}
	if _, err := tx.Exec(ctx, "UPDATE payments SET created_at = NOW() - INTERVAL '25 hours', square_payment_id = 'sqp_not_in_mock' WHERE id = $1", staleID); err != nil {
		t.Fatalf("failed to age the stale payment: %v", err)
	}

	// The default mock has no payment under 'sqp_not_in_mock' → GetPayment
	// returns not-found → the row must be failed, not left pending.
	origClient := SquareClient
	SquareClient = square.NewDevClient()
	defer func() { SquareClient = origClient }()

	pgxTx := db.TxFromContext(ctx)
	if pgxTx == nil {
		t.Fatal("no transaction in context")
	}
	if err := pgxTx.Commit(ctx); err != nil {
		t.Fatalf("failed to commit test tx: %v", err)
	}

	t.Cleanup(func() {
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM payments WHERE id = $1`, staleID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM bookings WHERE id = $1`, bookingID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM services WHERE id = $1`, serviceID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM users WHERE id = $1`, userID)
	})

	freshCtx := context.Background()
	if _, err := SweepStalePendingPayments(freshCtx); err != nil {
		t.Fatalf("sweep failed: %v", err)
	}

	var status string
	if err := db.Conn.QueryRow(freshCtx, "SELECT status FROM payments WHERE id = $1", staleID).Scan(&status); err != nil {
		t.Fatalf("failed to query payment: %v", err)
	}
	if status != "failed" {
		t.Errorf("expected stale pending payment with no COMPLETED charge at Square marked 'failed', got %q", status)
	}
}

// TestSweepStalePendingPayments_ReconcileTillSale_Completed locks the F3 fix
// for till_sales: a stale pending till sale whose square_payment_id resolves
// to a COMPLETED charge at Square is rescued to 'completed' like payments.
func TestSweepStalePendingPayments_ReconcileTillSale_Completed(t *testing.T) {
	ctx, tx := testutils.SetupTestTx(t)

	adminID, err := fixtures.CreateTestAdminUser(tx)
	if err != nil {
		t.Fatalf("failed to create admin user: %v", err)
	}

	origClient := SquareClient
	mock := square.NewDevClient().(*square.MockClient)
	pay, err := mock.CreatePayment(context.Background(), square.CreatePaymentReq{
		Amount:         5000,
		Currency:       "GBP",
		SourceID:       "cnon:test-card",
		IdempotencyKey: "seed-stale-till-completed",
	})
	if err != nil {
		t.Fatalf("failed to seed completed Square payment: %v", err)
	}
	SquareClient = mock
	defer func() { SquareClient = origClient }()

	var saleID string
	err = tx.QueryRow(ctx, `
		INSERT INTO till_sales (item_type, description, quantity, unit_price, total_amount, payment_method, status, square_payment_id, created_by, created_at, updated_at)
		VALUES ('gift_card', 'Gift Card create', 1, 50.00, 50.00, 'online_square', 'pending', $1, $2, NOW() - INTERVAL '25 hours', NOW())
		RETURNING id
	`, pay.SquarePayID, adminID).Scan(&saleID)
	if err != nil {
		t.Fatalf("failed to seed stale pending till sale: %v", err)
	}

	pgxTx := db.TxFromContext(ctx)
	if pgxTx == nil {
		t.Fatal("no transaction in context")
	}
	if err := pgxTx.Commit(ctx); err != nil {
		t.Fatalf("failed to commit test tx: %v", err)
	}

	t.Cleanup(func() {
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM till_sales WHERE id = $1`, saleID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM users WHERE id = $1`, adminID)
	})

	freshCtx := context.Background()
	if _, err := SweepStalePendingPayments(freshCtx); err != nil {
		t.Fatalf("sweep failed: %v", err)
	}

	var status string
	if err := db.Conn.QueryRow(freshCtx, "SELECT status FROM till_sales WHERE id = $1", saleID).Scan(&status); err != nil {
		t.Fatalf("failed to query till sale: %v", err)
	}
	if status != "completed" {
		t.Errorf("expected genuinely-charged stale till sale rescued to 'completed', got %q", status)
	}
}

// completedTerminalClient makes one checkout look COMPLETED at Square while
// delegating everything else to the real mock — used to prove the terminal
// sweep never cancels a checkout that may have completed.
type completedTerminalClient struct {
	square.SquareClient
	checkoutID string
}

func (c *completedTerminalClient) GetCheckout(ctx context.Context, checkoutID string) (*square.PaymentResult, error) {
	if checkoutID == c.checkoutID {
		return &square.PaymentResult{Status: "COMPLETED", SquarePayID: "sqp_terminal_completed"}, nil
	}
	return c.SquareClient.GetCheckout(ctx, checkoutID)
}

// TestSweepStaleTerminalCheckouts_CancelsStalePending locks the F4 fix: a
// terminal checkout still PENDING at Square after an hour is cancelled and its
// till_sales row moved to the terminal 'failed' state (the payment_status enum
// has no 'cancelled' value).
func TestSweepStaleTerminalCheckouts_CancelsStalePending(t *testing.T) {
	ctx, tx := testutils.SetupTestTx(t)

	adminID, err := fixtures.CreateTestAdminUser(tx)
	if err != nil {
		t.Fatalf("failed to create admin user: %v", err)
	}

	origClient := SquareClient
	mock := square.NewDevClient().(*square.MockClient)
	mock.HoldCheckouts = true
	checkout, err := mock.CreateCheckout(context.Background(), square.CreateCheckoutReq{
		Amount:         5000,
		Currency:       "GBP",
		IdempotencyKey: "chk-stale-terminal",
	})
	if err != nil {
		t.Fatalf("failed to create pending Square checkout: %v", err)
	}
	SquareClient = mock
	defer func() { SquareClient = origClient }()

	var saleID string
	err = tx.QueryRow(ctx, `
		INSERT INTO till_sales (item_type, description, quantity, unit_price, total_amount, payment_method, status, square_checkout_id, created_by, created_at, updated_at)
		VALUES ('gift_card', 'Gift Card create', 1, 50.00, 50.00, 'in_person_card', 'pending', $1, $2, NOW() - INTERVAL '2 hours', NOW())
		RETURNING id
	`, checkout.ID, adminID).Scan(&saleID)
	if err != nil {
		t.Fatalf("failed to seed stale terminal sale: %v", err)
	}

	pgxTx := db.TxFromContext(ctx)
	if pgxTx == nil {
		t.Fatal("no transaction in context")
	}
	if err := pgxTx.Commit(ctx); err != nil {
		t.Fatalf("failed to commit test tx: %v", err)
	}

	t.Cleanup(func() {
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM till_sales WHERE id = $1`, saleID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM users WHERE id = $1`, adminID)
	})

	freshCtx := context.Background()
	// Drop any other stale terminal rows left by parallel tests so the count is
	// deterministic.
	if _, err := db.Conn.Exec(freshCtx, `DELETE FROM till_sales WHERE status = 'pending' AND square_checkout_id IS NOT NULL AND id <> $1`, saleID); err != nil {
		t.Fatalf("failed to clean leftover stale terminal sales: %v", err)
	}
	if _, err := db.Conn.Exec(freshCtx, `DELETE FROM terminal_checkouts WHERE status IN ('PENDING', 'IN_PROGRESS')`); err != nil {
		t.Fatalf("failed to clean leftover stale booking terminal checkouts: %v", err)
	}

	n, err := SweepStaleTerminalCheckouts(freshCtx)
	if err != nil {
		t.Fatalf("sweep failed: %v", err)
	}
	if n != 1 {
		t.Errorf("expected exactly 1 cancelled stale terminal checkout, got %d", n)
	}

	var status string
	if err := db.Conn.QueryRow(freshCtx, "SELECT status FROM till_sales WHERE id = $1", saleID).Scan(&status); err != nil {
		t.Fatalf("failed to query sale: %v", err)
	}
	if status != "failed" {
		t.Errorf("expected cancelled stale terminal sale marked 'failed', got %q", status)
	}

	// The checkout must no longer be PENDING at Square (it was cancelled).
	if _, gErr := mock.GetCheckout(freshCtx, checkout.ID); gErr == nil || errors.Is(gErr, square.ErrCheckoutPending) {
		t.Errorf("expected checkout %s to be cancelled at Square (no longer pending), GetCheckout err=%v", checkout.ID, gErr)
	}
}

// TestSweepStaleTerminalCheckouts_LeavesCompletedAlone locks the conservative
// F4 rule: a checkout that has COMPLETED at Square is never cancelled — the
// poll handler records it; cancelling a completed checkout would orphan the
// charge.
func TestSweepStaleTerminalCheckouts_LeavesCompletedAlone(t *testing.T) {
	ctx, tx := testutils.SetupTestTx(t)

	adminID, err := fixtures.CreateTestAdminUser(tx)
	if err != nil {
		t.Fatalf("failed to create admin user: %v", err)
	}

	var saleID string
	err = tx.QueryRow(ctx, `
		INSERT INTO till_sales (item_type, description, quantity, unit_price, total_amount, payment_method, status, square_checkout_id, created_by, created_at, updated_at)
		VALUES ('gift_card', 'Gift Card create', 1, 50.00, 50.00, 'in_person_card', 'pending', 'chk_completed_terminal', $1, NOW() - INTERVAL '2 hours', NOW())
		RETURNING id
	`, adminID).Scan(&saleID)
	if err != nil {
		t.Fatalf("failed to seed stale terminal sale: %v", err)
	}

	origClient := SquareClient
	SquareClient = &completedTerminalClient{SquareClient: square.NewDevClient(), checkoutID: "chk_completed_terminal"}
	defer func() { SquareClient = origClient }()

	pgxTx := db.TxFromContext(ctx)
	if pgxTx == nil {
		t.Fatal("no transaction in context")
	}
	if err := pgxTx.Commit(ctx); err != nil {
		t.Fatalf("failed to commit test tx: %v", err)
	}

	t.Cleanup(func() {
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM till_sales WHERE id = $1`, saleID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM users WHERE id = $1`, adminID)
	})

	freshCtx := context.Background()
	n, err := SweepStaleTerminalCheckouts(freshCtx)
	if err != nil {
		t.Fatalf("sweep failed: %v", err)
	}
	if n != 0 {
		t.Errorf("expected a completed terminal checkout to be left alone, got %d cancellations", n)
	}

	var status string
	if err := db.Conn.QueryRow(freshCtx, "SELECT status FROM till_sales WHERE id = $1", saleID).Scan(&status); err != nil {
		t.Fatalf("failed to query sale: %v", err)
	}
	if status != "pending" {
		t.Errorf("expected completed terminal checkout's sale left 'pending' (poll handler records it), got %q", status)
	}
}

// =============================================================================
// SweepStalePendingPayments — tri-state reconcile (LOW money-integrity)
// =============================================================================

// staleGetPaymentClient forces GetPayment to return a fixed result/error so the
// reconcile tri-state branches can be exercised deterministically.
type staleGetPaymentClient struct {
	square.SquareClient
	result *square.PaymentResult
	err    error
}

func (c *staleGetPaymentClient) GetPayment(ctx context.Context, paymentID string) (*square.PaymentResult, error) {
	if c.err != nil {
		return nil, c.err
	}
	if c.result != nil {
		return c.result, nil
	}
	return c.SquareClient.GetPayment(ctx, paymentID)
}

func TestSweepStalePendingPayments_ReconcileTriState(t *testing.T) {
	cases := []struct {
		name      string
		result    *square.PaymentResult
		getErr    error
		wantFinal string // "completed", "failed", or "pending"
	}{
		{
			name:      "completed_rescues_row",
			result:    &square.PaymentResult{Status: "COMPLETED", SquarePayID: "sqp_tri_completed"},
			wantFinal: "completed",
		},
		{
			name:      "not_found_marks_failed",
			getErr:    fmt.Errorf("square: GET /v2/payments/sqp_x: [PAYMENT_NOT_FOUND/NOT_FOUND] payment does not exist"),
			wantFinal: "failed",
		},
		{
			name:      "ambiguous_error_leaves_pending",
			getErr:    fmt.Errorf("network error: connection reset by peer"),
			wantFinal: "pending",
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			ctx, tx := testutils.SetupTestTx(t)

			userID, err := fixtures.CreateTestUser(tx)
			if err != nil {
				t.Fatalf("failed to create user: %v", err)
			}
			serviceID, err := fixtures.CreateTestService(tx)
			if err != nil {
				t.Fatalf("failed to create service: %v", err)
			}
			bookingID, err := fixtures.CreateTestBookingAtTime(tx, userID, serviceID,
				time.Date(2099, 12, 31, 10, 0, 0, 0, time.UTC))
			if err != nil {
				t.Fatalf("failed to create booking: %v", err)
			}

			staleID, err := fixtures.CreateTestPayment(tx, bookingID, 2000.00, "online_square", "full", "pending")
			if err != nil {
				t.Fatalf("failed to create stale pending payment: %v", err)
			}
			if _, err := tx.Exec(ctx, "UPDATE payments SET created_at = NOW() - INTERVAL '25 hours', square_payment_id = 'sqp_tri_state' WHERE id = $1", staleID); err != nil {
				t.Fatalf("failed to age the stale payment: %v", err)
			}

			origClient := SquareClient
			SquareClient = &staleGetPaymentClient{SquareClient: square.NewDevClient(), result: tc.result, err: tc.getErr}
			defer func() { SquareClient = origClient }()

			pgxTx := db.TxFromContext(ctx)
			if pgxTx == nil {
				t.Fatal("no transaction in context")
			}
			if err := pgxTx.Commit(ctx); err != nil {
				t.Fatalf("failed to commit test tx: %v", err)
			}

			t.Cleanup(func() {
				_, _ = db.Conn.Exec(context.Background(), `DELETE FROM payments WHERE id = $1`, staleID)
				_, _ = db.Conn.Exec(context.Background(), `DELETE FROM bookings WHERE id = $1`, bookingID)
				_, _ = db.Conn.Exec(context.Background(), `DELETE FROM services WHERE id = $1`, serviceID)
				_, _ = db.Conn.Exec(context.Background(), `DELETE FROM users WHERE id = $1`, userID)
			})

			freshCtx := context.Background()
			if _, err := SweepStalePendingPayments(freshCtx); err != nil {
				t.Fatalf("sweep failed: %v", err)
			}

			var status string
			if err := db.Conn.QueryRow(freshCtx, "SELECT status FROM payments WHERE id = $1", staleID).Scan(&status); err != nil {
				t.Fatalf("failed to query payment: %v", err)
			}
			if status != tc.wantFinal {
				t.Errorf("expected stale pending payment %q after reconcile, got %q", tc.wantFinal, status)
			}
		})
	}
}

// =============================================================================
// SweepStaleTerminalCheckouts — completed-during-cancel re-check (TOCTOU)
// =============================================================================

// completingDuringCancelClient reports ErrCheckoutPending on the FIRST
// GetCheckout for the target checkout and COMPLETED on later calls — simulating
// a customer completing the payment between the sweep's status check and its
// CancelCheckout.
type completingDuringCancelClient struct {
	square.SquareClient
	checkoutID string
	calls      int
}

func (c *completingDuringCancelClient) GetCheckout(ctx context.Context, checkoutID string) (*square.PaymentResult, error) {
	if checkoutID == c.checkoutID {
		c.calls++
		if c.calls == 1 {
			return nil, square.ErrCheckoutPending
		}
		return &square.PaymentResult{Status: "COMPLETED", SquarePayID: "sqp_completed_during_cancel"}, nil
	}
	return c.SquareClient.GetCheckout(ctx, checkoutID)
}

func TestSweepStaleTerminalCheckouts_CompletedDuringCancel_MarkedCompleted(t *testing.T) {
	ctx, tx := testutils.SetupTestTx(t)
	userID, bookingID, serviceID := setupTestData(t, ctx, tx)

	const checkoutID = "chk_completes_during_cancel"
	if _, err := tx.Exec(ctx, `
		INSERT INTO terminal_checkouts (checkout_id, booking_id, payment_type, status, amount, created_at)
		VALUES ($1, $2, 'full', 'PENDING', 50.00, NOW() - INTERVAL '2 hours')
	`, checkoutID, bookingID); err != nil {
		t.Fatalf("failed to seed stale terminal checkout row: %v", err)
	}

	origClient := SquareClient
	SquareClient = &completingDuringCancelClient{SquareClient: square.NewDevClient(), checkoutID: checkoutID}
	defer func() { SquareClient = origClient }()

	pgxTx := db.TxFromContext(ctx)
	if pgxTx == nil {
		t.Fatal("no transaction in context")
	}
	if err := pgxTx.Commit(ctx); err != nil {
		t.Fatalf("failed to commit test tx: %v", err)
	}

	t.Cleanup(func() {
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM terminal_checkouts WHERE checkout_id = $1`, checkoutID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM bookings WHERE id = $1`, bookingID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM services WHERE id = $1`, serviceID)
		_, _ = db.Conn.Exec(context.Background(), `DELETE FROM users WHERE id = $1`, userID)
	})

	freshCtx := context.Background()
	// Drop any other stale terminal rows left by parallel tests so the count is
	// deterministic.
	if _, err := db.Conn.Exec(freshCtx, `DELETE FROM terminal_checkouts WHERE status IN ('PENDING', 'IN_PROGRESS') AND checkout_id <> $1`, checkoutID); err != nil {
		t.Fatalf("failed to clean leftover stale terminal checkouts: %v", err)
	}
	if _, err := db.Conn.Exec(freshCtx, `DELETE FROM till_sales WHERE status = 'pending' AND square_checkout_id IS NOT NULL`); err != nil {
		t.Fatalf("failed to clean leftover stale till sales: %v", err)
	}

	n, err := SweepStaleTerminalCheckouts(freshCtx)
	if err != nil {
		t.Fatalf("sweep failed: %v", err)
	}
	if n != 1 {
		t.Errorf("expected exactly 1 resolved terminal checkout (completed during cancel), got %d", n)
	}

	var status string
	if err := db.Conn.QueryRow(freshCtx, "SELECT status FROM terminal_checkouts WHERE checkout_id = $1", checkoutID).Scan(&status); err != nil {
		t.Fatalf("failed to query terminal checkout: %v", err)
	}
	if status != "COMPLETED" {
		t.Errorf("expected a checkout that completed during the cancel window marked 'COMPLETED', got %q", status)
	}
}