//go:build test && dev

package payments

import (
	"context"
	"errors"
	"testing"

	"crussell/db"
	"crussell/testutils"
	"crussell/testutils/fixtures"
)

// TestRevertGiftCardFunding_TopupPartiallySpent_InsertsCriticalNotification
// locks the M6 neither-path: when the top-up funding was already partially spent
// before the charge failed, RevertGiftCardFunding clamps the card to zero,
// returns errClawbackPartiallyReversed AND inserts a critical-payment admin
// notification so the residual is surfaced in the admin notification centre
// (a bare log line is not enough — an operator must see the reconciliation
// item).
func TestRevertGiftCardFunding_TopupPartiallySpent_InsertsCriticalNotification(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 cardID string
	if err := tx.QueryRow(ctx, `
		INSERT INTO gift_cards (total_funds_added, amount_remaining, created_by, is_inventory)
		VALUES (50.00, 10.00, $1, FALSE)
		RETURNING id
	`, adminID).Scan(&cardID); err != nil {
		t.Fatalf("failed to seed gift card: %v", err)
	}

	var saleID string
	if err := tx.QueryRow(ctx, `
		INSERT INTO till_sales (item_type, description, quantity, unit_price, total_amount, payment_method, status, created_by, created_at, updated_at)
		VALUES ('gift_card', 'Gift Card topup', 1, 50.00, 50.00, 'online_square', 'pending', $1, NOW(), NOW())
		RETURNING id
	`, adminID).Scan(&saleID); err != nil {
		t.Fatalf("failed to seed 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 setup tx: %v", err)
	}

	pool := context.Background()
	t.Cleanup(func() {
		_, _ = db.Conn.Exec(pool, `DELETE FROM admin_notifications WHERE reason = 'critical_payment_log'`)
		_, _ = db.Conn.Exec(pool, `DELETE FROM gift_card_transactions WHERE gift_card_id = $1`, cardID)
		_, _ = db.Conn.Exec(pool, `DELETE FROM till_sales WHERE id = $1`, saleID)
		_, _ = db.Conn.Exec(pool, `DELETE FROM gift_cards WHERE id = $1`, cardID)
		_, _ = db.Conn.Exec(pool, `DELETE FROM users WHERE id = $1`, adminID)
	})

	err = revertGiftCardFunding(pool, "topup", cardID, 50.00, nil, saleID)
	if !errors.Is(err, errClawbackPartiallyReversed) {
		t.Fatalf("expected errClawbackPartiallyReversed for the partially-spent top-up, got %v", err)
	}

	// M6: the CRITICAL admin notification must exist for the residual (a till
	// sale has no booking or user attribution, so the notification dedup key is
	// (nil, nil)).
	var notifCount int
	if err := db.Conn.QueryRow(pool, `SELECT COUNT(*) FROM admin_notifications WHERE reason = 'critical_payment_log' AND booking_id IS NULL AND user_id IS NULL`).Scan(&notifCount); err != nil {
		t.Fatalf("failed to count admin notifications: %v", err)
	}
	if notifCount < 1 {
		t.Errorf("expected a critical-payment admin notification for the partial clawback, got %d", notifCount)
	}
}

// TestRevertGiftCardFunding_CreateWithRedeemPartiallySpent_ClampsAndFlags locks
// the M6 create-with-redeem neither-path: a created card immediately redeemed to
// a user balance that was partially spent before the charge failed is deleted,
// the balance is clamped to zero, errClawbackPartiallyReversed is returned and
// a critical admin notification is inserted for the unrecoverable spent
// portion.
func TestRevertGiftCardFunding_CreateWithRedeemPartiallySpent_ClampsAndFlags(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)
	}
	customerID, err := fixtures.CreateTestUser(tx)
	if err != nil {
		t.Fatalf("failed to create customer user: %v", err)
	}

	var cardID string
	if err := tx.QueryRow(ctx, `
		INSERT INTO gift_cards (total_funds_added, amount_remaining, created_by, is_inventory)
		VALUES (50.00, 0.00, $1, FALSE)
		RETURNING id
	`, adminID).Scan(&cardID); err != nil {
		t.Fatalf("failed to seed gift card: %v", err)
	}
	// The redeem credited £50 to the customer, who spent £40 before the charge
	// failed.
	if _, err := tx.Exec(ctx, `
		INSERT INTO user_giftcard_balances (user_id, balance, updated_at)
		VALUES ($1, 10.00, NOW())
	`, customerID); err != nil {
		t.Fatalf("failed to seed user balance: %v", err)
	}

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

	pool := context.Background()
	t.Cleanup(func() {
		_, _ = db.Conn.Exec(pool, `DELETE FROM admin_notifications WHERE reason = 'critical_payment_log'`)
		_, _ = db.Conn.Exec(pool, `DELETE FROM user_giftcard_balances WHERE user_id = $1`, customerID)
		_, _ = db.Conn.Exec(pool, `DELETE FROM gift_card_transactions WHERE gift_card_id = $1`, cardID)
		_, _ = db.Conn.Exec(pool, `DELETE FROM till_sales WHERE id = $1`, saleID)
		_, _ = db.Conn.Exec(pool, `DELETE FROM gift_cards WHERE id = $1`, cardID)
		_, _ = db.Conn.Exec(pool, `DELETE FROM users WHERE id = ANY($1)`, []string{adminID, customerID})
	})

	err = revertGiftCardFunding(pool, "create", cardID, 50.00, &customerID, saleID)
	if !errors.Is(err, errClawbackPartiallyReversed) {
		t.Fatalf("expected errClawbackPartiallyReversed for the partially-spent redeemed balance, got %v", err)
	}

	// The created card is deleted and the balance clamped to zero.
	var cardCount int
	if err := db.Conn.QueryRow(pool, `SELECT COUNT(*) FROM gift_cards WHERE id = $1`, cardID).Scan(&cardCount); err != nil {
		t.Fatalf("failed to count gift cards: %v", err)
	}
	if cardCount != 0 {
		t.Errorf("expected the created card deleted by the clawback, got %d cards", cardCount)
	}
	var balance float64
	if err := db.Conn.QueryRow(pool, `SELECT balance FROM user_giftcard_balances WHERE user_id = $1`, customerID).Scan(&balance); err != nil {
		t.Fatalf("failed to query user balance: %v", err)
	}
	if balance != 0.00 {
		t.Errorf("expected the partially-spent redeemed balance clamped to zero, got £%.2f", balance)
	}

	// The sale is failed and a CRITICAL notification surfaced.
	var saleStatus string
	if err := db.Conn.QueryRow(pool, `SELECT status FROM till_sales WHERE id = $1`, saleID).Scan(&saleStatus); err != nil {
		t.Fatalf("failed to query till sale: %v", err)
	}
	if saleStatus != "failed" {
		t.Errorf("expected till sale marked failed, got %q", saleStatus)
	}
	var notifCount int
	if err := db.Conn.QueryRow(pool, `SELECT COUNT(*) FROM admin_notifications WHERE reason = 'critical_payment_log' AND user_id = $1`, customerID).Scan(&notifCount); err != nil {
		t.Fatalf("failed to count admin notifications: %v", err)
	}
	if notifCount < 1 {
		t.Errorf("expected a critical-payment admin notification for the partial clawback, got %d", notifCount)
	}
}