package repository_test

import (
	"context"
	"os"
	"sort"
	"testing"

	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"apskel-pos-be/internal/constants"
	"apskel-pos-be/internal/processor"
	"apskel-pos-be/internal/repository"
)

// Builds consistent wallets through the engine, checks the reconciliation is silent,
// then breaks each §7.5 invariant for a different customer and checks each break is
// found by the right checks and nothing else is. Needs TEST_DATABASE_URL pointing at
// a migrated database; see wallet_repository_test.go.
func TestWalletReconciliation_AgainstPostgres(t *testing.T) {
	dsn := os.Getenv("TEST_DATABASE_URL")
	if dsn == "" {
		t.Skip("TEST_DATABASE_URL not set")
	}
	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
	require.NoError(t, err)
	ctx := context.Background()

	org := uuid.New()
	names := []string{"clean", "balance", "lot", "allocation", "credit"}
	customers := map[string]uuid.UUID{}
	var ids []uuid.UUID
	require.NoError(t, db.Exec(`INSERT INTO organizations (id, name, plan_type) VALUES (?, 'recon test', 'basic')`, org).Error)
	for _, n := range names {
		customers[n] = uuid.New()
		ids = append(ids, customers[n])
		require.NoError(t, db.Exec(`INSERT INTO customers (id, organization_id, name) VALUES (?, ?, ?)`, customers[n], org, n).Error)
	}
	t.Cleanup(func() {
		db.Exec(`DELETE FROM wallet_lot_allocations WHERE lot_id IN (SELECT id FROM wallet_lots WHERE customer_id IN ?)`, ids)
		db.Exec(`DELETE FROM wallet_lot_allocations WHERE transaction_id IN (SELECT id FROM wallet_transactions WHERE customer_id IN ?)`, ids)
		db.Exec(`DELETE FROM wallet_lots WHERE customer_id IN ?`, ids)
		db.Exec(`DELETE FROM wallet_transactions WHERE customer_id IN ?`, ids)
		db.Exec(`DELETE FROM customer_wallets WHERE customer_id IN ?`, ids)
		db.Exec(`DELETE FROM customers WHERE id IN ?`, ids)
		db.Exec(`DELETE FROM organizations WHERE id = ?`, org)
	})

	// Every customer: +100 in two lots, +30 coins, -70 points across both lots.
	wallet := processor.NewWalletProcessor(repository.NewWalletRepository(db))
	txm := repository.NewTxManager(db)
	for _, id := range ids {
		require.NoError(t, txm.WithTransaction(ctx, func(ctx context.Context) error {
			if _, err := wallet.Credit(ctx, processor.WalletCreditInput{
				WalletEntry: processor.WalletEntry{CustomerID: id, Currency: constants.WalletCurrencyPoint,
					Type: constants.WalletTxTypeMigration, Amount: 100, ReferenceType: constants.WalletRefTypeLegacyPoints,
					ReferenceID: uuid.New(), Description: "Saldo awal"},
				Lots: []processor.WalletLotInput{{Amount: 60}, {Amount: 40}},
			}); err != nil {
				return err
			}
			if _, err := wallet.Credit(ctx, processor.WalletCreditInput{WalletEntry: processor.WalletEntry{
				CustomerID: id, Currency: constants.WalletCurrencyCoin, Type: constants.WalletTxTypeMigration,
				Amount: 30, ReferenceType: constants.WalletRefTypeLegacyTokens, ReferenceID: id, Description: "Saldo awal"}}); err != nil {
				return err
			}
			outlet := uuid.New()
			_, err := wallet.Debit(ctx, processor.WalletDebitInput{WalletEntry: processor.WalletEntry{
				CustomerID: id, Currency: constants.WalletCurrencyPoint, Type: constants.WalletTxTypePayment,
				Amount: 70, ReferenceType: constants.WalletRefTypePayment, ReferenceID: uuid.New(), OutletID: &outlet,
				Description: "Bayar"}})
			return err
		}))
	}

	recon := repository.NewWalletReconciliationRepository(db)
	// Other packages' tests may share the database, so only these customers count.
	checksByCustomer := func() map[string][]string {
		t.Helper()
		found, err := recon.FindDiscrepancies(ctx, 1000)
		require.NoError(t, err)
		byName := map[uuid.UUID]string{}
		for n, id := range customers {
			byName[id] = n
		}
		out := map[string][]string{}
		for _, d := range found {
			if n, ok := byName[d.CustomerID]; ok {
				assert.Equal(t, org, d.OrganizationID)
				out[n] = append(out[n], d.Check)
			}
		}
		for n := range out {
			sort.Strings(out[n])
		}
		return out
	}

	assert.Empty(t, checksByCustomer(), "consistent data reports nothing")

	exec := func(q string, args ...any) {
		t.Helper()
		require.NoError(t, db.Exec(q, args...).Error)
	}
	// A balance moved without a ledger row or a lot.
	exec(`UPDATE customer_wallets SET point_balance = point_balance + 5 WHERE customer_id = ?`, customers["balance"])
	// A lot's remainder changed without an allocation.
	exec(`UPDATE wallet_lots SET remaining_amount = remaining_amount - 1
		WHERE id = (SELECT id FROM wallet_lots WHERE customer_id = ? AND remaining_amount > 0 LIMIT 1)`, customers["lot"])
	// An allocation lost.
	exec(`DELETE FROM wallet_lot_allocations WHERE (transaction_id, lot_id) IN (
		SELECT a.transaction_id, a.lot_id FROM wallet_lot_allocations a
		JOIN wallet_transactions t ON t.id = a.transaction_id WHERE t.customer_id = ? LIMIT 1)`, customers["allocation"])
	// A credit whose lot was never written, with the balance moved to match the ledger.
	exec(`INSERT INTO wallet_transactions (organization_id, customer_id, currency, type, amount, balance_after, reference_type, reference_id, description)
		VALUES (?, ?, 'COIN', 'MIGRATION', 10, 40, 'LEGACY_TOKENS', ?, 'x')`, org, customers["credit"], customers["credit"])
	exec(`UPDATE customer_wallets SET coin_balance = coin_balance + 10 WHERE customer_id = ?`, customers["credit"])

	assert.Equal(t, map[string][]string{
		"balance":    {repository.WalletCheckBalanceVsLedger, repository.WalletCheckBalanceVsLots},
		"lot":        {repository.WalletCheckBalanceVsLots, repository.WalletCheckLotVsAllocations},
		"allocation": {repository.WalletCheckDebitVsAllocations, repository.WalletCheckLotVsAllocations},
		"credit":     {repository.WalletCheckBalanceVsLots, repository.WalletCheckCreditVsLots},
	}, checksByCustomer(), "each break is found by exactly the checks it violates, and the clean customer by none")

	// The per-check limit caps the report.
	found, err := recon.FindDiscrepancies(ctx, 1)
	require.NoError(t, err)
	perCheck := map[string]int{}
	for _, d := range found {
		perCheck[d.Check]++
	}
	for check, n := range perCheck {
		assert.LessOrEqual(t, n, 1, check)
	}
}