package parser

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"git.petrovv.com/nikola/money/internal/config"
)

// writeFile drops a statement in a temporary directory and returns its path.
func writeFile(t *testing.T, name, content string) string {
	t.Helper()
	path := filepath.Join(t.TempDir(), name)
	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
		t.Fatal(err)
	}
	return path
}

// A Revolut export: out of date order, mixed currencies, a pending row, a row
// with a fee, and a transfer carrying an IBAN.
const revolutCSV = `Type,Product,Started Date,Completed Date,Description,Amount,Fee,Currency,State,Balance
CARD_PAYMENT,Current,2026-01-06 09:12:00,2026-01-06 09:12:00,LIDL SOFIA 4412,-45.20,0.00,EUR,COMPLETED,1234.56
TOPUP,Current,2026-01-05 08:00:00,2026-01-05 08:00:00,Payment from ACME,2500.00,0.00,EUR,COMPLETED,1279.76
TRANSFER,Current,2026-01-10 10:00:00,2026-01-10 10:00:00,To savings SI56123456789012345,-500.00,0.35,EUR,COMPLETED,734.41
CARD_PAYMENT,Current,2026-01-11 10:00:00,,Pending coffee,-3.50,0.00,EUR,PENDING,
EXCHANGE,Current,2026-01-12 10:00:00,2026-01-12 10:00:00,Tokyo hotel,-15000,0,JPY,COMPLETED,50000
`

func revolutAccount(currency string, digits int) *config.Account {
	return &config.Account{Slug: "revolut", Currency: currency, MinorDigits: &digits, Parser: "revolut"}
}

func TestRevolutParse(t *testing.T) {
	path := writeFile(t, "account-statement.csv", revolutCSV)
	acc := revolutAccount("EUR", 2)

	p, err := For(acc)
	if err != nil {
		t.Fatal(err)
	}
	txns, err := p.Parse(path, acc)
	if err != nil {
		t.Fatal(err)
	}
	if len(txns) != 3 {
		t.Fatalf("got %d transactions, want 3: %+v", len(txns), txns)
	}

	// Rows come back in completed-date order, not file order.
	wantDates := []string{"2026-01-05", "2026-01-06", "2026-01-10"}
	for i, want := range wantDates {
		if txns[i].Date != want {
			t.Errorf("txn %d date = %q, want %q", i, txns[i].Date, want)
		}
	}

	if txns[0].Type != "TOPUP" {
		t.Errorf("type = %q, want TOPUP", txns[0].Type)
	}
	if txns[1].AmountMinor != -4520 {
		t.Errorf("card payment = %d, want -4520", txns[1].AmountMinor)
	}

	// The fee is folded into the amount and noted in the description.
	transfer := txns[2]
	if transfer.AmountMinor != -50035 {
		t.Errorf("transfer with fee = %d, want -50035 (amount minus fee)", transfer.AmountMinor)
	}
	if !strings.Contains(transfer.Description, "(fee 0.35)") {
		t.Errorf("description = %q, want a fee note", transfer.Description)
	}
	if transfer.BalanceMinor == nil || *transfer.BalanceMinor != 73441 {
		t.Errorf("balance = %v, want 73441", transfer.BalanceMinor)
	}

	// Pending and foreign-currency rows are skipped, and said so.
	warnings := strings.Join(p.(Warner).Warnings(), "\n")
	if !strings.Contains(warnings, "1 PENDING") {
		t.Errorf("warnings = %q, want a note about the pending row", warnings)
	}
	if !strings.Contains(warnings, "JPY") {
		t.Errorf("warnings = %q, want a note about the JPY row", warnings)
	}
}

// The same export read as a JPY account picks up the row the EUR account skipped.
func TestRevolutOtherCurrencyViaSecondAccount(t *testing.T) {
	path := writeFile(t, "account-statement.csv", revolutCSV)
	acc := revolutAccount("JPY", 0)

	p, err := For(acc)
	if err != nil {
		t.Fatal(err)
	}
	txns, err := p.Parse(path, acc)
	if err != nil {
		t.Fatal(err)
	}
	if len(txns) != 1 {
		t.Fatalf("got %d transactions, want 1: %+v", len(txns), txns)
	}
	// JPY has no minor unit, so the amount is whole yen.
	if txns[0].AmountMinor != -15000 {
		t.Errorf("amount = %d, want -15000", txns[0].AmountMinor)
	}
	if txns[0].BalanceMinor == nil || *txns[0].BalanceMinor != 50000 {
		t.Errorf("balance = %v, want 50000", txns[0].BalanceMinor)
	}
}

func TestRevolutMissingColumn(t *testing.T) {
	path := writeFile(t, "bad.csv", "Type,Description,Amount\nCARD_PAYMENT,X,-1.00\n")
	acc := revolutAccount("EUR", 2)
	p, err := For(acc)
	if err != nil {
		t.Fatal(err)
	}
	_, err = p.Parse(path, acc)
	if err == nil {
		t.Fatal("expected an error for a statement missing required columns")
	}
	if !strings.Contains(err.Error(), "Balance") {
		t.Errorf("error = %v, want it to name the missing columns", err)
	}
}