package parser

import (
	"strings"
	"testing"
)

// place builds a fixed-width line by putting each string at a given column,
// which keeps these fixtures honest about the layout the parser measures.
func place(cells map[int]string) string {
	width := 0
	for col, text := range cells {
		if end := col + len(text); end > width {
			width = end
		}
	}
	line := []byte(strings.Repeat(" ", width))
	for col, text := range cells {
		copy(line[col:], text)
	}
	return string(line)
}

// Column starts, spaced as a real statement is: wide enough that every token
// of "05 Jan 2026" stays closest to DATE rather than drifting into TYPE.
const (
	colDate     = 2
	colType     = 20
	colDesc     = 40
	colMoneyIn  = 75
	colMoneyOut = 90
	colBalance  = 105
)

func trHeaderLine() string {
	return place(map[int]string{
		colDate: "DATE", colType: "TYPE", colDesc: "DESCRIPTION",
		colMoneyIn: "MONEY IN", colMoneyOut: "MONEY OUT", colBalance: "BALANCE",
	})
}

// A statement mixing both layouts: one transaction on a single line, one with
// its fields stacked across three, and one whose description wraps.
func trStatement() string {
	lines := []string{
		"                    Trade Republic Bank GmbH",
		"",
		trHeaderLine(),
		"",
		// Everything on one line.
		place(map[int]string{
			colDate: "05 Jan 2026", colType: "Deposit", colDesc: "Payment from ACME",
			colMoneyIn: "€2,500.00", colBalance: "€2,500.00",
		}),
		"",
		// Stacked across three lines.
		place(map[int]string{
			colDate: "06 Jan 2026", colMoneyOut: "€45.20", colBalance: "€2,454.80",
		}),
		place(map[int]string{colType: "Card"}),
		place(map[int]string{colDesc: "LIDL SOFIA 4412"}),
		"",
		// Wrapped description, hyphen-broken on the first line, plus an IBAN.
		place(map[int]string{
			colDate: "10 Jan 2026", colType: "Transfer", colDesc: "Standing order to sav-",
			colMoneyOut: "€500.00", colBalance: "€1,954.80",
		}),
		place(map[int]string{colDesc: "ings SI56123456789012345"}),
		"",
		"  Page 1 of 2",
	}
	return strings.Join(lines, "\n")
}

func TestParseTradeRepublicText(t *testing.T) {
	txns, err := parseTradeRepublicText(trStatement(), 2)
	if err != nil {
		t.Fatal(err)
	}
	if len(txns) != 3 {
		t.Fatalf("got %d transactions, want 3: %+v", len(txns), txns)
	}

	deposit := txns[0]
	if deposit.Date != "2026-01-05" {
		t.Errorf("date = %q, want 2026-01-05", deposit.Date)
	}
	if deposit.AmountMinor != 250000 {
		t.Errorf("money in = %d, want 250000", deposit.AmountMinor)
	}
	if deposit.Type != "Deposit" {
		t.Errorf("type = %q, want Deposit", deposit.Type)
	}
	if deposit.Description != "Payment from ACME" {
		t.Errorf("description = %q", deposit.Description)
	}

	// The stacked layout must produce the same shape as the single-line one.
	card := txns[1]
	if card.Date != "2026-01-06" {
		t.Errorf("date = %q, want 2026-01-06", card.Date)
	}
	if card.AmountMinor != -4520 {
		t.Errorf("money out = %d, want -4520", card.AmountMinor)
	}
	if card.Type != "Card" {
		t.Errorf("type = %q, want Card", card.Type)
	}
	if card.Description != "LIDL SOFIA 4412" {
		t.Errorf("description = %q", card.Description)
	}
	if card.BalanceMinor == nil || *card.BalanceMinor != 245480 {
		t.Errorf("balance = %v, want 245480", card.BalanceMinor)
	}

	// A hyphen-broken word rejoins without a space. The hyphen itself is kept,
	// as the original script does, because descriptions contain real hyphens
	// that must not be swallowed.
	transfer := txns[2]
	if transfer.Description != "Standing order to sav-ings SI56123456789012345" {
		t.Errorf("description = %q, want the wrapped fragment joined without a space", transfer.Description)
	}
	if transfer.Counterparty != "SI56123456789012345" {
		t.Errorf("counterparty = %q", transfer.Counterparty)
	}
	if transfer.AmountMinor != -50000 {
		t.Errorf("amount = %d, want -50000", transfer.AmountMinor)
	}
}

// Pages with no transaction table (cover pages, disclaimers) are skipped.
func TestParseTradeRepublicSkipsPagesWithoutTable(t *testing.T) {
	text := "  Some cover page with no table at all\n" + "\f" + trStatement()
	txns, err := parseTradeRepublicText(text, 2)
	if err != nil {
		t.Fatal(err)
	}
	if len(txns) != 3 {
		t.Errorf("got %d transactions, want 3", len(txns))
	}
}

// A figure inside the description must not be mistaken for a money column.
func TestParseTradeRepublicIgnoresAmountsInDescription(t *testing.T) {
	text := strings.Join([]string{
		trHeaderLine(),
		"",
		place(map[int]string{
			colDate: "05 Jan 2026", colType: "Card", colDesc: "Refund of €12.00 order",
			colMoneyIn: "€12.00", colBalance: "€100.00",
		}),
	}, "\n")

	txns, err := parseTradeRepublicText(text, 2)
	if err != nil {
		t.Fatal(err)
	}
	if len(txns) != 1 {
		t.Fatalf("got %d transactions, want 1", len(txns))
	}
	if txns[0].AmountMinor != 1200 {
		t.Errorf("amount = %d, want 1200", txns[0].AmountMinor)
	}
	if !strings.Contains(txns[0].Description, "€12.00") {
		t.Errorf("description = %q, want the inline figure kept", txns[0].Description)
	}
}