import {
    dedupeBufferedRows,
    lineCountsFromRows,
    rowFromPayload,
    rowsFromHistory,
    rowWasLoadedInHistory,
} from '../src/lib/mainLogs.ts';

const assertEquals = <T>(actual: T, expected: T, message: string) => {
    if (actual !== expected) {
        throw new Error(`${message}: expected ${expected}, got ${actual}`);
    }
};

Deno.test('history rows parse levels and stable ids', () => {
    const rows = rowsFromHistory('[2026-06-07][12:00:00][app][WARN] careful\nplain line\n');

    assertEquals(rows.length, 2, 'history should skip trailing empty line');
    assertEquals(rows[0].id, 'history-0', 'history id should include row position');
    assertEquals(rows[0].level, 'WARN', 'explicit level should be parsed');
    assertEquals(rows[1].level, 'INFO', 'unknown level should default to info');
});

Deno.test('buffered main log rows covered by history sequence are removed', () => {
    const historyRows = rowsFromHistory('[2026-06-07][12:00:01][app][INFO] included\n');
    const included = rowFromPayload({
        line: '[2026-06-07][12:00:01][app][INFO] included',
        level: 'INFO',
        sequence: 4,
    });
    const fresh = rowFromPayload({
        line: '[2026-06-07][12:00:02][app][INFO] fresh',
        level: 'INFO',
        sequence: 5,
    });

    const deduped = dedupeBufferedRows(lineCountsFromRows(historyRows), [included, fresh], 4);

    assertEquals(rowWasLoadedInHistory(included, 4), true, 'included row should match history');
    assertEquals(deduped.length, 1, 'only fresh row should remain');
    assertEquals(deduped[0].line, fresh.line, 'fresh row should not be dropped');
});

Deno.test('buffered rows missing from trimmed history are retained', () => {
    const retained = rowFromPayload({
        line: '[2026-06-07][12:00:00][app][INFO] trimmed out',
        level: 'INFO',
        sequence: 2,
    });

    const deduped = dedupeBufferedRows(new Map(), [retained], 4);

    assertEquals(deduped.length, 1, 'trimmed row should remain visible');
    assertEquals(deduped[0].line, retained.line, 'trimmed row should be preserved');
});