<?php

/*
 * Standalone test for the RecoReco date math -- no Kanboard / PHPUnit harness needed.
 * Run with:  php Test/OccurrenceCalculatorTest.php
 *
 * OccurrenceCalculator is pure, so this exercises the highest-risk correctness surface (month
 * lengths, leap years, the last-day rule, the drift-free clamp).
 */

require __DIR__.'/../Model/OccurrenceCalculator.php';

use Kanboard\Plugin\RecoReco\Model\OccurrenceCalculator;

date_default_timezone_set('UTC');

$calc = new OccurrenceCalculator();
$failures = 0;

function ts($str)
{
    return strtotime($str.' UTC');
}

function check($label, $got, $expected, &$failures)
{
    $ok = $got === $expected;
    $g = $got === null ? 'null' : date('Y-m-d H:i', $got);
    $e = $expected === null ? 'null' : date('Y-m-d H:i', $expected);
    echo ($ok ? 'PASS' : 'FAIL').'  '.$label.'  got='.$g.'  expected='.$e."\n";
    if (! $ok) {
        $failures++;
    }
}

// 1. Plain day-of-month: the 15th, every month.
check(
    'monthly 15th, next after Jan 20',
    $calc->occurrenceFrom(ts('2023-01-15 10:30'), 'monthly_day', false, ts('2023-01-20 00:00'), false),
    ts('2023-02-15 10:30'),
    $failures
);

// 2. Drift-free clamp: the 30th -> Feb clamps to 28 -> back to 30 in March (NOT 28).
check(
    '30th -> Feb (non-leap) clamps to 28',
    $calc->occurrenceFrom(ts('2023-01-30 09:00'), 'monthly_day', false, ts('2023-01-30 09:00'), false),
    ts('2023-02-28 09:00'),
    $failures
);
check(
    '30th -> March returns to 30 (no drift)',
    $calc->occurrenceFrom(ts('2023-01-30 09:00'), 'monthly_day', false, ts('2023-02-28 09:00'), false),
    ts('2023-03-30 09:00'),
    $failures
);

// 3. Last-day rule: last day of each month.
check(
    'last-day: Jan 31 -> Feb 28 (non-leap)',
    $calc->occurrenceFrom(ts('2023-01-31 08:00'), 'monthly_day', true, ts('2023-01-31 08:00'), false),
    ts('2023-02-28 08:00'),
    $failures
);
check(
    'last-day: Feb -> March 31',
    $calc->occurrenceFrom(ts('2023-01-31 08:00'), 'monthly_day', true, ts('2023-02-28 08:00'), false),
    ts('2023-03-31 08:00'),
    $failures
);

// 4. Leap year: last day of Feb 2024 is the 29th.
check(
    'last-day: Feb 2024 -> 29th (leap)',
    $calc->occurrenceFrom(ts('2024-01-31 08:00'), 'monthly_day', true, ts('2024-02-01 00:00'), false),
    ts('2024-02-29 08:00'),
    $failures
);

// 5. Inclusive vs exclusive at an exact occurrence.
check(
    'inclusive returns the same instant',
    $calc->occurrenceFrom(ts('2023-03-10 12:00'), 'monthly_day', false, ts('2023-03-10 12:00'), true),
    ts('2023-03-10 12:00'),
    $failures
);
check(
    'exclusive skips to next month',
    $calc->occurrenceFrom(ts('2023-03-10 12:00'), 'monthly_day', false, ts('2023-03-10 12:00'), false),
    ts('2023-04-10 12:00'),
    $failures
);

// 6. Daily: same time every day.
check(
    'daily -> next day same time',
    $calc->occurrenceFrom(ts('2023-03-10 09:30'), 'daily', false, ts('2023-03-10 12:00'), false),
    ts('2023-03-11 09:30'),
    $failures
);

// 7. Weekly: same weekday every 7 days (2023-03-07 is a Tuesday).
check(
    'weekly -> +7 days on the same weekday',
    $calc->occurrenceFrom(ts('2023-03-07 08:00'), 'weekly', false, ts('2023-03-07 08:00'), false),
    ts('2023-03-14 08:00'),
    $failures
);

// 8. Monthly by weekday: 2nd Tuesday (2023-03-14) -> 2nd Tuesday of April (2023-04-11).
check(
    'monthly-by-weekday: 2nd Tuesday -> next month 2nd Tuesday',
    $calc->occurrenceFrom(ts('2023-03-14 07:00'), 'monthly_dow', false, ts('2023-03-14 07:00'), false),
    ts('2023-04-11 07:00'),
    $failures
);

// 9. Monthly by weekday, last: last Tuesday of March (2023-03-28) -> last Tuesday of April (04-25).
check(
    'monthly-by-weekday last: last Tue -> next month last Tue',
    $calc->occurrenceFrom(ts('2023-03-28 07:00'), 'monthly_dow', true, ts('2023-03-28 07:00'), false),
    ts('2023-04-25 07:00'),
    $failures
);

// 10. Yearly: same month/day next year.
check(
    'yearly -> next year same date',
    $calc->occurrenceFrom(ts('2023-03-15 10:00'), 'yearly', false, ts('2023-03-15 10:00'), false),
    ts('2024-03-15 10:00'),
    $failures
);

// 11. Yearly last-day on Feb 29 (leap) -> next year Feb 28.
check(
    'yearly last-day: 2024-02-29 -> 2025-02-28',
    $calc->occurrenceFrom(ts('2024-02-29 08:00'), 'yearly', true, ts('2024-02-29 08:00'), false),
    ts('2025-02-28 08:00'),
    $failures
);

// 12. Yearly numeric Feb 29 -> clamps to 28 in a non-leap year, back to 29 in the next leap year.
check(
    'yearly numeric 29-Feb -> 2025 clamps to 28',
    $calc->occurrenceFrom(ts('2024-02-29 08:00'), 'yearly', false, ts('2024-02-29 08:00'), false),
    ts('2025-02-28 08:00'),
    $failures
);
check(
    'yearly numeric 29-Feb -> 2028 back to 29 (leap)',
    $calc->occurrenceFrom(ts('2024-02-29 08:00'), 'yearly', false, ts('2027-03-01 00:00'), false),
    ts('2028-02-29 08:00'),
    $failures
);

// 13. Unknown frequency returns null.
check(
    'unknown frequency -> null',
    $calc->occurrenceFrom(ts('2023-03-10 12:00'), 'nope', false, ts('2023-03-10 12:00'), false),
    null,
    $failures
);

echo "\n".($failures === 0 ? 'ALL PASSED' : $failures.' FAILURE(S)')."\n";
exit($failures === 0 ? 0 : 1);