<?php

declare(strict_types=1);

namespace App\Tests\Config;

use App\Config\SeasonCalendar;
use PHPUnit\Framework\TestCase;

class SeasonCalendarTest extends TestCase
{
    private function winter(): SeasonCalendar
    {
        return new SeasonCalendar('11-01', '04-01');
    }

    #[\PHPUnit\Framework\Attributes\DataProvider('winterDates')]
    public function testSeasonYearForTheWrappingWinterWindow(string $date, ?int $expected): void
    {
        $this->assertSame($expected, $this->winter()->seasonYearFor(new \DateTimeImmutable($date)));
    }

    public static function winterDates(): iterable
    {
        yield 'first day of the season' => ['2024-11-01', 2024];
        yield 'december, same calendar year' => ['2024-12-20', 2024];
        yield 'february, next calendar year' => ['2025-02-10', 2024];
        yield 'last day of the season is inclusive' => ['2025-04-01', 2024];
        yield 'time of day does not matter' => ['2025-04-01 23:59:00', 2024];
        yield 'day after the season ends' => ['2025-04-02', null];
        yield 'high summer' => ['2025-07-15', null];
        yield 'day before the next season starts' => ['2025-10-31', null];
        yield 'start of the following season' => ['2025-11-01', 2025];
    }

    public function testLabel(): void
    {
        $calendar = $this->winter();

        $this->assertSame('Saison 2024/25', $calendar->label(2024));
        $this->assertSame('Saison 2009/10', $calendar->label(2009));
        $this->assertSame('außerhalb der Saison', $calendar->label(null));
    }

    #[\PHPUnit\Framework\Attributes\DataProvider('summerDates')]
    public function testSeasonYearForANonWrappingWindow(string $date, ?int $expected): void
    {
        $calendar = new SeasonCalendar('06-01', '09-01');

        $this->assertSame($expected, $calendar->seasonYearFor(new \DateTimeImmutable($date)));
    }

    public static function summerDates(): iterable
    {
        yield 'before the window' => ['2025-05-31', null];
        yield 'first day' => ['2025-06-01', 2025];
        yield 'inside' => ['2025-07-15', 2025];
        yield 'last day' => ['2025-09-01', 2025];
        yield 'after the window' => ['2025-09-02', null];
        yield 'turn of the year is not in season' => ['2025-01-01', null];
    }

    public function testAnInvalidBoundaryIsRejected(): void
    {
        $this->expectException(\InvalidArgumentException::class);

        (new SeasonCalendar('xx-yy', '04-01'))->seasonYearFor(new \DateTimeImmutable('2025-01-01'));
    }

    #[\PHPUnit\Framework\Attributes\DataProvider('currentOrUpcomingDates')]
    public function testCurrentOrUpcomingSeasonYear(string $date, int $expected): void
    {
        $this->assertSame(
            $expected,
            $this->winter()->currentOrUpcomingSeasonYear(new \DateTimeImmutable($date))
        );
    }

    public static function currentOrUpcomingDates(): iterable
    {
        yield 'inside the season' => ['2024-12-20', 2024];
        yield 'last day of the season' => ['2025-04-01', 2024];
        yield 'day after the season ends falls forward' => ['2025-04-02', 2025];
        yield 'high summer falls forward' => ['2025-07-15', 2025];
        yield 'day before the next season starts' => ['2025-10-31', 2025];
        yield 'first day of the next season' => ['2025-11-01', 2025];
        yield 'off-season in january is impossible for this window' => ['2025-01-05', 2024];
    }

    public function testCurrentOrUpcomingSeasonYearFallsForwardAcrossTheTurnOfTheYear(): void
    {
        // A window that ends before it starts in the same calendar year is the wrapping case;
        // one that does not wrap has its off-season on both sides of the window instead.
        $summer = new SeasonCalendar('05-01', '09-30');

        $this->assertSame(2025, $summer->currentOrUpcomingSeasonYear(new \DateTimeImmutable('2025-03-01')));
        $this->assertSame(2025, $summer->currentOrUpcomingSeasonYear(new \DateTimeImmutable('2025-06-01')));
        $this->assertSame(2026, $summer->currentOrUpcomingSeasonYear(new \DateTimeImmutable('2025-11-20')));
    }

    public function testWindowFor(): void
    {
        [$start, $end] = $this->winter()->windowFor(2024);

        $this->assertSame('2024-11-01', $start->format('Y-m-d'));
        $this->assertSame('2025-04-01', $end->format('Y-m-d'));

        [$start, $end] = (new SeasonCalendar('05-01', '09-30'))->windowFor(2025);

        $this->assertSame('2025-05-01', $start->format('Y-m-d'));
        $this->assertSame('2025-09-30', $end->format('Y-m-d'));
    }

    #[\PHPUnit\Framework\Attributes\DataProvider('provideUpcomingSeasonDates')]
    public function testTheCurrentOrUpcomingSeasonYear(string $date, int $expected): void
    {
        $calendar = new SeasonCalendar('11-01', '04-01');

        $this->assertSame($expected, $calendar->currentOrUpcomingSeasonYear(new \DateTimeImmutable($date)));
    }

    public static function provideUpcomingSeasonDates(): iterable
    {
        // Between two seasons: the winter ahead, which is what a recruiting mail means.
        yield 'September, before the season starts' => ['2026-09-24', 2026];
        yield 'the day the season starts' => ['2026-11-01', 2026];
        // Inside a season: that season, not the next one.
        yield 'December, mid season' => ['2026-12-15', 2026];
        yield 'the last day of the season' => ['2027-04-01', 2026];
        // After a season ended, so the next one to start.
        yield 'May, after the season ended' => ['2027-05-02', 2027];
    }

    public function testTheShortLabelIsTheTwoDigitSpan(): void
    {
        $calendar = new SeasonCalendar('11-01', '04-01');

        $this->assertSame('26/27', $calendar->shortLabel(2026));
        // The turn of the century has to stay two digits on both ends.
        $this->assertSame('99/00', $calendar->shortLabel(1999));
    }
}