<?php

declare(strict_types=1);

namespace BattleForge\Tests\Unit\Domain;

use BattleForge\Domain\Battlefield;
use BattleForge\Domain\Position;
use BattleForge\Domain\Terrain;
use InvalidArgumentException;
use PHPUnit\Framework\TestCase;

final class BattlefieldTest extends TestCase
{
    public function testItRejectsDimensionsOutsideTheSupportedRange(): void
    {
        $this->expectException(InvalidArgumentException::class);

        new Battlefield(7, 16);
    }

    public function testItAcceptsMinimumAndMaximumDimensions(): void
    {
        $minimum = new Battlefield(8, 8);
        $maximum = new Battlefield(16, 16);

        self::assertSame([8, 8], [$minimum->width, $minimum->height]);
        self::assertSame([16, 16], [$maximum->width, $maximum->height]);
    }

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

        new Battlefield(16, 17);
    }

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

        new Battlefield(8, 8, ['01:0' => Terrain::Forest]);
    }

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

        new Battlefield(8, 8, ['not-a-coordinate' => Terrain::Forest]);
    }

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

        // @phpstan-ignore argument.type
        new Battlefield(8, 8, ['0:0' => 'forest']);
    }

    public function testReachableRejectsAStartOutsideTheBattlefield(): void
    {
        $battlefield = new Battlefield(8, 8);

        $this->expectException(InvalidArgumentException::class);

        $battlefield->reachable(new Position(-1, 0), 2, []);
    }

    public function testReachableRejectsANegativeBudget(): void
    {
        $battlefield = new Battlefield(8, 8);

        $this->expectException(InvalidArgumentException::class);

        $battlefield->reachable(new Position(0, 0), -1, []);
    }

    public function testReachableRejectsOccupiedPositionsOutsideTheBattlefield(): void
    {
        $battlefield = new Battlefield(8, 8);

        $this->expectException(InvalidArgumentException::class);

        $battlefield->reachable(new Position(0, 0), 2, [new Position(8, 0)]);
    }

    public function testItFindsReachableTilesUsingTerrainCostsAndObstacles(): void
    {
        $battlefield = new Battlefield(8, 8, [
            '1:0' => Terrain::Forest,
            '0:1' => Terrain::Rough,
            '2:0' => Terrain::Water,
            '1:1' => Terrain::Blocking,
        ]);

        $reachable = $battlefield->reachable(
            new Position(0, 0),
            2,
            [new Position(0, 2)],
        );

        self::assertSame([
            '0:0' => 0,
            '1:0' => 2,
            '0:1' => 2,
        ], $reachable);
    }

    public function testReachableReplacesAHighCostRouteWithALowerCostDetour(): void
    {
        $battlefield = new Battlefield(8, 8, [
            '1:0' => Terrain::Forest,
            '2:0' => Terrain::Forest,
            '3:0' => Terrain::Forest,
        ]);

        $reachable = $battlefield->reachable(new Position(0, 0), 7, []);

        self::assertSame(6, $reachable['4:0']);
    }
}