<?php

declare(strict_types=1);

namespace BattleForge\Tests\Unit\Domain;

use BattleForge\Domain\Archetype;
use BattleForge\Domain\Battlefield;
use BattleForge\Domain\DeploymentZone;
use BattleForge\Domain\ObjectiveMarker;
use BattleForge\Domain\Position;
use BattleForge\Domain\Scenario;
use BattleForge\Domain\ScenarioValidator;
use BattleForge\Domain\Terrain;
use BattleForge\Domain\UnitState;
use BattleForge\Domain\VictoryCondition;
use PHPUnit\Framework\TestCase;

final class ScenarioValidatorTest extends TestCase
{
    public function testItReturnsAnEmptyListForAValidScenario(): void
    {
        $scenario = $this->validScenario();

        self::assertSame([], ScenarioValidator::validate($scenario));
    }

    public function testItRejectsAnObjectiveOnImpassableTerrain(): void
    {
        $scenario = $this->validScenario(
            terrain: ['4:4' => Terrain::Blocking],
            objectivePosition: new Position(4, 4),
        );

        $errors = ScenarioValidator::validate($scenario);

        self::assertNotEmpty($errors);
        self::assertTrue((bool) array_filter($errors, static fn (string $error): bool => str_contains($error, 'impassable')));
    }

    public function testItRejectsAnObjectiveUnreachableFromAnyDeploymentZone(): void
    {
        $scenario = $this->validScenario(
            terrain: [
                '3:4' => Terrain::Blocking,
                '4:3' => Terrain::Blocking,
                '5:4' => Terrain::Blocking,
                '4:5' => Terrain::Blocking,
            ],
            objectivePosition: new Position(4, 4),
        );

        $errors = ScenarioValidator::validate($scenario);

        self::assertTrue((bool) array_filter($errors, static fn (string $error): bool => str_contains($error, 'unreachable')));
    }

    public function testItRejectsOverlappingDeploymentZones(): void
    {
        $units = $this->unitSet();
        $battlefield = new Battlefield(8, 8);
        $scenario = new Scenario(
            id: 'demo',
            name: 'Demo',
            battlefield: $battlefield,
            units: $units,
            deploymentZones: [
                'alpha' => new DeploymentZone('alpha', [new Position(0, 0), new Position(1, 0), new Position(2, 0)]),
                'bravo' => new DeploymentZone('bravo', [new Position(1, 0), new Position(2, 0), new Position(7, 7), new Position(6, 7), new Position(5, 7)]),
            ],
            objectives: [],
            victoryCondition: VictoryCondition::EliminateAll,
            holdRoundsRequired: 1,
        );

        $errors = ScenarioValidator::validate($scenario);

        self::assertTrue((bool) array_filter($errors, static fn (string $error): bool => str_contains($error, 'overlap')));
    }

    public function testItRejectsDeploymentPositionsOnImpassableTerrain(): void
    {
        $units = $this->unitSet();
        $battlefield = new Battlefield(8, 8, ['0:0' => Terrain::Blocking]);
        $scenario = new Scenario(
            id: 'demo',
            name: 'Demo',
            battlefield: $battlefield,
            units: $units,
            deploymentZones: [
                'alpha' => new DeploymentZone('alpha', [new Position(0, 0), new Position(1, 0), new Position(2, 0)]),
                'bravo' => new DeploymentZone('bravo', [new Position(7, 7), new Position(6, 7), new Position(5, 7)]),
            ],
            objectives: [],
            victoryCondition: VictoryCondition::EliminateAll,
            holdRoundsRequired: 1,
        );

        $errors = ScenarioValidator::validate($scenario);

        self::assertTrue((bool) array_filter($errors, static fn (string $error): bool => str_contains($error, 'impassable')));
    }

    /**
     * @param array<string, Terrain> $terrain
     */
    private function validScenario(
        array $terrain = [],
        ?Position $objectivePosition = null,
    ): Scenario {
        $units = $this->unitSet();
        $battlefield = new Battlefield(8, 8, $terrain);
        $objectives = [];

        if ($objectivePosition !== null) {
            $objectives = ['objective-1' => new ObjectiveMarker('objective-1', $objectivePosition)];
        }

        return new Scenario(
            id: 'demo',
            name: 'Demo',
            battlefield: $battlefield,
            units: $units,
            deploymentZones: $this->zones(),
            objectives: $objectives,
            victoryCondition: $objectivePosition === null
                ? VictoryCondition::EliminateAll
                : VictoryCondition::HoldObjective,
            holdRoundsRequired: 1,
        );
    }

    /** @return array<string, DeploymentZone> */
    private function zones(): array
    {
        return [
            'alpha' => new DeploymentZone('alpha', [
                new Position(0, 0),
                new Position(1, 0),
                new Position(2, 0),
            ]),
            'bravo' => new DeploymentZone('bravo', [
                new Position(7, 7),
                new Position(6, 7),
                new Position(5, 7),
            ]),
        ];
    }

    /** @return list<UnitState> */
    private function unitSet(): array
    {
        return [
            new UnitState('alpha-1', 'alpha', new Position(0, 0), 10, 10, 4, 3, 2, 2, false, Archetype::Defender),
            new UnitState('alpha-2', 'alpha', new Position(1, 0), 8, 8, 5, 2, 3, 2, false, Archetype::Striker),
            new UnitState('alpha-3', 'alpha', new Position(2, 0), 7, 7, 2, 2, 3, 2, false, Archetype::Support),
            new UnitState('bravo-1', 'bravo', new Position(7, 7), 10, 10, 4, 3, 2, 2, false, Archetype::Defender),
            new UnitState('bravo-2', 'bravo', new Position(6, 7), 8, 8, 5, 2, 3, 2, false, Archetype::Striker),
            new UnitState('bravo-3', 'bravo', new Position(5, 7), 6, 6, 3, 1, 5, 2, false, Archetype::Scout),
        ];
    }
}