<?php

declare(strict_types=1);

namespace Magdev\WpPrometheus\Tests\Unit\Metrics;

use Magdev\WpPrometheus\Metrics\StorageFactory;
use Magdev\WpPrometheus\Tests\Helpers\GlobalFunctionState;
use Magdev\WpPrometheus\Tests\Unit\TestCase;
use PHPUnit\Framework\Attributes\CoversClass;
use PHPUnit\Framework\Attributes\Test;
use Prometheus\Storage\InMemory;

#[CoversClass(StorageFactory::class)]
class StorageFactoryTest extends TestCase
{
    /** @var list<string> Environment variables to clean up after each test. */
    private array $envVarsToClean = [];

    protected function setUp(): void
    {
        parent::setUp();
        StorageFactory::reset();
    }

    protected function tearDown(): void
    {
        StorageFactory::reset();
        foreach ($this->envVarsToClean as $var) {
            putenv($var);
        }
        $this->envVarsToClean = [];
        parent::tearDown();
    }

    // ── Adapter Constants ────────────────────────────────────────────

    #[Test]
    public function adapter_constants_are_defined(): void
    {
        $this->assertSame('inmemory', StorageFactory::ADAPTER_INMEMORY);
        $this->assertSame('redis', StorageFactory::ADAPTER_REDIS);
        $this->assertSame('apcu', StorageFactory::ADAPTER_APCU);
    }

    // ── get_available_adapters() ─────────────────────────────────────

    #[Test]
    public function get_available_adapters_returns_all_three(): void
    {
        $adapters = StorageFactory::get_available_adapters();

        $this->assertArrayHasKey(StorageFactory::ADAPTER_INMEMORY, $adapters);
        $this->assertArrayHasKey(StorageFactory::ADAPTER_REDIS, $adapters);
        $this->assertArrayHasKey(StorageFactory::ADAPTER_APCU, $adapters);
        $this->assertCount(3, $adapters);
    }

    // ── is_adapter_available() ───────────────────────────────────────

    #[Test]
    public function inmemory_adapter_is_always_available(): void
    {
        $this->assertTrue(StorageFactory::is_adapter_available(StorageFactory::ADAPTER_INMEMORY));
    }

    #[Test]
    public function unknown_adapter_is_not_available(): void
    {
        $this->assertFalse(StorageFactory::is_adapter_available('unknown'));
    }

    #[Test]
    public function redis_availability_depends_on_extension(): void
    {
        $extensionLoaded = $this->getFunctionMock(
            'Magdev\\WpPrometheus\\Metrics',
            'extension_loaded'
        );
        $extensionLoaded->expects($this->any())->willReturn(false);

        $this->assertFalse(StorageFactory::is_adapter_available(StorageFactory::ADAPTER_REDIS));
    }

    #[Test]
    public function apcu_availability_requires_extension_and_enabled(): void
    {
        $extensionLoaded = $this->getFunctionMock(
            'Magdev\\WpPrometheus\\Metrics',
            'extension_loaded'
        );
        $extensionLoaded->expects($this->any())->willReturn(true);

        $apcuEnabled = $this->getFunctionMock(
            'Magdev\\WpPrometheus\\Metrics',
            'apcu_enabled'
        );
        $apcuEnabled->expects($this->any())->willReturn(false);

        $this->assertFalse(StorageFactory::is_adapter_available(StorageFactory::ADAPTER_APCU));
    }

    // ── get_configured_adapter() ─────────────────────────────────────

    #[Test]
    public function default_configured_adapter_is_inmemory(): void
    {
        $this->assertSame('inmemory', StorageFactory::get_configured_adapter());
    }

    #[Test]
    public function configured_adapter_reads_from_env_var(): void
    {
        $this->setEnv('WP_PROMETHEUS_STORAGE_ADAPTER', 'redis');

        $this->assertSame('redis', StorageFactory::get_configured_adapter());
    }

    #[Test]
    public function configured_adapter_reads_from_option(): void
    {
        GlobalFunctionState::$options['wp_prometheus_storage_adapter'] = 'apcu';

        $this->assertSame('apcu', StorageFactory::get_configured_adapter());
    }

    #[Test]
    public function env_var_takes_precedence_over_option(): void
    {
        $this->setEnv('WP_PROMETHEUS_STORAGE_ADAPTER', 'redis');
        GlobalFunctionState::$options['wp_prometheus_storage_adapter'] = 'apcu';

        $this->assertSame('redis', StorageFactory::get_configured_adapter());
    }

    #[Test]
    public function configured_adapter_lowercases_env_value(): void
    {
        $this->setEnv('WP_PROMETHEUS_STORAGE_ADAPTER', 'REDIS');

        $this->assertSame('redis', StorageFactory::get_configured_adapter());
    }

    // ── get_redis_config() ───────────────────────────────────────────

    #[Test]
    public function get_redis_config_returns_defaults(): void
    {
        $config = StorageFactory::get_redis_config();

        $this->assertSame('127.0.0.1', $config['host']);
        $this->assertSame(6379, $config['port']);
        $this->assertSame('', $config['password']);
        $this->assertSame(0, $config['database']);
        $this->assertSame('WORDPRESS_PROMETHEUS_', $config['prefix']);
    }

    #[Test]
    public function get_redis_config_reads_from_env_vars(): void
    {
        $this->setEnv('WP_PROMETHEUS_REDIS_HOST', '10.0.0.1');
        $this->setEnv('WP_PROMETHEUS_REDIS_PORT', '6380');
        $this->setEnv('WP_PROMETHEUS_REDIS_PASSWORD', 's3cret');
        $this->setEnv('WP_PROMETHEUS_REDIS_DATABASE', '2');
        $this->setEnv('WP_PROMETHEUS_REDIS_PREFIX', 'MY_PREFIX_');

        $config = StorageFactory::get_redis_config();

        $this->assertSame('10.0.0.1', $config['host']);
        $this->assertSame(6380, $config['port']);
        $this->assertSame('s3cret', $config['password']);
        $this->assertSame(2, $config['database']);
        $this->assertSame('MY_PREFIX_', $config['prefix']);
    }

    #[Test]
    public function get_redis_config_reads_from_option(): void
    {
        GlobalFunctionState::$options['wp_prometheus_redis_config'] = [
            'host'     => '192.168.1.1',
            'port'     => 6381,
            'password' => 'optpass',
            'database' => 3,
            'prefix'   => 'OPT_',
        ];

        $config = StorageFactory::get_redis_config();

        $this->assertSame('192.168.1.1', $config['host']);
        $this->assertSame(6381, $config['port']);
        $this->assertSame('optpass', $config['password']);
        $this->assertSame(3, $config['database']);
        $this->assertSame('OPT_', $config['prefix']);
    }

    #[Test]
    public function get_redis_config_env_takes_precedence(): void
    {
        $this->setEnv('WP_PROMETHEUS_REDIS_HOST', 'env-host');
        GlobalFunctionState::$options['wp_prometheus_redis_config'] = [
            'host' => 'option-host',
        ];

        $config = StorageFactory::get_redis_config();
        $this->assertSame('env-host', $config['host']);
    }

    // ── get_apcu_prefix() ────────────────────────────────────────────

    #[Test]
    public function get_apcu_prefix_returns_default(): void
    {
        $this->assertSame('wp_prom', StorageFactory::get_apcu_prefix());
    }

    #[Test]
    public function get_apcu_prefix_reads_from_env(): void
    {
        $this->setEnv('WP_PROMETHEUS_APCU_PREFIX', 'custom_prefix');

        $this->assertSame('custom_prefix', StorageFactory::get_apcu_prefix());
    }

    #[Test]
    public function get_apcu_prefix_reads_from_option(): void
    {
        GlobalFunctionState::$options['wp_prometheus_apcu_prefix'] = 'opt_prefix';

        $this->assertSame('opt_prefix', StorageFactory::get_apcu_prefix());
    }

    // ── save_config() ────────────────────────────────────────────────

    #[Test]
    public function save_config_stores_adapter(): void
    {
        StorageFactory::save_config(['adapter' => 'redis']);

        $this->assertSame(
            'redis',
            GlobalFunctionState::$options['wp_prometheus_storage_adapter']
        );
    }

    #[Test]
    public function save_config_stores_redis_config(): void
    {
        StorageFactory::save_config([
            'redis' => [
                'host'     => '10.0.0.5',
                'port'     => 6390,
                'password' => 'pass123',
                'database' => 1,
                'prefix'   => 'TEST_',
            ],
        ]);

        $saved = GlobalFunctionState::$options['wp_prometheus_redis_config'];
        $this->assertSame('10.0.0.5', $saved['host']);
        $this->assertSame(6390, $saved['port']);
        $this->assertSame('pass123', $saved['password']);
        $this->assertSame(1, $saved['database']);
        // sanitize_key lowercases the prefix
        $this->assertSame('test_', $saved['prefix']);
    }

    #[Test]
    public function save_config_stores_apcu_prefix(): void
    {
        StorageFactory::save_config(['apcu_prefix' => 'my_apcu']);

        $this->assertSame(
            'my_apcu',
            GlobalFunctionState::$options['wp_prometheus_apcu_prefix']
        );
    }

    #[Test]
    public function save_config_resets_singleton(): void
    {
        // Get an adapter (creates singleton).
        $adapter1 = StorageFactory::get_adapter();

        // Save new config (should reset singleton).
        StorageFactory::save_config(['adapter' => 'inmemory']);

        // Get adapter again — should be a new instance.
        $adapter2 = StorageFactory::get_adapter();
        $this->assertNotSame($adapter1, $adapter2);
    }

    // ── test_connection() ────────────────────────────────────────────

    #[Test]
    public function test_connection_inmemory_always_succeeds(): void
    {
        $result = StorageFactory::test_connection(StorageFactory::ADAPTER_INMEMORY);

        $this->assertTrue($result['success']);
        $this->assertNotEmpty($result['message']);
    }

    #[Test]
    public function test_connection_unknown_adapter_fails(): void
    {
        $result = StorageFactory::test_connection('unknown');

        $this->assertFalse($result['success']);
        $this->assertStringContainsString('Unknown', $result['message']);
    }

    #[Test]
    public function test_connection_redis_fails_without_extension(): void
    {
        $extensionLoaded = $this->getFunctionMock(
            'Magdev\\WpPrometheus\\Metrics',
            'extension_loaded'
        );
        $extensionLoaded->expects($this->any())->willReturn(false);

        $result = StorageFactory::test_connection(StorageFactory::ADAPTER_REDIS);
        $this->assertFalse($result['success']);
        $this->assertStringContainsString('not installed', $result['message']);
    }

    #[Test]
    public function test_connection_apcu_fails_without_extension(): void
    {
        $extensionLoaded = $this->getFunctionMock(
            'Magdev\\WpPrometheus\\Metrics',
            'extension_loaded'
        );
        $extensionLoaded->expects($this->any())->willReturn(false);

        $result = StorageFactory::test_connection(StorageFactory::ADAPTER_APCU);
        $this->assertFalse($result['success']);
        $this->assertStringContainsString('not installed', $result['message']);
    }

    // ── get_adapter() / reset() / singleton ──────────────────────────

    #[Test]
    public function get_adapter_returns_inmemory_by_default(): void
    {
        $adapter = StorageFactory::get_adapter();
        $this->assertInstanceOf(InMemory::class, $adapter);
    }

    #[Test]
    public function get_adapter_returns_singleton(): void
    {
        $adapter1 = StorageFactory::get_adapter();
        $adapter2 = StorageFactory::get_adapter();

        $this->assertSame($adapter1, $adapter2);
    }

    #[Test]
    public function reset_clears_singleton_and_error(): void
    {
        StorageFactory::get_adapter();
        StorageFactory::reset();

        // After reset, get_last_error should be empty.
        $this->assertEmpty(StorageFactory::get_last_error());

        // Getting adapter again creates a new instance.
        $adapter = StorageFactory::get_adapter();
        $this->assertInstanceOf(InMemory::class, $adapter);
    }

    #[Test]
    public function get_adapter_falls_back_to_inmemory_when_redis_unavailable(): void
    {
        $this->setEnv('WP_PROMETHEUS_STORAGE_ADAPTER', 'redis');

        $extensionLoaded = $this->getFunctionMock(
            'Magdev\\WpPrometheus\\Metrics',
            'extension_loaded'
        );
        $extensionLoaded->expects($this->any())->willReturn(false);

        $adapter = StorageFactory::get_adapter();
        $this->assertInstanceOf(InMemory::class, $adapter);
        $this->assertNotEmpty(StorageFactory::get_last_error());
    }

    #[Test]
    public function get_adapter_falls_back_to_inmemory_when_apcu_unavailable(): void
    {
        $this->setEnv('WP_PROMETHEUS_STORAGE_ADAPTER', 'apcu');

        $extensionLoaded = $this->getFunctionMock(
            'Magdev\\WpPrometheus\\Metrics',
            'extension_loaded'
        );
        $extensionLoaded->expects($this->any())->willReturn(false);

        $adapter = StorageFactory::get_adapter();
        $this->assertInstanceOf(InMemory::class, $adapter);
        $this->assertNotEmpty(StorageFactory::get_last_error());
    }

    // ── Helpers ──────────────────────────────────────────────────────

    private function setEnv(string $name, string $value): void
    {
        putenv("$name=$value");
        $this->envVarsToClean[] = $name;
    }
}