<?php
declare(strict_types=1);

use PHPUnit\Framework\TestCase;

/**
 * Integration test: WPDO_Post_Migration::benchmark_query() (v2.10.2).
 *
 * Verifies the benchmark method produces sensible timing comparison
 * between wp_postmeta JOIN and flat-table JOIN for the same logical query.
 *
 * Tests focus on the API contract (input → output shape) since wall-clock
 * timing is non-deterministic. Real performance numbers come from running
 * `wp wpdo post-benchmark` on dev10 production data.
 */
class PostBenchmarkTest extends TestCase {

	private const POSTS    = 'wp_itest_posts';
	private const POSTMETA = 'wp_itest_postmeta';
	private const FLAT     = 'wp_itest_wpdo_post_wc_product';

	public static function setUpBeforeClass(): void {
		global $wpdb;

		if ( ! class_exists( 'WPDO_Schema_Manager' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/engine/class-tmdo-schema-manager.php';
		}
		if ( ! class_exists( 'WPDO_Post_Migration' ) ) {
			require_once WPDO_PLUGIN_DIR . 'includes/migration/class-tmdo-post-migration.php';
		}

		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::POSTS . '`' );
		$wpdb->query(
			'CREATE TABLE `' . self::POSTS . '` (
				ID bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				post_type varchar(20) NOT NULL DEFAULT \'post\',
				post_status varchar(20) NOT NULL DEFAULT \'publish\',
				PRIMARY KEY (ID),
				KEY post_type (post_type)
			) DEFAULT CHARACTER SET utf8mb4'
		);

		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::POSTMETA . '`' );
		$wpdb->query(
			'CREATE TABLE `' . self::POSTMETA . '` (
				meta_id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				post_id bigint(20) unsigned NOT NULL DEFAULT 0,
				meta_key varchar(255) DEFAULT NULL,
				meta_value longtext,
				PRIMARY KEY (meta_id),
				KEY post_id (post_id),
				KEY meta_key (meta_key(191))
			) DEFAULT CHARACTER SET utf8mb4'
		);

		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::FLAT . '`' );
		$wpdb->query(
			'CREATE TABLE `' . self::FLAT . '` (
				id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
				post_id bigint(20) unsigned NOT NULL,
				_price decimal(18,6) DEFAULT NULL,
				PRIMARY KEY (id),
				UNIQUE KEY uk_post_id (post_id),
				KEY idx__price (_price)
			) DEFAULT CHARACTER SET utf8mb4'
		);

		// Seed 50 products with _price = 10..59 in both tables.
		for ( $i = 1; $i <= 50; $i++ ) {
			$wpdb->insert( self::POSTS, array( 'ID' => $i, 'post_type' => 'product', 'post_status' => 'publish' ) );
			$price = (string) ( 10 + $i );
			$wpdb->insert( self::POSTMETA, array( 'post_id' => $i, 'meta_key' => '_price', 'meta_value' => $price ) );
			$wpdb->insert( self::FLAT, array( 'post_id' => $i, '_price' => $price ) );
		}
	}

	public static function tearDownAfterClass(): void {
		global $wpdb;
		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::POSTS . '`' );
		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::POSTMETA . '`' );
		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::FLAT . '`' );
	}

	// ── benchmark_query() ────────────────────────────────────────────────────

	public function test_benchmark_returns_expected_shape(): void {
		$result = WPDO_Post_Migration::benchmark_query(
			'product',
			'_price',
			'>=',
			'30',
			self::FLAT,
			5
		);

		$this->assertArrayHasKey( 'samples', $result );
		$this->assertArrayHasKey( 'postmeta_avg_ms', $result );
		$this->assertArrayHasKey( 'flat_avg_ms', $result );
		$this->assertArrayHasKey( 'speedup', $result );
		$this->assertArrayHasKey( 'postmeta_rows', $result );
		$this->assertArrayHasKey( 'flat_rows', $result );

		$this->assertSame( 5, $result['samples'] );
		$this->assertGreaterThan( 0.0, $result['postmeta_avg_ms'] );
		$this->assertGreaterThan( 0.0, $result['flat_avg_ms'] );
	}

	public function test_benchmark_finds_same_rows_via_both_paths(): void {
		// _price >= 30 should match products 20..50 (i.e. 31 rows).
		$result = WPDO_Post_Migration::benchmark_query(
			'product',
			'_price',
			'>=',
			'30',
			self::FLAT,
			3
		);

		// Both paths must return the same count — verifies router correctness.
		$this->assertSame( $result['postmeta_rows'], $result['flat_rows'] );
		$this->assertGreaterThan( 0, $result['postmeta_rows'] );
	}

	public function test_benchmark_speedup_is_positive_number(): void {
		$result = WPDO_Post_Migration::benchmark_query(
			'product',
			'_price',
			'=',
			'25',
			self::FLAT,
			3
		);

		$this->assertIsFloat( $result['speedup'] );
		$this->assertGreaterThan( 0.0, $result['speedup'] );
	}

	public function test_benchmark_rejects_zero_samples(): void {
		$this->expectException( InvalidArgumentException::class );
		WPDO_Post_Migration::benchmark_query( 'product', '_price', '=', '25', self::FLAT, 0 );
	}

	public function test_benchmark_rejects_invalid_compare(): void {
		$this->expectException( InvalidArgumentException::class );
		WPDO_Post_Migration::benchmark_query( 'product', '_price', 'BOGUS', '25', self::FLAT, 3 );
	}

	public function test_benchmark_throws_when_flat_table_missing(): void {
		$this->expectException( RuntimeException::class );
		WPDO_Post_Migration::benchmark_query(
			'product',
			'_price',
			'=',
			'25',
			'wp_itest_nonexistent_flat',
			3
		);
	}
}