<?php
declare(strict_types=1);

use PHPUnit\Framework\TestCase;

/**
 * Integration tests for WPDO_V2_Upgrader — atomic v1.3.x → v2.0.0 upgrade (PR-7).
 *
 * Covers the four upgrade scenarios from Part F.2:
 *   S1: clean install
 *   S2: v1.3.x → v2.0.0 (no UAE)  ← dev10 production case
 *   S3: v1.3.x + UAE coexistence
 *   S4: HPCT residue (covered by existing wpdo_hpct_imported flag)
 *
 * @covers WPDO_V2_Upgrader
 */
class UpgradeV2Test extends TestCase {

	public static function setUpBeforeClass(): void {
		global $wpdb;
		// Reset state for repeatability.
		foreach ( array( 'audit', 'shadow_diffs', 'site_metrics', 'uni_options' ) as $t ) {
			$wpdb->query( "DROP TABLE IF EXISTS `{$wpdb->prefix}wpdo_{$t}`" );
		}
		// Drop any leftover wp_uae_* probe tables from prior test runs.
		$wpdb->query( "DROP TABLE IF EXISTS `{$wpdb->prefix}uae_probe`" );
	}

	protected function setUp(): void {
		// Clean options between tests for clean preconditions.
		$GLOBALS['_wp_options'] = array();
	}

	// ── Pre-flight ──────────────────────────────────────────────────────────

	public function test_pre_flight_passes_in_clean_environment(): void {
		$checks = WPDO_V2_Upgrader::pre_flight_check();
		$this->assertIsArray( $checks );
		// PHP / WP / MySQL versions in this CI/dev environment must satisfy minimums.
		$this->assertTrue( $checks['php_version'] );
		$this->assertTrue( $checks['mysql_version'] );
	}

	public function test_pre_flight_detects_old_php(): void {
		// Simulating an old PHP is impossible from PHP itself, so we only
		// verify the keys are present + booleans.
		$checks = WPDO_V2_Upgrader::pre_flight_check();
		foreach ( array( 'php_version', 'wp_version', 'mysql_version', 'free_disk_mb', 'features_writable', 'no_active_migration' ) as $key ) {
			$this->assertArrayHasKey( $key, $checks );
			$this->assertIsBool( $checks[ $key ] );
		}
	}

	// ── S1: clean install ─────────────────────────────────────────────────

	public function test_s1_clean_install_creates_v2_schema(): void {
		WPDO_V2_Upgrader::upgrade_to_v2();
		$status = WPDO_Installer::v2_tables_status();
		foreach ( $status as $exists ) {
			$this->assertTrue( $exists );
		}
	}

	// ── S2: v1.3.x → v2.0.0 (no UAE) ───────────────────────────────────────

	public function test_s2_upgrade_marks_db_version(): void {
		// Simulate v1.3.x state.
		update_option( 'wpdo_db_version', '1.0.0' );

		$ok = WPDO_V2_Upgrader::upgrade_to_v2();
		$this->assertTrue( $ok );
		$this->assertSame( '2.0.0', get_option( 'wpdo_db_version' ) );
		$this->assertSame( 'complete', get_option( 'wpdo_v2_upgrade_status' ) );
	}

	public function test_s2_upgrade_seeds_entity_modules_in_features(): void {
		update_option( 'wpdo_features', array( 'hot_hp_listing' => 'cutover' ) );
		WPDO_V2_Upgrader::upgrade_to_v2();

		$flags = get_option( 'wpdo_features' );
		$this->assertSame( 'cutover', $flags['hot_hp_listing'], 'Pre-existing module state must be preserved' );

		foreach ( array( 'entity_user', 'entity_term', 'entity_comment', 'entity_options' ) as $module ) {
			$this->assertArrayHasKey( $module, $flags );
			$this->assertSame( 'idle', $flags[ $module ] );
		}
	}

	public function test_s2_upgrade_idempotent(): void {
		WPDO_V2_Upgrader::upgrade_to_v2();
		$ok = WPDO_V2_Upgrader::upgrade_to_v2(); // Second run must not fail.
		$this->assertTrue( $ok );
	}

	// ── S3: UAE coexistence ───────────────────────────────────────────────

	public function test_s3_detects_uae_data_when_table_present(): void {
		global $wpdb;
		$wpdb->query( "CREATE TABLE IF NOT EXISTS `{$wpdb->prefix}uae_probe` ( id BIGINT PRIMARY KEY ) ENGINE=InnoDB" );
		$this->assertTrue( WPDO_V2_Upgrader::detect_uae_data() );

		$wpdb->query( "DROP TABLE IF EXISTS `{$wpdb->prefix}uae_probe`" );
	}

	public function test_s3_no_uae_data_in_clean_environment(): void {
		// dev10 case: no wp_uae_* tables.
		$this->assertFalse( WPDO_V2_Upgrader::detect_uae_data() );
	}

	// ── Rollback ───────────────────────────────────────────────────────────

	public function test_rollback_restores_features_backup(): void {
		$original = array( 'hot_hp_listing' => 'cutover' );
		update_option( 'wpdo_features', $original );

		WPDO_V2_Upgrader::upgrade_to_v2();
		// Simulate user wants to roll back.
		WPDO_V2_Upgrader::rollback_v2( true );

		$this->assertSame( $original, get_option( 'wpdo_features' ) );
		$this->assertSame( '1.0.0', get_option( 'wpdo_db_version' ) );
		$this->assertSame( 'rolled_back', get_option( 'wpdo_v2_upgrade_status' ) );
	}

	public function test_rollback_with_keep_data_preserves_v2_tables(): void {
		WPDO_V2_Upgrader::upgrade_to_v2();
		WPDO_V2_Upgrader::rollback_v2( true );

		$status = WPDO_Installer::v2_tables_status();
		foreach ( $status as $table => $exists ) {
			$this->assertTrue( $exists, "{$table} must remain after rollback with --keep-data" );
		}
	}
}