<?php
declare(strict_types=1);

use PHPUnit\Framework\TestCase;

/**
 * Unit tests for the shadow_read_only sub-flag added by PR-4.
 *
 * Orthogonal to the main 7-state FSM. Only takes effect when a module is in
 * the `verify` state.
 *
 * @covers WPDO_Feature_Flags::enable_shadow_read
 * @covers WPDO_Feature_Flags::disable_shadow_read
 * @covers WPDO_Feature_Flags::is_shadow_read_active
 * @covers WPDO_Feature_Flags::all_shadow
 */
class ShadowReadFlagTest extends TestCase {

	protected function setUp(): void {
		$GLOBALS['_wp_options'] = array();
		// Reset both caches via reflection.
		$ref = new ReflectionClass( WPDO_Feature_Flags::class );
		foreach ( array( 'cache', 'shadow_cache' ) as $prop ) {
			$p = $ref->getProperty( $prop );
			$p->setAccessible( true );
			$p->setValue( null, null );
		}
	}

	public function test_default_is_inactive(): void {
		$this->assertFalse( WPDO_Feature_Flags::is_shadow_read_active( 'hot_hp_listing' ) );
	}

	public function test_enable_then_active_only_in_verify_state(): void {
		WPDO_Feature_Flags::enable_shadow_read( 'hot_hp_listing' );

		// idle → not active even though flag is on.
		$this->assertFalse( WPDO_Feature_Flags::is_shadow_read_active( 'hot_hp_listing' ) );

		// dual_write → still not active.
		WPDO_Feature_Flags::set( 'hot_hp_listing', 'dual_write' );
		$this->assertFalse( WPDO_Feature_Flags::is_shadow_read_active( 'hot_hp_listing' ) );

		// verify → active.
		WPDO_Feature_Flags::set( 'hot_hp_listing', 'verify' );
		$this->assertTrue( WPDO_Feature_Flags::is_shadow_read_active( 'hot_hp_listing' ) );

		// cutover → no longer active (verify-only sub-flag).
		WPDO_Feature_Flags::set( 'hot_hp_listing', 'cutover' );
		$this->assertFalse( WPDO_Feature_Flags::is_shadow_read_active( 'hot_hp_listing' ) );
	}

	public function test_disable_clears_active(): void {
		WPDO_Feature_Flags::enable_shadow_read( 'hot_hp_vendor' );
		WPDO_Feature_Flags::set( 'hot_hp_vendor', 'verify' );
		$this->assertTrue( WPDO_Feature_Flags::is_shadow_read_active( 'hot_hp_vendor' ) );

		WPDO_Feature_Flags::disable_shadow_read( 'hot_hp_vendor' );
		$this->assertFalse( WPDO_Feature_Flags::is_shadow_read_active( 'hot_hp_vendor' ) );
	}

	public function test_all_shadow_returns_only_enabled_modules(): void {
		WPDO_Feature_Flags::enable_shadow_read( 'mod_a' );
		WPDO_Feature_Flags::enable_shadow_read( 'mod_b' );
		WPDO_Feature_Flags::disable_shadow_read( 'mod_b' );

		$flags = WPDO_Feature_Flags::all_shadow();
		$this->assertArrayHasKey( 'mod_a', $flags );
		$this->assertArrayNotHasKey( 'mod_b', $flags );
	}

	public function test_shadow_flag_independent_per_module(): void {
		WPDO_Feature_Flags::enable_shadow_read( 'hot_hp_listing' );
		WPDO_Feature_Flags::set( 'hot_hp_listing', 'verify' );
		WPDO_Feature_Flags::set( 'hot_hp_vendor', 'verify' );

		$this->assertTrue( WPDO_Feature_Flags::is_shadow_read_active( 'hot_hp_listing' ) );
		$this->assertFalse( WPDO_Feature_Flags::is_shadow_read_active( 'hot_hp_vendor' ) );
	}
}