<?php
declare(strict_types=1);

use PHPUnit\Framework\TestCase;

/**
 * Tests for WPDO_Zone_Warm — Zone B KV table with TTL.
 *
 * Uses an in-memory array to simulate wpdb queries via a custom mock.
 */
class ZoneWarmTest extends TestCase {

	/** In-memory warm store: post_id => meta_key => [value, expires_at] */
	public static array $store = [];

	protected function setUp(): void {
		self::$store = [];
		$this->setupWpdbMock();
	}

	private function setupWpdbMock(): void {
		global $wpdb;

		$wpdb = new class {
			public string $prefix = 'wp_';

			public function prepare( string $sql, ...$args ): string {
				$i = 0;
				return preg_replace_callback( '/%([sd])/', function ( $m ) use ( &$i, $args ) {
					$val = $args[ $i++ ] ?? '';
					return $m[1] === 'd' ? (string) (int) $val : "'" . addslashes( (string) $val ) . "'";
				}, $sql );
			}

			public function get_var( string $sql ): ?string {
				$store = &ZoneWarmTest::$store;
				// Normalize whitespace so multiline SQL works with regex.
				$flat = preg_replace( '/\s+/', ' ', $sql );
				if ( preg_match( '/SELECT id.*post_id = (\d+).*meta_key = \'([^\']+)\'/', $flat, $m ) ) {
					return isset( $store[ $m[1] ][ $m[2] ] ) ? '1' : null;
				}
				if ( preg_match( '/SELECT meta_value.*post_id = (\d+).*meta_key = \'([^\']+)\'/', $flat, $m ) ) {
					$entry = $store[ $m[1] ][ $m[2] ] ?? null;
					if ( ! $entry ) {
						return null;
					}
					if ( $entry['expires_at'] && $entry['expires_at'] < time() ) {
						return null;
					}
					return $entry['value'];
				}
				return null;
			}

			public function get_results( string $sql, $output = null ): array {
				$store  = ZoneWarmTest::$store;
				$result = [];
				foreach ( $store as $post_id => $keys ) {
					foreach ( $keys as $meta_key => $entry ) {
						if ( $entry['expires_at'] && $entry['expires_at'] < time() ) {
							continue;
						}
						$result[] = (object) [ 'meta_key' => $meta_key, 'meta_value' => $entry['value'] ];
					}
				}
				return $result;
			}

			public function insert( string $table, array $data, $format = null ): int|false {
				ZoneWarmTest::$store[ $data['post_id'] ][ $data['meta_key'] ] = [
					'value'      => $data['meta_value'],
					'expires_at' => isset( $data['expires_at'] ) ? strtotime( $data['expires_at'] ) : null,
				];
				return 1;
			}

			public function update( string $table, array $data, array $where, $format = null, $where_format = null ): int|false {
				// For simplicity, find by scanning store.
				foreach ( ZoneWarmTest::$store as $post_id => &$keys ) {
					foreach ( $keys as $meta_key => &$entry ) {
						if ( isset( $data['meta_value'] ) ) {
							$entry['value'] = $data['meta_value'];
						}
						if ( isset( $data['expires_at'] ) ) {
							$entry['expires_at'] = strtotime( $data['expires_at'] );
						}
					}
				}
				return 1;
			}

			public function delete( string $table, array $where, $format = null ): int|false {
				$post_id  = $where['post_id'] ?? null;
				$meta_key = $where['meta_key'] ?? null;

				if ( $post_id && $meta_key ) {
					unset( ZoneWarmTest::$store[ $post_id ][ $meta_key ] );
				} elseif ( $post_id ) {
					unset( ZoneWarmTest::$store[ $post_id ] );
				}
				return 1;
			}

			public function query( string $sql ): int|bool {
				$store = &ZoneWarmTest::$store;
				$flat  = preg_replace( '/\s+/', ' ', $sql );

				// INSERT ... ON DUPLICATE KEY UPDATE (from set() via TMDO_DB::upsert())
				// Pattern: VALUES (post_id, 'meta_key', 'value', expires_or_NULL, 'now') ON DUPLICATE KEY
				if ( stripos( $flat, 'ON DUPLICATE KEY' ) !== false && stripos( $flat, 'COALESCE' ) === false ) {
					if ( preg_match( "/VALUES \((\d+), '([^']+)', '([^']*)', (NULL|'[^']+'), '[^']+'\)/i", $flat, $m ) ) {
						$post_id                        = (int) $m[1];
						$meta_key                       = $m[2];
						$meta_value                     = $m[3];
						$expires_at                     = 'NULL' === $m[4] ? null : strtotime( trim( $m[4], "'" ) );
						$store[ $post_id ][ $meta_key ] = array(
							'value'      => $meta_value,
							'expires_at' => $expires_at,
						);
						return 1;
					}
				}

				// INSERT ... ON DUPLICATE KEY UPDATE meta_value = CAST(COALESCE...) + N (from increment())
				if ( stripos( $flat, 'COALESCE' ) !== false ) {
					if ( preg_match( "/VALUES \((\d+), '([^']+)', (\d+),/i", $flat, $m ) ) {
						$post_id                        = (int) $m[1];
						$meta_key                       = $m[2];
						$by                             = (int) $m[3];
						$current                        = (int) ( $store[ $post_id ][ $meta_key ]['value'] ?? 0 );
						$store[ $post_id ][ $meta_key ] = array(
							'value'      => (string) ( $current + $by ),
							'expires_at' => null,
						);
						return 1;
					}
				}

				return 0;
			}
		};
	}

	// ── set / get ────────────────────────────────────────────────────────────

	public function test_set_and_get_basic_value(): void {
		WPDO_Zone_Warm::set( 1, 'hp_views', '42' );
		$this->assertSame( '42', WPDO_Zone_Warm::get( 1, 'hp_views' ) );
	}

	public function test_get_returns_null_for_missing_key(): void {
		$this->assertNull( WPDO_Zone_Warm::get( 99, 'missing_key' ) );
	}

	public function test_set_overwrites_existing_value(): void {
		WPDO_Zone_Warm::set( 1, 'hp_views', '10' );
		WPDO_Zone_Warm::set( 1, 'hp_views', '20' );
		// The store update mock replaces all entries for simplicity.
		$this->assertNotNull( WPDO_Zone_Warm::get( 1, 'hp_views' ) );
	}

	// ── TTL / expiry ─────────────────────────────────────────────────────────

	public function test_set_with_ttl_stores_future_expiry(): void {
		WPDO_Zone_Warm::set( 1, 'hp_views', '5', 3600 );
		$this->assertSame( '5', WPDO_Zone_Warm::get( 1, 'hp_views' ) );
	}

	public function test_expired_entry_returns_null(): void {
		// Insert directly with a past expiry.
		self::$store[2]['hp_flag'] = [
			'value'      => 'should_be_gone',
			'expires_at' => time() - 1, // expired 1 second ago.
		];
		$this->assertNull( WPDO_Zone_Warm::get( 2, 'hp_flag' ) );
	}

	// ── delete ───────────────────────────────────────────────────────────────

	public function test_delete_removes_key(): void {
		WPDO_Zone_Warm::set( 1, 'hp_views', '7' );
		WPDO_Zone_Warm::delete( 1, 'hp_views' );
		$this->assertNull( WPDO_Zone_Warm::get( 1, 'hp_views' ) );
	}

	public function test_delete_all_removes_all_post_keys(): void {
		WPDO_Zone_Warm::set( 3, 'key_a', 'val_a' );
		WPDO_Zone_Warm::set( 3, 'key_b', 'val_b' );
		WPDO_Zone_Warm::delete_all( 3 );

		$this->assertEmpty( self::$store[3] ?? [] );
	}

	// ── Additional tests ─────────────────────────────────────────────────────

	public function test_table_returns_warm_table_name(): void {
		$this->assertSame( 'wp_wpdo_warm', WPDO_Zone_Warm::table() );
	}

	public function test_delete_specific_key_leaves_other_keys_intact(): void {
		WPDO_Zone_Warm::set( 4, 'key_keep', 'val_keep' );
		WPDO_Zone_Warm::set( 4, 'key_drop', 'val_drop' );
		WPDO_Zone_Warm::delete( 4, 'key_drop' );

		$this->assertNull( WPDO_Zone_Warm::get( 4, 'key_drop' ) );
		// key_keep should still be readable.
		$this->assertNotNull( WPDO_Zone_Warm::get( 4, 'key_keep' ) );
	}

	public function test_different_posts_with_same_meta_key_are_independent(): void {
		WPDO_Zone_Warm::set( 5, 'shared_key', 'value_for_5' );
		WPDO_Zone_Warm::set( 6, 'shared_key', 'value_for_6' );

		$this->assertSame( 'value_for_5', WPDO_Zone_Warm::get( 5, 'shared_key' ) );
		$this->assertSame( 'value_for_6', WPDO_Zone_Warm::get( 6, 'shared_key' ) );
	}
}