<?php
declare(strict_types=1);

use PHPUnit\Framework\TestCase;

/**
 * Tests for WPDO_Zone_Cold — JSON blob storage with Object Cache integration.
 */
class ZoneColdTest extends TestCase {

	/** In-memory "database" store: post_id => json string */
	public static array $db_store = [];

	/** Control whether get_var returns the "id" existence check */
	public static bool $row_exists = false;

	protected function setUp(): void {
		self::$db_store   = [];
		self::$row_exists = false;
		$GLOBALS['_wp_cache'] = [];
		$this->setup_wpdb_mock();
	}

	private function setup_wpdb_mock(): 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 );
			}

			/**
			 * get_var is used for two things:
			 *  1. SELECT data ... → return JSON blob
			 *  2. SELECT id ...   → return '1' if exists, else null
			 */
			public function get_var( string $sql ): ?string {
				$flat = preg_replace( '/\s+/', ' ', $sql );

				// Existence check (save_blob path).
				if ( stripos( $flat, 'SELECT id' ) !== false ) {
					if ( preg_match( "/post_id = (\d+)/", $flat, $m ) ) {
						return isset( ZoneColdTest::$db_store[ (int) $m[1] ] ) ? '1' : null;
					}
					return null;
				}

				// Data fetch.
				if ( preg_match( "/post_id = (\d+)/", $flat, $m ) ) {
					return ZoneColdTest::$db_store[ (int) $m[1] ] ?? null;
				}

				return null;
			}

			public function get_row( string $sql, $output = OBJECT ) {
				return null;
			}

			public function get_results( string $sql, $output = OBJECT ): array {
				return [];
			}

			public function insert( string $table, array $data, $format = null ): int|false {
				if ( isset( $data['post_id'], $data['data'] ) ) {
					ZoneColdTest::$db_store[ (int) $data['post_id'] ] = $data['data'];
				}
				return 1;
			}

			public function update( string $table, array $data, array $where, $format = null, $where_format = null ): int|false {
				if ( isset( $where['post_id'], $data['data'] ) ) {
					ZoneColdTest::$db_store[ (int) $where['post_id'] ] = $data['data'];
				}
				return 1;
			}

			public function delete( string $table, array $where, $format = null ): int|false {
				if ( isset( $where['post_id'] ) ) {
					unset( ZoneColdTest::$db_store[ (int) $where['post_id'] ] );
				}
				return 1;
			}

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

				// JSON_REMOVE UPDATE — from TMDO_Zone_Cold::remove (MySQL path).
				// SQL: UPDATE `{table}` SET data = JSON_REMOVE(..., '$.key'), ... WHERE post_id = N
				if ( stripos( $flat, 'JSON_REMOVE' ) !== false ) {
					if ( preg_match( "/'\\\$\\.([^']+)'/", $flat, $km )
						&& preg_match( '/WHERE post_id = (\d+)/i', $flat, $wm ) ) {
						$post_id = (int) $wm[1];
						$key     = $km[1];
						$data    = json_decode( ZoneColdTest::$db_store[ $post_id ] ?? '{}', true );
						$data    = is_array( $data ) ? $data : array();
						unset( $data[ $key ] );
						ZoneColdTest::$db_store[ $post_id ] = (string) wp_json_encode( $data );
					}
					return 1;
				}

				// INSERT...ON DUPLICATE KEY with JSON_MERGE_PATCH — from save_patch (MySQL path).
				// Merges the patch into the existing blob, preserving untouched keys.
				if ( stripos( $flat, 'ON DUPLICATE KEY' ) !== false && stripos( $flat, 'JSON_MERGE_PATCH' ) !== false ) {
					if ( preg_match( "/VALUES \((\d+), '((?:[^'\\\\]|\\\\.)*)'/i", $flat, $m ) ) {
						$post_id                            = (int) $m[1];
						$patch                              = json_decode( stripslashes( $m[2] ), true );
						$patch                              = is_array( $patch ) ? $patch : array();
						$existing                           = json_decode( ZoneColdTest::$db_store[ $post_id ] ?? '{}', true );
						$existing                           = is_array( $existing ) ? $existing : array();
						ZoneColdTest::$db_store[ $post_id ] = (string) wp_json_encode( array_merge( $existing, $patch ) );
					}
					return 1;
				}

				// INSERT...ON DUPLICATE KEY UPDATE (from TMDO_DB::upsert via save_blob).
				// Pattern: VALUES (post_id, 'json_data', 'datetime') ON DUPLICATE KEY UPDATE col = VALUES(col)
				if ( stripos( $flat, 'ON DUPLICATE KEY' ) !== false ) {
					if ( preg_match( "/VALUES \((\d+), '((?:[^'\\\\]|\\\\.)*)'/i", $flat, $m ) ) {
						ZoneColdTest::$db_store[ (int) $m[1] ] = stripslashes( $m[2] );
					}
				}

				return 1;
			}
		};
	}

	// ── table() ──────────────────────────────────────────────────────────────

	public function test_table_returns_prefixed_name(): void {
		$this->assertSame( 'wp_wpdo_cold_hp_listing', WPDO_Zone_Cold::table( 'hp_listing' ) );
	}

	// ── get() ─────────────────────────────────────────────────────────────────

	public function test_get_returns_null_for_missing_key(): void {
		// Cache miss + no DB row → blob is empty array → key missing → null.
		$result = WPDO_Zone_Cold::get( 99, 'hp_listing', 'hp_description' );
		$this->assertNull( $result );
	}

	public function test_get_reads_from_cache_on_hit(): void {
		// Pre-populate cache so DB should NOT be hit.
		$group     = 'wpdo_cold_hp_listing';
		$cache_key = 'cold_1';
		$GLOBALS['_wp_cache'][ $group ][ $cache_key ] = [ 'hp_bio' => 'cached value' ];

		$result = WPDO_Zone_Cold::get( 1, 'hp_listing', 'hp_bio' );
		$this->assertSame( 'cached value', $result );

		// DB store should remain empty (DB was not queried for data).
		$this->assertEmpty( self::$db_store );
	}

	// ── get_blob() ───────────────────────────────────────────────────────────

	public function test_get_blob_queries_db_on_cache_miss(): void {
		self::$db_store[5] = json_encode( [ 'hp_description' => 'Hello World', 'hp_location' => 'Paris' ] );
		$blob = WPDO_Zone_Cold::get_blob( 5, 'hp_listing' );
		$this->assertSame( 'Hello World', $blob['hp_description'] );
		$this->assertSame( 'Paris', $blob['hp_location'] );
	}

	// ── set() ─────────────────────────────────────────────────────────────────

	public function test_set_merges_new_key_into_blob(): void {
		// Seed an existing blob.
		self::$db_store[10] = json_encode( [ 'a' => 1 ] );

		WPDO_Zone_Cold::set( 10, 'hp_listing', 'b', 2 );

		$stored = json_decode( self::$db_store[10], true );
		$this->assertArrayHasKey( 'a', $stored );
		$this->assertArrayHasKey( 'b', $stored );
		$this->assertSame( 1, $stored['a'] );
		$this->assertSame( 2, $stored['b'] );
	}

	// ── set_many() ───────────────────────────────────────────────────────────

	public function test_set_many_merges_multiple_keys(): void {
		WPDO_Zone_Cold::set_many( 20, 'hp_listing', [
			'key1' => 'v1',
			'key2' => 'v2',
			'key3' => 'v3',
		] );

		$stored = json_decode( self::$db_store[20], true );
		$this->assertSame( 'v1', $stored['key1'] );
		$this->assertSame( 'v2', $stored['key2'] );
		$this->assertSame( 'v3', $stored['key3'] );
	}

	// ── remove() ─────────────────────────────────────────────────────────────

	public function test_remove_deletes_key_from_blob(): void {
		self::$db_store[30] = json_encode( [ 'keep' => 'yes', 'drop' => 'no' ] );

		WPDO_Zone_Cold::remove( 30, 'hp_listing', 'drop' );

		$stored = json_decode( self::$db_store[30], true );
		$this->assertArrayHasKey( 'keep', $stored );
		$this->assertArrayNotHasKey( 'drop', $stored );
	}

	// ── delete() ─────────────────────────────────────────────────────────────

	public function test_delete_clears_cache(): void {
		$group     = 'wpdo_cold_hp_listing';
		$cache_key = 'cold_1';

		// Pre-populate cache.
		$GLOBALS['_wp_cache'][ $group ][ $cache_key ] = [ 'some' => 'data' ];

		WPDO_Zone_Cold::delete( 1, 'hp_listing' );

		// Cache entry must be gone.
		$this->assertFalse( isset( $GLOBALS['_wp_cache'][ $group ][ $cache_key ] ) );
	}

	// ── Additional edge-case tests ────────────────────────────────────────────

	public function test_set_invalidates_object_cache(): void {
		$group     = 'wpdo_cold_hp_listing';
		$cache_key = 'cold_50';

		// Pre-populate cache with stale data.
		$GLOBALS['_wp_cache'][ $group ][ $cache_key ] = [ 'stale' => 'old_value' ];

		WPDO_Zone_Cold::set( 50, 'hp_listing', 'fresh', 'new_value' );

		// Cache must be invalidated after write.
		$this->assertFalse( isset( $GLOBALS['_wp_cache'][ $group ][ $cache_key ] ) );
	}

	public function test_get_blob_populates_cache_on_db_hit(): void {
		// Seed the DB store so get_blob has something to fetch.
		self::$db_store[60] = json_encode( [ 'cached_key' => 'cached_val' ] );

		WPDO_Zone_Cold::get_blob( 60, 'hp_listing' );

		// Cache must now contain the fetched data.
		$group  = 'wpdo_cold_hp_listing';
		$cached = $GLOBALS['_wp_cache'][ $group ]['cold_60'] ?? false;
		$this->assertIsArray( $cached );
		$this->assertSame( 'cached_val', $cached['cached_key'] );
	}

	public function test_remove_nonexistent_key_is_safe(): void {
		// Store an existing blob.
		self::$db_store[70] = json_encode( [ 'keep' => 'this' ] );

		// Remove a key that doesn't exist — should not throw.
		WPDO_Zone_Cold::remove( 70, 'hp_listing', 'nonexistent_key' );

		$stored = json_decode( self::$db_store[70], true );
		$this->assertArrayHasKey( 'keep', $stored );
		$this->assertArrayNotHasKey( 'nonexistent_key', $stored );
	}
}