<?php
/**
 * Scale benchmark: native postmeta vs hot table vs entity table.
 *
 * Runs against the dataset from tests/bench/seed.php:
 *   TMDO_TEST_DB_NAME=wp_wpdo_bench php tests/bench/run.php [--iterations=20] [--seed=7]
 *
 * SQL mirrors what the code under test emits: WP_Query meta_query (INNER JOIN
 * per clause, CAST for numerics, SQL_CALC_FOUND_ROWS + FOUND_ROWS()),
 * TMDO_Query_Router (hot) and TMDO_Post_Query_Router (entity, %s-quoted values).
 * Writes run inside a transaction that is rolled back, so the dataset never changes.
 *
 * Output: a Markdown table on stdout (p50 / p95 / max in ms, result rows, index used).
 *
 * @package TMDO\Tests\Bench
 */

declare(strict_types=1);

if ( 'cli' !== PHP_SAPI ) {
	exit( 1 );
}

require_once __DIR__ . '/class-tmdo-bench-seeder.php';

const P = 'wp_itest_';

$opts       = getopt( '', array( 'iterations::', 'seed::' ) );
$iterations = max( 1, (int) ( $opts['iterations'] ?? 20 ) );
$warmup     = 3;
$db_name    = (string) getenv( 'TMDO_TEST_DB_NAME' );

try {
	TMDO_Bench_Seeder::assert_bench_db( $db_name );
} catch ( InvalidArgumentException $e ) {
	fwrite( STDERR, $e->getMessage() . PHP_EOL );
	exit( 2 );
}

$db = new mysqli(
	getenv( 'TMDO_TEST_DB_HOST' ) ?: '127.0.0.1',
	getenv( 'TMDO_TEST_DB_USER' ) ?: 'dbo',
	(string) getenv( 'TMDO_TEST_DB_PASS' ),
	$db_name
);
$db->set_charset( 'utf8mb4' );
$db->query( 'SET SESSION max_statement_time = 30' ); // MariaDB: cap runaway native queries.

$vendors  = (int) $db->query( 'SELECT COUNT(*) FROM `' . P . "posts` WHERE post_type = 'hp_vendor'" )->fetch_row()[0];
$listings = (int) $db->query( 'SELECT COUNT(*) FROM `' . P . "posts` WHERE post_type = 'hp_listing'" )->fetch_row()[0];
if ( 0 === $vendors || 0 === $listings ) {
	fwrite( STDERR, "No bench data — run tests/bench/seed.php first.\n" );
	exit( 3 );
}

mt_srand( (int) ( $opts['seed'] ?? 7 ) );

// ── SQL builders ──────────────────────────────────────────────────────────

/** WP_Query shape with one INNER JOIN per meta clause. */
function native_search( array $meta_where ): string {
	$joins = '';
	$where = array();
	foreach ( $meta_where as $n => $cond ) {
		$alias  = 0 === $n ? P . 'postmeta' : "mt{$n}";
		$joins .= ' INNER JOIN `' . P . 'postmeta`' . ( 0 === $n ? '' : " AS {$alias}" ) . " ON ( p.ID = {$alias}.post_id )";
		$where[] = '( ' . sprintf( $cond, $alias ) . ' )';
	}
	return 'SELECT SQL_CALC_FOUND_ROWS p.ID FROM `' . P . "posts` p{$joins} WHERE 1=1 AND ( " . implode( ' AND ', $where )
		. " ) AND p.post_type = 'hp_listing' AND ((p.post_status = 'publish')) GROUP BY p.ID ORDER BY p.post_date DESC LIMIT 0, 20";
}

/** TMDO router shape: one LEFT JOIN to a flat table plus flat WHERE clauses. */
function flat_search( string $table, string $alias, string $conditions ): string {
	return 'SELECT SQL_CALC_FOUND_ROWS p.ID FROM `' . P . "posts` p LEFT JOIN `" . P . "{$table}` AS `{$alias}` ON (p.ID = `{$alias}`.`post_id`)"
		. " WHERE 1=1 AND p.post_type = 'hp_listing' AND ((p.post_status = 'publish')){$conditions} GROUP BY p.ID ORDER BY p.post_date DESC LIMIT 0, 20";
}

/** TMDO router shape with post_status / post_date copies (PR-029): INNER JOIN, no GROUP BY. */
function flat_copy_search( string $table, string $alias, string $conditions ): string {
	return 'SELECT SQL_CALC_FOUND_ROWS p.ID FROM `' . P . "posts` p INNER JOIN `" . P . "{$table}` AS `{$alias}` ON (p.ID = `{$alias}`.`post_id`)"
		. " WHERE 1=1 AND p.post_type = 'hp_listing' AND ((p.post_status = 'publish')){$conditions} AND `{$alias}`.`post_status` IN ('publish') ORDER BY `{$alias}`.`post_date` DESC LIMIT 0, 20";
}

function random_ids( int $count, int $offset, int $max ): string {
	$ids = array();
	for ( $i = 0; $i < $count; $i++ ) {
		$ids[] = $offset + mt_rand( 1, $max );
	}
	return implode( ',', $ids );
}

// ── Scenarios: label => [ variant => fn(): string[] (statements) ] ─────────

$price = static function (): array {
	$lo = mt_rand( 100, 80000 );
	return array( $lo, $lo + 20000 ); // ~20% of the 100..100000 range.
};

$scenarios = array(
	'1. 價格區間搜尋（約 20%）'           => array(
		'native' => function () use ( $price ) {
			[ $lo, $hi ] = $price();
			return array( native_search( array( "%1\$s.meta_key = 'hp_price' AND CAST(%1\$s.meta_value AS DECIMAL(10,2)) BETWEEN '{$lo}' AND '{$hi}'" ) ), 'SELECT FOUND_ROWS()' );
		},
		'hot'    => function () use ( $price ) {
			[ $lo, $hi ] = $price();
			return array( flat_search( 'wpdo_hot_hp_listing', 'h', " AND `h`.`hp_price` BETWEEN {$lo} AND {$hi}" ), 'SELECT FOUND_ROWS()' );
		},
		'entity' => function () use ( $price ) {
			[ $lo, $hi ] = $price();
			return array( flat_search( 'wpdo_post_hp_listing_core', 'e', " AND `e`.`hp_price` BETWEEN '{$lo}' AND '{$hi}'" ), 'SELECT FOUND_ROWS()' );
		},
		'entity+copy' => function () use ( $price ) {
			[ $lo, $hi ] = $price();
			return array( flat_copy_search( 'wpdo_post_hp_listing_core', 'e', " AND `e`.`hp_price` BETWEEN '{$lo}' AND '{$hi}'" ), 'SELECT FOUND_ROWS()' );
		},
	),
	'2. 價格區間 + verified=1'            => array(
		'native' => function () use ( $price ) {
			[ $lo, $hi ] = $price();
			return array(
				native_search(
					array(
						"%1\$s.meta_key = 'hp_price' AND CAST(%1\$s.meta_value AS DECIMAL(10,2)) BETWEEN '{$lo}' AND '{$hi}'",
						"%1\$s.meta_key = 'hp_verified' AND %1\$s.meta_value = '1'",
					)
				),
				'SELECT FOUND_ROWS()',
			);
		},
		'hot'    => function () use ( $price ) {
			[ $lo, $hi ] = $price();
			return array( flat_search( 'wpdo_hot_hp_listing', 'h', " AND `h`.`hp_price` BETWEEN {$lo} AND {$hi} AND `h`.`hp_verified` = 1" ), 'SELECT FOUND_ROWS()' );
		},
		'entity' => function () use ( $price ) {
			[ $lo, $hi ] = $price();
			return array( flat_search( 'wpdo_post_hp_listing_core', 'e', " AND `e`.`hp_price` BETWEEN '{$lo}' AND '{$hi}' AND `e`.`hp_verified` = '1'" ), 'SELECT FOUND_ROWS()' );
		},
		'entity+copy' => function () use ( $price ) {
			[ $lo, $hi ] = $price();
			return array( flat_copy_search( 'wpdo_post_hp_listing_core', 'e', " AND `e`.`hp_price` BETWEEN '{$lo}' AND '{$hi}' AND `e`.`hp_verified` = '1'" ), 'SELECT FOUND_ROWS()' );
		},
	),
	'3. 某 vendor 名下 listing'          => array(
		'post_parent' => fn() => array( 'SELECT SQL_CALC_FOUND_ROWS p.ID FROM `' . P . "posts` p WHERE p.post_parent = " . mt_rand( 1, $vendors ) . " AND p.post_type = 'hp_listing' AND ((p.post_status = 'publish')) ORDER BY p.post_date DESC LIMIT 0, 20", 'SELECT FOUND_ROWS()' ),
		'native'      => fn() => array( native_search( array( "%1\$s.meta_key = 'hp_vendor' AND %1\$s.meta_value = '" . mt_rand( 1, $vendors ) . "'" ) ), 'SELECT FOUND_ROWS()' ),
		'hot'         => fn() => array( flat_search( 'wpdo_hot_hp_listing', 'h', ' AND `h`.`hp_vendor` = ' . mt_rand( 1, $vendors ) ), 'SELECT FOUND_ROWS()' ),
		'entity'      => fn() => array( flat_search( 'wpdo_post_hp_listing_core', 'e', " AND `e`.`hp_vendor` = '" . mt_rand( 1, $vendors ) . "'" ), 'SELECT FOUND_ROWS()' ),
	),
	'4. 單筆 listing 讀全部 meta'         => array(
		'native' => fn() => array( 'SELECT post_id, meta_key, meta_value FROM `' . P . 'postmeta` WHERE post_id IN (' . random_ids( 1, $vendors, $listings ) . ') ORDER BY meta_id ASC' ),
		'hot'    => fn() => array( 'SELECT * FROM `' . P . 'wpdo_hot_hp_listing` WHERE post_id = ' . random_ids( 1, $vendors, $listings ) ),
		'entity' => fn() => array( 'SELECT * FROM `' . P . 'wpdo_post_hp_listing_core` WHERE post_id = ' . random_ids( 1, $vendors, $listings ) ),
	),
	'5. 列表頁預載 20 筆 meta'            => array(
		'native' => fn() => array( 'SELECT post_id, meta_key, meta_value FROM `' . P . 'postmeta` WHERE post_id IN (' . random_ids( 20, $vendors, $listings ) . ') ORDER BY meta_id ASC' ),
		'hot'    => fn() => array( 'SELECT * FROM `' . P . 'wpdo_hot_hp_listing` WHERE post_id IN (' . random_ids( 20, $vendors, $listings ) . ')' ),
		'entity' => fn() => array( 'SELECT * FROM `' . P . 'wpdo_post_hp_listing_core` WHERE post_id IN (' . random_ids( 20, $vendors, $listings ) . ')' ),
	),
	'6. 單一 vendor 讀使用者 meta'        => array(
		'native' => fn() => array( 'SELECT user_id, meta_key, meta_value FROM `' . P . 'usermeta` WHERE user_id IN (' . mt_rand( 1, $vendors ) . ') ORDER BY umeta_id ASC' ),
		'entity' => fn() => array( 'SELECT * FROM `' . P . 'wpdo_user_hp_user` WHERE user_id = ' . mt_rand( 1, $vendors ) ),
	),
	'7. 寫入：更新一筆 listing 價格'      => array(
		'native'     => fn() => array( 'UPDATE `' . P . "postmeta` SET meta_value = '" . mt_rand( 100, 100000 ) . ".00' WHERE post_id = " . random_ids( 1, $vendors, $listings ) . " AND meta_key = 'hp_price'" ),
		'entity'     => fn() => array( 'UPDATE `' . P . "wpdo_post_hp_listing_core` SET hp_price = '" . mt_rand( 100, 100000 ) . "' WHERE post_id = " . random_ids( 1, $vendors, $listings ) ),
		'dual_write' => function () use ( $vendors, $listings ) {
			$id = random_ids( 1, $vendors, $listings );
			$v  = mt_rand( 100, 100000 );
			return array(
				'UPDATE `' . P . "postmeta` SET meta_value = '{$v}.00' WHERE post_id = {$id} AND meta_key = 'hp_price'",
				'UPDATE `' . P . "wpdo_post_hp_listing_core` SET hp_price = '{$v}' WHERE post_id = {$id}",
			);
		},
	),
);

// ── Run ───────────────────────────────────────────────────────────────────

/**
 * @return array{ms: float, rows: int|string, timeout: bool}
 */
function run_statements( mysqli $db, array $statements ): array {
	$is_write = str_starts_with( $statements[0], 'UPDATE' );
	if ( $is_write ) {
		$db->begin_transaction();
	}
	$rows    = 0;
	$timeout = false;
	$start   = hrtime( true );
	foreach ( $statements as $n => $sql ) {
		try {
			$res = $db->query( $sql );
		} catch ( mysqli_sql_exception $e ) {
			if ( 1969 !== $e->getCode() ) { // ER_STATEMENT_TIMEOUT.
				throw $e;
			}
			$timeout = true;
			break;
		}
		if ( $res instanceof mysqli_result ) {
			$rows = str_starts_with( $sql, 'SELECT FOUND_ROWS' ) ? (int) $res->fetch_row()[0] : ( 0 === $n ? $res->num_rows : $rows );
			$res->free();
		} elseif ( $is_write ) {
			$rows = $db->affected_rows;
		}
	}
	$ms = ( hrtime( true ) - $start ) / 1e6;
	if ( $is_write ) {
		$db->rollback();
	}
	return array( 'ms' => $ms, 'rows' => $rows, 'timeout' => $timeout );
}

function explain_keys( mysqli $db, string $sql ): string {
	if ( ! str_starts_with( $sql, 'SELECT' ) ) {
		return '—';
	}
	$keys = array();
	$res  = $db->query( 'EXPLAIN ' . $sql );
	while ( $row = $res->fetch_assoc() ) {
		$keys[] = $row['table'] . ':' . ( $row['key'] ?? 'ALL' );
	}
	return implode( ', ', $keys );
}

function percentile( array $sorted, float $p ): float {
	return $sorted[ (int) min( count( $sorted ) - 1, floor( $p * count( $sorted ) ) ) ];
}

printf( "Dataset: %d vendors, %d listings — %d iterations (+%d warm-up) per variant\n\n", $vendors, $listings, $iterations, $warmup );
echo "| 情境 | 形式 | p50 ms | p95 ms | max ms | 結果筆數(中位) | 使用索引 |\n|---|---|---:|---:|---:|---:|---|\n";

foreach ( $scenarios as $label => $variants ) {
	foreach ( $variants as $variant => $build ) {
		$times    = array();
		$rows     = array();
		$timeouts = 0;
		$keys     = explain_keys( $db, $build()[0] );
		for ( $i = 0; $i < $warmup + $iterations; $i++ ) {
			$r = run_statements( $db, $build() );
			if ( $i < $warmup ) {
				continue;
			}
			$timeouts += (int) $r['timeout'];
			$times[]   = $r['ms'];
			$rows[]    = $r['rows'];
		}
		sort( $times );
		sort( $rows );
		printf(
			"| %s | %s | %.2f | %.2f | %.2f | %s | %s |\n",
			$label,
			$variant . ( $timeouts ? " ⚠ {$timeouts}× timeout" : '' ),
			percentile( $times, 0.5 ),
			percentile( $times, 0.95 ),
			end( $times ),
			$rows[ intdiv( count( $rows ), 2 ) ],
			$keys
		);
	}
}