#!/usr/bin/env php
<?php
/**
 * Build PSR-4 class map for AKSRT theme classes.
 *
 * Usage: php tools/build-psr4-map.php [--write]
 * Writes tools/psr4-map/map.json when --write is passed.
 *
 * @package AKSRT
 */

declare(strict_types=1);

$root = dirname(__DIR__);
$write = in_array('--write', $argv, true);

/**
 * Domain folder (lowercase) → namespace segment.
 *
 * @var array<string, string>
 */
const DOMAIN_NS = [
	'admin' => 'Admin',
	'ai' => 'Ai',
	'auth' => 'Auth',
	'content' => 'Content',
	'core' => 'Core',
	'credits' => 'Credits',
	'extensions' => 'Extensions',
	'forum' => 'Forum',
	'frontend' => 'Frontend',
	'messages' => 'Messages',
	'payment' => 'Payment',
	'settings' => 'Settings',
	'shop' => 'Shop',
	'sms' => 'Sms',
	'user' => 'User',
	'widgets' => 'Widgets',
];

/**
 * Explicit short-name overrides (old global → short class under domain).
 * Used for reserved words / clarity.
 *
 * @var array<string, string>
 */
const SHORT_OVERRIDES = [
	'AKSRT_Admin_Schema_Global' => 'GlobalSchema',
	'AKSRT_Payment_Gateway_Interface' => 'PaymentGatewayInterface',
	'AKSRT_SMS_Provider' => 'SmsProviderInterface',
	// Preserve brand/acronym casing in short names after segment join.
	'AKSRT_OAuth' => 'OAuth',
	'AKSRT_OAuth_Part_1' => 'OAuthPart1',
	'AKSRT_OAuth_Part_2' => 'OAuthPart2',
	'AKSRT_OAuth_Proxy_Client' => 'OAuthProxyClient',
	'AKSRT_OAuth_Proxy_Server' => 'OAuthProxyServer',
	'AKSRT_WeChat_Notify' => 'WeChatNotify',
	'AKSRT_WechatPay_Gateway' => 'WechatPayGateway',
	'AKSRT_PayPal_Gateway' => 'PayPalGateway',
	'AKSRT_MeiliSearch' => 'MeiliSearch',
	'AKSRT_Custom_HTML_Gap_Widget' => 'CustomHtmlGapWidget',
];

/**
 * Forced domain for helpers moved into the tree.
 *
 * @var array<string, string>
 */
const HELPER_DOMAIN = [
	'AKSRT_Nav_Walker' => 'Frontend',
	'AKSRT_Shortcodes' => 'Core',
	'AKSRT_Domain_Model' => 'Core',
];

/**
 * Convert AKSRT_Foo_Bar_2 → FooBar2 (preserve short ALLCAPS tokens like AI, SEO, SMS, DB, IP, API).
 */
function aksrt_to_short(string $old): string {
	if (isset(SHORT_OVERRIDES[$old])) {
		return SHORT_OVERRIDES[$old];
	}
	if (!str_starts_with($old, 'AKSRT_')) {
		throw new RuntimeException("Unexpected name: {$old}");
	}
	$parts = explode('_', substr($old, 6));
	$out = '';
	foreach ($parts as $p) {
		if ($p === '') {
			continue;
		}
		if (preg_match('/^\d+$/', $p)) {
			$out .= $p;
			continue;
		}
		// Keep short uppercase acronyms as-is.
		if (preg_match('/^[A-Z]{2,5}$/', $p)) {
			$out .= $p;
			continue;
		}
		$out .= ucfirst(strtolower($p));
	}
	return $out;
}

/**
 * Nested path segments under domain → extra namespace segments.
 *
 * @return list<string>
 */
function aksrt_path_ns_segments(string $rel_under_domain): array {
	$rel_under_domain = str_replace('\\', '/', $rel_under_domain);
	if ($rel_under_domain === '' || $rel_under_domain === '.') {
		return [];
	}
	$parts = array_values(array_filter(explode('/', $rel_under_domain), static fn($p) => $p !== '' && $p !== '.'));
	// Drop filename.
	array_pop($parts);
	$segs = [];
	foreach ($parts as $p) {
		// Trait dump folders → no extra NS (class short name already unique).
		if (str_ends_with($p, '-traits') || $p === 'user-parts') {
			continue;
		}
		if ($p === 'gateways') {
			$segs[] = 'Gateways';
			continue;
		}
		if ($p === 'schema') {
			$segs[] = 'Schema';
			continue;
		}
		if ($p === 'post-list') {
			$segs[] = 'PostList';
			continue;
		}
		if ($p === 'native') {
			$segs[] = 'Native';
			continue;
		}
		// Unknown nested folder: PascalCase the slug.
		$segs[] = str_replace(' ', '', ucwords(str_replace(['-', '_'], ' ', $p)));
	}
	return $segs;
}

/**
 * Scan PHP files for top-level type declarations.
 *
 * @return list<array{kind:string,name:string,path:string}>
 */
function aksrt_scan_types(string $root): array {
	$out = [];
	$dirs = [
		$root . '/inc/classes',
	];
	$extra_files = [
		$root . '/inc/helpers/class-aksrt-nav-walker.php',
		$root . '/inc/helpers/aksrt-shortcodes.php',
		$root . '/inc/helpers/aksrt-domain-model.php',
	];

	$rii = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($dirs[0]));
	$files = [];
	foreach ($rii as $file) {
		if ($file->isFile() && str_ends_with($file->getFilename(), '.php')) {
			$files[] = $file->getPathname();
		}
	}
	foreach ($extra_files as $f) {
		if (is_file($f)) {
			$files[] = $f;
		}
	}

	$re = '/^(?:abstract\s+|final\s+)?(class|trait|interface)\s+(\w+)/m';
	foreach ($files as $abs) {
		$rel = str_replace('\\', '/', substr($abs, strlen($root) + 1));
		$text = file_get_contents($abs);
		if ($text === false) {
			continue;
		}
		if (!preg_match_all($re, $text, $m, PREG_SET_ORDER)) {
			$out[] = [
				'kind' => 'procedural',
				'name' => null,
				'path' => $rel,
			];
			continue;
		}
		foreach ($m as $match) {
			$out[] = [
				'kind' => $match[1],
				'name' => $match[2],
				'path' => $rel,
			];
		}
	}
	return $out;
}

/**
 * @param list<array{kind:string,name:?string,path:string}> $scanned
 * @return array{entries: list<array<string,mixed>>, procedural: list<string>, errors: list<string>}
 */
function aksrt_build_map(array $scanned, string $root): array {
	$entries = [];
	$procedural = [];
	$errors = [];
	$by_old = [];

	foreach ($scanned as $row) {
		if ($row['kind'] === 'procedural') {
			$procedural[] = $row['path'];
			continue;
		}
		$old = $row['name'];
		$path = $row['path'];
		$kind = $row['kind'];

		if (!str_starts_with($old, 'AKSRT_') && $old !== 'AKSRT') {
			$errors[] = "Non-AKSRT type {$old} in {$path}";
			continue;
		}

		// Domain
		$domain_ns = null;
		$rel_under = '';
		if (str_starts_with($path, 'inc/helpers/')) {
			$domain_ns = HELPER_DOMAIN[$old] ?? 'Core';
			$rel_under = '';
		} elseif (preg_match('#^inc/classes/([^/]+)(?:/(.*))?$#', $path, $pm)) {
			$dom = $pm[1];
			if (!isset(DOMAIN_NS[$dom])) {
				$errors[] = "Unknown domain folder {$dom} for {$path}";
				continue;
			}
			$domain_ns = DOMAIN_NS[$dom];
			$rel_under = $pm[2] ?? '';
		} else {
			$errors[] = "Unmapped path {$path}";
			continue;
		}

		$extra = aksrt_path_ns_segments($rel_under);
		$short = aksrt_to_short($old);

		// Strip redundant leading domain token from short name when not emptying it.
		// AKSRT_Admin_AI_Controller → AdminAIController → AIController under Admin\.
		if (str_starts_with($short, $domain_ns) && strlen($short) > strlen($domain_ns)) {
			$rest = substr($short, strlen($domain_ns));
			if ($rest !== '' && preg_match('/^[A-Z]/', $rest)) {
				$short = $rest;
			}
		}

		// PSR-4 root: src/AKSRT/ (avoids Windows case-collision with inc/classes/admin vs Admin).
		$ns_parts = array_merge(['AKSRT', $domain_ns], $extra);
		$fqcn = implode('\\', $ns_parts) . '\\' . $short;
		$new_rel = 'src/AKSRT/' . implode('/', array_slice($ns_parts, 1)) . '/' . $short . '.php';

		$entry = [
			'kind' => $kind,
			'old' => $old,
			'new_fqcn' => $fqcn,
			'namespace' => implode('\\', $ns_parts),
			'short' => $short,
			'old_path' => $path,
			'new_path' => $new_rel,
			'multi_source' => false,
		];

		if (isset($by_old[$old])) {
			$errors[] = "Duplicate old name {$old}: {$by_old[$old]['old_path']} vs {$path}";
		}
		$by_old[$old] = $entry;
		$entries[] = $entry;
	}

	// Mark multi-decl sources.
	$by_path = [];
	foreach ($entries as $i => $e) {
		$by_path[$e['old_path']][] = $i;
	}
	foreach ($by_path as $path => $idxs) {
		if (count($idxs) > 1) {
			foreach ($idxs as $i) {
				$entries[$i]['multi_source'] = true;
			}
		}
	}

	// Detect FQCN collisions.
	$by_new = [];
	foreach ($entries as $e) {
		$k = $e['new_fqcn'];
		if (isset($by_new[$k])) {
			$errors[] = "FQCN collision {$k}: {$by_new[$k]} vs {$e['old']}";
		}
		$by_new[$k] = $e['old'];
	}

	// Detect new_path collisions (two types → same file).
	$by_new_path = [];
	foreach ($entries as $e) {
		$k = $e['new_path'];
		if (isset($by_new_path[$k])) {
			$errors[] = "Path collision {$k}: {$by_new_path[$k]} vs {$e['old']}";
		}
		$by_new_path[$k] = $e['old'];
	}

	return [
		'entries' => $entries,
		'procedural' => $procedural,
		'errors' => $errors,
		'by_old' => $by_old,
	];
}

$scanned = aksrt_scan_types($root);
$map = aksrt_build_map($scanned, $root);

$summary = [
	'generated_at' => gmdate('c'),
	'counts' => [
		'types' => count($map['entries']),
		'classes' => count(array_filter($map['entries'], static fn($e) => $e['kind'] === 'class')),
		'traits' => count(array_filter($map['entries'], static fn($e) => $e['kind'] === 'trait')),
		'interfaces' => count(array_filter($map['entries'], static fn($e) => $e['kind'] === 'interface')),
		'procedural_files' => count($map['procedural']),
		'multi_source_types' => count(array_filter($map['entries'], static fn($e) => $e['multi_source'])),
		'errors' => count($map['errors']),
	],
	'procedural' => $map['procedural'],
	'errors' => $map['errors'],
	'entries' => $map['entries'],
];

echo "Types: {$summary['counts']['types']} (class={$summary['counts']['classes']} trait={$summary['counts']['traits']} iface={$summary['counts']['interfaces']})\n";
echo "Procedural files: {$summary['counts']['procedural_files']}\n";
echo "Multi-source types: {$summary['counts']['multi_source_types']}\n";
echo "Errors: {$summary['counts']['errors']}\n";
if ($map['errors']) {
	foreach ($map['errors'] as $err) {
		echo "  ERROR: {$err}\n";
	}
}

// Sample print.
foreach (array_slice($map['entries'], 0, 8) as $e) {
	echo "  {$e['old']} => {$e['new_fqcn']}\n    {$e['old_path']} -> {$e['new_path']}\n";
}

if ($write) {
	$dir = $root . '/tools/psr4-map';
	if (!is_dir($dir) && !mkdir($dir, 0777, true) && !is_dir($dir)) {
		fwrite(STDERR, "Cannot create {$dir}\n");
		exit(1);
	}
	$file = $dir . '/map.json';
	file_put_contents($file, json_encode($summary, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES) . "\n");
	// Also CSV for quick review.
	$csv = $dir . '/map.csv';
	$fh = fopen($csv, 'wb');
	fputcsv($fh, ['kind', 'old', 'new_fqcn', 'old_path', 'new_path', 'multi_source'], ',', '"', '\\');
	foreach ($map['entries'] as $e) {
		fputcsv($fh, [$e['kind'], $e['old'], $e['new_fqcn'], $e['old_path'], $e['new_path'], $e['multi_source'] ? '1' : '0'], ',', '"', '\\');
	}
	fclose($fh);
	echo "Wrote {$file} and {$csv}\n";
}

exit($map['errors'] ? 1 : 0);