<?php

declare(strict_types=1);

namespace StaticPHP\Util;

use StaticPHP\Attribute\PatchDescription;
use StaticPHP\Exception\PatchException;

/**
 * SourcePatcher provides static utility methods for patching source files.
 */
class SourcePatcher
{
    /**
     * Use existing patch file for patching.
     *
     * @param  string $patch_name Patch file name in src/globals/patch/ or absolute path
     * @param  string $cwd        Working directory for patch command
     * @param  bool   $reverse    Reverse patches (default: false)
     * @return bool   True if patch was applied or already applied
     */
    public static function patchFile(string $patch_name, string $cwd, bool $reverse = false): bool
    {
        logger()->debug('Applying ' . ($reverse ? 'reverse ' : '') . "patch [{$patch_name}] at [{$cwd}]");
        if (FileSystem::isRelativePath($patch_name)) {
            $patch_file = ROOT_DIR . "/src/globals/patch/{$patch_name}";
        } else {
            $patch_file = $patch_name;
        }

        if (!file_exists($patch_file)) {
            throw new PatchException($patch_name, "Patch file [{$patch_file}] does not exist");
        }

        $patch_str = FileSystem::convertPath($patch_file);
        if (!file_exists($patch_str)) {
            throw new PatchException($patch_name, "Patch file [{$patch_str}] does not exist");
        }

        // Copy patch from phar
        if (str_starts_with($patch_str, 'phar://')) {
            $filename = pathinfo($patch_file, PATHINFO_BASENAME);
            file_put_contents(SOURCE_PATH . "/{$filename}", file_get_contents($patch_file));
            $patch_str = FileSystem::convertPath(SOURCE_PATH . "/{$filename}");
        }

        // Detect if patch is already applied (reverse detection)
        $detect_reverse = !$reverse;
        $detect_cmd = 'cd ' . escapeshellarg($cwd) . ' && '
            . (PHP_OS_FAMILY === 'Windows' ? 'type' : 'cat') . ' ' . escapeshellarg($patch_str)
            . ' | patch --dry-run -p1 -s -f ' . ($detect_reverse ? '-R' : '')
            . ' > ' . (PHP_OS_FAMILY === 'Windows' ? 'NUL' : '/dev/null') . ' 2>&1';
        exec($detect_cmd, $output, $detect_status);

        if ($detect_status === 0) {
            // Patch already applied
            return true;
        }

        // Apply patch
        $apply_cmd = 'cd ' . escapeshellarg($cwd) . ' && '
            . (PHP_OS_FAMILY === 'Windows' ? 'type' : 'cat') . ' ' . escapeshellarg($patch_str)
            . ' | patch -p1 ' . ($reverse ? '-R' : '');

        exec($apply_cmd, $apply_output, $apply_status);
        if ($apply_status !== 0) {
            throw new PatchException($patch_name, "Patch file [{$patch_name}] failed to apply");
        }

        return true;
    }

    /**
     * Patch hardcoded INI values into PHP SAPI files.
     *
     * @param  string $php_source_dir PHP source directory path
     * @param  array  $ini            Associative array of INI key-value pairs
     * @return bool   True if patch was applied successfully
     */
    #[PatchDescription('Patch hardcoded INI values into PHP SAPI files')]
    public static function patchHardcodedINI(string $php_source_dir, array $ini = []): bool
    {
        $sapi_files = [
            'cli' => "{$php_source_dir}/sapi/cli/php_cli.c",
            'micro' => "{$php_source_dir}/sapi/micro/php_micro.c",
            'embed' => "{$php_source_dir}/sapi/embed/php_embed.c",
        ];

        // Build patch string
        $find_str = 'const char HARDCODED_INI[] =';
        $patch_str = '';
        foreach ($ini as $key => $value) {
            $patch_str .= "\"{$key}={$value}\\n\"\n";
        }
        $patch_str = "const char HARDCODED_INI[] =\n{$patch_str}";

        // Detect and restore from backup if exists
        $has_backup = false;
        foreach ($sapi_files as $file) {
            if (file_exists("{$file}.bak")) {
                $has_backup = true;
                break;
            }
        }
        if ($has_backup) {
            self::unpatchHardcodedINI($php_source_dir);
        }

        // Backup and patch each SAPI file
        $result = true;
        foreach ($sapi_files as $file) {
            if (!file_exists($file)) {
                continue;
            }
            // Backup
            $result = $result && file_put_contents("{$file}.bak", file_get_contents($file)) !== false;
            // Patch
            FileSystem::replaceFileStr($file, $find_str, $patch_str);
        }

        return $result;
    }

    /**
     * Restore PHP SAPI files from backup (unpatch hardcoded INI).
     *
     * @param  string $php_source_dir PHP source directory path
     * @return bool   True if backup was restored successfully
     */
    public static function unpatchHardcodedINI(string $php_source_dir): bool
    {
        $sapi_files = [
            'cli' => "{$php_source_dir}/sapi/cli/php_cli.c",
            'micro' => "{$php_source_dir}/sapi/micro/php_micro.c",
            'embed' => "{$php_source_dir}/sapi/embed/php_embed.c",
        ];

        $has_backup = false;
        foreach ($sapi_files as $file) {
            if (file_exists("{$file}.bak")) {
                $has_backup = true;
                break;
            }
        }

        if (!$has_backup) {
            return false;
        }

        $result = true;
        foreach ($sapi_files as $file) {
            $backup = "{$file}.bak";
            if (file_exists($backup)) {
                $result = $result && file_put_contents($file, file_get_contents($backup)) !== false;
                @unlink($backup);
            }
        }

        return $result;
    }
}