<?php
// ============================================
// 文件: lib/storage/local.php
// 说明: 本地硬盘存储驱动（默认，行为与改造前一致）
// ============================================

class StorageLocal {

    public function id() { return 'local'; }

    public function label() { return '本地硬盘'; }

    // 把文件落到站点目录下（先尝试 rename，跨文件系统时退化为 copy+unlink）
    public function putFile($srcPath, $key, $mime = null) {
        $target = $this->absPath($key);
        $dir = dirname($target);
        if (!is_dir($dir) && !@mkdir($dir, 0755, true)) {
            return ['ok' => false, 'error' => "无法创建目录：{$dir}"];
        }
        if (@rename($srcPath, $target)) {
            @chmod($target, 0644);
            return ['ok' => true, 'error' => ''];
        }
        if (@copy($srcPath, $target)) {
            @unlink($srcPath);
            @chmod($target, 0644);
            return ['ok' => true, 'error' => ''];
        }
        return ['ok' => false, 'error' => "写入文件失败：{$key}（请检查目录权限）"];
    }

    public function putContents($binary, $key, $mime = null) {
        $target = $this->absPath($key);
        $dir = dirname($target);
        if (!is_dir($dir) && !@mkdir($dir, 0755, true)) {
            return ['ok' => false, 'error' => "无法创建目录：{$dir}"];
        }
        if (@file_put_contents($target, $binary) === false) {
            return ['ok' => false, 'error' => "写入文件失败：{$key}（请检查目录权限）"];
        }
        @chmod($target, 0644);
        return ['ok' => true, 'error' => ''];
    }

    public function delete($key) {
        $target = $this->absPath($key);
        if (is_file($target)) {
            return @unlink($target);
        }
        return true; // 不存在视为成功
    }

    public function url($key) {
        return '/' . ltrim((string)$key, '/');
    }

    public function exists($key) {
        return is_file($this->absPath($key));
    }

    /**
     * 服务端读取对象。本地驱动直接读盘。
     * 返回结构与 storageHttp() 同构（etag / last-modified 供 media.php 做 304 判断）。
     */
    public function get($key, array $extra = []) {
        $abs = $this->absPath($key);
        if (!is_file($abs) || !is_readable($abs)) {
            return ['ok' => false, 'status' => 404, 'headers' => [], 'body' => '', 'error' => '对象不存在'];
        }
        $body = @file_get_contents($abs);
        if ($body === false) {
            return ['ok' => false, 'status' => 500, 'headers' => [], 'body' => '', 'error' => '读取文件失败'];
        }
        return [
            'ok' => true,
            'status' => 200,
            'headers' => [
                'content-type'   => storageMimeOfFile($abs),
                'content-length' => (string)strlen($body),
                'etag'           => '"' . md5($body) . '"',
                'last-modified'  => gmdate('D, d M Y H:i:s \G\M\T', (int)@filemtime($abs)),
            ],
            'body' => $body,
            'error' => '',
        ];
    }

    public function test() {
        // 验证上传目录可写
        $probe = UPLOAD_DIR . '.storage_test_' . uniqid();
        if (@file_put_contents($probe, 'ok') === false) {
            return ['ok' => false, 'error' => '上传目录不可写：' . UPLOAD_DIR];
        }
        @unlink($probe);
        $free = @disk_free_space(ROOT_DIR);
        $msg = '本地存储正常，上传目录可写。';
        if ($free !== false) {
            $msg .= ' 剩余空间 ' . formatBytes($free) . '。';
        }
        return ['ok' => true, 'error' => '', 'message' => $msg];
    }

    private function absPath($key) {
        return ROOT_DIR . '/' . ltrim((string)$key, '/');
    }
}

// 字节数格式化（设置页展示用）
function formatBytes($bytes, $precision = 2) {
    $units = ['B', 'KB', 'MB', 'GB', 'TB'];
    $bytes = max(0, (float)$bytes);
    $i = 0;
    while ($bytes >= 1024 && $i < count($units) - 1) {
        $bytes /= 1024;
        $i++;
    }
    return round($bytes, $i === 0 ? 0 : $precision) . ' ' . $units[$i];
}