<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Filesystem;

use Symfony\Component\Filesystem\Exception\IOException;

/**
 * Provides basic utility to manipulate the file system.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class Filesystem
{
    /**
     * Copies a file.
     *
     * This method only copies the file if the origin file is newer than the target file.
     *
     * By default, if the target already exists, it is not overridden.
     *
     * @param string $originFile The original filename
     * @param string $targetFile The target filename
     * @param bool   $override   Whether to override an existing file or not
     *
     * @throws IOException When copy fails
     */
    public function copy($originFile, $targetFile, $override = false)
    {
        if (stream_is_local($originFile) && !is_file($originFile)) {
            throw new IOException(sprintf('Failed to copy %s because file not exists', $originFile));
        }

        $this->mkdir(dirname($targetFile));

        $doCopy = true;
        if (!$override && null === parse_url($originFile, PHP_URL_HOST) && is_file($targetFile)) {
            $doCopy = filemtime($originFile) > filemtime($targetFile);
        }

        if ($doCopy) {
            // https://bugs.php.net/bug.php?id=64634
            $source = fopen($originFile, 'r');
            // Stream context created to allow files overwrite when using FTP stream wrapper - disabled by default
            $target = fopen($targetFile, 'w', null, stream_context_create(array('ftp' => array('overwrite' => true))));
            stream_copy_to_stream($source, $target);
            fclose($source);
            fclose($target);
            unset($source, $target);

            if (!is_file($targetFile)) {
                throw new IOException(sprintf('Failed to copy %s to %s', $originFile, $targetFile));
            }
        }
    }

    /**
     * Creates a directory recursively.
     *
     * @param string|array|\Traversable $dirs The directory path
     * @param int                       $mode The directory mode
     *
     * @throws IOException On any directory creation failure
     */
    public function mkdir($dirs, $mode = 0777)
    {
        foreach ($this->toIterator($dirs) as $dir) {
            if (is_dir($dir)) {
                continue;
            }

            if (true !== @mkdir($dir, $mode, true)) {
                $error = error_get_last();
                if (!is_dir($dir)) {
                    // The directory was not created by a concurrent process. Let's throw an exception with a developer friendly error message if we have one
                    if ($error) {
                        throw new IOException(sprintf('Failed to create "%s": %s.', $dir, $error['message']));
                    }
                    throw new IOException(sprintf('Failed to create "%s"', $dir));
                }
            }
        }
    }

    /**
     * Checks the existence of files or directories.
     *
     * @param string|array|\Traversable $files A filename, an array of files, or a \Traversable instance to check
     *
     * @return bool true if the file exists, false otherwise
     */
    public function exists($files)
    {
        foreach ($this->toIterator($files) as $file) {
            if ('\\' === DIRECTORY_SEPARATOR && strlen($file) > 258) {
                throw new IOException(sprintf('Could not check if file exist because path length exceeds 258 characters for file "%s"', $file));
            }

            if (!file_exists($file)) {
                return false;
            }
        }

        return true;
    }

    /**
     * Sets access and modification time of file.
     *
     * @param string|array|\Traversable $files A filename, an array of files, or a \Traversable instance to create
     * @param int                       $time  The touch time as a Unix timestamp
     * @param int                       $atime The access time as a Unix timestamp
     *
     * @throws IOException When touch fails
     */
    public function touch($files, $time = null, $atime = null)
    {
        foreach ($this->toIterator($files) as $file) {
            $touch = $time ? @touch($file, $time, $atime) : @touch($file);
            if (true !== $touch) {
                throw new IOException(sprintf('Failed to touch %s', $file));
            }
        }
    }

    /**
     * Removes files or directories.
     *
     * @param string|array|\Traversable $files A filename, an array of files, or a \Traversable instance to remove
     *
     * @throws IOException When removal fails
     */
    public function remove($files)
    {
        $files = iterator_to_array($this->toIterator($files));
        $files = array_reverse($files);
        foreach ($files as $file) {
            if (@(unlink($file) || rmdir($file))) {
                continue;
            }
            if (is_link($file)) {
                // See https://bugs.php.net/52176
                $error = error_get_last();
                throw new IOException(sprintf('Failed to remove symlink "%s": %s.', $file, $error['message']));
            } elseif (is_dir($file)) {
                $this->remove(new \FilesystemIterator($file));

                if (!@rmdir($file)) {
                    $error = error_get_last();
                    throw new IOException(sprintf('Failed to remove directory "%s": %s.', $file, $error['message']));
                }
            } elseif (file_exists($file)) {
                $error = error_get_last();
                throw new IOException(sprintf('Failed to remove file "%s": %s.', $file, $error['message']));
            }
        }
    }

    /**
     * Change mode for an array of files or directories.
     *
     * @param string|array|\Traversable $files     A filename, an array of files, or a \Traversable instance to change mode
     * @param int                       $mode      The new mode (octal)
     * @param int                       $umask     The mode mask (octal)
     * @param bool                      $recursive Whether change the mod recursively or not
     *
     * @throws IOException When the change fail
     */
    public function chmod($files, $mode, $umask = 0000, $recursive = false)
    {
        foreach ($this->toIterator($files) as $file) {
            if (true !== @chmod($file, $mode & ~$umask)) {
                throw new IOException(sprintf('Failed to chmod file %s', $file));
            }
            if ($recursive && is_dir($file) && !is_link($file)) {
                $this->chmod(new \FilesystemIterator($file), $mode, $umask, true);
            }
        }
    }

    /**
     * Change the owner of an array of files or directories.
     *
     * @param string|array|\Traversable $files     A filename, an array of files, or a \Traversable instance to change owner
     * @param string                    $user      The new owner user name
     * @param bool                      $recursive Whether change the owner recursively or not
     *
     * @throws IOException When the change fail
     */
    public function chown($files, $user, $recursive = false)
    {
        foreach ($this->toIterator($files) as $file) {
            if ($recursive && is_dir($file) && !is_link($file)) {
                $this->chown(new \FilesystemIterator($file), $user, true);
            }
            if (is_link($file) && function_exists('lchown')) {
                if (true !== @lchown($file, $user)) {
                    throw new IOException(sprintf('Failed to chown file %s', $file));
                }
            } else {
                if (true !== @chown($file, $user)) {
                    throw new IOException(sprintf('Failed to chown file %s', $file));
                }
            }
        }
    }

    /**
     * Change the group of an array of files or directories.
     *
     * @param string|array|\Traversable $files     A filename, an array of files, or a \Traversable instance to change group
     * @param string                    $group     The group name
     * @param bool                      $recursive Whether change the group recursively or not
     *
     * @throws IOException When the change fail
     */
    public function chgrp($files, $group, $recursive = false)
    {
        foreach ($this->toIterator($files) as $file) {
            if ($recursive && is_dir($file) && !is_link($file)) {
                $this->chgrp(new \FilesystemIterator($file), $group, true);
            }
            if (is_link($file) && function_exists('lchgrp')) {
                if (true !== @lchgrp($file, $group) || (defined('HHVM_VERSION') && !posix_getgrnam($group))) {
                    throw new IOException(sprintf('Failed to chgrp file %s', $file));
                }
            } else {
                if (true !== @chgrp($file, $group)) {
                    throw new IOException(sprintf('Failed to chgrp file %s', $file));
                }
            }
        }
    }

    /**
     * Renames a file or a directory.
     *
     * @param string $origin    The origin filename or directory
     * @param string $target    The new filename or directory
     * @param bool   $overwrite Whether to overwrite the target if it already exists
     *
     * @throws IOException When target file or directory already exists
     * @throws IOException When origin cannot be renamed
     */
    public function rename($origin, $target, $overwrite = false)
    {
        // we check that target does not exist
        if (!$overwrite && $this->isReadable($target)) {
            throw new IOException(sprintf('Cannot rename because the target "%s" already exist.', $target));
        }

        if (true !== @rename($origin, $target)) {
            throw new IOException(sprintf('Cannot rename "%s" to "%s".', $origin, $target));
        }
    }

    /**
     * Tells whether a file exists and is readable.
     *
     * @param string $filename Path to the file.
     *
     * @throws IOException When windows path is longer than 258 characters
     */
    private function isReadable($filename)
    {
        if ('\\' === DIRECTORY_SEPARATOR && strlen($filename) > 258) {
            throw new IOException(sprintf('Could not check if file is readable because path length exceeds 258 characters for file "%s"', $filename));
        }

        return is_readable($filename);
    }

    /**
     * Creates a symbolic link or copy a directory.
     *
     * @param string $originDir     The origin directory path
     * @param string $targetDir     The symbolic link name
     * @param bool   $copyOnWindows Whether to copy files if on Windows
     *
     * @throws IOException When symlink fails
     */
    public function symlink($originDir, $targetDir, $copyOnWindows = false)
    {
        if ('\\' === DIRECTORY_SEPARATOR) {
            $originDir = strtr($originDir, '/', '\\');
            $targetDir = strtr($targetDir, '/', '\\');

            if ($copyOnWindows) {
                $this->mirror($originDir, $targetDir);

                return;
            }
        }

        $this->mkdir(dirname($targetDir));

        $ok = false;
        if (is_link($targetDir)) {
            if (readlink($targetDir) != $originDir) {
                $this->remove($targetDir);
            } else {
                $ok = true;
            }
        }

        if (!$ok && true !== @symlink($originDir, $targetDir)) {
            $report = error_get_last();
            if (is_array($report)) {
                if ('\\' === DIRECTORY_SEPARATOR && false !== strpos($report['message'], 'error code(1314)')) {
                    throw new IOException('Unable to create symlink due to error code 1314: \'A required privilege is not held by the client\'. Do you have the required Administrator-rights?');
                }
            }
            throw new IOException(sprintf('Failed to create symbolic link from %s to %s', $originDir, $targetDir));
        }
    }

    /**
     * Given an existing path, convert it to a path relative to a given starting path.
     *
     * @param string $endPath   Absolute path of target
     * @param string $startPath Absolute path where traversal begins
     *
     * @return string Path of target relative to starting path
     */
    public function makePathRelative($endPath, $startPath)
    {
        // Normalize separators on Windows
        if ('\\' === DIRECTORY_SEPARATOR) {
            $endPath = str_replace('\\', '/', $endPath);
            $startPath = str_replace('\\', '/', $startPath);
        }

        // Split the paths into arrays
        $startPathArr = explode('/', trim($startPath, '/'));
        $endPathArr = explode('/', trim($endPath, '/'));

        // Find for which directory the common path stops
        $index = 0;
        while (isset($startPathArr[$index]) && isset($endPathArr[$index]) && $startPathArr[$index] === $endPathArr[$index]) {
            ++$index;
        }

        // Determine how deep the start path is relative to the common path (ie, "web/bundles" = 2 levels)
        $depth = count($startPathArr) - $index;

        // When we need to traverse from the start, and we are starting from a root path, don't add '../'
        if ('/' === $startPath[0] && 0 === $index && 1 === $depth) {
            $traverser = '';
        } else {
            // Repeated "../" for each level need to reach the common path
            $traverser = str_repeat('../', $depth);
        }

        $endPathRemainder = implode('/', array_slice($endPathArr, $index));

        // Construct $endPath from traversing to the common path, then to the remaining $endPath
        $relativePath = $traverser.('' !== $endPathRemainder ? $endPathRemainder.'/' : '');

        return '' === $relativePath ? './' : $relativePath;
    }

    /**
     * Mirrors a directory to another.
     *
     * @param string       $originDir The origin directory
     * @param string       $targetDir The target directory
     * @param \Traversable $iterator  A Traversable instance
     * @param array        $options   An array of boolean options
     *                                Valid options are:
     *                                - $options['override'] Whether to override an existing file on copy or not (see copy())
     *                                - $options['copy_on_windows'] Whether to copy files instead of links on Windows (see symlink())
     *                                - $options['delete'] Whether to delete files that are not in the source directory (defaults to false)
     *
     * @throws IOException When file type is unknown
     */
    public function mirror($originDir, $targetDir, \Traversable $iterator = null, $options = array())
    {
        $targetDir = rtrim($targetDir, '/\\');
        $originDir = rtrim($originDir, '/\\');

        // Iterate in destination folder to remove obsolete entries
        if ($this->exists($targetDir) && isset($options['delete']) && $options['delete']) {
            $deleteIterator = $iterator;
            if (null === $deleteIterator) {
                $flags = \FilesystemIterator::SKIP_DOTS;
                $deleteIterator = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($targetDir, $flags), \RecursiveIteratorIterator::CHILD_FIRST);
            }
            foreach ($deleteIterator as $file) {
                $origin = str_replace($targetDir, $originDir, $file->getPathname());
                if (!$this->exists($origin)) {
                    $this->remove($file);
                }
            }
        }

        $copyOnWindows = false;
        if (isset($options['copy_on_windows'])) {
            $copyOnWindows = $options['copy_on_windows'];
        }

        if (null === $iterator) {
            $flags = $copyOnWindows ? \FilesystemIterator::SKIP_DOTS | \FilesystemIterator::FOLLOW_SYMLINKS : \FilesystemIterator::SKIP_DOTS;
            $iterator = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($originDir, $flags), \RecursiveIteratorIterator::SELF_FIRST);
        }

        if ($this->exists($originDir)) {
            $this->mkdir($targetDir);
        }

        foreach ($iterator as $file) {
            $target = str_replace($originDir, $targetDir, $file->getPathname());

            if ($copyOnWindows) {
                if (is_file($file)) {
                    $this->copy($file, $target, isset($options['override']) ? $options['override'] : false);
                } elseif (is_dir($file)) {
                    $this->mkdir($target);
                } else {
                    throw new IOException(sprintf('Unable to guess "%s" file type.', $file));
                }
            } else {
                if (is_link($file)) {
                    $this->symlink($file->getLinkTarget(), $target);
                } elseif (is_dir($file)) {
                    $this->mkdir($target);
                } elseif (is_file($file)) {
                    $this->copy($file, $target, isset($options['override']) ? $options['override'] : false);
                } else {
                    throw new IOException(sprintf('Unable to guess "%s" file type.', $file));
                }
            }
        }
    }

    /**
     * Returns whether the file path is an absolute path.
     *
     * @param string $file A file path
     *
     * @return bool
     */
    public function isAbsolutePath($file)
    {
        return strspn($file, '/\\', 0, 1)
            || (strlen($file) > 3 && ctype_alpha($file[0])
                && substr($file, 1, 1) === ':'
                && strspn($file, '/\\', 2, 1)
            )
            || null !== parse_url($file, PHP_URL_SCHEME)
        ;
    }

    /**
     * @param mixed $files
     *
     * @return \Traversable
     */
    private function toIterator($files)
    {
        if (!$files instanceof \Traversable) {
            $files = new \ArrayObject(is_array($files) ? $files : array($files));
        }

        return $files;
    }

    /**
     * Atomically dumps content into a file.
     *
     * @param string   $filename The file to be written to.
     * @param string   $content  The data to write into the file.
     * @param null|int $mode     The file mode (octal). If null, file permissions are not modified
     *                           Deprecated since version 2.3.12, to be removed in 3.0.
     *
     * @throws IOException If the file cannot be written to.
     */
    public function dumpFile($filename, $content, $mode = 0666)
    {
        $dir = dirname($filename);

        if (!is_dir($dir)) {
            $this->mkdir($dir);
        } elseif (!is_writable($dir)) {
            throw new IOException(sprintf('Unable to write in the %s directory.', $dir));
        }

        $tmpFile = tempnam($dir, basename($filename));

        if (false === @file_put_contents($tmpFile, $content)) {
            throw new IOException(sprintf('Failed to write file "%s".', $filename));
        }

        if (null !== $mode) {
            $this->chmod($tmpFile, $mode);
        }
        $this->rename($tmpFile, $filename, true);
    }
}
