#!/usr/bin/env php
<?php

require_once __DIR__ . '/../argvParser.php';
require_once __DIR__ . '/../functions.php';

readonly class stow
{
    public function __construct(
        private string $action = 'stow',
        private bool   $backup = false,
        private bool   $force = false,
    ) {}

    private function getNoStow(string $path): array
    {
        if (file_exists(path($path, '.nostow'))) {
            $noStow = file_get_contents(path($path, '.nostow'));
            if ($noStow === false) {
                return [];
            }
            return array_values(array_filter(array_map('trim', explode(PHP_EOL, $noStow))));
        } else {
            return [];
        }
    }

    function run(string $sourcePath, string $targetPath): void
    {
        $noStow = $this->getNoStow($sourcePath);
        $sourceFiles = array_diff(scandir($sourcePath), ['..', '.', '.nostow', ...$noStow]);

        foreach ($sourceFiles as $sourceFile) {
            $targetFile = path($targetPath, $sourceFile);
            $stowFile = path($sourcePath, $sourceFile);

            if ($this->action === 'stow') {
                if (is_link($targetFile)) {
                    $targetLink = readlink($targetFile);
                    if ($targetLink === $stowFile) {
                        line("File $targetFile is already stowed from $stowFile");
                    } else {
                        line("File $targetFile is linked from $targetLink");
                    }
                    continue;
                }
                if (is_dir($targetFile)) {
                    if (is_dir($stowFile)) {
                        line("File $targetFile and $stowFile are folders, recurse into existing folders");
                        $this->run($stowFile, $targetFile);
                    } else {
                        line("File $targetFile is a folder, but stow file $stowFile is not a folder");
                    }
                    continue;
                }
                if (is_file($targetFile)) {
                    if ($this->backup) {
                        $backFile = $targetFile . '.bak';
                        if (is_file($backFile)) {
                            line("Backup file $backFile already exists");
                            continue;
                        }
                        rename($targetFile, $backFile);
                        line("Backup file $targetFile to $backFile");
                    } elseif ($this->force) {
                        line("Todo: delete file $targetFile");
                        continue;
                    } else {
                        line("File $targetFile already exists");
                        continue;
                    }
                }
                line("Stow $targetFile from $stowFile");
                symlink($stowFile, $targetFile);
            } elseif ($this->action === 'unstow') {
                if (is_link($targetFile) && readlink($targetFile) === $stowFile) {
                    line("Unstow $targetFile from $stowFile");
                    unlink($targetFile);
                    continue;
                }
                if (is_dir($targetFile)) {
                    if (is_dir($stowFile)) {
                        line("File $targetFile and $stowFile are folders, recurse into existing folders");
                        $this->run($stowFile, $targetFile);
                        continue;
                    } else {
                        line("File $targetFile is a folder, but stow file $stowFile is not a folder");
                    }
                }
                line("File $targetFile is not stowed from $stowFile");
            }
        }
    }
}

$argvParser = new ArgvParser(
    ['u' => 'Unstow files', 'b' => 'Backup existing files', 'f' => 'Force overwrite'],
    ['stow-directory' => 'The directory to stow']
);
$parsed = $argvParser->parseArgv($argv);
if ($parsed === false) {
    line('Usage: ' . __FILE__ . ' ' . $argvParser->getOptionsHelp());
    exit(1);
}

$cwd = getcwd();
$action = $parsed->get('u') ? 'unstow' : 'stow';
$backup = $parsed->get('b');
$force = $parsed->get('f');

$stowName = $parsed->get('stow-directory');
$stowPath = path($cwd, $stowName);
$targetPath = dirname($stowPath, 2);

if (!is_dir($stowPath)) {
    line("Directory '$stowName' does not exist");
    exit(1);
}

$stow = new stow($action, $backup, $force);
$stow->run($stowPath, $targetPath);

exit(0);