<?php

/* Copyright (C) 2026 Moko Consulting <hello@mokoconsulting.tech>
 *
 * This file is part of a Moko Consulting project.
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * FILE INFORMATION
 * DEFGROUP: MokoStandards.Enterprise
 * INGROUP: MokoStandards.Lib
 * REPO: https://git.mokoconsulting.tech/MokoConsulting/moko-platform
 * PATH: /lib/Enterprise/FileFixUtility.php
 * BRIEF: Utility class for fixing file formatting issues (line endings, permissions, tabs, trailing spaces)
 */

declare(strict_types=1);

namespace MokoEnterprise;

use RecursiveDirectoryIterator;
use RecursiveIteratorIterator;
use SplFileInfo;

/**
 * Static utility class for common file-formatting fix operations.
 *
 * Methods mirror the behaviour of the original shell fix scripts and support
 * dry-run mode.  Each method returns a list of files that were changed (or
 * would be changed in dry-run mode).
 */
class FileFixUtility
{
    /** @var list<string>  Extensions processed by fixLineEndings(). */
    private const LINE_ENDING_EXTENSIONS = ['php', 'js', 'css', 'xml', 'sh', 'md'];

    /** @var list<string>  Extensions processed when $fileType = 'all' in fixTabs(). */
    private const TABS_ALL_EXTENSIONS = ['yml', 'yaml', 'py', 'sh', 'bash'];

    /** @var array<string,list<string>>  Extension sets per file-type name in fixTabs(). */
    private const TABS_TYPE_EXTENSIONS = [
        'yaml'   => ['yml', 'yaml'],
        'python' => ['py'],
        'shell'  => ['sh', 'bash'],
        'all'    => self::TABS_ALL_EXTENSIONS,
    ];

    /** @var list<string>  Extensions processed when $fileType = 'all' in fixTrailingSpaces(). */
    private const TRAILING_ALL_EXTENSIONS = ['yml', 'yaml', 'py', 'sh', 'bash', 'md', 'markdown'];

    /** @var array<string,list<string>>  Extension sets per file-type name in fixTrailingSpaces(). */
    private const TRAILING_TYPE_EXTENSIONS = [
        'yaml'     => ['yml', 'yaml'],
        'python'   => ['py'],
        'shell'    => ['sh', 'bash'],
        'markdown' => ['md', 'markdown'],
        'all'      => self::TRAILING_ALL_EXTENSIONS,
    ];

    // ── Public API ────────────────────────────────────────────────────────────

    /**
     * Fix CRLF line endings to LF in tracked source files.
     *
     * Operates on all git-tracked files with extensions: php, js, css, xml, sh, md.
     * In dry-run mode, returns the list of files that would be changed without
     * modifying them.
     *
     * @param string $repoRoot  Absolute path to the repository root.
     * @param bool   $dryRun    When true, report changes without writing.
     * @return list<string>  Files that were (or would be) changed.
     */
    public static function fixLineEndings(string $repoRoot, bool $dryRun = false): array
    {
        $patterns = array_map(
            static fn(string $ext): string => '*.' . $ext,
            self::LINE_ENDING_EXTENSIONS
        );
        $files   = self::gitLsFiles($repoRoot, $patterns);
        $changed = [];

        foreach ($files as $file) {
            $path = $repoRoot . '/' . $file;
            if (!is_file($path)) {
                continue;
            }

            $content = (string) file_get_contents($path);
            if (strpos($content, "\r\n") === false) {
                continue;
            }

            $changed[] = $file;

            if (!$dryRun) {
                file_put_contents($path, str_replace("\r\n", "\n", $content));
            }
        }

        return $changed;
    }

    /**
     * Fix file permissions: directories 755, regular files 644, .php/.sh scripts 755.
     *
     * Skips the .git/ directory tree.  In dry-run mode, no changes are applied.
     *
     * @param string $repoRoot  Absolute path to the repository root.
     * @param bool   $dryRun    When true, report what would change without writing.
     */
    public static function fixPermissions(string $repoRoot, bool $dryRun = false): void
    {
        if ($dryRun) {
            return;
        }

        $iterator = new RecursiveIteratorIterator(
            new RecursiveDirectoryIterator($repoRoot, RecursiveDirectoryIterator::SKIP_DOTS),
            RecursiveIteratorIterator::SELF_FIRST
        );

        foreach ($iterator as $item) {
            /** @var SplFileInfo $item */
            $path = $item->getPathname();

            if (str_contains($path, '/.git/') || str_ends_with($path, '/.git')) {
                continue;
            }

            if ($item->isDir()) {
                chmod($path, 0755);
            } elseif ($item->isFile()) {
                $ext  = strtolower($item->getExtension());
                $perm = in_array($ext, ['php', 'sh'], true) ? 0755 : 0644;
                chmod($path, $perm);
            }
        }
    }

    /**
     * Convert tab characters to spaces in tracked source files.
     *
     * YAML files use 2-space indentation; all other supported types use 4 spaces.
     * Makefile variants are always skipped.  In dry-run mode, returns the list of
     * files that would be changed without modifying them.
     *
     * @param string $repoRoot  Absolute path to the repository root.
     * @param string $fileType  One of yaml, python, shell, all (default: all).
     * @param bool   $dryRun    When true, report changes without writing.
     * @return list<string>  Files that were (or would be) changed.
     * @throws \InvalidArgumentException  When $fileType is unrecognised.
     */
    public static function fixTabs(string $repoRoot, string $fileType = 'all', bool $dryRun = false): array
    {
        if (!array_key_exists($fileType, self::TABS_TYPE_EXTENSIONS)) {
            throw new \InvalidArgumentException(
                "Unknown file type: {$fileType}. Valid types: " .
                implode(', ', array_keys(self::TABS_TYPE_EXTENSIONS))
            );
        }

        $extensions = self::TABS_TYPE_EXTENSIONS[$fileType];
        $patterns   = array_map(static fn(string $ext): string => '*.' . $ext, $extensions);
        $files      = self::gitLsFiles($repoRoot, $patterns);
        $changed    = [];

        foreach ($files as $file) {
            $path = $repoRoot . '/' . $file;
            if (!is_file($path)) {
                continue;
            }

            if (self::isMakefile($file)) {
                continue;
            }

            $content = (string) file_get_contents($path);
            if (strpos($content, "\t") === false) {
                continue;
            }

            $changed[] = $file;

            if (!$dryRun) {
                $spaces = self::spacesForFile($file);
                $pad    = str_repeat(' ', $spaces);
                file_put_contents($path, str_replace("\t", $pad, $content));
            }
        }

        return $changed;
    }

    /**
     * Remove trailing whitespace from tracked source files.
     *
     * In dry-run mode, returns the list of files that would be changed without
     * modifying them.
     *
     * @param string $repoRoot  Absolute path to the repository root.
     * @param string $fileType  One of yaml, python, shell, markdown, all (default: all).
     * @param bool   $dryRun    When true, report changes without writing.
     * @return list<string>  Files that were (or would be) changed.
     * @throws \InvalidArgumentException  When $fileType is unrecognised.
     */
    public static function fixTrailingSpaces(string $repoRoot, string $fileType = 'all', bool $dryRun = false): array
    {
        if (!array_key_exists($fileType, self::TRAILING_TYPE_EXTENSIONS)) {
            throw new \InvalidArgumentException(
                "Unknown file type: {$fileType}. Valid types: " .
                implode(', ', array_keys(self::TRAILING_TYPE_EXTENSIONS))
            );
        }

        $extensions = self::TRAILING_TYPE_EXTENSIONS[$fileType];
        $patterns   = array_map(static fn(string $ext): string => '*.' . $ext, $extensions);
        $files      = self::gitLsFiles($repoRoot, $patterns);
        $changed    = [];

        foreach ($files as $file) {
            $path = $repoRoot . '/' . $file;
            if (!is_file($path)) {
                continue;
            }

            $content = (string) file_get_contents($path);
            if (!preg_match('/[[:space:]]+$/m', $content)) {
                continue;
            }

            $changed[] = $file;

            if (!$dryRun) {
                $fixed = preg_replace('/[[:space:]]+$/m', '', $content);
                file_put_contents($path, (string) $fixed);
            }
        }

        return $changed;
    }

    // ── Private helpers ───────────────────────────────────────────────────────

    /**
     * Run git ls-files in the given root with the provided glob patterns.
     *
     * @param  string       $repoRoot  Repository root path.
     * @param  list<string> $patterns  Shell glob patterns.
     * @return list<string>  Relative file paths.
     */
    private static function gitLsFiles(string $repoRoot, array $patterns): array
    {
        $quoted = implode(' ', array_map('escapeshellarg', $patterns));
        $cmd    = 'git -C ' . escapeshellarg($repoRoot) . " ls-files {$quoted} 2>/dev/null";
        $output = shell_exec($cmd) ?? '';
        return array_values(array_filter(explode("\n", $output)));
    }

    /**
     * Return true when the filename matches a Makefile variant.
     *
     * @param string $path  File path (only basename is examined).
     */
    private static function isMakefile(string $path): bool
    {
        $base = strtolower(basename($path));
        return $base === 'makefile'
            || $base === 'gnumakefile'
            || str_starts_with($base, 'makefile.');
    }

    /**
     * Return the number of spaces to substitute for a tab in a given file.
     *
     * @param  string $path  File path (extension determines width).
     * @return int           2 for YAML, 4 for everything else.
     */
    private static function spacesForFile(string $path): int
    {
        $ext = strtolower(pathinfo($path, PATHINFO_EXTENSION));
        return in_array($ext, ['yml', 'yaml'], true) ? 2 : 4;
    }
}