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

/* Copyright (C) 2026 Moko Consulting <hello@mokoconsulting.tech>
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * FILE INFORMATION
 * DEFGROUP: moko-platform.CLI
 * INGROUP: moko-platform
 * REPO: https://git.mokoconsulting.tech/MokoConsulting/moko-platform
 * PATH: /cli/changelog_prune.php
 * BRIEF: Prune old CHANGELOG.md entries — keeps [Unreleased] + last N releases
 */

declare(strict_types=1);

require_once __DIR__ . '/../lib/Enterprise/CliFramework.php';

use MokoEnterprise\CliFramework;

class ChangelogPruneCli extends CliFramework
{
    protected function configure(): void
    {
        $this->setDescription('Prune old CHANGELOG.md entries — keeps [Unreleased] + last N releases');
        $this->addArgument('--path', 'Repository path', '.');
        $this->addArgument('--keep', 'Number of versioned releases to keep', '5');
    }

    protected function run(): int
    {
        $path = $this->getArgument('--path');
        $keep = (int) $this->getArgument('--keep');

        $changelog = realpath($path) . '/CHANGELOG.md';
        if (!file_exists($changelog)) {
            $this->log('ERROR', "No CHANGELOG.md found at {$path}");
            return 1;
        }

        $content = file_get_contents($changelog);
        $lines = explode("\n", $content);

        // Split into sections by ## headings
        $sections = [];
        $current = [];
        $currentHeading = null;

        foreach ($lines as $line) {
            if (preg_match('/^## /', $line)) {
                if ($currentHeading !== null) {
                    $sections[] = ['heading' => $currentHeading, 'lines' => $current];
                }
                $currentHeading = $line;
                $current = [$line];
            } else {
                $current[] = $line;
            }
        }
        if ($currentHeading !== null) {
            $sections[] = ['heading' => $currentHeading, 'lines' => $current];
        }

        // Find the header (everything before the first ## section)
        $header = [];
        $contentLines = explode("\n", $content);
        foreach ($contentLines as $line) {
            if (preg_match('/^## /', $line)) {
                break;
            }
            $header[] = $line;
        }

        // Separate [Unreleased] from versioned sections
        $unreleased = null;
        $versioned = [];

        foreach ($sections as $section) {
            if (preg_match('/\[Unreleased\]/i', $section['heading'])) {
                $unreleased = $section;
            } else {
                $versioned[] = $section;
            }
        }

        $totalVersioned = count($versioned);
        $pruned = $totalVersioned - $keep;

        if ($pruned <= 0) {
            echo "CHANGELOG has {$totalVersioned} versioned entries — nothing to prune (keeping {$keep})\n";
            return 0;
        }

        // Keep only the first N versioned sections
        $keptVersioned = array_slice($versioned, 0, $keep);
        $droppedVersioned = array_slice($versioned, $keep);

        // Report
        echo "CHANGELOG: {$totalVersioned} versioned entries found\n";
        echo "  Keeping: {$keep} most recent\n";
        echo "  Pruning: {$pruned} old entries\n";

        foreach ($droppedVersioned as $section) {
            $heading = trim($section['heading']);
            echo "    - {$heading}\n";
        }

        if ($this->dryRun) {
            echo "\n(dry-run) No changes written\n";
            return 0;
        }

        // Rebuild the file
        $output = implode("\n", $header);

        if ($unreleased !== null) {
            $output .= implode("\n", $unreleased['lines']) . "\n";
        }

        foreach ($keptVersioned as $section) {
            $output .= implode("\n", $section['lines']) . "\n";
        }

        // Clean up excessive blank lines at end
        $output = rtrim($output) . "\n";

        file_put_contents($changelog, $output);
        echo "\nCHANGELOG pruned: removed {$pruned} old entries\n";
        return 0;
    }
}

$app = new ChangelogPruneCli();
exit($app->execute());