#!/usr/bin/env php
<?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.Automation
 * INGROUP: MokoStandards
 * REPO: https://git.mokoconsulting.tech/MokoConsulting/moko-platform
 * PATH: /automation/migrate_to_gitea.php
 * BRIEF: Migrate repositories from GitHub to self-hosted Gitea instance
 *
 * USAGE
 *   php automation/migrate_to_gitea.php --dry-run
 *   php automation/migrate_to_gitea.php --repos MokoCRM MokoDoliMods
 *   php automation/migrate_to_gitea.php --exclude MokoStandards --skip-archived
 *   php automation/migrate_to_gitea.php --resume
 */

declare(strict_types=1);

require_once __DIR__ . '/../vendor/autoload.php';

use MokoEnterprise\CheckpointManager;
use MokoEnterprise\CliFramework;
use MokoEnterprise\Config;
use MokoEnterprise\PlatformAdapterFactory;
use MokoEnterprise\GitHubAdapter;
use MokoEnterprise\MokoGiteaAdapter;

/**
 * Gitea Migration Script
 *
 * Migrates repositories from GitHub to a self-hosted Gitea instance.
 * Uses Gitea's built-in migration endpoint for git history, tags, releases,
 * issues, and labels. Post-migration applies branch protection, topics,
 * and workflow conversion.
 */
class MigrateToGitea extends CliFramework
{
    private ?GitHubAdapter $github = null;
    private ?MokoGiteaAdapter $gitea  = null;
    private ?CheckpointManager $checkpoints = null;

    protected function configure(): void
    {
        $this->setDescription('Migrate repositories from GitHub to Gitea');
        $this->addArgument('--dry-run', 'Show what would be migrated without making changes', false);
        $this->addArgument('--repos', 'Specific repositories to migrate (space-separated)', '');
        $this->addArgument('--exclude', 'Repositories to exclude (space-separated)', '');
        $this->addArgument('--skip-archived', 'Skip archived repositories', false);
        $this->addArgument('--resume', 'Resume from last checkpoint', false);
        $this->addArgument('--github-token', 'GitHub token override', '');
        $this->addArgument('--gitea-token', 'Gitea token override', '');
    }

    protected function run(): int
    {
        $dryRun       = (bool) $this->getArgument('--dry-run');
        $specificRepos = array_filter(explode(' ', (string) $this->getArgument('--repos')));
        $excludeRepos  = array_filter(explode(' ', (string) $this->getArgument('--exclude')));
        $skipArchived  = (bool) $this->getArgument('--skip-archived');
        $resume        = (bool) $this->getArgument('--resume');

        $config = Config::load();

        // Override tokens if provided
        $ghToken = (string) $this->getArgument('--github-token');
        $giteaToken = (string) $this->getArgument('--gitea-token');
        if ($ghToken !== '') {
            $config->set('github.token', $ghToken);
        }
        if ($giteaToken !== '') {
            $config->set('gitea.token', $giteaToken);
        }

        // Create both adapters
        try {
            $adapters = PlatformAdapterFactory::createBoth($config);
            $this->github = $adapters['github'];
            $this->gitea  = $adapters['gitea'];
        } catch (\RuntimeException $e) {
            $this->log('ERROR', $e->getMessage());
            return 1;
        }

        $this->checkpoints = new CheckpointManager('.checkpoints/migration');
        $org = $config->getString('github.organization', 'MokoConsulting');
        $giteaOrg = $config->getString('gitea.organization', 'MokoConsulting');

        echo "=== Gitea Migration Tool ===\n";
        echo "Source:      GitHub ({$org})\n";
        echo "Destination: Gitea ({$giteaOrg}) at " . $config->getString('gitea.url') . "\n";
        echo "Mode:        " . ($dryRun ? 'DRY RUN' : 'LIVE') . "\n\n";

        // ── Phase 1: Discovery ──────────────────────────────────────────
        $this->section('Phase 1: Discovery');

        $ghRepos = $this->github->listOrgRepos($org, $skipArchived);
        echo "Found " . count($ghRepos) . " repositories on GitHub\n";

        // Filter repos
        if (!empty($specificRepos)) {
            $ghRepos = array_filter($ghRepos, fn($r) => in_array($r['name'], $specificRepos, true));
        }
        if (!empty($excludeRepos)) {
            $ghRepos = array_filter($ghRepos, fn($r) => !in_array($r['name'], $excludeRepos, true));
        }

        // Check which already exist on Gitea
        $giteaRepos = [];
        try {
            $existing = $this->gitea->listOrgRepos($giteaOrg);
            foreach ($existing as $r) {
                $giteaRepos[$r['name']] = true;
            }
        } catch (\Exception $e) {
            echo "Note: Could not list Gitea repos (org may not exist yet): {$e->getMessage()}\n";
        }

        $toMigrate = [];
        $toSkip    = [];
        foreach ($ghRepos as $repo) {
            $name = $repo['name'];
            if (isset($giteaRepos[$name])) {
                $toSkip[] = $name;
            } else {
                $toMigrate[] = $repo;
            }
        }

        echo "\nMigration plan:\n";
        echo "  Migrate: " . count($toMigrate) . " repositories\n";
        echo "  Skip:    " . count($toSkip) . " (already on Gitea)\n";
        if (!empty($toSkip)) {
            echo "  Skipped: " . implode(', ', $toSkip) . "\n";
        }
        echo "\n";

        if (empty($toMigrate)) {
            echo "Nothing to migrate.\n";
            return 0;
        }

        if ($dryRun) {
            echo "Repositories to migrate:\n";
            foreach ($toMigrate as $repo) {
                $vis = $repo['private'] ? 'private' : 'public';
                echo "  - {$repo['name']} ({$vis})\n";
            }
            echo "\nDry run complete. Use without --dry-run to execute.\n";
            return 0;
        }

        // ── Phase 2: Migrate ────────────────────────────────────────────
        $this->section('Phase 2: Migration');

        $ghToken = $config->getString('github.token');
        $results = ['migrated' => [], 'failed' => [], 'skipped' => $toSkip];

        // Resume support
        $checkpoint = $resume ? $this->checkpoints->loadCheckpoint('gitea_migration') : null;
        $startFrom = $checkpoint['last_completed'] ?? '';
        $skipUntil = !empty($startFrom);

        foreach ($toMigrate as $index => $repo) {
            $name = $repo['name'];

            if ($skipUntil) {
                if ($name === $startFrom) {
                    $skipUntil = false;
                }
                echo "  Skipping {$name} (already migrated)\n";
                continue;
            }

            echo "\n  [{$index}/{" . count($toMigrate) . "}] Migrating {$name}...\n";

            try {
                // Shallow migration — copy current branch state only, no past
                // commit history. This gives every repo a clean start on Gitea.
                $this->gitea->migrateRepository([
                    'clone_addr'  => "https://github.com/{$org}/{$name}.git",
                    'repo_name'   => $name,
                    'repo_owner'  => $giteaOrg,
                    'service'     => 'github',
                    'auth_token'  => $ghToken,
                    'mirror'      => false,
                    'private'     => $repo['private'],
                    'issues'      => false,
                    'labels'      => true,
                    'milestones'  => false,
                    'releases'    => false,
                    'pull_requests' => false,
                    'wiki'        => false,
                ]);

                echo "    Migrated successfully\n";
                $results['migrated'][] = $name;

                // Save checkpoint after each successful migration
                $this->checkpoints->saveCheckpoint('gitea_migration', [
                    'last_completed' => $name,
                    'migrated'       => $results['migrated'],
                    'failed'         => $results['failed'],
                ]);
            } catch (\Exception $e) {
                echo "    FAILED: " . $e->getMessage() . "\n";
                $results['failed'][] = ['name' => $name, 'error' => $e->getMessage()];
                $this->gitea->getApiClient()->resetCircuitBreaker();
            }
        }

        // ── Phase 3: Post-migration ─────────────────────────────────────
        $this->section('Phase 3: Post-migration');

        foreach ($results['migrated'] as $name) {
            echo "  Post-processing {$name}...\n";

            try {
                // Apply topics from GitHub
                $ghTopics = $this->github->getRepoTopics($org, $name);
                if (!empty($ghTopics)) {
                    $this->gitea->setRepoTopics($giteaOrg, $name, $ghTopics);
                    echo "    Topics applied\n";
                }

                // Apply branch protection
                $this->gitea->setBranchProtection($giteaOrg, $name, 'main', [
                    'required_reviews' => 1,
                    'dismiss_stale'    => true,
                    'block_on_rejected' => true,
                ]);
                echo "    Branch protection applied\n";
            } catch (\Exception $e) {
                echo "    Warning: post-processing issue: " . $e->getMessage() . "\n";
                $this->gitea->getApiClient()->resetCircuitBreaker();
            }
        }

        // ── Phase 4: Verification ───────────────────────────────────────
        $this->section('Phase 4: Verification');

        $report = "## Migration Report\n\n";
        $report .= "**Date:** " . gmdate('Y-m-d H:i:s') . " UTC\n";
        $report .= "**Source:** GitHub ({$org})\n";
        $report .= "**Destination:** Gitea ({$giteaOrg})\n\n";

        $report .= "### Results\n\n";
        $report .= "| Status | Count |\n|--------|-------|\n";
        $report .= "| Migrated | " . count($results['migrated']) . " |\n";
        $report .= "| Failed | " . count($results['failed']) . " |\n";
        $report .= "| Skipped (existing) | " . count($results['skipped']) . " |\n\n";

        if (!empty($results['migrated'])) {
            $report .= "### Migrated Repositories\n\n";
            foreach ($results['migrated'] as $name) {
                $report .= "- {$name}\n";
            }
            $report .= "\n";
        }

        if (!empty($results['failed'])) {
            $report .= "### Failed Repositories\n\n";
            foreach ($results['failed'] as $fail) {
                $report .= "- **{$fail['name']}**: {$fail['error']}\n";
            }
            $report .= "\n";
        }

        echo $report;

        // Create summary issue on Gitea
        try {
            $this->gitea->createIssue(
                $giteaOrg,
                'MokoStandards',
                'chore: GitHub → Gitea migration report — ' . count($results['migrated']) . ' repos migrated',
                $report,
                ['labels' => ['automation', 'type: chore']]
            );
            echo "Migration report issue created on Gitea.\n";
        } catch (\Exception $e) {
            echo "Could not create report issue: " . $e->getMessage() . "\n";
        }

        echo "\nMigration complete: " . count($results['migrated']) . " migrated, "
            . count($results['failed']) . " failed, "
            . count($results['skipped']) . " skipped\n";

        return count($results['failed']) > 0 ? 1 : 0;
    }
}

$script = new MigrateToGitea('migrate_to_gitea', 'Migrate repositories from GitHub to Gitea');
exit($script->execute());