<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;

return new class extends Migration {
    /**
     * Übergeordnete Gruppen (Parent Groups, im UI z. B. „Bund"): jeder Mandant (Local Group) gehört zu genau einer.
     * Eine Veranstaltung fragt bei der Anmeldung entweder nach der Local Group oder nach der Parent Group.
     *
     * Die Vorbelegung steht hier und nicht im Seeder: der Fremdschlüssel am Tenant ist Pflicht, bestehende
     * Installationen brauchen die Fallback-Gruppe also schon beim Migrieren.
     *
     * Dazu die globalen Einstellungen mit den Bezeichnungen der beiden Ebenen -- aus demselben Grund vorbelegt.
     */
    public function up(): void
    {
        Schema::create('parent_groups', function (Blueprint $table) {
            $table->id();
            $table->string('name');
            // Die Gruppe für Mandanten ohne Zuordnung; sie ist umbenennbar, aber nie löschbar.
            $table->boolean('is_fallback')->default(false);
            $table->timestamps();
        });

        $now = now();
        $fallbackId = DB::table('parent_groups')->insertGetId([
            'name' => 'Ohne Zuordnung',
            'is_fallback' => true,
            'created_at' => $now,
            'updated_at' => $now,
        ]);

        foreach (['BdP', 'DPV', 'DPSG', 'VCP'] as $name) {
            DB::table('parent_groups')->insert([
                'name' => $name,
                'is_fallback' => false,
                'created_at' => $now,
                'updated_at' => $now,
            ]);
        }

        Schema::table('tenants', function (Blueprint $table) {
            $table->foreignId('parent_group_id')->nullable()->constrained('parent_groups')->restrictOnDelete();
        });

        DB::table('tenants')->update(['parent_group_id' => $fallbackId]);

        Schema::table('tenants', function (Blueprint $table) {
            $table->foreignId('parent_group_id')->nullable(false)->change();
        });

        Schema::table('events', function (Blueprint $table) {
            $table->string('participant_group_type')->default('local_group');
        });

        Schema::table('event_participants', function (Blueprint $table) {
            $table->foreignId('parent_group_id')->nullable()->constrained('parent_groups')->restrictOnDelete();
        });

        Schema::create('global_settings', function (Blueprint $table) {
            $table->string('key')->primary();
            $table->text('value');
            $table->timestamps();
        });

        foreach ([
            'local_group_label' => 'Stamm',
            'local_group_label_plural' => 'Stämme',
            'parent_group_label' => 'Bund',
            'parent_group_label_plural' => 'Bünde',
        ] as $key => $value) {
            DB::table('global_settings')->insert([
                'key' => $key,
                'value' => $value,
                'created_at' => $now,
                'updated_at' => $now,
            ]);
        }
    }

    public function down(): void
    {
        Schema::dropIfExists('global_settings');

        Schema::table('event_participants', function (Blueprint $table) {
            $table->dropConstrainedForeignId('parent_group_id');
        });

        Schema::table('events', function (Blueprint $table) {
            $table->dropColumn('participant_group_type');
        });

        Schema::table('tenants', function (Blueprint $table) {
            $table->dropConstrainedForeignId('parent_group_id');
        });

        Schema::dropIfExists('parent_groups');
    }
};