<?php

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

return new class extends Migration
{
    /**
     * Run the migrations.
     */
    public function up(): void
    {
        $this->renameDepartureBoardColumn('registration', 'aircraft_registration');
    }

    /**
     * Reverse the migrations.
     */
    public function down(): void
    {
        $this->renameDepartureBoardColumn('aircraft_registration', 'registration');
    }

    /**
     * Walk every user's settings JSON and rename a value inside
     * departure_board_columns, if present.
     */
    private function renameDepartureBoardColumn(string $from, string $to): void
    {
        DB::table('users')
            ->select('id', 'settings')
            ->whereNotNull('settings')
            ->orderBy('id')
            ->chunkById(500, function ($users) use ($from, $to) {
                foreach ($users as $user) {
                    $settings = json_decode($user->settings, true);

                    // Skip rows with malformed/empty JSON rather than blowing up the migration.
                    if (! is_array($settings) || ! isset($settings['departure_board_columns'])) {
                        continue;
                    }

                    if (! is_array($settings['departure_board_columns'])) {
                        continue;
                    }

                    $columns = $settings['departure_board_columns'];
                    $key = array_search($from, $columns, true);

                    if ($key === false) {
                        continue; // nothing to change for this user
                    }

                    $columns[$key] = $to;
                    $settings['departure_board_columns'] = $columns;

                    DB::table('users')
                        ->where('id', $user->id)
                        ->update([
                            'settings' => json_encode($settings),
                        ]);
                }
            });
    }
};