<?php

namespace Modules\Enterprise\Services;

use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
use Illuminate\Support\Facades\Storage;
use Throwable;

final class SystemHealthService
{
    public function run(): array
    {
        $checks = [
            $this->database(),
            $this->cache(),
            $this->storage(),
            $this->queue(),
            $this->environment(),
        ];

        return [
            'status' => collect($checks)->contains(fn (array $check): bool => $check['status'] === 'failed') ? 'failed' : (collect($checks)->contains(fn (array $check): bool => $check['status'] === 'warning') ? 'warning' : 'healthy'),
            'checks' => $checks,
            'generated_at' => now()->toIso8601String(),
        ];
    }

    private function database(): array
    {
        try {
            DB::connection()->getPdo();

            return $this->result('Database', 'healthy', DB::connection()->getDriverName());
        } catch (Throwable $e) {
            return $this->result('Database', 'failed', $e->getMessage());
        }
    }

    private function cache(): array
    {
        try {
            $key = 'enterprise-health-'.bin2hex(random_bytes(6));
            Cache::put($key, 'ok', 10);
            $healthy = Cache::get($key) === 'ok';
            Cache::forget($key);

            return $this->result('Cache', $healthy ? 'healthy' : 'failed', config('cache.default'));
        } catch (Throwable $e) {
            return $this->result('Cache', 'failed', $e->getMessage());
        }
    }

    private function storage(): array
    {
        try {
            Storage::disk('local')->put('enterprise-health.txt', now()->toIso8601String());
            Storage::disk('local')->delete('enterprise-health.txt');
            $freeMb = (int) floor(disk_free_space(storage_path()) / 1024 / 1024);
            $minimum = (int) config('enterprise.health.minimum_free_disk_mb', 512);

            return $this->result('Storage', $freeMb < $minimum ? 'warning' : 'healthy', $freeMb.' MB free');
        } catch (Throwable $e) {
            return $this->result('Storage', 'failed', $e->getMessage());
        }
    }

    private function queue(): array
    {
        $failed = Schema::hasTable('failed_jobs') ? DB::table('failed_jobs')->count() : 0;
        $maximum = (int) config('enterprise.health.maximum_failed_jobs', 0);

        return $this->result('Queue', $failed > $maximum ? 'warning' : 'healthy', $failed.' failed jobs');
    }

    private function environment(): array
    {
        $warnings = [];
        if (app()->environment('production') && config('app.debug')) {
            $warnings[] = 'APP_DEBUG is enabled';
        }
        if (! app()->environment('production')) {
            $warnings[] = 'Not running in production';
        }

        return $this->result('Environment', $warnings ? 'warning' : 'healthy', $warnings ? implode('; ', $warnings) : app()->environment());
    }

    private function result(string $name, string $status, string $message): array
    {
        return compact('name', 'status', 'message');
    }
}