<?php

namespace Modules\Maintenance\Services;

use Illuminate\Support\Facades\DB;
use Modules\Maintenance\Models\IotAlert;
use Modules\Maintenance\Models\IotDevice;
use Modules\Maintenance\Models\IotPredictiveRule;
use Modules\Maintenance\Models\IotTelemetry;

class IotIngestionService
{
    public function ingest(int $businessId, string $deviceUid, array $readings): void
    {
        $device = IotDevice::where('business_id', $businessId)->where('device_uid', $deviceUid)->first();
        if (! $device) {
            return;
        }

        $device->update(['last_seen_at' => now(), 'status' => 'active']);

        foreach ($readings as $reading) {
            IotTelemetry::create([
                'business_id' => $businessId,
                'device_id' => $device->id,
                'equipment_id' => $device->equipment_id,
                'metric' => $reading['metric'],
                'value' => $reading['value'],
                'unit' => $reading['unit'] ?? null,
                'recorded_at' => $reading['recorded_at'] ?? now(),
                'raw_payload' => $reading,
            ]);

            $this->evaluateRules($businessId, $device, $reading['metric'], (float) $reading['value']);
        }
    }

    protected function evaluateRules(int $businessId, IotDevice $device, string $metric, float $value): void
    {
        $rules = IotPredictiveRule::where('business_id', $businessId)
            ->where('is_active', true)
            ->where(function ($q) use ($device) {
                $q->whereNull('equipment_id')->orWhere('equipment_id', $device->equipment_id);
            })
            ->where('metric', $metric)
            ->get();

        foreach ($rules as $rule) {
            if (! $this->thresholdBreached($value, (float) $rule->threshold, $rule->operator)) {
                continue;
            }

            $alert = IotAlert::create([
                'business_id' => $businessId,
                'device_id' => $device->id,
                'equipment_id' => $device->equipment_id,
                'alert_type' => 'threshold_breach',
                'severity' => 'warning',
                'message' => "Metric {$metric} breached threshold ({$value} {$rule->operator} {$rule->threshold})",
                'threshold_value' => $rule->threshold,
                'actual_value' => $value,
                'triggered_at' => now(),
            ]);

            if ($rule->auto_work_order && $device->equipment_id) {
                $woId = $this->createPredictiveWorkOrder($businessId, $device->equipment_id, $alert);
                $alert->update(['work_order_id' => $woId]);
            }
        }
    }

    protected function thresholdBreached(float $value, float $threshold, string $operator): bool
    {
        return match ($operator) {
            'gt' => $value > $threshold,
            'lt' => $value < $threshold,
            'gte' => $value >= $threshold,
            'lte' => $value <= $threshold,
            'eq' => abs($value - $threshold) < 0.0001,
            default => false,
        };
    }

    protected function createPredictiveWorkOrder(int $businessId, int $equipmentId, IotAlert $alert): ?int
    {
        if (! DB::getSchemaBuilder()->hasTable('mt_work_orders')) {
            return null;
        }

        return DB::table('mt_work_orders')->insertGetId([
            'business_id' => $businessId,
            'equipment_id' => $equipmentId,
            'title' => 'Predictive: '.$alert->message,
            'type' => 'corrective',
            'priority' => 'high',
            'status' => 'open',
            'description' => 'Auto-created from IoT alert #'.$alert->id,
            'created_at' => now(),
            'updated_at' => now(),
        ]);
    }
}