<?php

namespace App\Services;

use App\Models\Automation;
use App\Models\Entity;
use Illuminate\Support\Facades\Log;

/**
 * Minimal trigger → condition → action engine (handoff §13.6). Every automation carries a
 * cooldown (motion sensors flood the queue otherwise) and can run in dry-run mode, which
 * logs the action instead of switching — never develop against the live home (H5).
 */
class AutomationEngine
{
    public function __construct(private readonly DeviceCommandService $commands) {}

    /** Evaluate state-change automations after a device entity changed. */
    public function onStateChange(string $deviceUuid, string $entityKey, array $state): void
    {
        Automation::where('enabled', true)->where('trigger_type', 'state_change')->get()
            ->each(function (Automation $automation) use ($deviceUuid, $entityKey, $state) {
                if ($this->matchesStateTrigger($automation, $deviceUuid, $entityKey, $state)) {
                    $this->maybeRun($automation);
                }
            });
    }

    /** Evaluate time-based automations (called every minute by the scheduler). */
    public function tick(): void
    {
        $hhmm = now()->format('H:i');

        Automation::where('enabled', true)->where('trigger_type', 'time')->get()
            ->each(function (Automation $automation) use ($hhmm) {
                if (data_get($automation->trigger_config, 'at') === $hhmm) {
                    $this->maybeRun($automation);
                }
            });
    }

    private function matchesStateTrigger(Automation $automation, string $deviceUuid, string $entityKey, array $state): bool
    {
        $cfg = $automation->trigger_config ?? [];

        if (($cfg['device'] ?? null) !== $deviceUuid || ($cfg['entity_key'] ?? null) !== $entityKey) {
            return false;
        }

        $field = $cfg['field'] ?? 'on';

        return array_key_exists($field, $state) && $state[$field] == ($cfg['equals'] ?? true);
    }

    private function maybeRun(Automation $automation): void
    {
        if ($automation->cooldown_seconds > 0
            && $automation->last_triggered_at !== null
            && $automation->last_triggered_at->gt(now()->subSeconds($automation->cooldown_seconds))) {
            return;
        }

        foreach ($automation->actions ?? [] as $action) {
            $this->runAction($automation, $action);
        }

        $automation->forceFill(['last_triggered_at' => now()])->save();
    }

    private function runAction(Automation $automation, array $action): void
    {
        $type = $action['type'] ?? null;

        if ($type === 'switch') {
            $entity = Entity::query()
                ->whereHas('device', fn ($q) => $q->where('uuid', $action['device'] ?? null))
                ->where('key', $action['entity_key'] ?? null)
                ->with('device', 'state')->first();

            if ($entity === null) {
                return;
            }

            if ($automation->dry_run) {
                Log::info("[automation dry-run] {$automation->name}: switch {$entity->key}", $action);

                return;
            }

            $this->commands->setOn($entity, (bool) ($action['on'] ?? true), 'automation');
        } elseif ($type === 'notify') {
            Log::info("[automation".($automation->dry_run ? ' dry-run' : '')."] {$automation->name}: ".($action['message'] ?? ''));
        }
    }
}