<?php

namespace App\Support\Mqtt;

/**
 * Normalizes a Shelly Gen2+ status payload for one component into protocol-agnostic
 * entity updates ({key, type, state}). One message can update several entities
 * (e.g. a switch also carries power). Vendor specifics stay here (H3).
 */
class ShellyNormalizer
{
    /**
     * Entity types that identify a real device component (vs. housekeeping topics like sys/wifi).
     * A new prefix is auto-onboarded only when one of these arrives, so `sys`/`cloud`/`mqtt`
     * status noise never creates a junk device.
     */
    public const PRIMARY_TYPES = ['switch', 'light', 'cover', 'contact', 'temperature', 'humidity', 'battery', 'power', 'motion'];

    /**
     * @param  array<string,mixed>  $payload
     * @return array<int, array{key:string,type:string,state:array<string,mixed>}>
     */
    public static function normalize(string $component, array $payload): array
    {
        [$kind, $index] = array_pad(explode(':', $component, 2), 2, '0');
        $updates = [];

        switch ($kind) {
            case 'switch':
                $updates[] = ['key' => "switch:{$index}", 'type' => 'switch', 'state' => ['on' => (bool) ($payload['output'] ?? false)]];
                if (array_key_exists('apower', $payload)) {
                    $updates[] = ['key' => "power:{$index}", 'type' => 'power', 'state' => ['watts' => (int) round((float) $payload['apower'])]];
                }
                break;

            case 'light':
                $updates[] = ['key' => "light:{$index}", 'type' => 'light', 'state' => ['on' => (bool) ($payload['output'] ?? $payload['ison'] ?? false)]];
                break;

            case 'cover':
                $updates[] = ['key' => "cover:{$index}", 'type' => 'cover', 'state' => ['position' => $payload['current_pos'] ?? null, 'state' => $payload['state'] ?? null]];
                break;

            case 'input':
                // A reed/switch input — a window or door contact wired to a Shelly input.
                // Only the digital (switch) mode is a contact; analog/count inputs are skipped.
                if (! is_bool($payload['state'] ?? null)) {
                    break;
                }
                $open = (bool) $payload['state'];
                $updates[] = ['key' => "input:{$index}", 'type' => 'contact', 'state' => ['open' => $open, 'position' => $open ? 'open' : 'closed']];
                break;

            case 'contact':
            case 'window':
                // Dedicated contact/window sensor — supports a 3-state position (closed/open/tilted).
                $updates[] = ['key' => "contact:{$index}", 'type' => 'contact', 'state' => self::contactState($payload)];
                break;

            case 'temperature':
                $updates[] = ['key' => "temperature:{$index}", 'type' => 'temperature', 'state' => ['celsius' => $payload['tC'] ?? null]];
                break;

            case 'humidity':
                $updates[] = ['key' => "humidity:{$index}", 'type' => 'humidity', 'state' => ['percent' => $payload['rh'] ?? null]];
                break;

            case 'devicepower':
                if (($pct = data_get($payload, 'battery.percent')) !== null) {
                    $updates[] = ['key' => "battery:{$index}", 'type' => 'battery', 'state' => ['percent' => (int) $pct]];
                }
                break;

            default:
                // Unknown component — store the raw payload under its own key.
                $updates[] = ['key' => $component, 'type' => $kind, 'state' => $payload];
        }

        return $updates;
    }

    /**
     * Normalize a contact/window payload to {open, position}. `position` is the richer signal
     * (closed | open | tilted) when the sensor reports it; otherwise it is derived from a boolean.
     *
     * @param  array<string,mixed>  $payload
     * @return array{open:bool,position:string}
     */
    private static function contactState(array $payload): array
    {
        // Prefer an explicit 3-state position/tilt string when the sensor provides one.
        $position = $payload['position'] ?? $payload['tilt'] ?? null;

        if (is_string($position)) {
            $position = strtolower($position);
            $position = in_array($position, ['closed', 'open', 'tilted'], true) ? $position : null;
        } else {
            $position = null;
        }

        if ($position === null) {
            $open = (bool) ($payload['open'] ?? $payload['state'] ?? false);
            $position = $open ? 'open' : 'closed';
        }

        return ['open' => $position !== 'closed', 'position' => $position];
    }
}