<?php
declare(strict_types=1);

final class HomeAssistantClient
{
    private array $config;
    private bool $demoMode;

    public function __construct(array $config)
    {
        $this->config = $config;
        $baseUrl = trim((string)($config['home_assistant']['base_url'] ?? ''));
        $token = trim((string)($config['home_assistant']['token'] ?? ''));
        $this->demoMode = $baseUrl === '' || $token === '' || str_contains($baseUrl, 'example.com') || str_contains($token, 'PASTE_') || str_contains($token, 'YOUR_');
    }

    public function isDemo(): bool
    {
        return $this->demoMode;
    }

    public function fetchSnapshotData(): array
    {
        if ($this->demoMode) {
            return $this->demoData();
        }
        $states = $this->request('GET', '/api/states');
        $areas = $this->fetchWsList('config/area_registry/list') ?? $this->tryRequest('GET', '/api/areas') ?? [];
        $floors = $this->fetchWsList('config/floor_registry/list') ?? [];
        $entities = $this->fetchWsList('config/entity_registry/list_for_display') ?? $this->tryRequest('GET', '/api/config/entity_registry/list') ?? [];
        $devices = $this->fetchWsList('config/device_registry/list') ?? $this->tryRequest('GET', '/api/config/device_registry/list') ?? [];

        return [
            'states' => is_array($states) ? $states : [],
            'areas' => is_array($areas) ? $areas : [],
            'floors' => is_array($floors) ? $floors : [],
            'entity_registry' => is_array($entities) ? $entities : [],
            'device_registry' => is_array($devices) ? $devices : [],
        ];
    }

    public function fetchEntityHistory(string $entityId, int $hours = 24): array
    {
        $entityId = trim($entityId);
        $hours = max(1, min(168, $hours));

        if ($this->demoMode) {
            return $this->demoHistory($entityId, $hours);
        }

        if ($entityId === '') {
            return [];
        }

        $start = (new DateTimeImmutable('now', new DateTimeZone('UTC')))
            ->modify('-' . $hours . ' hours')
            ->format(DATE_ATOM);

        $path = '/api/history/period/' . rawurlencode($start) . '?' . http_build_query([
            'filter_entity_id' => $entityId,
            'minimal_response' => 1,
            'no_attributes' => 1,
        ]);

        $response = $this->request('GET', $path);
        return is_array($response) ? $response : [];
    }

    public function callService(string $domain, string $service, array $data): array
    {
        if ($this->demoMode) {
            return [
                'ok' => true,
                'demo' => true,
                'domain' => $domain,
                'service' => $service,
                'data' => $data,
            ];
        }

        return $this->request('POST', '/api/services/' . rawurlencode($domain) . '/' . rawurlencode($service), $data);
    }

    private function request(string $method, string $path, ?array $body = null): array
    {
        $response = $this->tryRequest($method, $path, $body, true);
        if (!is_array($response)) {
            throw new RuntimeException('Unexpected response from Home Assistant');
        }

        return $response;
    }

    private function tryRequest(string $method, string $path, ?array $body = null, bool $throwOnHttpError = false): array|null
    {
        $baseUrl = rtrim((string)$this->config['home_assistant']['base_url'], '/');
        $url = $baseUrl . $path;
        $token = trim((string)$this->config['home_assistant']['token']);

        $ch = curl_init($url);
        if ($ch === false) {
            throw new RuntimeException('Failed to initialize HTTP client');
        }

        $headers = [
            'Authorization: Bearer ' . $token,
            'Content-Type: application/json',
            'Accept: application/json',
        ];

        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_CUSTOMREQUEST => $method,
            CURLOPT_HTTPHEADER => $headers,
            CURLOPT_TIMEOUT => 15,
            CURLOPT_CONNECTTIMEOUT => 7,
            CURLOPT_SSL_VERIFYPEER => (bool)($this->config['home_assistant']['verify_ssl'] ?? true),
            CURLOPT_SSL_VERIFYHOST => (bool)($this->config['home_assistant']['verify_ssl'] ?? true) ? 2 : 0,
        ]);

        if ($body !== null) {
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($body, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES));
        }

        $raw = curl_exec($ch);
        $errno = curl_errno($ch);
        $error = curl_error($ch);
        $status = (int)curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
        curl_close($ch);

        if ($errno !== 0) {
            if ($throwOnHttpError) {
                throw new RuntimeException('Home Assistant request failed: ' . $error);
            }
            return null;
        }

        if ($status >= 400) {
            if ($throwOnHttpError) {
                throw new RuntimeException('Home Assistant returned HTTP ' . $status);
            }
            return null;
        }

        $decoded = json_decode((string)$raw, true);
        return is_array($decoded) ? $decoded : [];
    }

    private function fetchWsList(string $type): array|null
    {
        $response = $this->wsCall($type);
        if (!is_array($response)) {
            return null;
        }

        if (isset($response['result']) && is_array($response['result'])) {
            return $this->normalizeWsResultList($type, $response['result']);
        }

        return null;
    }

    private function normalizeWsResultList(string $type, array $result): array
    {
        if (array_is_list($result)) {
            return match ($type) {
                'config/entity_registry/list_for_display' => $this->normalizeEntityRegistryForDisplay($result),
                'config/area_registry/list' => $this->normalizeAreaRegistry($result),
                'config/floor_registry/list' => $this->normalizeFloorRegistry($result),
                'config/device_registry/list' => $this->normalizeDeviceRegistryForDisplay($result),
                default => $result,
            };
        }

        return match ($type) {
            'config/entity_registry/list_for_display' => $this->normalizeEntityRegistryForDisplay($result['entities'] ?? []),
            'config/area_registry/list' => $this->normalizeAreaRegistry($result['areas'] ?? []),
            'config/floor_registry/list' => $this->normalizeFloorRegistry($result['floors'] ?? []),
            'config/device_registry/list' => $this->normalizeDeviceRegistryForDisplay($result['devices'] ?? $result['device_registry'] ?? $result['items'] ?? []),
            default => $result,
        };
    }

    private function wsCall(string $type): array|null
    {
        $baseUrl = rtrim((string)$this->config['home_assistant']['base_url'], '/');
        $parts = parse_url($baseUrl);
        if (!is_array($parts) || empty($parts['host'])) {
            return null;
        }

        $scheme = strtolower((string)($parts['scheme'] ?? 'http'));
        $secure = in_array($scheme, ['https', 'wss'], true);
        $host = (string)$parts['host'];
        $port = (int)($parts['port'] ?? ($secure ? 443 : 80));
        $path = '/api/websocket';
        $target = ($secure ? 'tls' : 'tcp') . '://' . $host . ':' . $port;
        $contextOptions = [
            'ssl' => [
                'verify_peer' => (bool)($this->config['home_assistant']['verify_ssl'] ?? true),
                'verify_peer_name' => (bool)($this->config['home_assistant']['verify_ssl'] ?? true),
                'allow_self_signed' => !(bool)($this->config['home_assistant']['verify_ssl'] ?? true),
                'SNI_enabled' => true,
                'peer_name' => $host,
            ],
        ];

        $stream = @stream_socket_client(
            $target,
            $errno,
            $error,
            15,
            STREAM_CLIENT_CONNECT,
            stream_context_create($contextOptions)
        );

        if ($stream === false) {
            return null;
        }

        stream_set_timeout($stream, 15);
        $key = base64_encode(random_bytes(16));
        $request = implode("\r\n", [
            'GET ' . $path . ' HTTP/1.1',
            'Host: ' . $host . ':' . $port,
            'Upgrade: websocket',
            'Connection: Upgrade',
            'Sec-WebSocket-Key: ' . $key,
            'Sec-WebSocket-Version: 13',
            '',
            '',
        ]);
        fwrite($stream, $request);

        $status = $this->readHttpHeader($stream);
        if ($status === null || !str_contains($status, ' 101 ')) {
            fclose($stream);
            return null;
        }

        $auth = $this->readWsJson($stream);
        if (!is_array($auth) || ($auth['type'] ?? '') !== 'auth_required') {
            fclose($stream);
            return null;
        }

        $this->writeWsJson($stream, [
            'type' => 'auth',
            'access_token' => (string)$this->config['home_assistant']['token'],
        ]);

        $authResult = $this->readWsJson($stream);
        if (!is_array($authResult) || ($authResult['type'] ?? '') !== 'auth_ok') {
            fclose($stream);
            return null;
        }

        $requestId = random_int(1, 1_000_000);
        $this->writeWsJson($stream, [
            'id' => $requestId,
            'type' => $type,
        ]);

        while (($message = $this->readWsJson($stream)) !== null) {
            if (($message['id'] ?? null) === $requestId) {
                fclose($stream);
                if (($message['success'] ?? false) !== true) {
                    return null;
                }
                return is_array($message) ? $message : null;
            }
        }

        fclose($stream);
        return null;
    }

    private function normalizeEntityRegistryForDisplay(array $result): array
    {
        $entityCategories = is_array($result['entity_categories'] ?? null) ? $result['entity_categories'] : [];
        $entities = $result;
        if (!array_is_list($entities)) {
            $entities = $result['entities'] ?? [];
        }
        if (!is_array($entities)) {
            return [];
        }

        $normalized = [];
        foreach ($entities as $entity) {
            if (!is_array($entity)) {
                continue;
            }

            $normalized[] = [
                'entity_id' => $entity['ei'] ?? null,
                'area_id' => $entity['ai'] ?? null,
                'labels' => $this->normalizeWsLabels($entity['lb'] ?? null),
                'device_id' => $entity['di'] ?? null,
                'icon' => $entity['ic'] ?? null,
                'translation_key' => $entity['tk'] ?? null,
                'entity_category' => isset($entity['ec']) ? ($entityCategories[$entity['ec']] ?? null) : null,
                'hidden_by' => !empty($entity['hb']) ? 'true' : null,
                'name' => $entity['en'] ?? null,
                'has_entity_name' => !empty($entity['hn']),
                'platform' => $entity['pl'] ?? null,
            ];
        }

        return $normalized;
    }

    private function normalizeAreaRegistry(array $areas): array
    {
        $normalized = [];
        foreach ($areas as $area) {
            if (!is_array($area)) {
                continue;
            }

            $normalized[] = [
                'area_id' => $area['area_id'] ?? $area['id'] ?? null,
                'name' => $area['name'] ?? $area['en'] ?? null,
                'icon' => $area['icon'] ?? $area['ic'] ?? null,
                'picture' => $area['picture'] ?? $area['pi'] ?? null,
                'floor_id' => $area['floor_id'] ?? $area['fi'] ?? $area['floor'] ?? null,
            ];
        }

        return $normalized;
    }

    private function normalizeFloorRegistry(array $floors): array
    {
        $normalized = [];
        foreach ($floors as $floor) {
            if (!is_array($floor)) {
                continue;
            }

            $normalized[] = [
                'floor_id' => $floor['floor_id'] ?? $floor['id'] ?? null,
                'name' => $floor['name'] ?? $floor['en'] ?? null,
                'icon' => $floor['icon'] ?? $floor['ic'] ?? null,
                'level' => $floor['level'] ?? $floor['lv'] ?? null,
            ];
        }

        return $normalized;
    }

    private function normalizeDeviceRegistryForDisplay(array $devices): array
    {
        $normalized = [];
        foreach ($devices as $device) {
            if (!is_array($device)) {
                continue;
            }

            $normalized[] = [
                'device_id' => $device['device_id'] ?? $device['id'] ?? $device['di'] ?? null,
                'area_id' => $device['area_id'] ?? $device['ai'] ?? null,
                'name' => $device['name'] ?? $device['en'] ?? null,
                'manufacturer' => $device['manufacturer'] ?? $device['mf'] ?? null,
                'model' => $device['model'] ?? $device['md'] ?? null,
            ];
        }

        return $normalized;
    }

    private function normalizeWsLabels(mixed $labels): array
    {
        if ($labels === null) {
            return [];
        }

        if (is_string($labels) || is_numeric($labels)) {
            return [(string)$labels];
        }

        if (!is_array($labels)) {
            return [];
        }

        return array_values(array_unique(array_map('strval', $labels)));
    }

    private function readHttpHeader($stream): ?string
    {
        $buffer = '';
        while (!feof($stream)) {
            $chunk = fgets($stream);
            if ($chunk === false) {
                break;
            }
            $buffer .= $chunk;
            if (str_contains($buffer, "\r\n\r\n")) {
                break;
            }
        }

        return $buffer !== '' ? $buffer : null;
    }

    private function writeWsJson($stream, array $payload): void
    {
        fwrite($stream, $this->encodeWsFrame(json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES) ?: '{}'));
    }

    private function readWsJson($stream): array|null
    {
        $payload = $this->readWsFrame($stream);
        if ($payload === null || $payload === '') {
            return null;
        }

        $decoded = json_decode($payload, true);
        return is_array($decoded) ? $decoded : null;
    }

    private function encodeWsFrame(string $payload): string
    {
        $finOpcode = chr(0x81);
        $len = strlen($payload);
        $maskBit = 0x80;
        $mask = random_bytes(4);
        $header = '';

        if ($len <= 125) {
            $header = chr($maskBit | $len);
        } elseif ($len <= 65535) {
            $header = chr($maskBit | 126) . pack('n', $len);
        } else {
            $header = chr($maskBit | 127) . pack('J', $len);
        }

        $masked = '';
        for ($i = 0; $i < $len; $i++) {
            $masked .= $payload[$i] ^ $mask[$i % 4];
        }

        return $finOpcode . $header . $mask . $masked;
    }

    private function readWsFrame($stream): ?string
    {
        $first = fread($stream, 2);
        if ($first === false || strlen($first) < 2) {
            return null;
        }

        $bytes = array_values(unpack('C2', $first));
        $opcode = $bytes[0] & 0x0f;
        $isMasked = (bool)($bytes[1] & 0x80);
        $len = $bytes[1] & 0x7f;

        if ($len === 126) {
            $extended = fread($stream, 2);
            if ($extended === false || strlen($extended) < 2) {
                return null;
            }
            $len = unpack('n', $extended)[1];
        } elseif ($len === 127) {
            $extended = fread($stream, 8);
            if ($extended === false || strlen($extended) < 8) {
                return null;
            }
            $parts = unpack('N2', $extended);
            $len = ((int)$parts[1] << 32) | (int)$parts[2];
        }

        $mask = '';
        if ($isMasked) {
            $mask = fread($stream, 4);
            if ($mask === false || strlen($mask) < 4) {
                return null;
            }
        }

        $payload = '';
        while (strlen($payload) < $len && !feof($stream)) {
            $chunk = fread($stream, $len - strlen($payload));
            if ($chunk === false || $chunk === '') {
                break;
            }
            $payload .= $chunk;
        }

        if ($isMasked && $mask !== '') {
            $unmasked = '';
            for ($i = 0, $payloadLen = strlen($payload); $i < $payloadLen; $i++) {
                $unmasked .= $payload[$i] ^ $mask[$i % 4];
            }
            $payload = $unmasked;
        }

        if ($opcode === 0x9) {
            $this->writeWsPong($stream, $payload);
            return $this->readWsFrame($stream);
        }

        if ($opcode === 0x8) {
            return null;
        }

        return $payload;
    }

    private function writeWsPong($stream, string $payload): void
    {
        $len = strlen($payload);
        $header = chr(0x8A);
        if ($len <= 125) {
            $header .= chr($len);
        } elseif ($len <= 65535) {
            $header .= chr(126) . pack('n', $len);
        } else {
            $header .= chr(127) . pack('J', $len);
        }
        fwrite($stream, $header . $payload);
    }

    private function demoData(): array
    {
        return [
            'states' => [
                [
                    'entity_id' => 'light.living_room_main',
                    'state' => 'on',
                    'attributes' => [
                        'friendly_name' => 'Основной свет',
                        'icon' => 'mdi:ceiling-light',
                        'labels' => ['auto'],
                    ],
                ],
                [
                    'entity_id' => 'switch.tv_power',
                    'state' => 'off',
                    'attributes' => [
                        'friendly_name' => 'ТВ',
                        'icon' => 'mdi:television',
                        'labels' => ['auto'],
                    ],
                ],
                [
                    'entity_id' => 'cover.living_room_curtain',
                    'state' => 'open',
                    'attributes' => [
                        'friendly_name' => 'Штора',
                        'icon' => 'mdi:curtains',
                        'current_position' => 82,
                    ],
                ],
                [
                    'entity_id' => 'climate.living_room_ac',
                    'state' => 'cool',
                    'attributes' => [
                        'friendly_name' => 'Кондиционер',
                        'icon' => 'mdi:air-conditioner',
                        'temperature' => 22,
                        'current_temperature' => 24.5,
                        'hvac_action' => 'cooling',
                        'fan_mode' => 'auto',
                    ],
                ],
                [
                    'entity_id' => 'light.kitchen_counter',
                    'state' => 'off',
                    'attributes' => [
                        'friendly_name' => 'Подсветка',
                        'icon' => 'mdi:lightbulb',
                        'labels' => ['auto'],
                    ],
                ],
                [
                    'entity_id' => 'switch.coffee_machine',
                    'state' => 'on',
                    'attributes' => [
                        'friendly_name' => 'Кофемашина',
                        'icon' => 'mdi:coffee-maker',
                        'labels' => ['auto'],
                    ],
                ],
                [
                    'entity_id' => 'weather.yandex_weather',
                    'state' => 'sunny',
                    'attributes' => [
                        'friendly_name' => 'Yandex Weather',
                        'temperature' => 18.3,
                        'humidity' => 56,
                        'wind_speed' => 4.8,
                    ],
                ],
                [
                    'entity_id' => 'sensor.weather_temperature',
                    'state' => '17.8',
                    'attributes' => [
                        'friendly_name' => 'Weather temperature',
                    ],
                ],
                [
                    'entity_id' => 'sensor.modeco_2_temperature',
                    'state' => '57.0',
                    'attributes' => [
                        'friendly_name' => 'ModEco 2 Temperature',
                    ],
                ],
            ],
            'areas' => [
                ['area_id' => 'living_room', 'name' => 'Гостиная', 'icon' => 'mdi:sofa'],
                ['area_id' => 'kitchen', 'name' => 'Кухня', 'icon' => 'mdi:stove'],
            ],
            'entity_registry' => [
                ['entity_id' => 'light.living_room_main', 'area_id' => 'living_room', 'labels' => ['auto']],
                ['entity_id' => 'switch.tv_power', 'area_id' => 'living_room', 'labels' => ['auto']],
                ['entity_id' => 'cover.living_room_curtain', 'area_id' => 'living_room', 'labels' => []],
                ['entity_id' => 'climate.living_room_ac', 'area_id' => 'living_room', 'labels' => []],
                ['entity_id' => 'light.kitchen_counter', 'area_id' => 'kitchen', 'labels' => ['auto']],
                ['entity_id' => 'switch.coffee_machine', 'area_id' => 'kitchen', 'labels' => ['auto']],
                ['entity_id' => 'weather.yandex_weather', 'area_id' => null, 'labels' => []],
                ['entity_id' => 'sensor.weather_temperature', 'area_id' => null, 'labels' => []],
                ['entity_id' => 'sensor.modeco_2_temperature', 'area_id' => null, 'labels' => []],
            ],
            'device_registry' => [],
        ];
    }

    private function demoHistory(string $entityId, int $hours): array
    {
        if ($entityId === '') {
            return [];
        }

        $now = time();
        $start = $now - ($hours * 3600);
        $steps = max(24, min(96, $hours * 4));
        $points = [];
        $base = 57.0;

        for ($index = 0; $index <= $steps; $index++) {
            $ratio = $steps > 0 ? ($index / $steps) : 1;
            $timestamp = $start + (int)(($now - $start) * $ratio);
            $drift = sin($ratio * M_PI * 5.5) * 0.8 + cos($ratio * M_PI * 11) * 0.35;
            $value = $base + $drift;

            $points[] = [
                'entity_id' => $entityId,
                'state' => number_format($value, 1, '.', ''),
                'last_changed' => gmdate(DATE_ATOM, $timestamp),
                'last_updated' => gmdate(DATE_ATOM, $timestamp),
            ];
        }

        return [$points];
    }
}