<?php

class OCPPMessage
{
    public string $version;
    public string $direction;
    public string $action;
    public string $uniqueId;
    public array $payload;
    public int $timestamp;
    public string $chargePointId;
    public int $messageTypeId;

    public function __construct(
        string $version,
        string $direction,
        string $action,
        string $uniqueId,
        array $payload,
        string $chargePointId = '',
        int $messageTypeId = 0
    ) {
        $this->version = $version;
        $this->direction = $direction;
        $this->action = $action;
        $this->uniqueId = $uniqueId;
        $this->payload = $payload;
        $this->timestamp = time();
        $this->chargePointId = $chargePointId;
        $this->messageTypeId = $messageTypeId;
    }

    public static function fromJson(string $json, string $version = 'auto', string $chargePointId = ''): ?self
    {
        $frame = json_decode($json, true);
        if (!is_array($frame) || count($frame) < 3) {
            return null;
        }

        $type = (int)($frame[0] ?? 0);
        $uniqueId = (string)($frame[1] ?? '');

        if ($type === 2) {
            return new self($version, 'in', (string)($frame[2] ?? ''), $uniqueId, (array)($frame[3] ?? []), $chargePointId, $type);
        }

        if ($type === 3) {
            return new self($version, 'in_result', 'CallResult', $uniqueId, (array)($frame[2] ?? []), $chargePointId, $type);
        }

        if ($type === 4) {
            return new self($version, 'in_error', (string)($frame[2] ?? 'CallError'), $uniqueId, [
                'errorCode' => (string)($frame[2] ?? ''),
                'errorDescription' => (string)($frame[3] ?? ''),
                'errorDetails' => (array)($frame[4] ?? [])
            ], $chargePointId, $type);
        }

        return null;
    }

    public static function call(string $action, array $payload, string $version = 'auto', string $chargePointId = ''): self
    {
        return new self($version, 'out', $action, self::newUniqueId(), $payload, $chargePointId, 2);
    }

    public static function callResult(string $uniqueId, array $payload, string $version = 'auto', string $chargePointId = ''): self
    {
        return new self($version, 'out_result', 'CallResult', $uniqueId, $payload, $chargePointId, 3);
    }

    public static function callError(string $uniqueId, string $code, string $description, array $details = [], string $version = 'auto', string $chargePointId = ''): self
    {
        return new self($version, 'out_error', $code, $uniqueId, [
            'errorCode' => $code,
            'errorDescription' => $description,
            'errorDetails' => $details
        ], $chargePointId, 4);
    }

    public function toFrame(): array
    {
        if ($this->messageTypeId === 2) {
            return [2, $this->uniqueId, $this->action, $this->payload];
        }
        if ($this->messageTypeId === 3) {
            return [3, $this->uniqueId, $this->payload];
        }
        if ($this->messageTypeId === 4) {
            return [
                4,
                $this->uniqueId,
                (string)($this->payload['errorCode'] ?? $this->action),
                (string)($this->payload['errorDescription'] ?? ''),
                (array)($this->payload['errorDetails'] ?? [])
            ];
        }
        return [$this->messageTypeId, $this->uniqueId, $this->action, $this->payload];
    }

    public function toJson(): string
    {
        return json_encode($this->toFrame());
    }

    public function toArray(): array
    {
        return [
            'version' => $this->version,
            'direction' => $this->direction,
            'action' => $this->action,
            'uniqueId' => $this->uniqueId,
            'payload' => $this->payload,
            'timestamp' => $this->timestamp,
            'chargePointId' => $this->chargePointId,
            'messageTypeId' => $this->messageTypeId
        ];
    }

    private static function newUniqueId(): string
    {
        return str_replace('.', '', uniqid('ips-', true));
    }
}

?>