<?php

namespace AsyncAws\DynamoDb\ValueObject;

use AsyncAws\Core\Exception\InvalidArgument;
use AsyncAws\DynamoDb\Enum\StreamViewType;

/**
 * Represents the DynamoDB Streams configuration for a table in DynamoDB.
 */
final class StreamSpecification
{
    /**
     * Indicates whether DynamoDB Streams is enabled (true) or disabled (false) on the table.
     *
     * @var bool
     */
    private $streamEnabled;

    /**
     * When an item in the table is modified, `StreamViewType` determines what information is written to the stream for this
     * table. Valid values for `StreamViewType` are:
     *
     * - `KEYS_ONLY` - Only the key attributes of the modified item are written to the stream.
     * - `NEW_IMAGE` - The entire item, as it appears after it was modified, is written to the stream.
     * - `OLD_IMAGE` - The entire item, as it appeared before it was modified, is written to the stream.
     * - `NEW_AND_OLD_IMAGES` - Both the new and the old item images of the item are written to the stream.
     *
     * @var StreamViewType::*|null
     */
    private $streamViewType;

    /**
     * @param array{
     *   StreamEnabled: bool,
     *   StreamViewType?: StreamViewType::*|null,
     * } $input
     */
    public function __construct(array $input)
    {
        $this->streamEnabled = $input['StreamEnabled'] ?? $this->throwException(new InvalidArgument('Missing required field "StreamEnabled".'));
        $this->streamViewType = $input['StreamViewType'] ?? null;
    }

    /**
     * @param array{
     *   StreamEnabled: bool,
     *   StreamViewType?: StreamViewType::*|null,
     * }|StreamSpecification $input
     */
    public static function create($input): self
    {
        return $input instanceof self ? $input : new self($input);
    }

    public function getStreamEnabled(): bool
    {
        return $this->streamEnabled;
    }

    /**
     * @return StreamViewType::*|null
     */
    public function getStreamViewType(): ?string
    {
        return $this->streamViewType;
    }

    /**
     * @internal
     */
    public function requestBody(): array
    {
        $payload = [];
        $v = $this->streamEnabled;
        $payload['StreamEnabled'] = (bool) $v;
        if (null !== $v = $this->streamViewType) {
            if (!StreamViewType::exists($v)) {
                throw new InvalidArgument(\sprintf('Invalid parameter "StreamViewType" for "%s". The value "%s" is not a valid "StreamViewType".', __CLASS__, $v));
            }
            $payload['StreamViewType'] = $v;
        }

        return $payload;
    }

    /**
     * @return never
     */
    private function throwException(\Throwable $exception)
    {
        throw $exception;
    }
}
