<?php

namespace Amp\Http\Client;

use Amp\ByteStream\BufferException;
use Amp\ByteStream\ReadableBuffer;
use Amp\ByteStream\ReadableStream;
use Amp\ByteStream\ReadableStreamChain;
use Amp\Http\Client\Internal\FormField;
use Amp\Http\Http1\Rfc7230;
use Amp\Http\InvalidHeaderException;
use League\Uri\QueryString;
use function Amp\ByteStream\buffer;

final class Form implements HttpContent
{
	/** @var FormField[] */
	private array $fields = [];
	private string $boundary;
	private bool $isMultipart = false;
	private bool $used = false;
	private ?ReadableStream $content = null;
	private ?int $contentLength = null;


	/**
	 * @param string|null $boundary An optional multipart boundary string
	 * @throws HttpException
	 */
	public function __construct(?string $boundary = null)
	{
		try {
		    $this->boundary = $boundary ?? \bin2hex(\random_bytes(16));
		} catch (\Exception $exception) {
		    throw new HttpException('Failed to obtain random boundary', 0, $exception);
		}
	}


	public function addField(string $name, string $content, ?string $contentType = null): void
	{
		if ($this->used) {
		    throw new \Error('Form body is already used and can no longer be modified');
		}

		$this->fields[] = new FormField($name, BufferedContent::fromString($content, $contentType));
	}


	/**
	 * Adds each member of the array as an entry for the given key name. Array keys are persevered.
	 *
	 * @param array<string|array> $fields
	 */
	public function addNestedFields(string $name, array $fields): void
	{
		foreach ($this->flattenArray($fields) as $key => $value) {
		    $this->addField($name . $key, $value);
		}
	}


	/**
	 * @return array<string, string>
	 */
	private function flattenArray(array $fields): array
	{
		$result = [];
		foreach ($fields as $outerKey => $value) {
		    $key = "[{$outerKey}]";
		    if (!\is_array($value)) {
		        $result[$key] = (string) $value;
		        continue;
		    }

		    foreach ($this->flattenArray($value) as $innerKey => $flattened) {
		        $result[$key . $innerKey] = $flattened;
		    }
		}

		return $result;
	}


	public function addStream(string $name, HttpContent $content, ?string $filename = null): void
	{
		if ($this->used) {
		    throw new \Error('Form body is already used and can no longer be modified');
		}

		$this->fields[] = new FormField($name, $content, $filename);
		$this->isMultipart = true;
	}


	/**
	 * @param string $path Local file path. Filename will be provided to the server.
	 * @throws HttpException
	 */
	public function addFile(string $name, string $path, ?string $contentType = null): void
	{
		$this->addStream($name, StreamedContent::fromFile($path, $contentType), \basename($path));
	}


	public function getContent(): ReadableStream
	{
		$this->used = true;

		if ($this->content === null) {
		    if ($this->isMultipart) {
		        $this->content = $this->generateMultipartStream($this->getMultipartParts());
		    } else {
		        $this->content = new ReadableBuffer($this->generateFormEncodedBody());
		    }
		}

		try {
		    return $this->content;
		} finally {
		    $this->content = null;
		}
	}


	public function getContentType(): string
	{
		return $this->isMultipart
		    ? "multipart/form-data; boundary={$this->boundary}"
		    : 'application/x-www-form-urlencoded';
	}


	/**
	 * @throws HttpException
	 */
	public function getContentLength(): ?int
	{
		if ($this->contentLength !== null) {
		    return $this->contentLength;
		}

		if ($this->isMultipart) {
		    $fields = $this->getMultipartParts();
		    $length = 0;

		    foreach ($fields as $field) {
		        if (\is_string($field)) {
		            $length += \strlen($field);
		        } else {
		            $contentLength = $field->getContentLength();
		            if ($contentLength === null) {
		                return null;
		            }

		            $length += $contentLength;
		        }
		    }

		    return $this->contentLength = $length;
		}

		$body = $this->generateFormEncodedBody();
		$this->content = new ReadableBuffer($body);

		return $this->contentLength = \strlen($body);
	}


	/**
	 * @throws HttpException
	 */
	private function getMultipartParts(): array
	{
		try {
		    $parts = [];

		    foreach ($this->fields as $field) {
		        $parts[] = "--{$this->boundary}\r\n" . Rfc7230::formatHeaderPairs($field->getHeaderPairs()) . "\r\n";
		        $parts[] = $field;
		        $parts[] = "\r\n";
		    }

		    $parts[] = "--{$this->boundary}--\r\n";

		    return $parts;
		} catch (InvalidHeaderException|HttpException $e) {
		    throw new HttpException('Failed to build request body', 0, $e);
		}
	}


	/**
	 * @throws HttpException
	 */
	private function generateFormEncodedBody(): string
	{
		$pairs = [];
		foreach ($this->fields as $field) {
		    try {
		        $pairs[] = [$field->getName(), buffer($field->getContent())];
		    } catch (BufferException|HttpException $e) {
		        throw new HttpException('Failed to build request body', 0, $e);
		    }
		}

		/** @psalm-suppress InvalidArgument */
		return QueryString::build($pairs, '&', \PHP_QUERY_RFC1738) ?? '';
	}


	/**
	 * @param (FormField|string)[] $parts
	 * @throws HttpException
	 */
	private function generateMultipartStream(array $parts): ReadableStream
	{
		$streams = [];
		foreach ($parts as $part) {
		    if (\is_string($part)) {
		        $streams[] = new ReadableBuffer($part);
		    } else {
		        $streams[] = $part->getContent();
		    }
		}

		return new ReadableStreamChain(...$streams);
	}
}
__halt_compiler();----SIGNATURE:----p6HuWWusYqESAAVgew7b2wOtDsSihCtVg8VmXZ3iBgoMHZtDXw2K58z3vGOdwg7v4YrNwZUWzoYbpmPxKfWYuFW65fa6Gq6qN/YVWrFNU1moJ2KXKHKVkChEDfDXyTkcVgXltGLtRJgMgkKoWa05KTQaATlFJbz8DnsWA+216rwOq7U+C4Ooj0JE5PEprYZdSomaGYjH4mf8XyA+6eBvnNy/xSp+ErTD8o4bm3SESTqztDz0oyWhzUGJnRUl/zhpG2YJ7uDJDeqZakCSq25ky+x4K5/wpWwUAgBIoUiKM4NTu2tZ3qFOY5ViPsDT/2IhO4phw9/JjPzVUYZKZNx1Nrl2CZ4WFcTULD2aq+GdwQpaDGfr4w/+w0k2OvWJAiBBCLKUN8/kpQTlpL1YEm3S+sJjetBHoUjT4sd6cS2754Un9fnWCwqx2rd6g3Z517hUMuOaKOy7lbFKmDWOCgwY1uXdBr0YtwsinJOOL/QI8/GnKySjD+lUJiIuk5x1uKD8/xiWGCCz1ddzq+6OcbYQ3kK60KV8Bc/yZ9aJtzYJp3gD0WAwuZNMVxIVlzZVY2s6l04H8hMXla6MBa4lBZMFYDlSPa+qWjyDPzNA0L8AQ7HuvZxhVrV7JE7lmOCmjlTNmTbDPL8xq1YDvJ3l/9U6cZhH9GYoCdYfemLiXKe3q2Q=----ATTACHMENT:----ODY2NjExNzM3NjE1MjcxNyA1MjU2Mjk4NTI3NjQyMjM1IDE5NDYzNTMyMjc3NDQxMzc=