<?php

declare(strict_types=1);

namespace KTXM\ProviderImap\Client\Protocol\Command;

use KTXM\ProviderImap\Client\Protocol\CompletionChecker;
use KTXM\ProviderImap\Client\Protocol\StringEncoder;
use KTXM\ProviderImap\Client\Protocol\Parser\ListResponseParser;
use KTXM\ProviderImap\Client\Protocol\Parser\StatusResponseParser;
use Generator;
use KTXM\ProviderImap\Client\ImapException;
use KTXM\ProviderImap\Client\Protocol\Command\Argument\ListReturnOptions;
use KTXM\ProviderImap\Client\Protocol\Command\Argument\ListSelectionOptions;
use KTXM\ProviderImap\Client\Mailbox;
use KTXM\ProviderImap\Client\Result\MailboxStatusResult;
use KTXM\ProviderImap\Client\Protocol\RequestFrame;
use KTXM\ProviderImap\Client\Protocol\Response\TaggedResponse;
use KTXM\ProviderImap\Client\Protocol\Response\UntaggedResponse;
use KTXM\ProviderImap\Client\Protocol\ResponseStream;
use KTXM\ProviderImap\Client\Protocol\SessionContext;
use KTXM\ProviderImap\Client\Protocol\SessionState;

/**
 * @implements CommandInterface<Generator<int, Mailbox>>
 */
final class ListCommand implements CommandInterface
{
    private readonly ListSelectionOptions $selectionOptions;
    private readonly ListReturnOptions $returnOptions;
    private readonly ListResponseParser $listResponseParser;
    private readonly StatusResponseParser $statusResponseParser;

    public function __construct(
        private readonly string $reference = '',
        private readonly string $pattern = '*',
        ?ListSelectionOptions $selectionOptions = null,
        ?ListReturnOptions $returnOptions = null,
    ) {
        $this->selectionOptions = $selectionOptions ?? ListSelectionOptions::none();
        $this->returnOptions = $returnOptions ?? ListReturnOptions::none();
        $this->listResponseParser = new ListResponseParser();
        $this->statusResponseParser = new StatusResponseParser();
    }

    public function name(): string
    {
        return 'LIST';
    }

    public function allowedStates(): array
    {
        return [
            SessionState::Authenticated,
            SessionState::Selected,
        ];
    }

    public function encode(string $tag, SessionContext $context): RequestFrame
    {
        unset($tag, $context);

        $command = 'LIST';

        $selectionOptions = $this->selectionOptions->toCommand();
        if ($selectionOptions !== null) {
            $command .= ' ' . $selectionOptions;
        }

        $command .= sprintf(
            ' %s %s',
            StringEncoder::quote($this->reference),
            StringEncoder::quote($this->pattern),
        );

        $returnOptions = $this->returnOptions->toCommand();
        if ($returnOptions !== null) {
            $command .= ' RETURN ' . $returnOptions;
        }

        return new RequestFrame($command);
    }

    public function handle(ResponseStream $responses, SessionContext $context): Generator
    {
        unset($context);

        if (!$this->returnOptions->hasStatus()) {
            foreach ($responses as $response) {
                if ($response instanceof UntaggedResponse && $response->label() === 'LIST') {
                    yield $this->listResponseParser->parse($response->payload());
                    continue;
                }

                if ($response instanceof TaggedResponse) {
                    CompletionChecker::assertSuccess($this->name(), $response);

                    return;
                }
            }

            throw new ImapException('LIST did not receive a tagged completion response.');
        }

        $mailboxes = [];
        $statuses = [];

        foreach ($responses as $response) {
            if ($response instanceof UntaggedResponse && $response->label() === 'LIST') {
                $mailbox = $this->listResponseParser->parse($response->payload());
                $mailboxes[$mailbox->name()] = $this->applyStatus(
                    $mailbox,
                    $statuses[$mailbox->name()] ?? [],
                );
                continue;
            }

            if ($response instanceof UntaggedResponse && $response->label() === 'STATUS') {
                [$mailboxName, $status] = $this->statusResponseParser->parse($response->payload());
                $statuses[$mailboxName] = $status;

                if (isset($mailboxes[$mailboxName])) {
                    $mailboxes[$mailboxName] = $this->applyStatus($mailboxes[$mailboxName], $status);
                }

                continue;
            }

            if ($response instanceof TaggedResponse) {
                CompletionChecker::assertSuccess($this->name(), $response);

                foreach ($mailboxes as $mailbox) {
                    yield $mailbox;
                }

                return;
            }
        }

        throw new ImapException('LIST did not receive a tagged completion response.');
    }

    /**
     * @param array<string, int> $status
     */
    private function applyStatus(Mailbox $mailbox, array $status): Mailbox
    {
        return $mailbox->fromStatus(new MailboxStatusResult($mailbox->name(), $status));
    }
}