<?php

declare(strict_types=1);

/*
 * This file is part of the league/commonmark package.
 *
 * (c) Colin O'Dell <colinodell@gmail.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace League\CommonMark\Extension\Mention;

use League\CommonMark\Extension\Mention\Generator\CallbackGenerator;
use League\CommonMark\Extension\Mention\Generator\MentionGeneratorInterface;
use League\CommonMark\Extension\Mention\Generator\StringTemplateLinkGenerator;
use League\CommonMark\Parser\Inline\InlineParserInterface;
use League\CommonMark\Parser\Inline\InlineParserMatch;
use League\CommonMark\Parser\InlineParserContext;

final class MentionParser implements InlineParserInterface
{
    /** @psalm-readonly */
    private string $name;

    /** @psalm-readonly */
    private string $prefix;

    /** @psalm-readonly */
    private string $identifierPattern;

    /** @psalm-readonly */
    private MentionGeneratorInterface $mentionGenerator;

    public function __construct(string $name, string $prefix, string $identifierPattern, MentionGeneratorInterface $mentionGenerator)
    {
        $this->name              = $name;
        $this->prefix            = $prefix;
        $this->identifierPattern = $identifierPattern;
        $this->mentionGenerator  = $mentionGenerator;
    }

    public function getMatchDefinition(): InlineParserMatch
    {
        return InlineParserMatch::join(
            InlineParserMatch::string($this->prefix),
            InlineParserMatch::regex($this->identifierPattern)
        );
    }

    public function parse(InlineParserContext $inlineContext): bool
    {
        $cursor = $inlineContext->getCursor();

        // The prefix must not have any other characters immediately prior
        $previousChar = $cursor->peek(-1);
        if ($previousChar !== null && \preg_match('/\w/', $previousChar)) {
            // peek() doesn't modify the cursor, so no need to restore state first
            return false;
        }

        [$prefix, $identifier] = $inlineContext->getSubMatches();

        $mention = $this->mentionGenerator->generateMention(new Mention($this->name, $prefix, $identifier));

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

        $cursor->advanceBy($inlineContext->getFullMatchLength());
        $inlineContext->getContainer()->appendChild($mention);

        return true;
    }

    public static function createWithStringTemplate(string $name, string $prefix, string $mentionRegex, string $urlTemplate): MentionParser
    {
        return new self($name, $prefix, $mentionRegex, new StringTemplateLinkGenerator($urlTemplate));
    }

    public static function createWithCallback(string $name, string $prefix, string $mentionRegex, callable $callback): MentionParser
    {
        return new self($name, $prefix, $mentionRegex, new CallbackGenerator($callback));
    }
}