<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\apidoc\helpers;

use cebe\markdown\GithubMarkdown;
use phpDocumentor\Reflection\DocBlock\Type\Collection;
use yii\apidoc\models\MethodDoc;
use yii\apidoc\models\TypeDoc;
use yii\apidoc\renderers\BaseRenderer;
use yii\helpers\Inflector;
use yii\helpers\Markdown;

/**
 * A Markdown helper with support for class reference links.
 *
 * @author Carsten Brandt <mail@cebe.cc>
 * @since 2.0
 */
class ApiMarkdown extends GithubMarkdown
{
    /**
     * @var BaseRenderer
     */
    public static $renderer;

    protected $context;

    public function prepare()
    {
        parent::prepare();

        // add references to guide pages
        $this->references = array_merge($this->references, static::$renderer->guideReferences);
    }

    /**
     * @inheritDoc
     */
    protected function identifyLine($lines, $current)
    {
        if (strncmp($lines[$current], '~~~', 3) === 0) {
            return 'fencedCode';
        }

        return parent::identifyLine($lines, $current);
    }

    /**
     * Consume lines for a fenced code block
     */
    protected function consumeFencedCode($lines, $current)
    {
        // consume until ```
        $block = [
            'type' => 'code',
            'content' => [],
        ];
        $line = rtrim($lines[$current]);
        if (strncmp($lines[$current], '~~~', 3) === 0) {
            $fence = '~~~';
            $language = 'php';
        } else {
            $fence = substr($line, 0, $pos = strrpos($line, '`') + 1);
            $language = substr($line, $pos);
        }
        if (!empty($language)) {
            $block['language'] = $language;
        }
        for ($i = $current + 1, $count = count($lines); $i < $count; $i++) {
            if (rtrim($line = $lines[$i]) !== $fence) {
                $block['content'][] = $line;
            } else {
                break;
            }
        }

        return [$block, $i];
    }

    /**
     * Renders a code block
     */
    protected function renderCode($block)
    {
        if (isset($block['language'])) {
            $class = isset($block['language']) ? ' class="language-' . $block['language'] . '"' : '';

            return "<pre><code$class>" . $this->highlight(implode("\n", $block['content']) . "\n", $block['language']) . '</code></pre>';
        } else {
            return parent::renderCode($block);
        }
    }

    public static function highlight($code, $language)
    {
        if ($language !== 'php') {
            return htmlspecialchars($code, ENT_NOQUOTES, 'UTF-8');
        }

        // TODO improve code highlighting
        if (strncmp($code, '<?php', 5) === 0) {
            $text = @highlight_string(trim($code), true);
        } else {
            $text = highlight_string("<?php ".trim($code), true);
            $text = str_replace('&lt;?php', '', $text);
            if (($pos = strpos($text, '&nbsp;')) !== false) {
                $text = substr($text, 0, $pos) . substr($text, $pos + 6);
            }
        }
        // remove <code><span style="color: #000000">\n and </span>tags added by php
        $text = substr(trim($text), 36, -16);

        return $text;
    }

    protected function inlineMarkers()
    {
        return array_merge(parent::inlineMarkers(), [
            '[[' => 'parseApiLinks',
        ]);
    }

    protected function parseApiLinks($text)
    {
        $context = $this->context;

        if (preg_match('/^\[\[([\w\d\\\\\(\):$]+)(\|[^\]]*)?\]\]/', $text, $matches)) {

            $offset = strlen($matches[0]);

            $object = $matches[1];
            $title = (empty($matches[2]) || $matches[2] == '|') ? null : substr($matches[2], 1);

            if (($pos = strpos($object, '::')) !== false) {
                $typeName = substr($object, 0, $pos);
                $subjectName = substr($object, $pos + 2);
                if ($context !== null) {
                    // Collection resolves relative types
                    $typeName = (new Collection([$typeName], $context->phpDocContext))->__toString();
                }
                $type = static::$renderer->apiContext->getType($typeName);
                if ($type === null) {
                    static::$renderer->apiContext->errors[] = [
                        'file' => ($context !== null) ? $context->sourceFile : null,
                        'message' => 'broken link to ' . $typeName . '::' . $subjectName . (($context !== null) ? ' in ' . $context->name : ''),
                    ];

                    return [
                        '<span style="background: #f00;">' . $typeName . '::' . $subjectName . '</span>',
                        $offset
                    ];
                } else {
                    if (($subject = $type->findSubject($subjectName)) !== null) {
                        if ($title === null) {
                            $title = $type->name . '::' . $subject->name;
                            if ($subject instanceof MethodDoc) {
                                $title .= '()';
                            }
                        }

                        return [
                            static::$renderer->createSubjectLink($subject, $title),
                            $offset
                        ];
                    } else {
                        static::$renderer->apiContext->errors[] = [
                            'file' => ($context !== null) ? $context->sourceFile : null,
                            'message' => 'broken link to ' . $type->name . '::' . $subjectName . (($context !== null) ? ' in ' . $context->name : ''),
                        ];

                        return [
                            '<span style="background: #ff0;">' . $type->name . '</span><span style="background: #f00;">::' . $subjectName . '</span>',
                            $offset
                        ];
                    }
                }
            } elseif ($context !== null && ($subject = $context->findSubject($object)) !== null) {
                return [
                    static::$renderer->createSubjectLink($subject, $title),
                    $offset
                ];
            }

            if ($context !== null) {
                // Collection resolves relative types
                $object = (new Collection([$object], $context->phpDocContext))->__toString();
            }
            if (($type = static::$renderer->apiContext->getType($object)) !== null) {
                return [
                    static::$renderer->createTypeLink($type, null, $title),
                    $offset
                ];
            } elseif (strpos($typeLink = static::$renderer->createTypeLink($object, null, $title), '<a href') !== false) {
                return [
                    $typeLink,
                    $offset
                ];
            }
            static::$renderer->apiContext->errors[] = [
                'file' => ($context !== null) ? $context->sourceFile : null,
                'message' => 'broken link to ' . $object . (($context !== null) ? ' in ' . $context->name : ''),
            ];

            return [
                '<span style="background: #f00;">' . $object . '</span>',
                $offset
            ];
        }

        return ['[[', 2];
    }

    /**
     * @inheritDoc
     */
    protected function renderHeadline($block)
    {
        $content = $this->parseInline($block['content']);
        $hash = Inflector::slug(strip_tags($content));
        $hashLink = "<a href=\"#$hash\" name=\"$hash\">&para;</a>";
        $tag = 'h' . $block['level'];

        return "<$tag>$content $hashLink</$tag>";
    }

    /**
     * Converts markdown into HTML
     *
     * @param  string  $content
     * @param  TypeDoc $context
     * @param  boolean $paragraph
     * @return string
     */
    public static function process($content, $context = null, $paragraph = false)
    {
        if (!isset(Markdown::$flavors['api'])) {
            Markdown::$flavors['api'] = new static;
        }

        if (is_string($context)) {
            $context = static::$renderer->apiContext->getType($context);
        }
        Markdown::$flavors['api']->context = $context;

        if ($paragraph) {
            return Markdown::processParagraph($content, 'api');
        } else {
            return Markdown::process($content, 'api');
        }
    }
}
