<?php namespace markdownBlog;

use Exception;
use MardownBlog\Parsedown\ParsedownExtension;

class Post
{

    private $name;

    private $meta;
    private $metaPath;
    private $metaExists;

    private $markdown;
    private $markdownPath;
    private $markdownHash;
    private $markdownExists;

    private $abstractSeparator = '<!-- more -->';

    private $HTML;

    /**
     * Post constructor.
     * @param $name
     */
    public function __construct($name)
    {
        $this->name = str_replace(' ', '-', $name);

        $this->markdownPath = 'posts/'.$this->getName().'/content.md';
        $this->markdownExists = file_exists($this->markdownPath);

        $this->metaPath = 'posts/'.$this->getName().'/meta.json';
        $this->metaExists = file_exists($this->metaPath);
    }

    private function getMarkdownHash()
    {
        if ($this->markdownExists === false) {
            throw new Exception('Can\'t hash the markdown as it doesn\'t exist');
        }

        if (empty($this->markdownHash) === true) {
            $this->markdownHash = md5_file($this->markdownPath);
        }

        return $this->markdownHash;
    }

    /**
     * @return mixed
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Get the posts markdown
     *
     * @return string
     */
    private function getMarkdown()
    {
        if (empty($this->markdown) === true && $this->markdownExists === true) {
            $this->markdown = file_get_contents($this->markdownPath);
        }

        return $this->markdown;
    }

    /**
     * Get the posts meta data
     *
     * @return object
     */
    public function getMeta()
    {
        if (empty($this->meta) === true && $this->metaExists === true) {
            $metaRaw = json_decode(file_get_contents($this->metaPath));

            // Check values exist and set defaults
            if (empty($metaRaw->tags) === true || is_array($metaRaw->tags) === false) {
                $metaRaw->tags = [];
            }

            // Make all tags lowercase
            $metaRaw->tags = array_map('strtolower', $metaRaw->tags);

            // Order the tags A-Z
            asort($metaRaw->tags);

            $this->meta = $metaRaw;

        }

        return $this->meta;
    }

    public function isCached()
    {
        return file_exists('cache/'.$this->getMarkdownHash().'.html');
    }

    private function writeCache($content)
    {
        return file_put_contents('cache/'.$this->getMarkdownHash().'.html', $content);
    }

    private function getCache()
    {
        if ($this->isCached() === false) {
            return false;
        }

        return file_get_contents('cache/'.$this->getMarkdownHash().'.html');
    }

    /**
     * Get the HTML content of this post
     *
     * @param bool|false $fresh Whether or not to load from the cache
     * @return string
     */
    public function getHTML($fresh = false)
    {
        if (empty($this->HTML) === true) {

            if ($this->isCached() && $fresh !== true) {
                $this->HTML = $this->getCache();
            } else {
                $this->HTML = $this->generateHTML();
                $this->writeCache($this->getHTML());
            }

        }

        return $this->HTML;
    }

    /**
     * Generate the HTML for this post
     *
     * @return string
     */
    private function generateHTML()
    {
        $parsedown = new ParsedownExtension();

        return $parsedown->parse($this->getMarkdown());
    }

    public function hasMoreToRead()
    {
        return strpos($this->getHTML(), $this->abstractSeparator) !== false;
    }

    public function getAbstract()
    {
        $html =  $this->getHTML();

        $paras = explode($this->abstractSeparator, $html);

        return $paras[0];
    }

    public function getURI()
    {
        return '/'.date('Y/m/d', $this->getMeta()->date).'/'.str_replace(' ', '-', $this->getMeta()->title);
    }

    public function hasBannerImage()
    {
        return file_exists('posts/' . $this->getName() . '/images/banner.jpg');
    }

    public function getBannerImage()
    {
        if ($this->hasBannerImage() === false) {
            return false;
        }

        return $this->getURI().'/images/banner.jpg';
    }

    public function getBannerFilePath()
    {
        if ($this->hasBannerImage() === false) {
            return false;
        }
        return 'posts/'.$this->getName().'/images/banner.jpg';
    }

    public function getBannerWidth()
    {
        $imageSizes = getimagesize($this->getBannerFilePath());

        return ($imageSizes) ? $imageSizes[0]:false;
    }

    public function getBannerHeight()
    {
        $imageSizes = getimagesize($this->getBannerFilePath());

        return ($imageSizes) ? $imageSizes[1]:false;
    }

    public function getWordCount()
    {
        return str_word_count($this->getMarkdown());
    }
}