<?php 

class Post implements ArrayAccess {
    public $handler;

    private $content_html;
    private $content_markdown;

    public $data;

    public $html_data;
    public $raw_data;

    private $_child_posts;
    private $_parent_post;

    public static function _generate_404($post_data) {
        $post_data ??= [
            'id' => -1,
            'path' => '/404.md',
            'title' => '404 Page',
            'metadata' => [
                'type' => '404'
            ]
        ];

        return $post_data;
    } 

    public static function deduce_type($path) {
        $ext = pathinfo($path, PATHINFO_EXTENSION);

		if(preg_match("/\.(\w+)\.md$/", $path, $ext_match)) {
			$ext = $ext_match[1];
		}

		$ext_mapping = [
			'' => 'directory',
			'md' => 'text/markdown',
			'png' => 'image',
			'jpg' => 'image',
			'jpeg' => 'image'
		];

		return $ext_mapping[$ext] ?? '?';
    }

    public static function deduce_media_url($path) {
		if(preg_match("/^(.*\.\w+)\.md$/", $path, $ext_match)) {
			return $ext_match[1];
		}

        return null;
    }

    public static function deduce_icon($type) {
        $icon_mapping = [
			'' => 'question',
			'text/markdown' => 'markdown',
            'markdown' => 'markdown',
            'blog' => 'markdown',
			'blog_list' => 'rectangle-list',
			'directory' => 'folder',
			'gallery' => 'images',
			'image' => 'image'
		];

        return $icon_mapping[$type] ?? 'unknown';
    }

    public static function deduce_template($type) {
        $template_mapping = [
            'directory' => 'directory',
            'gallery' => 'gallery',
            'image' => 'image'
		];

        return $template_mapping[$type] ?? 'vanilla';
    }

    function __construct($post_handler, $post_data, $site_defaults) {
        $this->handler = $post_handler;
    
        $this->content_html = null;
        $this->content_markdown  = null;

        if(!isset($post_data) or !isset($post_data['id'])) {
            $post_data = $this->_generate_404($post_data);
        }
    
        $data = array_merge($site_defaults, $post_data);

        if($data['path'] == '') {
            $data['path'] = '/';
            $data['title'] ??= 'root';
            $data['basename'] ??= 'root';
        }


        $data['basename'] ??= basename($data['path']);
        $data['title'] ??= basename($data['path']);

        $data['tags'] ??= [];

        $data['type'] ??= self::deduce_type($post_data['path']);

		if(!isset($data['url'])) {
        	$url = $site_defaults['uri_prefix'] . $post_data['path'];
        	// Adding a trailing slash for "non-filename" paths that
        	// need a trail to render properly
        	
 			if(!preg_match('/\.\w+$/', $url)) {
 				$url .= '/';
 			}
 			$data['url'] = $url;
		}

        $data['icon'] ??= self::deduce_icon($data['type']);
        $data['template'] ??= self::deduce_template($data['type']);

        $data['media_url'] ??= self::deduce_media_url($data['path']);
        $data['media_preview_url'] ??= $data['media_url'];

        // TODO: Try to check for thumb image automatically here
        $data['preview_image'] ??= $data['media_preview_url'] ??
            $data['banners'][0]['src'] ?? null;

        $data['brief'] ??= $data['title'];

        if($data['type'] == 'gallery') {
            $data['search'] ??= [
                'path' => $data['path'],
                'tags' => [
                    '+type:image'
                ]
            ];
        }

        $this->data = $data;
    }

    public function __get($name) {
        if($name == 'html') {
            return $this->get_html();
        }
        if($name == 'markdown') {
            return $this->get_markdown();
        }
        if($name == 'json') {
            return $this->to_json();
        }
        if($name == 'child_posts') {
            return $this->get_child_posts();
        }
        if($name == 'parent') {
            return $this->get_parent_post();
        }

        if(isset($this->data[$name])) {
            return $this->data[$name];
        }

       return null;
    }

    public function offsetGet($offset) : mixed {
        return $this->__get($offset) ?? null;
    }
    public function offsetExists($offset) : bool {
        if(isset($this->data[$offset])) {
            return true;
        }

        return !is_null($this->offsetGet($offset));
    }
    public function offsetSet($offset, $value) : void {
        $this->data[$offset] = $value;
    }
    public function offsetUnset($offset) : void {
        unset($this->data[$offset]);
    }

    public function get_html() {
        $this->content_html ??= $this->handler->render_post($this);

        return $this->content_html;
    }
    public function get_markdown() {
        $this->content_markdown ??= 
            $this->handler->get_markdown_for($this);
        
        return $this->content_markdown;
    }

    public function get_child_posts(...$search_args) {
        if(count($search_args) == 0) {
            $this->_child_posts ??=
                $this->handler->get_children_for($this);

            return $this->_child_posts;
        }
        else {
            return $this->handler->get_children_for($this, ...$search_args);
        }
    }

    public function to_array($options = []) {
        $out_data = $this->data;

        if(isset($options['markdown'])) {
            $out_data['markdown'] = $this->get_markdown();
        }
        if(isset($options['html'])) {
            $out_data['html'] = $this->get_html();
        }
        if(isset($options['children'])) {
            $children = $this->get_child_posts();
            $child_arrays = [];

            foreach($children AS $child) {
                array_push($child_arrays, $child->to_array());
            }

            $out_data['children'] = $child_arrays;
        }

        return $out_data;
    }
    public function to_json($options = []) {
        return json_encode($this->to_array($options));
    }


    public function get_parent_post() {
        $parent_path = dirname($this->data['path']);
        if($parent_path == '')
            return null;

        $this->_parent_post ??= $this->handler->get_post($parent_path);

        return $this->_parent_post;
    }
}

?>