<?php

/*
   _____               _               _____ _ _          _____                           _             
  / ____|             | |             / ____(_) |        / ____|                         | |            
 | |  __  __ _ _ __ __| | ___ _ __   | (___  _| |_ ___  | |  __  ___ _ __   ___ _ __ __ _| |_ ___  _ __ 
 | | |_ |/ _` | '__/ _` |/ _ \ '_ \   \___ \| | __/ _ \ | | |_ |/ _ \ '_ \ / _ \ '__/ _` | __/ _ \| '__|
 | |__| | (_| | | | (_| |  __/ | | |  ____) | | ||  __/ | |__| |  __/ | | |  __/ | | (_| | || (_) | |   
  \_____|\__,_|_|  \__,_|\___|_| |_| |_____/|_|\__\___|  \_____|\___|_| |_|\___|_|  \__,_|\__\___/|_|

 */

function output_debug(...$str_segments) {
	$str = join('', $str_segments);
	echo($str . PHP_EOL);
}

function output_error(...$str_segments) {
	$str = join('', $str_segments);
	die($str);
}

///////////////////////////////////////////////////////////////////////////////
// Paths
///////////////////////////////////////////////////////////////////////////////

function garden_path(...$path_segments) {
	$segments = array();
	foreach ($path_segments as $path_segment) {
		$inner_segments = explode(DIRECTORY_SEPARATOR, $path_segment);
		foreach ($inner_segments as $inner_segment) {
			if ($inner_segment != '') {
				$segments[] = $inner_segment;
			}
		}
	}
	array_unshift($segments, '');
	return join(DIRECTORY_SEPARATOR, $segments);
}

///////////////////////////////////////////////////////////////////////////////
// String
///////////////////////////////////////////////////////////////////////////////

function garden_slug($str) {
	$str = preg_replace('/\s+/', '-', $str);
	$str = preg_replace('/\-+/', '-', $str);
	$str = preg_replace('/[^\w\s\-\.]+/', '', $str);
	$str = strtolower($str);
	return $str;
}

function garden_url(...$url_segments) {
	$segments = array();
	foreach ($url_segments as $url_segment) {
		$inner_segments = explode(DIRECTORY_SEPARATOR, $url_segment);
		foreach ($inner_segments as $inner_segment) {
			if ($inner_segment != '') {
				$segments[] = garden_slug($inner_segment);
			}
		}
	}
	array_unshift($segments, '');
	return join(DIRECTORY_SEPARATOR, $segments);
}

///////////////////////////////////////////////////////////////////////////////
// I/O
///////////////////////////////////////////////////////////////////////////////

function garden_read_file($filename) {
	return file_get_contents($filename);
}

function garden_write_file($filename, $content) {
	$utf8_bom = "\xEF\xBB\xBF";
	file_put_contents($filename, $utf8_bom . $content);
}

///////////////////////////////////////////////////////////////////////////////
// Items to process
///////////////////////////////////////////////////////////////////////////////

enum GardenItemType {
	case Article;
	case Image;
	case Raw;
}

class GardenItem {
	public $path;
	public $type;
	public $id;
	public $title;
	public $category;
	public $url;
	public $date;
	public $source_filename;
	public $target_filename;

	public function __construct($path, $type, $id, $title, $category, $url, $date, $source_filename, $target_filename) {
		$this->path = $path;
		$this->type = $type;
		$this->id = $id;
		$this->title = $title;
		$this->category = $category;
		$this->url = $url;
		$this->date = $date;
		$this->source_filename = $source_filename;
		$this->target_filename = $target_filename;
	}
}

function garden_make_process_items($output_directory, $content_paths) {
	$output_items = [];

	foreach ($content_paths as $item) {
		$id = garden_slug($item->filename);

		$target_extension = $item->extension;

		$ignore_file = false;
		$type = GardenItemType::Raw;
		switch ($item->extension) {
			case 'php':
				$ignore_file = true;
				break;

			case 'md':
				$type = GardenItemType::Article;
				$target_extension = 'html';
				break;

			case 'png':
			case 'jpg':
			case 'jpeg':
			case 'gif':
				$type = GardenItemType::Image;
				break;
		}

		if ($ignore_file == true) {
			continue;
		}

		$target_basename = $item->filename;
		if ($target_extension != '') {
			$target_basename .= '.' . $target_extension;
		}

		$category_components = explode(DIRECTORY_SEPARATOR, $item->path);
		$category = count($category_components) >= 2 ? $category_components[1] : "";

		$url = GARDEN_SITE_BASE_URL . garden_url($item->path, $target_basename);
		$target_path = garden_path($output_directory, garden_url($item->path, $target_basename));

		$date = filemtime($item->full_path);

		$output_items[] = new GardenItem($item, $type, $id, $item->filename, $category, $url, $date, $item->full_path, $target_path);
	}

	return $output_items;
}

///////////////////////////////////////////////////////////////////////////////
// Paths
///////////////////////////////////////////////////////////////////////////////

class GardenContentPath {
	public $full_path;
	public $root;
	public $path;
	public $basename;
	public $filename;
	public $extension;

	public function __construct($full_path, $root, $path, $path_parts) {
		$this->full_path = $full_path;
		$this->root = $root;
		$this->path = $path;
		$this->basename = $path_parts['basename'];
		$this->filename = $path_parts['filename'];
		$this->extension = $path_parts['extension'];
	}
}

function garden_find_content_files($content_dir) {
	$content_dir = realpath($content_dir);

	$scan_paths = [''];
	$output_paths = [];

	while (count($scan_paths) > 0) {
		$scan_path = array_shift($scan_paths);
		$path_contents = scandir(garden_path($content_dir, $scan_path));
		foreach ($path_contents as $item) {
			if (str_starts_with($item, '.')) {
				continue;
			}

			$full_path = garden_path($content_dir, $scan_path, $item);
			if (is_dir($full_path)) {
				$scan_paths[] = garden_path($scan_path, $item);
				continue;
			}

			$path_parts = pathinfo($full_path);
			$output_paths[] = new GardenContentPath($full_path, $content_dir, $scan_path, $path_parts);
		}
	}

	return $output_paths;
}

///////////////////////////////////////////////////////////////////////////////
// Directories
///////////////////////////////////////////////////////////////////////////////

function garden_make_directories($content_items) {
	foreach ($content_items as $item) {
		$path_parts = pathinfo($item->target_filename);

		$directory = $path_parts['dirname'];
		if (is_dir($directory ) == false) {
			mkdir($directory , 0777, true); // FIXME, permissions...
		}
	}

	return $content_items;
}

function garden_move_raw($content_items) {
	foreach ($content_items as $item) {
		if ($item->type != GardenItemType::Raw && $item->type != GardenItemType::Image) { // FIXME, do we need to copy images?
			continue;
		}

		$success = copy($item->source_filename, $item->target_filename);
		if ($success != true) {
			error('Failed to copy file: filename="', $item->source_filename, '"');
		}
	}

	return $content_items;
}

///////////////////////////////////////////////////////////////////////////////
// Template
///////////////////////////////////////////////////////////////////////////////

function garden_template_render($name, $variables = null) {
	global $garden_template_base, $garden_template_content;
	
	$base_template = null;

	$output = '';
	while ($name != null) {
		$path = garden_path(GARDEN_TEMPLATE_DIR, $name . '.php');
		
		$base_template = null;
		$base_template_variables = null;

		$garden_template_base_previous = $garden_template_base;
		$garden_template_base = function($name, $base_variables) use (&$base_template, &$base_template_variables) {
			$base_template = $name;
			$base_template_variables = $base_variables;
		};

		$garden_template_content_previous = $garden_template_content;
		$garden_template_content = function() use ($output) {
			return $output;
		};

		if ($variables != null) {
			extract($variables);
		}

		ob_start();
		include($path);
		$output = ob_get_contents();
		ob_end_clean();

		$garden_template_base = $garden_template_base_previous;
		$garden_template_content = $garden_template_content_previous;

		$name = $base_template;
		$variables = $base_template_variables;
	}

	return $output;
}

///////////////////////////////////////////////////////////////////////////////
// Images
///////////////////////////////////////////////////////////////////////////////

class GardenImage {
	public $content_item;
	public $width;
	public $height;
	public $url;
	public $target_filename;
	
	public function __construct($content_item, $width, $height, $url, $target_filename) {
		$this->content_item = $content_item;
		$this->width = $width;
		$this->height = $height;
		$this->url = $url;
		$this->target_filename = $target_filename;
	}
}

function garden_make_images($post_process_items) {
	foreach ($post_process_items as $item) {
		$image = new Imagick($item->content_item->source_filename);
		$image->thumbnailImage($item->width, $item->height);
		$image->writeImage($item->target_filename);
	}
}

///////////////////////////////////////////////////////////////////////////////
// Template helpers
///////////////////////////////////////////////////////////////////////////////

function garden_template_base($name, $variables = null) {
	global $garden_template_base;
	$garden_template_base($name, $variables);
}

function garden_template_content() {
	global $garden_template_content;
	return $garden_template_content();
}

function garden_site_url(...$url_segments) {
	return GARDEN_SITE_BASE_URL . garden_url(...$url_segments);
}

///////////////////////////////////////////////////////////////////////////////
// HTML
///////////////////////////////////////////////////////////////////////////////

require_once(garden_path(__DIR__, 'third_party', 'parsedown', 'Parsedown.php'));

class GardenExtendedParsedown extends Parsedown {
	public $post_process_items;
	private $output_directory;
	private $content_items;

	public function __construct($output_directory, $content_items) {
		$this->post_process_items = [];
		$this->output_directory = $output_directory;
		$this->content_items = $content_items;
		$this->InlineTypes['!'][] = 'Youtube';
		$this->InlineTypes['!'][] = 'Image';
		$this->InlineTypes['['][] = 'WikiLinks';
		$this->inlineMarkerList .= '!';
		$this->inlineMarkerList .= '[';
	}

	protected function inlineImage($excerpt) {
		if (preg_match('/^!\[\[([^\|\]]+)(\|([0-9]+)x([0-9]+))?\]\]/', $excerpt['text'], $matches)) {
			$image_name = $matches[1];
			$image_width = count($matches) == 5 ? $matches[3] : null;
			$image_height = count($matches) == 5 ? $matches[4] : null;

			if ($image_name == null) {
				return;
			}

			$image_content_item = null;
			foreach ($this->content_items as $content_item) {
				if ($content_item->path->basename == $image_name) {
					$image_content_item = $content_item;
					break;
				}
			}

			if ($image_content_item == null) {
				return;
			}

			$target_url = $image_content_item->url;
			if ($image_width != null && $image_height != null) {
				$original_path = $image_content_item->path;

				$target_basename = $original_path->filename . '_' . $image_width . 'x' . $image_height . '.png';

				$target_url = GARDEN_SITE_BASE_URL . garden_url($original_path->path, $target_basename);
				$target_path = garden_path($this->output_directory, garden_url($original_path->path, $target_basename));

				$post_process_item = new GardenImage($image_content_item, $image_width, $image_height, $target_url, $target_path);
				$this->post_process_items[] = $post_process_item;
			}

			return array(
				'extent' => strlen($matches[0]), 
				'element' => array(
					'name' => 'img',
					'text' => '',
					'attributes' => array(
						'src' => $target_url,
					),
				),
			);
		}
	}

	protected function inlineYoutube($excerpt) {
		if (preg_match('/^!\[\[yt:([^\]]+)\]\]/', $excerpt['text'], $matches)) {
			$video_id = $matches[1];

			if ($video_id == null) {
				return;
			}

			return array(
				'extent' => strlen($matches[0]), 
				'element' => array(
					'name' => 'iframe',
					'text' => '',
					'attributes' => array(
						'class' => "video",
						'type' => "text/html",
						//'width' => "640",
						//'height' => "360",
						'src' => "https://www.youtube.com/embed/" . $video_id,
						'frameborder' => "0",
						'loading' => "lazy",
						'referrerpolicy' => "no-referrer",
						'sandbox' => "allow-same-origin allow-scripts",
					),
				),
			);
		}
	}

	protected function inlineWikiLinks($excerpt) {
		if (preg_match('/^\[\[(.+)\]\]/', $excerpt['text'], $matches)) {
			$target_title = $matches[1];

			if ($target_title == null) {
				return;
			}

			$target_url = null;
			foreach ($this->content_items as $content_item) {
				if ($content_item->title == $target_title) {
					$target_url = $content_item->url;
					break;
				}
			}

			if ($target_url == null) {
				return;
			}

			return array(
				'extent' => strlen($matches[0]), 
				'element' => array(
					'name' => 'a',
					'text' => $target_title,
					'attributes' => array(
						'href' => $target_url,
					),
				),
			);
		}
	}
}

function garden_generate_html($output_directory, $content_items) {
	$output_items = [];

	$categorised_items = [];
	foreach ($content_items as $item) {
		if ($item->type != GardenItemType::Article) {
			continue;
		}

		if (isset($categorised_items[$item->category]) == false) {
			$categorised_items[$item->category] = [];
		}
		$categorised_items[$item->category][] = $item;
	}

	foreach ($content_items as $item) {
		if ($item->type != GardenItemType::Article) {
			continue;
		}

		$markdown_data = garden_read_file($item->source_filename);

		$parsedown = new GardenExtendedParsedown($output_directory, $content_items);
		$markdown_html = $parsedown->text($markdown_data);

		if (count($parsedown->post_process_items) > 0) {
			array_push($output_items, ...$parsedown->post_process_items);
		}

		$html_data = garden_template_render('article', [ 'article' => $item, 'article_content' => $markdown_html, 'categorised_items' => $categorised_items ]);

		garden_write_file($item->target_filename, $html_data);
	}

	return $output_items;
}

///////////////////////////////////////////////////////////////////////////////
// Main
///////////////////////////////////////////////////////////////////////////////

function garden() {
	$content_files = garden_find_content_files(GARDEN_CONTENT_DIR);
	array_push($content_files, ...garden_find_content_files(GARDEN_TEMPLATE_DIR));
	$process_items = garden_make_process_items(GARDEN_OUTPUT_DIR, $content_files);
	garden_make_directories($process_items);
	garden_move_raw($process_items);
	$post_process_items = garden_generate_html(GARDEN_OUTPUT_DIR, $process_items);
	garden_make_images($post_process_items);
}

///////////////////////////////////////////////////////////////////////////////
// Main code!
///////////////////////////////////////////////////////////////////////////////

assert($argc >= 2);

// First parameter needs to be the configuration php
$config_file = $argv[1];
output_debug("Will use configuration: file='", $config_file, "'");
require_once($config_file);

garden();