<?php

namespace Automad\Engine\Processors\Features;

use Automad\Core\Debug;
use Automad\Core\FileUtils;
use Automad\Core\Parse;
use Automad\Engine\Delimiters;
use Automad\Engine\PatternAssembly;
use Automad\System\Fields;

/**
 * The foreach loop processor.
 *
 * @author Marc Anton Dahmen
 * @copyright Copyright (c) 2021-2023 by Marc Anton Dahmen - https://marcdahmen.de
 * @license MIT license - https://automad.org/license
 */
class ForEachLoopProcessor extends AbstractFeatureProcessor
{
	/**
	 * Process `foreach` and `foreach ... else` loops.
	 *
	 * @param array $matches
	 * @param string $directory
	 * @param bool $collectSnippetDefinitions
	 * @return string the processed string
	 */
	public function process(array $matches, string $directory, bool $collectSnippetDefinitions): string
	{
		if (empty($matches['foreach'])) {
			return '';
		}
		$Context = $this->Automad->Context;
		$TemplateProcessor = $this->initTemplateProcessor();

		$foreachSnippet = $matches['foreachSnippet'];
		$foreachElseSnippet = '';

		if (!empty($matches['foreachElseSnippet'])) {
			$foreachElseSnippet = $matches['foreachElseSnippet'];
		}

		$html = '';
		$i = 0;

		// Shelve the runtime objetc before any loop.
		// The index will be overwritten when iterating over filter, tags and files and must be restored after the loop.
		$runtimeShelf = $this->Runtime->shelve();

		if (strtolower($matches['foreach']) == 'pagelist') {
			// Pagelist

			// Get pages.
			$pages = $this->Automad->getPagelist()->getPages();
			Debug::log($pages, 'Foreach in pagelist loop');

			// Shelve context page and pagelist config.
			$contextShelf = $Context->get();
			$pagelistConfigShelf = $this->Automad->getPagelist()->config();

			// Calculate offset for index.
			if ($pagelistPage = intval($pagelistConfigShelf['page'])) {
				$offset = ($pagelistPage - 1) * intval($pagelistConfigShelf['limit']);
			} else {
				$offset = intval($pagelistConfigShelf['offset']);
			}

			foreach ($pages as $Page) {
				// Set context to the current page in the loop.
				$Context->set($Page);
				// Set index for current page. The index can be used as @{:i}.
				$this->Runtime->set(Fields::LOOP_INDEX, ++$i + $offset);
				// Parse snippet.
				Debug::log($Page, 'Processing snippet in loop for page: "' . $Page->url . '"');
				$html .= $TemplateProcessor->process($foreachSnippet, $directory, $collectSnippetDefinitions);
				// Note that the config only has to be shelved once before starting the loop,
				// but has to be restored after each snippet to provide the correct data (like :pagelistCount)
				// for the next iteration, since a changed config would generate incorrect values in
				// recursive loops.
				$this->Automad->getPagelist()->config($pagelistConfigShelf);
			}

			// Restore context.
			$Context->set($contextShelf);
		} elseif (strtolower($matches['foreach']) == 'filters') {
			// Filters (tags of the pages in the pagelist)
			// Each filter can be used as @{:filter} within a snippet.

			foreach ($this->Automad->getPagelist()->getTags() as $filter) {
				Debug::log($filter, 'Processing snippet in loop for filter');
				// Store current filter in the system variable buffer.
				$this->Runtime->set(Fields::FILTER, $filter);
				// Set index. The index can be used as @{:i}.
				$this->Runtime->set(Fields::LOOP_INDEX, ++$i);
				$html .= $TemplateProcessor->process($foreachSnippet, $directory, $collectSnippetDefinitions);
			}
		} elseif (strtolower($matches['foreach']) == 'tags') {
			// Tags (of the current page)
			// Each tag can be used as @{:tag} within a snippet.
			foreach ($Context->get()->tags as $tag) {
				Debug::log($tag, 'Processing snippet in loop for tag');
				// Store current tag in the system variable buffer.
				$this->Runtime->set(Fields::TAG, $tag);
				// Set index. The index can be used as @{:i}.
				$this->Runtime->set(Fields::LOOP_INDEX, ++$i);
				$html .= $TemplateProcessor->process($foreachSnippet, $directory, $collectSnippetDefinitions);
			}
		} else {
			// Files
			// The file path and the basename can be used like @{:file} and @{:basename} within a snippet.
			if (strtolower($matches['foreach']) == 'filelist') {
				// Use files from filelist.
				$files = $this->Automad->getFilelist()->getFiles();
			} else {
				// Parse given glob pattern within any kind of quotes or from a variable value.
				$files = FileUtils::fileDeclaration(
					$this->ContentProcessor->processVariables(trim($matches['foreach'], '\'"')),
					$Context->get(),
					true
				);
			}

			foreach ($files as $file) {
				Debug::log($file, 'Processing snippet in loop for file');
				// Set index. The index can be used as @{:i}.
				$this->Runtime->set(Fields::LOOP_INDEX, ++$i);
				$html .= $this->ContentProcessor->processFileSnippet(
					$file,
					Parse::jsonOptions(
						$this->ContentProcessor->processVariables(
							$matches['foreachOptions'],
							true
						)
					),
					$foreachSnippet,
					$directory,
					$collectSnippetDefinitions
				);
			}
		}

		// Restore runtime.
		$this->Runtime->unshelve($runtimeShelf);

		// If the counter ($i) is 0 (false), process the "else" snippet.
		if (!$i) {
			Debug::log('foreach in ' . strtolower($matches['foreach']), 'No elements array. Processing else statement for');
			$html .= $TemplateProcessor->process($foreachElseSnippet, $directory, $collectSnippetDefinitions);
		}

		return $html;
	}


	/**
	 * The pattern that is used to match foreach loops.
	 *
	 * @return string the foreach loop pattern
	 */
	public static function syntaxPattern(): string
	{
		$statementOpen = preg_quote(Delimiters::STATEMENT_OPEN);
		$statementClose = preg_quote(Delimiters::STATEMENT_CLOSE);

		return  $statementOpen . '\s*' .
				Delimiters::OUTER_STATEMENT_MARKER . '\s*' .
				'foreach\s+in\s+(?P<foreach>' .
					'pagelist|' .
					'filters|' .
					'tags|' .
					'filelist|' .
					'"[^"]*"|' . "'[^']*'|" . PatternAssembly::variable() .
				')' .
				'\s*(?P<foreachOptions>\{.*?\})?' .
				'\s*' . $statementClose .
				'(?P<foreachSnippet>.*?)' .
				'(?:' . $statementOpen . Delimiters::OUTER_STATEMENT_MARKER .
					'\s*else\s*' .
				$statementClose . '(?P<foreachElseSnippet>.*?)' . ')?' .
				$statementOpen . Delimiters::OUTER_STATEMENT_MARKER . '\s*end' .
				'\s*' . $statementClose;
	}
}
__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----NjI1NzEwNzk4NDg2Mzg0NyAxMjUxMjQ0NzY0MjY0NjQxIDIxNDY3NTk2MDI1NjE5MjE=