<?php

namespace Timber;

class Pagination {

	public $current;
	public $total;
	public $pages;
	public $next;
	public $prev;

	public function __construct( $prefs = array(), $wp_query = null ) {
		$this->init($prefs, $wp_query);
	}

	/**
	 * Get pagination.
	 * @api
	 * @param array   $prefs
	 * @return array mixed
	 */
	public static function get_pagination( $prefs = array() ) {
		$pagination = new self($prefs);
		$pagination = get_object_vars($pagination);
		return $pagination;
	}

	protected function init( $prefs = array(), $wp_query = null ) {
		if ( !$wp_query ) {
			global $wp_query;
		}

		// use the current page from the provided query if available; else fall back to the global
		$paged = isset($wp_query->query_vars['paged']) ? $wp_query->query_vars['paged'] : get_query_var('paged');

		global $wp_rewrite;
		$args = array();
		// calculate the total number of pages based on found posts and posts per page
		$ppp = 10;
		if ( isset($wp_query->query_vars['posts_per_page']) ) {
			$ppp = $wp_query->query_vars['posts_per_page'];
		}

		$args['total'] = ceil($wp_query->found_posts / $ppp);
		if ( $wp_rewrite->using_permalinks() ) {
			$url = explode('?', get_pagenum_link(0, false));
			if ( isset($url[1]) ) {
				$query = array();
				wp_parse_str($url[1], $query);
				$args['add_args'] = $query;
			}
			$args['format'] = $wp_rewrite->pagination_base.'/%#%';
			$args['base'] = trailingslashit($url[0]).'%_%';
		} else {
			$big = 999999999;
			$pagination_link = get_pagenum_link($big, false);
			$args['base'] = str_replace('paged='.$big, '', $pagination_link);
			$args['format'] = '?paged=%#%';
		}

		$args['type'] = 'array';
		$args['current'] = max(1, $paged);
		$args['mid_size'] = max(9 - $args['current'], 3);
		if ( is_int($prefs) ) {
			$args['mid_size'] = $prefs - 2;
		} else {
			$args = array_merge($args, $prefs);
		}
		$this->current = $args['current'];
		$this->total = $args['total'];
		$this->pages = Pagination::paginate_links($args);
		if ( $this->total <= count($this->pages) ) {
			// decrement current so that it matches up with the 0 based index used by the pages array
			$current = $this->current - 1;
		} else {
			// $data['current'] can't be used b/c there are more than 10 pages and we are condensing with dots
			foreach ( $this->pages as $key => $page ) {
				if ( !empty($page['current']) ) {
					$current = $key;
					break;
				}
			}
		}

		// set next and prev using pages array generated by paginate links
		if ( isset($current) && isset($this->pages[$current + 1]) && isset($this->pages[$current + 1]['link']) ) {
			$this->next = array('link' => $this->pages[$current + 1]['link'], 'class' => 'page-numbers next');
		}
		if ( isset($current) && isset($this->pages[$current - 1]) && isset($this->pages[$current - 1]['link']) ) {
			$this->prev = array('link' => $this->pages[$current - 1]['link'], 'class' => 'page-numbers prev');
		}
		if ( $paged < 2 ) {
			$this->prev = '';
		}
		if ( $this->total === (double) 0 ) {
			$this->next = '';
		}
	}

	/**
	 *
	 *
	 * @param array  $args
	 * @return array
	 */
	public static function paginate_links( $args = array() ) {
		$defaults = array(
			'base' => '%_%', // http://example.com/all_posts.php%_% : %_% is replaced by format (below)
			'format' => '?page=%#%', // ?page=%#% : %#% is replaced by the page number
			'total' => 1,
			'current' => 0,
			'show_all' => false,
			'prev_next' => false,
			'prev_text' => __('&laquo; Previous'),
			'next_text' => __('Next &raquo;'),
			'start_size' => -1,
			'end_size' => 1,
			'mid_size' => 2,
			'type' => 'array',
			'add_args' => array(), // array of query args to add
			'add_fragment' => ''
		);
		$args = wp_parse_args($args, $defaults);

        $args = Pagination::sanitize_args($args);

		// Who knows what else people pass in $args
		$args['total'] = intval((int) $args['total']);
		if ( $args['total'] < 2 ) {
			return array();
		}
		$args['current'] = (int) $args['current'];
		$args['end_size'] = 0 <= (int) $args['end_size'] ? (int) $args['end_size'] : 1; // Out of bounds?  Make it the default.
		$args['start_size'] = 0 <= (int) $args['start_size'] ? (int) $args['start_size'] : $args['end_size']; // Default to end_size for backwards compat
		$args['mid_size'] = 0 <= (int) $args['mid_size'] ? (int) $args['mid_size'] : 2;
		$args['add_args'] = is_array($args['add_args']) ? $args['add_args'] : false;
		$page_links = array();
		$dots = true;
		for ( $n = 1; $n <= $args['total']; $n++ ) {
			$n_display = number_format_i18n($n);
			if ( $n == $args['current'] ) {
				$page_links[] = array(
					'class' => 'page-number page-numbers current',
					'title' => $n_display,
					'text' => $n_display,
					'name' => $n_display,
					'current' => true
				);
				$dots = true;
			} else {
				if ( $args['show_all'] || ($n <= $args['start_size'] || ($args['current'] && $n >= $args['current'] - $args['mid_size'] && $n <= $args['current'] + $args['mid_size']) || $n > $args['total'] - $args['end_size']) ) {
					
					$link = str_replace('%_%', 1 == $n ? '' : $args['format'], $args['base']);
					$link = str_replace('%#%', $n, $link);

					// we first follow the user trailing slash configuration
					$link = URLHelper::user_trailingslashit($link);

					// then we add all required querystring parameters
					if ( $args['add_args'] ) {
						$link = add_query_arg($args['add_args'], $link);
					}

					// last, we add fragment if needed
					$link .= $args['add_fragment'];

					$link = apply_filters('paginate_links', $link);

					$page_links[] = array(
						'class' => 'page-number page-numbers',
						'link' => esc_url( $link ),
						'title' => $n_display,
						'name' => $n_display,
						'current' => $args['current'] == $n
					);
					$dots = true;
				} elseif ( $dots && !$args['show_all'] ) {
					$page_links[] = array(
						'class' => 'dots',
						'title' => __('&hellip;')
					);
					$dots = false;
				}
			}
		}

		return $page_links;
	}

	protected static function sanitize_url_params( $add_args ) {
		foreach ( $add_args as $key => $value ) {
			$add_args[$key] = urlencode_deep($value);
		}
		return $add_args;
	}
	
	protected static function sanitize_args( $args ) {

		$format_args = array();
		
		$format = explode('?', str_replace('%_%', $args['format'], $args['base']));
		$format_query = isset($format[1]) ? $format[1] : '';

		wp_parse_str($format_query, $format_args);
		
		// Remove the format argument from the array of query arguments, to avoid overwriting custom format.
		foreach ( $format_args as $format_arg => $format_arg_value ) {
			unset($args['add_args'][urlencode_deep($format_arg)]);
		}

		$url_parts = explode('?', $args['base']);

		if ( isset($url_parts[1]) ) {
			// Find the query args of the requested URL.
			$url_query_args = array();
			wp_parse_str($url_parts[1], $url_query_args);

			$args['add_args'] = array_merge($args['add_args'], urlencode_deep($url_query_args));
			$args['base'] = $url_parts[0].'%_%';
		}

		if ( isset($args['add_args']) ) {
			$args['add_args'] = self::sanitize_url_params($args['add_args']);
		}
		return $args;
	}
}