<?php

namespace Barn2\Plugin\Posts_Table_Search_Sort;

/**
 * This class is responsible for generating a HTML table from a list of supplied attributes.
 *
 * @author    Barn2 Media <info@barn2.co.uk>
 * @license   GPL-3.0
 * @copyright Barn2 Media Ltd
 */
class Simple_Posts_Table {

    /**
     * Stores the number of tables on this page. Used to generate the table ID.
     *
     * @var int
     */
    private static $table_count = 1;

    /**
     * The complete list of table attributes, and their defaults.
     *
     * @var array
     */
    public static $default_args = array(
        'columns'         => 'title,content,date,author,category',
        'rows_per_page'   => 20,
        'sort_by'         => 'date',
        'sort_order'      => '',
        'category'        => '',
        'tag'             => '',
        'author'          => '',
        'post_status'     => '',
        'date_format'     => 'Y/m/d',
        'search_on_click' => true,
        'wrap'            => true,
        'content_length'  => 15,
        'scroll_offset'   => 15
    );

    /**
     * An array of all possible columns and their default heading, priority, and column width.
     *
     * @var array
     */
    private static $column_defaults = array();

    /**
     * An array of all allowed column keys.
     *
     * @var array
     */
    private static $allowed_columns = array();

    public static function get_defaults() {
        return \wp_parse_args( Settings::get_table_args(), self::$default_args );
    }

    public static function get_column_defaults() {
        if ( empty( self::$column_defaults ) ) {
            /**
             * Priority values are used to determine visiblity at small screen sizes (1 = highest priority, 6 = lowest priority).
             * Column widths are automatically calculated by DataTables, but can be overridden by using filter 'posts_data_table_column_defaults'.
             */
            self::$column_defaults = array(
                'id'       => array(
                    'heading'  => __( 'ID', 'posts-data-table' ),
                    'priority' => 3,
                    'width'    => ''
                ),
                'title'    => array(
                    'heading'  => __( 'Title', 'posts-data-table' ),
                    'priority' => 1,
                    'width'    => ''
                ),
                'category' => array(
                    'heading'  => __( 'Categories', 'posts-data-table' ),
                    'priority' => 6,
                    'width'    => ''
                ),
                'tags'     => array(
                    'heading'  => __( 'Tags', 'posts-data-table' ),
                    'priority' => 7,
                    'width'    => ''
                ),
                'date'     => array(
                    'heading'  => __( 'Date', 'posts-data-table' ),
                    'priority' => 2,
                    'width'    => ''
                ),
                'author'   => array(
                    'heading'  => __( 'Author', 'posts-data-table' ),
                    'priority' => 4,
                    'width'    => ''
                ),
                'content'  => array(
                    'heading'  => __( 'Content', 'posts-data-table' ),
                    'priority' => 5,
                    'width'    => ''
                )
            );
        }

        return self::$column_defaults;
    }

    public static function get_allowed_columns() {
        if ( empty( self::$allowed_columns ) ) {
            self::$allowed_columns = \array_keys( self::get_column_defaults() );
        }
        return self::$allowed_columns;
    }

    /**
     * Retrieves a data table containing a list of posts based on the specified arguments.
     *
     * @param array $args An array of options used to display the posts table
     * @return string The posts table HTML output
     */
    public function get_table( $args ) {
        $args = \wp_parse_args( $args, self::get_defaults() );

        if ( empty( $args['columns'] ) ) {
            $args['columns'] = self::$default_args['columns'];
        }

        $args['rows_per_page'] = \filter_var( $args['rows_per_page'], \FILTER_VALIDATE_INT );

        if ( $args['rows_per_page'] < 1 || ! $args['rows_per_page'] ) {
            $args['rows_per_page'] = false;
        }

        if ( ! \in_array( $args['sort_by'], self::get_allowed_columns() ) ) {
            $args['sort_by'] = self::$default_args['sort_by'];
        }

        if ( ! \in_array( $args['sort_order'], array( 'asc', 'desc' ) ) ) {
            $args['sort_order'] = self::$default_args['sort_order'];
        }

        // Set default sort direction
        if ( ! $args['sort_order'] ) {
            if ( $args['sort_by'] === 'date' ) {
                $args['sort_order'] = 'desc';
            } else {
                $args['sort_order'] = 'asc';
            }
        }

        $args['search_on_click'] = filter_var( $args['search_on_click'], \FILTER_VALIDATE_BOOLEAN );
        $args['wrap']            = filter_var( $args['wrap'], \FILTER_VALIDATE_BOOLEAN );
        $args['content_length']  = filter_var( $args['content_length'], \FILTER_VALIDATE_INT );
        $args['scroll_offset']   = filter_var( $args['scroll_offset'], \FILTER_VALIDATE_INT );

        if ( empty( $args['date_format'] ) ) {
            $args['date_format'] = self::$default_args['date_format'];
        }

        $output       = $table_head   = $table_body   = $body_row_fmt = '';

        // Start building the args needed for our posts query
        $post_args = array(
            'post_type'        => 'post',
            'posts_per_page'   => \apply_filters( 'posts_data_table_post_limit', 1000 ),
            'post_status'      => 'publish',
            'suppress_filters' => false // Ensure WPML filters run on this query
        );

        if ( ! empty( $args['category'] ) ) {
            if ( \is_numeric( $args['category'] ) ) {
                $post_args['cat'] = $args['category'];
            } else {
                $category = \get_category_by_slug( $args['category'] );

                if ( $category ) {
                    $post_args['category_name'] = $category->slug;
                }
            }
        }

        if ( ! empty( $args['tag'] ) ) {
            if ( \is_numeric( $args['tag'] ) ) {
                $post_args['tag_id'] = $args['tag'];
            } else {
                $post_args['tag'] = $args['tag'];
            }
        }

        if ( ! empty( $args['author'] ) ) {
            $author = $args['author'];

            if ( \is_numeric( $author ) || false !== \strpos( $author, ',' ) ) {
                $post_args['author'] = $author;
            } else {
                $post_args['author_name'] = $author;
            }
        }

        if ( ! empty( $args['post_status'] ) ) {
            $post_args['post_status'] = $args['post_status'];
        }

        // Get all published posts in the current language
        $all_posts = \get_posts( \apply_filters( 'posts_data_table_query_args', $post_args, $args ) );

        // Bail early if no posts found
        if ( ! $all_posts || ! \is_array( $all_posts ) ) {
            return $output;
        }

        // Allow theme/plugins to override defaults
        $column_defaults = \apply_filters( 'posts_data_table_column_defaults_' . self::$table_count, \apply_filters( 'posts_data_table_column_defaults', self::get_column_defaults() ) );

        // Get the columns to be used in this table
        $columns        = \array_filter( \array_map( 'trim', \explode( ',', \strtolower( $args['columns'] ) ) ) );
        $hidden_columns = array();

        // If none of the user-specfied columns are valid, use the default columns instead
        if ( ! \array_intersect( self::get_allowed_columns(), $columns ) ) {
            $columns = \explode( ',', self::$default_args['columns'] );
        }

        // Set hidden columns and sort indexes
        $table_sort_index = \array_search( $args['sort_by'], $columns );
        $date_sort_index  = false;
        $hidden_date      = \in_array( 'date', $columns ) || 'date' === $args['sort_by'];

        if ( $hidden_date ) {
            $hidden_columns[] = 'timestamp';
            $date_sort_index  = \count( $columns );

            // If we're sorting by date, make sure we use this hidden column for the initial table sort
            if ( 'date' === $args['sort_by'] && false === $table_sort_index ) {
                $table_sort_index = $date_sort_index;
            }
        }

        if ( false === $table_sort_index ) {
            // Sort column is not in list of displayed columns so we'll add it as a hidden column at end of table
            $hidden_columns[] = $args['sort_by'];

            // Set the table sort index to the index of the hidden sort column
            $table_sort_index = $date_sort_index ? $date_sort_index + 1 : \count( $columns );
        }

        // Build table header
        $heading_fmt = '<th data-name="%1$s" data-priority="%2$u" data-width="%3$s"%5$s>%4$s</th>';
        $cell_fmt    = '<td>{%s}</td>';

        foreach ( $columns as $column ) {
            // Double-check column name is valid
            if ( ! \in_array( $column, self::get_allowed_columns() ) ) {
                continue;
            }

            // Do we need to use custom data for ordering this column?
            $order_data = '';

            if ( 'date' === $column && false !== $date_sort_index ) {
                $order_data = \sprintf( ' data-order-data="%u"', $date_sort_index );
            }

            // Add heading to table
            $table_head .= \sprintf( $heading_fmt, $column, $column_defaults[$column]['priority'], $column_defaults[$column]['width'], $column_defaults[$column]['heading'], $order_data );

            // Add placeholder to table body format string so that content for this column is included in table output
            $body_row_fmt .= \sprintf( $cell_fmt, $column );
        }

        foreach ( $hidden_columns as $column ) {
            $table_head .= \sprintf( '<th data-name="%s" data-visible="false"></th>', $column );

            // Make sure data for the hidden column is included in table content
            $body_row_fmt .= \sprintf( $cell_fmt, $column );
        }

        $table_head = \sprintf( '<thead><tr>%s</tr></thead>', $table_head );

        // Build table body
        $body_row_fmt = '<tr>' . $body_row_fmt . '</tr>';

        // Loop through posts and add a row for each
        foreach ( (array) $all_posts as $_post ) {
            \setup_postdata( $_post );

            // Format title
            $title = \sprintf( '<a href="%1$s">%2$s</a>', \get_permalink( $_post ), \ get_the_title( $_post ) );

            // Format author
            $author = \sprintf(
                '<a href="%1$s" title="%2$s" rel="author">%3$s</a>',
                \esc_url( \get_author_posts_url( $_post->post_author ) ),
                \esc_attr( \sprintf( __( 'Posts by %s', 'posts-data-table' ), \get_the_author() ) ),
                \get_the_author()
            );

            $post_data_trans = \apply_filters( 'posts_data_table_row_data_format', array(
                '{id}'        => $_post->ID,
                '{title}'     => $title,
                '{category}'  => \get_the_category_list( ', ', '', $_post->ID ),
                '{tags}'      => \get_the_tag_list( '', ', ', '', $_post->ID ),
                '{date}'      => \get_the_date( $args['date_format'], $_post ),
                '{author}'    => $author,
                '{content}'   => $this->get_post_content( $args['content_length'] ),
                '{timestamp}' => $_post->post_date
                ) );

            $table_body .= \strtr( $body_row_fmt, $post_data_trans );
        } // foreach post

        \wp_reset_postdata();

        $table_body = \sprintf( '<tbody>%s</tbody>', $table_body );

        $paging_attr = 'false';

        if ( $args['rows_per_page'] && $args['rows_per_page'] < \count( $all_posts ) ) {
            $paging_attr = 'true';
        }

        $order_attr = '';

        if ( false !== $table_sort_index ) {
            // Order attribute should be escaped here rather than in sprintf below as we don't want to escape the double-quotes around "asc" or "desc"
            $order_attr = \sprintf( '[[%u, "%s"]]', \esc_attr( $table_sort_index ), \esc_attr( $args['sort_order'] ) );
        }

        $offset_attr = ( $args['scroll_offset'] === false ) ? 'false' : $args['scroll_offset'];
        $table_class = 'posts-data-table';

        if ( ! $args['wrap'] ) {
            $table_class .= ' nowrap';
        }

        $table_attributes = sprintf(
            'id="posts-table-%1$u" class="%2$s" data-page-length="%3$u" data-paging="%4$s" data-order=\'%5$s\' data-click-filter="%6$s" data-scroll-offset="%7$s" cellspacing="0" width="100%%"',
            self::$table_count,
            \esc_attr( $table_class ),
            \esc_attr( $args['rows_per_page'] ),
            \esc_attr( $paging_attr ),
            $order_attr, // escaped above
            \esc_attr( $args['search_on_click'] ? 'true' : 'false' ),
            \esc_attr( $offset_attr )
        );

        $output = \sprintf( '<table %1$s>%2$s%3$s</table>', $table_attributes, $table_head, $table_body );

        // Increment the table count
        self::$table_count ++;

        return \apply_filters( 'posts_data_table_html_output', $output, $args );
    }

    /**
     * Retrieve the post content, truncated to the number of words specified by $num_words.
     *
     * Must be called with the Loop or a secondary loop after a call to setup_postdata().
     *
     * @param int $num_words The number of words to trim the content to
     * @return string The (truncated) post content
     */
    private function get_post_content( $num_words = 15 ) {
        $text = \get_the_content( '' );
        $text = \strip_shortcodes( $text );
        $text = \apply_filters( 'the_content', $text );

        if ( $num_words > 0 ) {
            $text = \wp_trim_words( $text, $num_words, ' &hellip;' );
        }
        return $text;
    }

}