<?php

namespace PostTypes;

/**
 * Columns
 *
 * Used to help manage a post types columns in the admin table
 */
class Columns
{
    /**
     * Holds an array of all the defined columns.
     *
     * @var array
     */
    public $items = [];

    /**
     * An array of columns to add.
     *
     * @var array
     */
    public $add = [];

    /**
     * An array of columns to hide.
     *
     * @var array
     */
    public $hide = [];

    /**
     * An array of columns to reposition.
     *
     * @var array
     */
    public $positions = [];

    /**
     * An array of custom populate callbacks.
     *
     * @var array
     */
    public $populate = [];

    /**
     * An array of columns that are sortable.
     *
     * @var array
     */
    public $sortable = [];

    /**
     * Set the all columns
     * @param array $columns an array of all the columns to replace
     */
    public function set($columns)
    {
        $this->items = $columns;
    }

    /**
     * Add a new column
     * @param string  $column   the slug of the column
     * @param string  $label    the label for the column
     */
    public function add($columns, $label = null)
    {

        if (!is_array($columns)) {
            $columns = [$columns => $label];
        }

        foreach ($columns as $column => $label) {
            if (is_null($label)) {
                $label = str_replace(['_', '-'], ' ', ucfirst($column));
            }

            $this->add[$column] = $label;
        }

        return $this;
    }

    /**
     * Add a column to hide
     * @param  string $column the slug of the column to hdie
     */
    public function hide($columns)
    {
        if (!is_array($columns)) {
            $columns = [$columns];
        }

        foreach ($columns as $column) {
            $this->hide[] = $column;
        }

        return $this;
    }

    /**
     * Set a custom callback to populate a column
     * @param  string $column   the column slug
     * @param  mixed  $callback callback function
     */
    public function populate($column, $callback)
    {
        $this->populate[$column] = $callback;

        return $this;
    }

    /**
     * Define the postion for a columns
     * @param  string  $columns  an array of columns
     */
    public function order($columns)
    {
        foreach ($columns as $column => $position) {
            $this->positions[$column] = $position;
        }

        return $this;
    }

    /**
     * Set columns that are sortable
     * @param  string  $column     the slug of the column
     * @param  string  $meta_value the meta_value to orderby
     * @param  boolean $is_num     whether to order by string/number
     */
    public function sortable($sortable)
    {
        foreach ($sortable as $column => $options) {
            $this->sortable[$column] = $options;
        }

        return $this;
    }

    /**
     * Check if an orderby field is a custom sort option.
     * @param  string  $orderby  the orderby value from query params
     */
    public function isSortable($orderby)
    {
        if (is_string($orderby) && array_key_exists($orderby, $this->sortable)) {
            return true;
        }

        foreach ($this->sortable as $column => $options) {
            if (is_string($options) && $options === $orderby) {
                return true;
            }
            if (is_array($options) && isset($options[0]) && $options[0] === $orderby) {
                return true;
            }
        }

        return false;
    }

    /**
     * Get meta key for an orderby.
     * @param  string  $orderby  the orderby value from query params
     */
    public function sortableMeta($orderby)
    {
        if (array_key_exists($orderby, $this->sortable)) {
            return $this->sortable[$orderby];
        }

        foreach ($this->sortable as $column => $options) {
            if (is_string($options) && $options === $orderby) {
                return $options;
            }
            if (is_array($options) && isset($options[0]) && $options[0] === $orderby) {
                return $options;
            }
        }

        return '';
    }

    /**
     * Modify the columns for the object
     * @param  array  $columns WordPress default columns
     * @return array           The modified columns
     */
    public function modifyColumns($columns)
    {
        // if user defined set columns, return those
        if (!empty($this->items)) {
            return $this->items;
        }

        // add additional columns
        if (!empty($this->add)) {
            foreach ($this->add as $key => $label) {
                $columns[$key] = $label;
            }
        }

        // unset hidden columns
        if (!empty($this->hide)) {
            foreach ($this->hide as $key) {
                unset($columns[$key]);
            }
        }

        // if user has made added custom columns
        if (!empty($this->positions)) {
            foreach ($this->positions as $key => $position) {
                // find index of the element in the array
                $index = array_search($key, array_keys($columns));
                // retrieve the element in the array of columns
                $item = array_slice($columns, $index, 1);
                // remove item from the array
                unset($columns[$key]);

                // split columns array into two at the desired position
                $start = array_slice($columns, 0, $position, true);
                $end = array_slice($columns, $position, count($columns) - 1, true);

                // insert column into position
                $columns = $start + $item + $end;
            }
        }

        return $columns;
    }
}