<?php namespace Illuminate\Support;

use Illuminate\Support\Traits\Macroable;

class Arr
{

    use Macroable;

    /**
     * Add an element to an array using "dot" notation if it doesn't exist.
     *
     * @param  array $array
     * @param  string $key
     * @param  mixed $value
     * @return array
     */
    public static function add($array, $key, $value)
    {
        if (is_null(static::get($array, $key))) {
            static::set($array, $key, $value);
        }

        return $array;
    }

    /**
     * Build a new array using a callback.
     *
     * @param  array $array
     * @param  callable $callback
     * @return array
     */
    public static function build($array, callable $callback)
    {
        $results = [];

        foreach ($array as $key => $value) {
            list($innerKey, $innerValue) = call_user_func($callback, $key, $value);

            $results[$innerKey] = $innerValue;
        }

        return $results;
    }

    /**
     * Collapse an array of arrays into a single array.
     *
     * @param  array|\ArrayAccess $array
     * @return array
     */
    public static function collapse($array)
    {
        $results = [];

        foreach ($array as $values) {
            if ($values instanceof Collection) $values = $values->all();

            $results = array_merge($results, $values);
        }

        return $results;
    }

    /**
     * Divide an array into two arrays. One with keys and the other with values.
     *
     * @param  array $array
     * @return array
     */
    public static function divide($array)
    {
        return [array_keys($array), array_values($array)];
    }

    /**
     * Flatten a multi-dimensional associative array with dots.
     *
     * @param  array $array
     * @param  string $prepend
     * @return array
     */
    public static function dot($array, $prepend = '')
    {
        $results = [];

        foreach ($array as $key => $value) {
            if (is_array($value)) {
                $results = array_merge($results, static::dot($value, $prepend . $key . '.'));
            } else {
                $results[$prepend . $key] = $value;
            }
        }

        return $results;
    }

    /**
     * Get all of the given array except for a specified array of items.
     *
     * @param  array $array
     * @param  array|string $keys
     * @return array
     */
    public static function except($array, $keys)
    {
        static::forget($array, $keys);

        return $array;
    }

    /**
     * Fetch a flattened array of a nested array element.
     *
     * @param  array $array
     * @param  string $key
     * @return array
     */
    public static function fetch($array, $key)
    {
        foreach (explode('.', $key) as $segment) {
            $results = [];

            foreach ($array as $value) {
                if (array_key_exists($segment, $value = (array)$value)) {
                    $results[] = $value[$segment];
                }
            }

            $array = array_values($results);
        }

        return array_values($results);
    }

    /**
     * Return the first element in an array passing a given truth test.
     *
     * @param  array $array
     * @param  callable $callback
     * @param  mixed $default
     * @return mixed
     */
    public static function first($array, callable $callback, $default = null)
    {
        foreach ($array as $key => $value) {
            if (call_user_func($callback, $key, $value)) return $value;
        }

        return value($default);
    }

    /**
     * Return the last element in an array passing a given truth test.
     *
     * @param  array $array
     * @param  callable $callback
     * @param  mixed $default
     * @return mixed
     */
    public static function last($array, callable $callback, $default = null)
    {
        return static::first(array_reverse($array), $callback, $default);
    }

    /**
     * Flatten a multi-dimensional array into a single level.
     *
     * @param  array $array
     * @return array
     */
    public static function flatten($array)
    {
        $return = [];

        array_walk_recursive($array, function ($x) use (&$return) {
            $return[] = $x;
        });

        return $return;
    }

    /**
     * Remove one or many array items from a given array using "dot" notation.
     *
     * @param  array $array
     * @param  array|string $keys
     * @return void
     */
    public static function forget(&$array, $keys)
    {
        $original =& $array;

        foreach ((array)$keys as $key) {
            $parts = explode('.', $key);

            while (count($parts) > 1) {
                $part = array_shift($parts);

                if (isset($array[$part]) && is_array($array[$part])) {
                    $array =& $array[$part];
                }
            }

            unset($array[array_shift($parts)]);

            // clean up after each pass
            $array =& $original;
        }
    }

    /**
     * Get an item from an array using "dot" notation.
     *
     * @param  array $array
     * @param  string $key
     * @param  mixed $default
     * @return mixed
     */
    public static function get($array, $key, $default = null)
    {
        if (is_null($key)) return $array;

        if (isset($array[$key])) return $array[$key];

        foreach (explode('.', $key) as $segment) {
            if (!is_array($array) || !array_key_exists($segment, $array)) {
                return value($default);
            }

            $array = $array[$segment];
        }

        return $array;
    }

    /**
     * Check if an item exists in an array using "dot" notation.
     *
     * @param  array $array
     * @param  string $key
     * @return bool
     */
    public static function has($array, $key)
    {
        if (empty($array) || is_null($key)) return false;

        if (array_key_exists($key, $array)) return true;

        foreach (explode('.', $key) as $segment) {
            if (!is_array($array) || !array_key_exists($segment, $array)) {
                return false;
            }

            $array = $array[$segment];
        }

        return true;
    }

    /**
     * Get a subset of the items from the given array.
     *
     * @param  array $array
     * @param  array|string $keys
     * @return array
     */
    public static function only($array, $keys)
    {
        return array_intersect_key($array, array_flip((array)$keys));
    }

    /**
     * Pluck an array of values from an array.
     *
     * @param  array $array
     * @param  string $value
     * @param  string $key
     * @return array
     */
    public static function pluck($array, $value, $key = null)
    {
        $results = [];

        foreach ($array as $item) {
            $itemValue = data_get($item, $value);

            // If the key is "null", we will just append the value to the array and keep
            // looping. Otherwise we will key the array using the value of the key we
            // received from the developer. Then we'll return the final array form.
            if (is_null($key)) {
                $results[] = $itemValue;
            } else {
                $itemKey = data_get($item, $key);

                $results[$itemKey] = $itemValue;
            }
        }

        return $results;
    }

    /**
     * Get a value from the array, and remove it.
     *
     * @param  array $array
     * @param  string $key
     * @param  mixed $default
     * @return mixed
     */
    public static function pull(&$array, $key, $default = null)
    {
        $value = static::get($array, $key, $default);

        static::forget($array, $key);

        return $value;
    }

    /**
     * Set an array item to a given value using "dot" notation.
     *
     * If no key is given to the method, the entire array will be replaced.
     *
     * @param  array $array
     * @param  string $key
     * @param  mixed $value
     * @return array
     */
    public static function set(&$array, $key, $value)
    {
        if (is_null($key)) return $array = $value;

        $keys = explode('.', $key);

        while (count($keys) > 1) {
            $key = array_shift($keys);

            // If the key doesn't exist at this depth, we will just create an empty array
            // to hold the next value, allowing us to create the arrays to hold final
            // values at the correct depth. Then we'll keep digging into the array.
            if (!isset($array[$key]) || !is_array($array[$key])) {
                $array[$key] = [];
            }

            $array =& $array[$key];
        }

        $array[array_shift($keys)] = $value;

        return $array;
    }

    /**
     * Sort the array using the given callback.
     *
     * @param  array $array
     * @param  callable $callback
     * @return array
     */
    public static function sort($array, callable $callback)
    {
        return Collection::make($array)->sortBy($callback)->all();
    }

    /**
     * Filter the array using the given callback.
     *
     * @param  array $array
     * @param  callable $callback
     * @return array
     */
    public static function where($array, callable $callback)
    {
        $filtered = [];

        foreach ($array as $key => $value) {
            if (call_user_func($callback, $key, $value)) $filtered[$key] = $value;
        }

        return $filtered;
    }

}