<?php

namespace Illuminate\Support\Traits;

use CachingIterator;
use Exception;
use Illuminate\Contracts\Support\Arrayable;
use Illuminate\Contracts\Support\Jsonable;
use Illuminate\Support\Arr;
use Illuminate\Support\Collection;
use Illuminate\Support\Enumerable;
use Illuminate\Support\HigherOrderCollectionProxy;
use Illuminate\Support\HigherOrderWhenProxy;
use JsonSerializable;
use Symfony\Component\VarDumper\VarDumper;
use Traversable;

/**
 * @property-read HigherOrderCollectionProxy $average
 * @property-read HigherOrderCollectionProxy $avg
 * @property-read HigherOrderCollectionProxy $contains
 * @property-read HigherOrderCollectionProxy $each
 * @property-read HigherOrderCollectionProxy $every
 * @property-read HigherOrderCollectionProxy $filter
 * @property-read HigherOrderCollectionProxy $first
 * @property-read HigherOrderCollectionProxy $flatMap
 * @property-read HigherOrderCollectionProxy $groupBy
 * @property-read HigherOrderCollectionProxy $keyBy
 * @property-read HigherOrderCollectionProxy $map
 * @property-read HigherOrderCollectionProxy $max
 * @property-read HigherOrderCollectionProxy $min
 * @property-read HigherOrderCollectionProxy $partition
 * @property-read HigherOrderCollectionProxy $reject
 * @property-read HigherOrderCollectionProxy $some
 * @property-read HigherOrderCollectionProxy $sortBy
 * @property-read HigherOrderCollectionProxy $sortByDesc
 * @property-read HigherOrderCollectionProxy $sum
 * @property-read HigherOrderCollectionProxy $unique
 */
trait EnumeratesValues
{
    /**
     * The methods that can be proxied.
     *
     * @var array
     */
    protected static $proxies = [
        'average', 'avg', 'contains', 'each', 'every', 'filter', 'first',
        'flatMap', 'groupBy', 'keyBy', 'map', 'max', 'min', 'partition',
        'reject', 'some', 'sortBy', 'sortByDesc', 'sum', 'unique',
    ];

    /**
     * Create a new collection instance if the value isn't one already.
     *
     * @param  mixed  $items
     * @return static
     */
    public static function make($items = [])
    {
        return new static($items);
    }

    /**
     * Wrap the given value in a collection if applicable.
     *
     * @param  mixed  $value
     * @return static
     */
    public static function wrap($value)
    {
        return $value instanceof Enumerable
            ? new static($value)
            : new static(Arr::wrap($value));
    }

    /**
     * Get the underlying items from the given collection if applicable.
     *
     * @param  array|static  $value
     * @return array
     */
    public static function unwrap($value)
    {
        return $value instanceof Enumerable ? $value->all() : $value;
    }

    /**
     * Alias for the "avg" method.
     *
     * @param  callable|string|null  $callback
     * @return mixed
     */
    public function average($callback = null)
    {
        return $this->avg($callback);
    }

    /**
     * Alias for the "contains" method.
     *
     * @param  mixed  $key
     * @param  mixed  $operator
     * @param  mixed  $value
     * @return bool
     */
    public function some($key, $operator = null, $value = null)
    {
        return $this->contains(...func_get_args());
    }

    /**
     * Determine if an item exists, using strict comparison.
     *
     * @param  mixed  $key
     * @param  mixed  $value
     * @return bool
     */
    public function containsStrict($key, $value = null)
    {
        if (func_num_args() === 2) {
            return $this->contains(function ($item) use ($key, $value) {
                return data_get($item, $key) === $value;
            });
        }

        if ($this->useAsCallable($key)) {
            return ! is_null($this->first($key));
        }

        foreach ($this as $item) {
            if ($item === $key) {
                return true;
            }
        }

        return false;
    }

    /**
     * Dump the items and end the script.
     *
     * @param  mixed  ...$args
     * @return void
     */
    public function dd(...$args)
    {
        call_user_func_array([$this, 'dump'], $args);

        die(1);
    }

    /**
     * Dump the items.
     *
     * @return $this
     */
    public function dump()
    {
        (new static(func_get_args()))
            ->push($this)
            ->each(function ($item) {
                VarDumper::dump($item);
            });

        return $this;
    }

    /**
     * Execute a callback over each item.
     *
     * @param  callable  $callback
     * @return $this
     */
    public function each(callable $callback)
    {
        foreach ($this as $key => $item) {
            if ($callback($item, $key) === false) {
                break;
            }
        }

        return $this;
    }

    /**
     * Execute a callback over each nested chunk of items.
     *
     * @param  callable  $callback
     * @return static
     */
    public function eachSpread(callable $callback)
    {
        return $this->each(function ($chunk, $key) use ($callback) {
            $chunk[] = $key;

            return $callback(...$chunk);
        });
    }

    /**
     * Determine if all items pass the given truth test.
     *
     * @param  string|callable  $key
     * @param  mixed  $operator
     * @param  mixed  $value
     * @return bool
     */
    public function every($key, $operator = null, $value = null)
    {
        if (func_num_args() === 1) {
            $callback = $this->valueRetriever($key);

            foreach ($this as $k => $v) {
                if (! $callback($v, $k)) {
                    return false;
                }
            }

            return true;
        }

        return $this->every($this->operatorForWhere(...func_get_args()));
    }

    /**
     * Get the first item by the given key value pair.
     *
     * @param  string  $key
     * @param  mixed  $operator
     * @param  mixed  $value
     * @return mixed
     */
    public function firstWhere($key, $operator = null, $value = null)
    {
        return $this->first($this->operatorForWhere(...func_get_args()));
    }

    /**
     * Determine if the collection is not empty.
     *
     * @return bool
     */
    public function isNotEmpty()
    {
        return ! $this->isEmpty();
    }

    /**
     * Run a map over each nested chunk of items.
     *
     * @param  callable  $callback
     * @return static
     */
    public function mapSpread(callable $callback)
    {
        return $this->map(function ($chunk, $key) use ($callback) {
            $chunk[] = $key;

            return $callback(...$chunk);
        });
    }

    /**
     * Run a grouping map over the items.
     *
     * The callback should return an associative array with a single key/value pair.
     *
     * @param  callable  $callback
     * @return static
     */
    public function mapToGroups(callable $callback)
    {
        $groups = $this->mapToDictionary($callback);

        return $groups->map([$this, 'make']);
    }

    /**
     * Map a collection and flatten the result by a single level.
     *
     * @param  callable  $callback
     * @return static
     */
    public function flatMap(callable $callback)
    {
        return $this->map($callback)->collapse();
    }

    /**
     * Map the values into a new class.
     *
     * @param  string  $class
     * @return static
     */
    public function mapInto($class)
    {
        return $this->map(function ($value, $key) use ($class) {
            return new $class($value, $key);
        });
    }

    /**
     * Get the min value of a given key.
     *
     * @param  callable|string|null  $callback
     * @return mixed
     */
    public function min($callback = null)
    {
        $callback = $this->valueRetriever($callback);

        return $this->map(function ($value) use ($callback) {
            return $callback($value);
        })->filter(function ($value) {
            return ! is_null($value);
        })->reduce(function ($result, $value) {
            return is_null($result) || $value < $result ? $value : $result;
        });
    }

    /**
     * Get the max value of a given key.
     *
     * @param  callable|string|null  $callback
     * @return mixed
     */
    public function max($callback = null)
    {
        $callback = $this->valueRetriever($callback);

        return $this->filter(function ($value) {
            return ! is_null($value);
        })->reduce(function ($result, $item) use ($callback) {
            $value = $callback($item);

            return is_null($result) || $value > $result ? $value : $result;
        });
    }

    /**
     * "Paginate" the collection by slicing it into a smaller collection.
     *
     * @param  int  $page
     * @param  int  $perPage
     * @return static
     */
    public function forPage($page, $perPage)
    {
        $offset = max(0, ($page - 1) * $perPage);

        return $this->slice($offset, $perPage);
    }

    /**
     * Partition the collection into two arrays using the given callback or key.
     *
     * @param  callable|string  $key
     * @param  mixed  $operator
     * @param  mixed  $value
     * @return static
     */
    public function partition($key, $operator = null, $value = null)
    {
        $passed = [];
        $failed = [];

        $callback = func_num_args() === 1
                ? $this->valueRetriever($key)
                : $this->operatorForWhere(...func_get_args());

        foreach ($this as $key => $item) {
            if ($callback($item, $key)) {
                $passed[$key] = $item;
            } else {
                $failed[$key] = $item;
            }
        }

        return new static([new static($passed), new static($failed)]);
    }

    /**
     * Get the sum of the given values.
     *
     * @param  callable|string|null  $callback
     * @return mixed
     */
    public function sum($callback = null)
    {
        if (is_null($callback)) {
            $callback = function ($value) {
                return $value;
            };
        } else {
            $callback = $this->valueRetriever($callback);
        }

        return $this->reduce(function ($result, $item) use ($callback) {
            return $result + $callback($item);
        }, 0);
    }

    /**
     * Apply the callback if the value is truthy.
     *
     * @param  bool|mixed  $value
     * @param  callable|null  $callback
     * @param  callable|null  $default
     * @return static|mixed
     */
    public function when($value, callable $callback = null, callable $default = null)
    {
        if (! $callback) {
            return new HigherOrderWhenProxy($this, $value);
        }

        if ($value) {
            return $callback($this, $value);
        } elseif ($default) {
            return $default($this, $value);
        }

        return $this;
    }

    /**
     * Apply the callback if the collection is empty.
     *
     * @param  callable  $callback
     * @param  callable|null  $default
     * @return static|mixed
     */
    public function whenEmpty(callable $callback, callable $default = null)
    {
        return $this->when($this->isEmpty(), $callback, $default);
    }

    /**
     * Apply the callback if the collection is not empty.
     *
     * @param  callable  $callback
     * @param  callable|null  $default
     * @return static|mixed
     */
    public function whenNotEmpty(callable $callback, callable $default = null)
    {
        return $this->when($this->isNotEmpty(), $callback, $default);
    }

    /**
     * Apply the callback if the value is falsy.
     *
     * @param  bool  $value
     * @param  callable  $callback
     * @param  callable|null  $default
     * @return static|mixed
     */
    public function unless($value, callable $callback, callable $default = null)
    {
        return $this->when(! $value, $callback, $default);
    }

    /**
     * Apply the callback unless the collection is empty.
     *
     * @param  callable  $callback
     * @param  callable|null  $default
     * @return static|mixed
     */
    public function unlessEmpty(callable $callback, callable $default = null)
    {
        return $this->whenNotEmpty($callback, $default);
    }

    /**
     * Apply the callback unless the collection is not empty.
     *
     * @param  callable  $callback
     * @param  callable|null  $default
     * @return static|mixed
     */
    public function unlessNotEmpty(callable $callback, callable $default = null)
    {
        return $this->whenEmpty($callback, $default);
    }

    /**
     * Filter items by the given key value pair.
     *
     * @param  string  $key
     * @param  mixed  $operator
     * @param  mixed  $value
     * @return static
     */
    public function where($key, $operator = null, $value = null)
    {
        return $this->filter($this->operatorForWhere(...func_get_args()));
    }

    /**
     * Filter items where the given key is not null.
     *
     * @param  string|null  $key
     * @return static
     */
    public function whereNull($key = null)
    {
        return $this->whereStrict($key, null);
    }

    /**
     * Filter items where the given key is null.
     *
     * @param  string|null  $key
     * @return static
     */
    public function whereNotNull($key = null)
    {
        return $this->where($key, '!==', null);
    }

    /**
     * Filter items by the given key value pair using strict comparison.
     *
     * @param  string  $key
     * @param  mixed  $value
     * @return static
     */
    public function whereStrict($key, $value)
    {
        return $this->where($key, '===', $value);
    }

    /**
     * Filter items by the given key value pair.
     *
     * @param  string  $key
     * @param  mixed  $values
     * @param  bool  $strict
     * @return static
     */
    public function whereIn($key, $values, $strict = false)
    {
        $values = $this->getArrayableItems($values);

        return $this->filter(function ($item) use ($key, $values, $strict) {
            return in_array(data_get($item, $key), $values, $strict);
        });
    }

    /**
     * Filter items by the given key value pair using strict comparison.
     *
     * @param  string  $key
     * @param  mixed  $values
     * @return static
     */
    public function whereInStrict($key, $values)
    {
        return $this->whereIn($key, $values, true);
    }

    /**
     * Filter items such that the value of the given key is between the given values.
     *
     * @param  string  $key
     * @param  array  $values
     * @return static
     */
    public function whereBetween($key, $values)
    {
        return $this->where($key, '>=', reset($values))->where($key, '<=', end($values));
    }

    /**
     * Filter items such that the value of the given key is not between the given values.
     *
     * @param  string  $key
     * @param  array  $values
     * @return static
     */
    public function whereNotBetween($key, $values)
    {
        return $this->filter(function ($item) use ($key, $values) {
            return data_get($item, $key) < reset($values) || data_get($item, $key) > end($values);
        });
    }

    /**
     * Filter items by the given key value pair.
     *
     * @param  string  $key
     * @param  mixed  $values
     * @param  bool  $strict
     * @return static
     */
    public function whereNotIn($key, $values, $strict = false)
    {
        $values = $this->getArrayableItems($values);

        return $this->reject(function ($item) use ($key, $values, $strict) {
            return in_array(data_get($item, $key), $values, $strict);
        });
    }

    /**
     * Filter items by the given key value pair using strict comparison.
     *
     * @param  string  $key
     * @param  mixed  $values
     * @return static
     */
    public function whereNotInStrict($key, $values)
    {
        return $this->whereNotIn($key, $values, true);
    }

    /**
     * Filter the items, removing any items that don't match the given type.
     *
     * @param  string  $type
     * @return static
     */
    public function whereInstanceOf($type)
    {
        return $this->filter(function ($value) use ($type) {
            return $value instanceof $type;
        });
    }

    /**
     * Pass the collection to the given callback and return the result.
     *
     * @param  callable  $callback
     * @return mixed
     */
    public function pipe(callable $callback)
    {
        return $callback($this);
    }

    /**
     * Pass the collection to the given callback and then return it.
     *
     * @param  callable  $callback
     * @return $this
     */
    public function tap(callable $callback)
    {
        $callback(clone $this);

        return $this;
    }

    /**
     * Create a collection of all elements that do not pass a given truth test.
     *
     * @param  callable|mixed  $callback
     * @return static
     */
    public function reject($callback = true)
    {
        $useAsCallable = $this->useAsCallable($callback);

        return $this->filter(function ($value, $key) use ($callback, $useAsCallable) {
            return $useAsCallable
                ? ! $callback($value, $key)
                : $value != $callback;
        });
    }

    /**
     * Return only unique items from the collection array.
     *
     * @param  string|callable|null  $key
     * @param  bool  $strict
     * @return static
     */
    public function unique($key = null, $strict = false)
    {
        $callback = $this->valueRetriever($key);

        $exists = [];

        return $this->reject(function ($item, $key) use ($callback, $strict, &$exists) {
            if (in_array($id = $callback($item, $key), $exists, $strict)) {
                return true;
            }

            $exists[] = $id;
        });
    }

    /**
     * Return only unique items from the collection array using strict comparison.
     *
     * @param  string|callable|null  $key
     * @return static
     */
    public function uniqueStrict($key = null)
    {
        return $this->unique($key, true);
    }

    /**
     * Collect the values into a collection.
     *
     * @return \Illuminate\Support\Collection
     */
    public function collect()
    {
        return new Collection($this->all());
    }

    /**
     * Get the collection of items as a plain array.
     *
     * @return array
     */
    public function toArray()
    {
        return $this->map(function ($value) {
            return $value instanceof Arrayable ? $value->toArray() : $value;
        })->all();
    }

    /**
     * Convert the object into something JSON serializable.
     *
     * @return array
     */
    public function jsonSerialize()
    {
        return array_map(function ($value) {
            if ($value instanceof JsonSerializable) {
                return $value->jsonSerialize();
            } elseif ($value instanceof Jsonable) {
                return json_decode($value->toJson(), true);
            } elseif ($value instanceof Arrayable) {
                return $value->toArray();
            }

            return $value;
        }, $this->all());
    }

    /**
     * Get the collection of items as JSON.
     *
     * @param  int  $options
     * @return string
     */
    public function toJson($options = 0)
    {
        return json_encode($this->jsonSerialize(), $options);
    }

    /**
     * Get a CachingIterator instance.
     *
     * @param  int  $flags
     * @return \CachingIterator
     */
    public function getCachingIterator($flags = CachingIterator::CALL_TOSTRING)
    {
        return new CachingIterator($this->getIterator(), $flags);
    }

    /**
     * Count the number of items in the collection using a given truth test.
     *
     * @param  callable|null  $callback
     * @return static
     */
    public function countBy($callback = null)
    {
        if (is_null($callback)) {
            $callback = function ($value) {
                return $value;
            };
        }

        return new static($this->groupBy($callback)->map(function ($value) {
            return $value->count();
        }));
    }

    /**
     * Convert the collection to its string representation.
     *
     * @return string
     */
    public function __toString()
    {
        return $this->toJson();
    }

    /**
     * Add a method to the list of proxied methods.
     *
     * @param  string  $method
     * @return void
     */
    public static function proxy($method)
    {
        static::$proxies[] = $method;
    }

    /**
     * Dynamically access collection proxies.
     *
     * @param  string  $key
     * @return mixed
     *
     * @throws \Exception
     */
    public function __get($key)
    {
        if (! in_array($key, static::$proxies)) {
            throw new Exception("Property [{$key}] does not exist on this collection instance.");
        }

        return new HigherOrderCollectionProxy($this, $key);
    }

    /**
     * Results array of items from Collection or Arrayable.
     *
     * @param  mixed  $items
     * @return array
     */
    protected function getArrayableItems($items)
    {
        if (is_array($items)) {
            return $items;
        } elseif ($items instanceof Enumerable) {
            return $items->all();
        } elseif ($items instanceof Arrayable) {
            return $items->toArray();
        } elseif ($items instanceof Jsonable) {
            return json_decode($items->toJson(), true);
        } elseif ($items instanceof JsonSerializable) {
            return (array) $items->jsonSerialize();
        } elseif ($items instanceof Traversable) {
            return iterator_to_array($items);
        }

        return (array) $items;
    }

    /**
     * Get an operator checker callback.
     *
     * @param  string  $key
     * @param  string|null  $operator
     * @param  mixed  $value
     * @return \Closure
     */
    protected function operatorForWhere($key, $operator = null, $value = null)
    {
        if (func_num_args() === 1) {
            $value = true;

            $operator = '=';
        }

        if (func_num_args() === 2) {
            $value = $operator;

            $operator = '=';
        }

        return function ($item) use ($key, $operator, $value) {
            $retrieved = data_get($item, $key);

            $strings = array_filter([$retrieved, $value], function ($value) {
                return is_string($value) || (is_object($value) && method_exists($value, '__toString'));
            });

            if (count($strings) < 2 && count(array_filter([$retrieved, $value], 'is_object')) == 1) {
                return in_array($operator, ['!=', '<>', '!==']);
            }

            switch ($operator) {
                default:
                case '=':
                case '==':  return $retrieved == $value;
                case '!=':
                case '<>':  return $retrieved != $value;
                case '<':   return $retrieved < $value;
                case '>':   return $retrieved > $value;
                case '<=':  return $retrieved <= $value;
                case '>=':  return $retrieved >= $value;
                case '===': return $retrieved === $value;
                case '!==': return $retrieved !== $value;
            }
        };
    }

    /**
     * Determine if the given value is callable, but not a string.
     *
     * @param  mixed  $value
     * @return bool
     */
    protected function useAsCallable($value)
    {
        return ! is_string($value) && is_callable($value);
    }

    /**
     * Get a value retrieving callback.
     *
     * @param  callable|string|null  $value
     * @return callable
     */
    protected function valueRetriever($value)
    {
        if ($this->useAsCallable($value)) {
            return $value;
        }

        return function ($item) use ($value) {
            return data_get($item, $value);
        };
    }
}
