// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

package cache

import "time"

type cacheItem struct {
	value     bool
	expiresAt time.Time
	ttl       time.Duration
}

type DefaultCache map[string]cacheItem

func (c *DefaultCache) Set(key string, value bool, extra ...interface{}) error {
	ttl := time.Duration(-1)
	if len(extra) > 0 {
		ttl = extra[0].(time.Duration)
	}
	(*c)[key] = cacheItem{
		value:     value,
		expiresAt: time.Now().Add(ttl),
		ttl:       ttl,
	}
	return nil
}

func (c *DefaultCache) Get(key string) (bool, error) {
	if res, ok := (*c)[key]; !ok {
		return false, ErrNoSuchKey
	} else {
		if res.ttl > 0 && time.Now().After(res.expiresAt) {
			delete(*c, key)
			return false, ErrNoSuchKey
		}
		return res.value, nil
	}
}

func (c *DefaultCache) Delete(key string) error {
	if _, ok := (*c)[key]; !ok {
		return ErrNoSuchKey
	} else {
		delete(*c, key)
		return nil
	}
}

func (c *DefaultCache) Clear() error {
	*c = make(DefaultCache)
	return nil
}

func NewDefaultCache() (Cache, error) {
	cache := make(DefaultCache)
	return &cache, nil
}