package utl

import (
	"errors"
	"sync"
)

var (
	ErrKeyExists    = errors.New("key already exists")
	ErrKeyNotExists = errors.New("key not exists")
)

// secure map
// exports funny interfaces
type SMap struct {
	*sync.RWMutex
	m map[interface{}]interface{}
}

func NewSMap() *SMap {
	return &SMap{
		RWMutex: &sync.RWMutex{},
		m:       make(map[interface{}]interface{}),
	}
}

func (self *SMap) Exists(k interface{}) bool {
	self.RLock()
	_, ok := self.m[k]
	self.RUnlock()

	return ok
}

func (self *SMap) Get(k interface{}) (interface{}, bool) {
	self.RLock()
	defer self.RUnlock()

	v, ok := self.m[k]
	return v, ok
}

func (self *SMap) Set(k, v interface{}) {
	self.Lock()
	self.m[k] = v
	self.Unlock()
}

func (self *SMap) Del(k interface{}) {
	self.Lock()
	delete(self.m, k)
	self.Unlock()
}

func (self *SMap) Insert(k, v interface{}) error {
	self.Lock()
	defer self.Unlock()

	_, ok := self.m[k]
	if ok {
		return ErrKeyExists
	}

	self.m[k] = v

	return nil
}

func (self *SMap) Update(k, v interface{}) error {
	self.Lock()
	defer self.Unlock()

	_, ok := self.m[k]
	if !ok {
		return ErrKeyNotExists
	}

	self.m[k] = v

	return nil
}

func (self *SMap) Keys() []interface{} {
	var retval []interface{}

	self.RLock()
	defer self.RUnlock()

	for k, _ := range self.m {
		retval = append(retval, k)
	}

	return retval
}

func (self *SMap) Values() []interface{} {
	var retval []interface{}

	self.RLock()
	defer self.RUnlock()

	for _, v := range self.m {
		retval = append(retval, v)
	}

	return retval
}

func (self *SMap) Foreach(each func(k, v interface{})) {
	self.RLock()
	for k, v := range self.m {
		each(k, v)
	}
	self.RUnlock()
}