package session

import (
	"errors"
	"git.noahlan.cn/northlan/ngs/service"
	"net"
	"sync"
	"sync/atomic"
	"time"
)

// NetworkEntity represent low-level network instance
type NetworkEntity interface {
	Push(route string, v interface{}) error
	RPC(route string, v interface{}) error
	LastMid() uint64
	Response(v interface{}) error
	ResponseMid(mid uint64, v interface{}) error
	Close() error
	RemoteAddr() net.Addr
}

var (
	// ErrIllegalUID represents a invalid uid
	ErrIllegalUID = errors.New("illegal uid")
)

// Session represents a client session which could storage temp data during low-level
// keep connected, all data will be released when the low-level connection was broken.
// Session instance related to the client will be passed to Handler method as the first
// parameter.
type Session struct {
	sync.RWMutex                        // protect data
	id           int64                  // session global unique id
	uid          int64                  // binding user id
	lastTime     int64                  // last heartbeat time
	entity       NetworkEntity          // low-level network entity
	data         map[string]interface{} // session data store
	router       *Router
}

// New returns a new session instance
// a NetworkEntity is a low-level network instance
func New(entity NetworkEntity) *Session {
	return &Session{
		id:       service.Connections.SessionID(),
		entity:   entity,
		data:     make(map[string]interface{}),
		lastTime: time.Now().Unix(),
		router:   newRouter(),
	}
}

// NetworkEntity returns the low-level network agent object
func (s *Session) NetworkEntity() NetworkEntity {
	return s.entity
}

// Router returns the service router
func (s *Session) Router() *Router {
	return s.router
}

// RPC sends message to remote server
func (s *Session) RPC(route string, v interface{}) error {
	return s.entity.RPC(route, v)
}

// Push message to client
func (s *Session) Push(route string, v interface{}) error {
	return s.entity.Push(route, v)
}

// Response message to client
func (s *Session) Response(v interface{}) error {
	return s.entity.Response(v)
}

// ResponseMID responses message to client, mid is
// request message ID
func (s *Session) ResponseMID(mid uint64, v interface{}) error {
	return s.entity.ResponseMid(mid, v)
}

// ID returns the session id
func (s *Session) ID() int64 {
	return s.id
}

// UID returns uid that bind to current session
func (s *Session) UID() int64 {
	return atomic.LoadInt64(&s.uid)
}

// LastMid returns the last message id
func (s *Session) LastMid() uint64 {
	return s.entity.LastMid()
}

// Bind UID to current session
func (s *Session) Bind(uid int64) error {
	if uid < 1 {
		return ErrIllegalUID
	}

	atomic.StoreInt64(&s.uid, uid)
	return nil
}

// Close terminate current session, session related data will not be released,
// all related data should be Clear explicitly in Session closed callback
func (s *Session) Close() {
	_ = s.entity.Close()
}

// RemoteAddr returns the remote network address.
func (s *Session) RemoteAddr() net.Addr {
	return s.entity.RemoteAddr()
}

// Remove delete data associated with the key from session storage
func (s *Session) Remove(key string) {
	s.Lock()
	defer s.Unlock()

	delete(s.data, key)
}

// Set associates value with the key in session storage
func (s *Session) Set(key string, value interface{}) {
	s.Lock()
	defer s.Unlock()

	s.data[key] = value
}

// HasKey decides whether a key has associated value
func (s *Session) HasKey(key string) bool {
	s.RLock()
	defer s.RUnlock()

	_, has := s.data[key]
	return has
}

// Int returns the value associated with the key as a int.
func (s *Session) Int(key string) int {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(int)
	if !ok {
		return 0
	}
	return value
}

// Int8 returns the value associated with the key as a int8.
func (s *Session) Int8(key string) int8 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(int8)
	if !ok {
		return 0
	}
	return value
}

// Int16 returns the value associated with the key as a int16.
func (s *Session) Int16(key string) int16 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(int16)
	if !ok {
		return 0
	}
	return value
}

// Int32 returns the value associated with the key as a int32.
func (s *Session) Int32(key string) int32 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(int32)
	if !ok {
		return 0
	}
	return value
}

// Int64 returns the value associated with the key as a int64.
func (s *Session) Int64(key string) int64 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(int64)
	if !ok {
		return 0
	}
	return value
}

// Uint returns the value associated with the key as a uint.
func (s *Session) Uint(key string) uint {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(uint)
	if !ok {
		return 0
	}
	return value
}

// Uint8 returns the value associated with the key as a uint8.
func (s *Session) Uint8(key string) uint8 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(uint8)
	if !ok {
		return 0
	}
	return value
}

// Uint16 returns the value associated with the key as a uint16.
func (s *Session) Uint16(key string) uint16 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(uint16)
	if !ok {
		return 0
	}
	return value
}

// Uint32 returns the value associated with the key as a uint32.
func (s *Session) Uint32(key string) uint32 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(uint32)
	if !ok {
		return 0
	}
	return value
}

// Uint64 returns the value associated with the key as a uint64.
func (s *Session) Uint64(key string) uint64 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(uint64)
	if !ok {
		return 0
	}
	return value
}

// Float32 returns the value associated with the key as a float32.
func (s *Session) Float32(key string) float32 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(float32)
	if !ok {
		return 0
	}
	return value
}

// Float64 returns the value associated with the key as a float64.
func (s *Session) Float64(key string) float64 {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return 0
	}

	value, ok := v.(float64)
	if !ok {
		return 0
	}
	return value
}

// String returns the value associated with the key as a string.
func (s *Session) String(key string) string {
	s.RLock()
	defer s.RUnlock()

	v, ok := s.data[key]
	if !ok {
		return ""
	}

	value, ok := v.(string)
	if !ok {
		return ""
	}
	return value
}

// Value returns the value associated with the key as a interface{}.
func (s *Session) Value(key string) interface{} {
	s.RLock()
	defer s.RUnlock()

	return s.data[key]
}

// State returns all session state
func (s *Session) State() map[string]interface{} {
	s.RLock()
	defer s.RUnlock()

	return s.data
}

// Restore session state after reconnect
func (s *Session) Restore(data map[string]interface{}) {
	s.Lock()
	defer s.Unlock()

	s.data = data
}

// Clear releases all data related to current session
func (s *Session) Clear() {
	s.Lock()
	defer s.Unlock()

	s.uid = 0
	s.data = map[string]interface{}{}
}