package v1

import (
	"cwtch.im/cwtch/event"
	"cwtch.im/cwtch/model"
	"encoding/json"
	"git.openprivacy.ca/openprivacy/log"
	"io/ioutil"
	"os"
	"path"
	"time"
)

const groupIDLen = 32
const peerIDLen = 56
const profileFilename = "profile"
const version = "1"
const versionFile = "VERSION"
const saltFile = "SALT"

//ProfileStoreV1 storage for profiles and message streams that uses in memory key and fs stored salt instead of in memory password
type ProfileStoreV1 struct {
	fs           FileStore
	streamStores map[string]StreamStore // map [groupId|onion] StreamStore
	directory    string
	profile      *model.Profile
	key          [32]byte
	salt         [128]byte
	eventManager event.Manager
	queue        event.Queue
	writer       bool
}

func initV1Directory(directory, password string) ([32]byte, [128]byte, error) {
	key, salt, err := createKeySalt(password)
	if err != nil {
		log.Errorf("Could not create key for profile store from password: %v\n", err)
		return [32]byte{}, [128]byte{}, err
	}

	ioutil.WriteFile(path.Join(directory, versionFile), []byte(version), 0600)
	ioutil.WriteFile(path.Join(directory, saltFile), salt[:], 0600)

	return key, salt, nil
}

// CreateProfileWriterStore creates a profile store backed by a filestore listening for events and saving them
// directory should be $appDir/profiles/$rand
func CreateProfileWriterStore(eventManager event.Manager, directory, password string, profile *model.Profile) *ProfileStoreV1 {
	os.Mkdir(directory, 0700)

	key, salt, err := initV1Directory(directory, password)
	if err != nil {
		return nil
	}

	ps := &ProfileStoreV1{fs: NewFileStore(directory, profileFilename, key), key: key, salt: salt, directory: directory, profile: profile, eventManager: eventManager, streamStores: map[string]StreamStore{}, writer: true}
	ps.save()

	ps.initProfileWriterStore()

	return ps
}

func (ps *ProfileStoreV1) initProfileWriterStore() {
	ps.queue = event.NewQueue()
	go ps.eventHandler()

	ps.eventManager.Subscribe(event.BlockPeer, ps.queue)
	ps.eventManager.Subscribe(event.UnblockPeer, ps.queue)
	ps.eventManager.Subscribe(event.PeerCreated, ps.queue)
	ps.eventManager.Subscribe(event.GroupCreated, ps.queue)
	ps.eventManager.Subscribe(event.SetProfileName, ps.queue)
	ps.eventManager.Subscribe(event.SetAttribute, ps.queue)
	ps.eventManager.Subscribe(event.SetPeerAttribute, ps.queue)
	ps.eventManager.Subscribe(event.SetGroupAttribute, ps.queue)
	ps.eventManager.Subscribe(event.AcceptGroupInvite, ps.queue)
	ps.eventManager.Subscribe(event.NewGroupInvite, ps.queue)
	ps.eventManager.Subscribe(event.NewMessageFromGroup, ps.queue)
	ps.eventManager.Subscribe(event.PeerStateChange, ps.queue)
	ps.eventManager.Subscribe(event.ServerStateChange, ps.queue)
	ps.eventManager.Subscribe(event.DeleteContact, ps.queue)
	ps.eventManager.Subscribe(event.DeleteGroup, ps.queue)
	ps.eventManager.Subscribe(event.ChangePassword, ps.queue)
}

// LoadProfileWriterStore loads a profile store from filestore listening for events and saving them
// directory should be $appDir/profiles/$rand
func LoadProfileWriterStore(eventManager event.Manager, directory, password string) (*ProfileStoreV1, error) {
	salt, err := ioutil.ReadFile(path.Join(directory, saltFile))
	if err != nil {
		return nil, err
	}

	key := createKey(password, salt)

	ps := &ProfileStoreV1{fs: NewFileStore(directory, profileFilename, key), key: key, directory: directory, profile: nil, eventManager: eventManager, streamStores: map[string]StreamStore{}, writer: true}
	copy(ps.salt[:], salt)

	ps.initProfileWriterStore()

	ps.load()

	return ps, nil
}

// ReadProfile reads a profile from storqage and returns the profile
// directory should be $appDir/profiles/$rand
func ReadProfile(directory string, key [32]byte, salt [128]byte) (*model.Profile, error) {
	os.Mkdir(directory, 0700)
	ps := &ProfileStoreV1{fs: NewFileStore(directory, profileFilename, key), key: key, salt: salt, directory: directory, profile: nil, eventManager: nil, streamStores: map[string]StreamStore{}, writer: true}

	err := ps.load()
	if err != nil {
		return nil, err
	}

	profile := ps.GetProfileCopy(true)

	return profile, nil
}

// UpgradeV0Profile takes a profile (presumably from a V0 store) and creates and writes a V1 store
func UpgradeV0Profile(profile *model.Profile, directory, password string) error {
	key, salt, err := initV1Directory(directory, password)
	if err != nil {
		return err
	}

	ps := &ProfileStoreV1{fs: NewFileStore(directory, profileFilename, key), key: key, salt: salt, directory: directory, profile: profile, eventManager: nil, streamStores: map[string]StreamStore{}, writer: true}
	ps.save()

	for gid, group := range ps.profile.Groups {
		ss := NewStreamStore(ps.directory, group.LocalID, ps.key)
		ss.WriteN(ps.profile.Groups[gid].Timeline.Messages)
	}

	return nil
}

// NewProfile creates a new profile for use in the profile store.
func NewProfile(name string) *model.Profile {
	profile := model.GenerateNewProfile(name)
	return profile
}

// GetNewPeerMessage is for AppService to call on Reload events, to reseed the AppClient with the loaded peers
func (ps *ProfileStoreV1) GetNewPeerMessage() *event.Event {
	message := event.NewEventList(event.NewPeer, event.Identity, ps.profile.LocalID, event.Key, string(ps.key[:]), event.Salt, string(ps.salt[:]))
	return &message
}

// GetStatusMessages creates an array of status messages for all peers and group servers from current information
func (ps *ProfileStoreV1) GetStatusMessages() []*event.Event {
	messages := []*event.Event{}
	for _, contact := range ps.profile.Contacts {
		message := event.NewEvent(event.PeerStateChange, map[event.Field]string{
			event.RemotePeer:      string(contact.Onion),
			event.ConnectionState: contact.State,
		})
		messages = append(messages, &message)
	}

	doneServers := make(map[string]bool)
	for _, group := range ps.profile.Groups {
		if _, exists := doneServers[group.GroupServer]; !exists {
			message := event.NewEvent(event.ServerStateChange, map[event.Field]string{
				event.GroupServer:     string(group.GroupServer),
				event.ConnectionState: group.State,
			})
			messages = append(messages, &message)
			doneServers[group.GroupServer] = true
		}
	}

	return messages
}

// ChangePassword restores all data under a new password's encryption
func (ps *ProfileStoreV1) ChangePassword(oldpass, newpass, eventID string) {
	oldkey := createKey(oldpass, ps.salt[:])

	if oldkey != ps.key {
		ps.eventManager.Publish(event.NewEventList(event.ChangePasswordError, event.Error, "Supplied current password does not match", event.EventID, eventID))
		return
	}

	newkey := createKey(newpass, ps.salt[:])

	newStreamStores := map[string]StreamStore{}
	idToNewLocalID := map[string]string{}

	// Generate all new StreamStores with the new password and write all the old StreamStore data into these ones
	for ssid, ss := range ps.streamStores {
		// New ss with new pass and new localID
		newlocalID := model.GenerateRandomID()
		idToNewLocalID[ssid] = newlocalID

		newSS := NewStreamStore(ps.directory, newlocalID, newkey)
		newStreamStores[ssid] = newSS

		// write whole store
		messages := ss.Read()
		newSS.WriteN(messages)
	}

	// Switch over
	oldStreamStores := ps.streamStores
	ps.streamStores = newStreamStores
	for ssid, newLocalID := range idToNewLocalID {
		if len(ssid) == groupIDLen {
			ps.profile.Groups[ssid].LocalID = newLocalID
		} else {
			ps.profile.Contacts[ssid].LocalID = newLocalID
		}
	}

	ps.key = newkey
	ps.fs.ChangeKey(newkey)
	ps.save()

	// Clean up
	for _, oldss := range oldStreamStores {
		oldss.Delete()
	}

	ps.eventManager.Publish(event.NewEventList(event.ChangePasswordSuccess, event.EventID, eventID))
	return
}

func (ps *ProfileStoreV1) save() error {
	if ps.writer {
		bytes, _ := json.Marshal(ps.profile)
		return ps.fs.Write(bytes)
	}
	return nil
}

// load instantiates a cwtchPeer from the file store
func (ps *ProfileStoreV1) load() error {
	decrypted, err := ps.fs.Read()
	if err != nil {
		return err
	}
	cp := new(model.Profile)
	err = json.Unmarshal(decrypted, &cp)
	if err == nil {
		ps.profile = cp

		for gid, group := range cp.Groups {
			ss := NewStreamStore(ps.directory, group.LocalID, ps.key)

			cp.Groups[gid].Timeline.SetMessages(ss.Read())
			ps.streamStores[group.GroupID] = ss
		}
	}

	return err
}

// GetProfileCopy returns a copy of the stored profile
func (ps *ProfileStoreV1) GetProfileCopy(timeline bool) *model.Profile {
	return ps.profile.GetCopy(timeline)
}

func (ps *ProfileStoreV1) eventHandler() {
	log.Debugln("eventHandler()!")
	for {
		ev := ps.queue.Next()
		log.Debugf("eventHandler event %v %v\n", ev.EventType, ev.EventID)

		switch ev.EventType {
		case event.BlockPeer:
			contact, exists := ps.profile.GetContact(ev.Data[event.RemotePeer])
			if exists {
				contact.Blocked = true
				ps.save()
			}
		case event.UnblockPeer:
			contact, exists := ps.profile.GetContact(ev.Data[event.RemotePeer])
			if exists {
				contact.Blocked = false
				ps.save()
			}
		case event.PeerCreated:
			var pp *model.PublicProfile
			json.Unmarshal([]byte(ev.Data[event.Data]), &pp)
			ps.profile.AddContact(ev.Data[event.RemotePeer], pp)
			// TODO: configure - allow peers to be configured to turn on limited storage
			/*ss := NewStreamStore(ps.directory, pp.LocalID, ps.password)
			pp.Timeline.SetMessages(ss.Read())
			ps.streamStores[pp.Onion] = ss
			ps.save()*/
		case event.GroupCreated:
			var group *model.Group
			json.Unmarshal([]byte(ev.Data[event.Data]), &group)
			ps.profile.AddGroup(group)
			ps.streamStores[group.GroupID] = NewStreamStore(ps.directory, group.LocalID, ps.key)
			ps.save()
		case event.SetProfileName:
			ps.profile.Name = ev.Data[event.ProfileName]
			ps.profile.SetAttribute("name", ev.Data[event.ProfileName])
			ps.save()
		case event.SetAttribute:
			ps.profile.SetAttribute(ev.Data[event.Key], ev.Data[event.Data])
			ps.save()
		case event.SetPeerAttribute:
			contact, exists := ps.profile.GetContact(ev.Data[event.RemotePeer])
			if exists {
				contact.SetAttribute(ev.Data[event.Key], ev.Data[event.Data])
				ps.save()
			} else {
				log.Errorf("error setting attribute on peer %v peer does not exist", ev)
			}
		case event.SetGroupAttribute:
			group := ps.profile.GetGroup(ev.Data[event.GroupID])
			if group != nil {
				group.SetAttribute(ev.Data[event.Key], ev.Data[event.Data])
				ps.save()
			} else {
				log.Errorf("error setting attribute on group %v group does not exist", ev)
			}
		case event.AcceptGroupInvite:
			err := ps.profile.AcceptInvite(ev.Data[event.GroupID])
			if err == nil {
				ps.save()
			} else {
				log.Errorf("error accepting group invite")
			}
		case event.NewGroupInvite:
			gid, err := ps.profile.ProcessInvite(ev.Data[event.GroupInvite], ev.Data[event.RemotePeer])
			log.Errorf("gid: %v err:%v\n", gid, err)
			if err == nil {
				ps.save()
				group := ps.profile.Groups[gid]
				ps.streamStores[group.GroupID] = NewStreamStore(ps.directory, group.LocalID, ps.key)
			} else {
				log.Errorf("error storing new group invite: %v (%v)", err, ev)
			}
		case event.NewMessageFromGroup:
			groupid := ev.Data[event.GroupID]
			received, _ := time.Parse(time.RFC3339Nano, ev.Data[event.TimestampReceived])
			sent, _ := time.Parse(time.RFC3339Nano, ev.Data[event.TimestampSent])
			message := model.Message{Received: received, Timestamp: sent, Message: ev.Data[event.Data], PeerID: ev.Data[event.RemotePeer], Signature: []byte(ev.Data[event.Signature]), PreviousMessageSig: []byte(ev.Data[event.PreviousSignature])}
			ss, exists := ps.streamStores[groupid]
			if exists {
				ss.Write(message)
			} else {
				log.Errorf("error storing new group message: %v stream store does not exist", ev)
			}
		case event.PeerStateChange:
			if _, exists := ps.profile.Contacts[ev.Data[event.RemotePeer]]; exists {
				ps.profile.Contacts[ev.Data[event.RemotePeer]].State = ev.Data[event.ConnectionState]
			}
		case event.ServerStateChange:
			for _, group := range ps.profile.Groups {
				if group.GroupServer == ev.Data[event.GroupServer] {
					group.State = ev.Data[event.ConnectionState]
				}
			}
		case event.DeleteContact:
			onion := ev.Data[event.RemotePeer]
			ps.profile.DeleteContact(onion)
			ps.save()
		case event.DeleteGroup:
			groupID := ev.Data[event.GroupID]
			ps.profile.DeleteGroup(groupID)
			ps.save()
			ss, exists := ps.streamStores[groupID]
			if exists {
				ss.Delete()
				delete(ps.streamStores, groupID)
			}
		case event.ChangePassword:
			oldpass := ev.Data[event.Password]
			newpass := ev.Data[event.NewPassword]
			ps.ChangePassword(oldpass, newpass, ev.EventID)
		default:
			return
		}

	}
}

// Shutdown shuts down the queue / thread
func (ps *ProfileStoreV1) Shutdown() {
	if ps.queue != nil {
		ps.queue.Shutdown()
	}
}

// Delete removes all stored files for this stored profile
func (ps *ProfileStoreV1) Delete() {
	log.Debugf("Delete ProfileStore for %v\n", ps.profile.Onion)

	for _, ss := range ps.streamStores {
		ss.Delete()
	}

	ps.fs.Delete()

	err := os.RemoveAll(ps.directory)
	if err != nil {
		log.Errorf("ProfileStore Delete error on RemoveAll on %v was %v\n", ps.directory, err)
	}
}