golias/handlers/actions.go

package handlers

import (
	"context"
	"encoding/json"
	"errors"
	"golias/models"
	"golias/utils"
)

func createRoom(ctx context.Context, req *models.RoomReq) (*models.Room, error) {
	creator, ok := ctx.Value(models.CtxUsernameKey).(string)
	if !ok {
		err := errors.New("failed to extract user from ctx")
		return nil, err
	}
	room := req.CreateRoom(creator)
	if err := saveRoom(room); err != nil {
		return nil, err
	}
	return room, nil
}

func saveRoom(room *models.Room) error {
	data, err := json.Marshal(room)
	if err != nil {
		return err
	}
	memcache.Set(models.CacheRoomPrefix+room.ID, data)
	return nil
}

func getRoomByID(roomID string) (*models.Room, error) {
	roomBytes, err := memcache.Get(models.CacheRoomPrefix + roomID)
	if err != nil {
		return nil, err
	}
	resp := &models.Room{}
	if err := json.Unmarshal(roomBytes, &resp); err != nil {
		return nil, err
	}
	return resp, nil
}

// context
func getRoomIDFromCtx(ctx context.Context) string {
	id, _ := ctx.Value(models.CtxRoomIDKey).(string)
	return id
}

func getStateByCtx(ctx context.Context) (*models.UserState, error) {
	username, ok := ctx.Value(models.CtxUsernameKey).(string)
	if !ok {
		log.Debug("no username in ctx")
		return &models.UserState{}, errors.New("no username in ctx")
	}
	us, err := loadState(username)
	if err != nil {
		return &models.UserState{}, err
	}
	return us, nil
}

func saveStateByCtx(ctx context.Context, state *models.UserState) error {
	username, ok := ctx.Value(models.CtxUsernameKey).(string)
	if !ok {
		log.Debug("no username in ctx")
		return errors.New("no username in ctx")
	}
	return saveState(username, state)
}

func saveFullInfo(fi *models.FullInfo) error {
	// INFO: unfortunately working no transactions; so case are possible where first object is updated but the second is not
	if err := saveState(fi.State.Username, fi.State); err != nil {
		return err
	}
	// can room be nil?
	// if fi.Room == nil {
	// 	return nil
	// }
	if err := saveRoom(fi.Room); err != nil {
		return err
	}
	return nil
}

// cache

func saveState(username string, state *models.UserState) error {
	key := models.CacheStatePrefix + username
	data, err := json.Marshal(state)
	if err != nil {
		return err
	}
	memcache.Set(key, data)
	return nil
}

func loadState(username string) (*models.UserState, error) {
	key := models.CacheStatePrefix + username
	data, err := memcache.Get(key)
	if err != nil {
		return nil, err
	}
	resp := &models.UserState{}
	if err := json.Unmarshal(data, &resp); err != nil {
		return nil, err
	}
	return resp, nil
}

func getAllNames() []string {
	names := []string{}
	// will not scale
	wholeMemStore := memcache.GetAll()
	session := &models.Session{}
	// filter by key size only sessions
	for k, v := range wholeMemStore {
		// xid is 20 in len
		if len(k) != 20 {
			continue
		}
		if err := json.Unmarshal(v, &session); err != nil {
			log.Error("failed to unmarshal", "error", err)
			continue
		}
		names = append(names, session.Username)
	}
	return names
}

// can room exists without state? I think no
func getFullInfoByCtx(ctx context.Context) (*models.FullInfo, error) {
	resp := &models.FullInfo{}
	state, err := getStateByCtx(ctx)
	if err != nil {
		return nil, err
	}
	resp.State = state
	if state.RoomID == "" {
		return resp, nil
	}
	room, err := getRoomByID(state.RoomID)
	if err != nil {
		log.Warn("failed to find room despite knowing room_id;",
			"room_id", state.RoomID)
		return nil, err
	}
	resp.Room = room
	return resp, nil
}

func joinTeam(ctx context.Context, role, team string) (*models.FullInfo, error) {
	// get username
	fi, _ := getFullInfoByCtx(ctx)
	fi.Room.RedTeam.Guessers = utils.RemoveFromSlice(fi.State.Username, fi.Room.RedTeam.Guessers)
	fi.Room.BlueTeam.Guessers = utils.RemoveFromSlice(fi.State.Username, fi.Room.BlueTeam.Guessers)
	// get room
	if role == "mime" {
		if team == "blue" {
			if fi.Room.BlueTeam.Mime != "" {
				// error: alredy taken
				err := errors.New("Mime role already taken!")
				return fi, err
			}
			fi.Room.BlueTeam.Mime = fi.State.Username
			fi.State.Team = "blue"
			fi.State.Role = "mime"
			if fi.Room.RedTeam.Mime == fi.State.Username {
				fi.Room.RedTeam.Mime = ""
			}
		} else if team == "red" {
			if fi.Room.RedTeam.Mime != "" {
				// error: alredy taken
				err := errors.New("Mime role already taken!")
				return fi, err
			}
			fi.Room.RedTeam.Mime = fi.State.Username
			fi.State.Team = "red"
			fi.State.Role = "mime"
			if fi.Room.BlueTeam.Mime == fi.State.Username {
				fi.Room.BlueTeam.Mime = ""
			}
		} else {
			err := errors.New("uknown team:" + team)
			return nil, err
		}
	} else if role == "guesser" {
		if team == "blue" {
			fi.Room.BlueTeam.Guessers = append(fi.Room.BlueTeam.Guessers, fi.State.Username)
			fi.State.Team = "blue"
			fi.State.Role = "guesser"
		} else if team == "red" {
			fi.Room.RedTeam.Guessers = append(fi.Room.RedTeam.Guessers, fi.State.Username)
			fi.State.Team = "red"
			fi.State.Role = "guesser"
		} else {
			err := errors.New("uknown team:" + team)
			return nil, err
		}
	} else {
		err := errors.New("uknown role:" + role)
		return nil, err
	}
	if err := saveFullInfo(fi); err != nil {
		return nil, err
	}
	return fi, nil
}