package main import ( "fmt" "io" "strconv" "time" "github.com/dirtbags/moth/pkg/award" ) // Category represents a puzzle category. type Category struct { Name string Puzzles []int } // ReadSeekCloser defines a struct that can read, seek, and close. type ReadSeekCloser interface { io.Reader io.Seeker io.Closer } // Configuration stores information about server configuration. type Configuration struct { Devel bool } // StateExport is given to clients requesting the current state. type StateExport struct { Config Configuration Messages string TeamNames map[string]string PointsLog award.List Puzzles map[string][]int } // PuzzleProvider defines what's required to provide puzzles. type PuzzleProvider interface { Open(cat string, points int, path string) (ReadSeekCloser, time.Time, error) Inventory() []Category CheckAnswer(cat string, points int, answer string) (bool, error) Mothball(cat string, w io.Writer) error Maintainer } // ThemeProvider defines what's required to provide a theme. type ThemeProvider interface { Open(path string) (ReadSeekCloser, time.Time, error) Maintainer } // StateProvider defines what's required to provide MOTH state. type StateProvider interface { Messages() string PointsLog() award.List TeamName(teamID string) (string, error) SetTeamName(teamID, teamName string) error AwardPoints(teamID string, cat string, points int) error LogEvent(event, participantID, teamID, cat string, points int, extra ...string) Maintainer } // Maintainer is something that can be maintained. type Maintainer interface { // Maintain is the maintenance loop. // It will only be called once, when execution begins. // It's okay to just exit if there's no maintenance to be done. Maintain(updateInterval time.Duration) // refresh is a shortcut used internally for testing refresh() } // MothServer gathers together the providers that make up a MOTH server. type MothServer struct { PuzzleProviders []PuzzleProvider Theme ThemeProvider State StateProvider Config Configuration } // NewMothServer returns a new MothServer. func NewMothServer(config Configuration, theme ThemeProvider, state StateProvider, puzzleProviders ...PuzzleProvider) *MothServer { return &MothServer{ Config: config, PuzzleProviders: puzzleProviders, Theme: theme, State: state, } } // NewHandler returns a new http.RequestHandler for the provided teamID. func (s *MothServer) NewHandler(participantID, teamID string) MothRequestHandler { return MothRequestHandler{ MothServer: s, participantID: participantID, teamID: teamID, } } // MothRequestHandler provides http.RequestHandler for a MothServer. type MothRequestHandler struct { *MothServer participantID string teamID string } // PuzzlesOpen opens a file associated with a puzzle. // BUG(neale): Multiple providers with the same category name are not detected or handled well. func (mh *MothRequestHandler) PuzzlesOpen(cat string, points int, path string) (r ReadSeekCloser, ts time.Time, err error) { export := mh.exportStateIfRegistered(true) found := false for _, p := range export.Puzzles[cat] { if p == points { found = true } } if !found { return nil, time.Time{}, fmt.Errorf("puzzle does not exist or is locked") } // Try every provider until someone doesn't return an error for _, provider := range mh.PuzzleProviders { r, ts, err = provider.Open(cat, points, path) if err != nil { return r, ts, err } } // Log puzzle.json loads if path == "puzzle.json" { mh.State.LogEvent("load", mh.participantID, mh.teamID, cat, points) } return } // CheckAnswer returns an error if answer is not a correct answer for puzzle points in category cat func (mh *MothRequestHandler) CheckAnswer(cat string, points int, answer string) error { correct := false for _, provider := range mh.PuzzleProviders { if ok, err := provider.CheckAnswer(cat, points, answer); err != nil { return err } else if ok { correct = true } } if !correct { mh.State.LogEvent("wrong", mh.participantID, mh.teamID, cat, points) return fmt.Errorf("incorrect answer") } mh.State.LogEvent("correct", mh.participantID, mh.teamID, cat, points) if _, err := mh.State.TeamName(mh.teamID); err != nil { return fmt.Errorf("invalid team ID") } if err := mh.State.AwardPoints(mh.teamID, cat, points); err != nil { return fmt.Errorf("error awarding points: %s", err) } return nil } // ThemeOpen opens a file from a theme. func (mh *MothRequestHandler) ThemeOpen(path string) (ReadSeekCloser, time.Time, error) { return mh.Theme.Open(path) } // Register associates a team name with a team ID. func (mh *MothRequestHandler) Register(teamName string) error { // BUG(neale): Register returns an error if a team is already registered; it may make more sense to return success if teamName == "" { return fmt.Errorf("empty team name") } mh.State.LogEvent("register", mh.participantID, mh.teamID, "", 0) return mh.State.SetTeamName(mh.teamID, teamName) } // ExportState anonymizes team IDs and returns StateExport. // If a teamID has been specified for this MothRequestHandler, // the anonymized team name for this teamID has the special value "self". // If not, the puzzles list is empty. func (mh *MothRequestHandler) ExportState() *StateExport { return mh.exportStateIfRegistered(false) } func (mh *MothRequestHandler) exportStateIfRegistered(override bool) *StateExport { export := StateExport{} export.Config = mh.Config teamName, err := mh.State.TeamName(mh.teamID) registered := override || mh.Config.Devel || (err == nil) export.Messages = mh.State.Messages() export.TeamNames = make(map[string]string) // Anonymize team IDs in points log, and write out team names pointsLog := mh.State.PointsLog() exportIDs := make(map[string]string) maxSolved := make(map[string]int) export.PointsLog = make(award.List, len(pointsLog)) if registered { export.TeamNames["self"] = teamName exportIDs[mh.teamID] = "self" } for logno, awd := range pointsLog { if id, ok := exportIDs[awd.TeamID]; ok { awd.TeamID = id } else { exportID := strconv.Itoa(logno) name, _ := mh.State.TeamName(awd.TeamID) exportIDs[awd.TeamID] = exportID awd.TeamID = exportID export.TeamNames[exportID] = name } export.PointsLog[logno] = awd // Record the highest-value unlocked puzzle in each category if awd.Points > maxSolved[awd.Category] { maxSolved[awd.Category] = awd.Points } } export.Puzzles = make(map[string][]int) if registered { // We used to hand this out to everyone, // but then we got a bad reputation on some secretive blacklist, // and now the Navy can't register for events. for _, provider := range mh.PuzzleProviders { for _, category := range provider.Inventory() { // Append sentry (end of puzzles) allPuzzles := append(category.Puzzles, 0) max := maxSolved[category.Name] puzzles := make([]int, 0, len(allPuzzles)) for i, val := range allPuzzles { puzzles = allPuzzles[:i+1] if !mh.Config.Devel && (val > max) { break } } export.Puzzles[category.Name] = puzzles } } } return &export } // Mothball generates a mothball for the given category. func (mh *MothRequestHandler) Mothball(cat string, w io.Writer) error { var err error if !mh.Config.Devel { return fmt.Errorf("cannot mothball in production mode") } for _, provider := range mh.PuzzleProviders { if err = provider.Mothball(cat, w); err == nil { return nil } } return err }