package main import ( "bufio" "fmt" "github.com/spf13/afero" "log" "math/rand" "os" "path/filepath" "strings" "time" ) // Stuff people with mediocre handwriting could write down unambiguously, and can be entered without holding down shift const DistinguishableChars = "234678abcdefhikmnpqrtwxyz=" // We use the filesystem for synchronization between threads. // The only thing State methods need to know is the path to the state directory. type State struct { afero.Fs Enabled bool } func NewState(fs afero.Fs) *State { return &State{ Fs: fs, Enabled: true, } } // Check a few things to see if this state directory is "enabled". func (s *State) UpdateEnabled() { if _, err := s.Stat("enabled"); os.IsNotExist(err) { s.Enabled = false log.Println("Suspended: enabled file missing") return } nextEnabled := true untilFile, err := s.Open("hours") if err != nil { return } defer untilFile.Close() scanner := bufio.NewScanner(untilFile) for scanner.Scan() { line := scanner.Text() if len(line) < 1 { continue } thisEnabled := true switch line[0] { case '+': thisEnabled = true line = line[1:] case '-': thisEnabled = false line = line[1:] case '#': continue default: log.Println("Misformatted line in hours file") } line = strings.TrimSpace(line) until, err := time.Parse(time.RFC3339, line) if err != nil { log.Println("Suspended: Unparseable until date:", line) continue } if until.Before(time.Now()) { nextEnabled = thisEnabled } } if nextEnabled != s.Enabled { s.Enabled = nextEnabled log.Println("Setting enabled to", s.Enabled, "based on hours file") } } // Returns team name given a team ID. func (s *State) TeamName(teamId string) (string, error) { // XXX: directory traversal teamFile := filepath.Join("teams", teamId) teamNameBytes, err := afero.ReadFile(s, teamFile) teamName := strings.TrimSpace(string(teamNameBytes)) if os.IsNotExist(err) { return "", fmt.Errorf("Unregistered team ID: %s", teamId) } else if err != nil { return "", fmt.Errorf("Unregistered team ID: %s (%s)", teamId, err) } return teamName, nil } // Write out team name. This can only be done once. func (s *State) SetTeamName(teamId, teamName string) error { if f, err := s.Open("teamids.txt"); err != nil { return fmt.Errorf("Team IDs file does not exist") } else { found := false scanner := bufio.NewScanner(f) for scanner.Scan() { if scanner.Text() == teamId { found = true break } } f.Close() if !found { return fmt.Errorf("Team ID not found in list of valid Team IDs") } } teamFile := filepath.Join("teams", teamId) err := afero.WriteFile(s, teamFile, []byte(teamName), os.ModeExclusive|0644) if os.IsExist(err) { return fmt.Errorf("Team ID is already registered") } return err } // Retrieve the current points log func (s *State) PointsLog() []*Award { f, err := s.Open("points.log") if err != nil { log.Println(err) return nil } defer f.Close() pointsLog := make([]*Award, 0, 200) scanner := bufio.NewScanner(f) for scanner.Scan() { line := scanner.Text() cur, err := ParseAward(line) if err != nil { log.Printf("Skipping malformed award line %s: %s", line, err) continue } pointsLog = append(pointsLog, cur) } return pointsLog } // Retrieve current messages func (s *State) Messages() string { bMessages, _ := afero.ReadFile(s, "messages.html") return string(bMessages) } // AwardPoints gives points to teamId in category. // It first checks to make sure these are not duplicate points. // This is not a perfect check, you can trigger a race condition here. // It's just a courtesy to the user. // The update task makes sure we never have duplicate points in the log. func (s *State) AwardPoints(teamId, category string, points int) error { a := Award{ When: time.Now().Unix(), TeamId: teamId, Category: category, Points: points, } _, err := s.TeamName(teamId) if err != nil { return err } for _, e := range s.PointsLog() { if a.Same(e) { return fmt.Errorf("Points already awarded to this team in this category") } } fn := fmt.Sprintf("%s-%s-%d", teamId, category, points) tmpfn := filepath.Join("points.tmp", fn) newfn := filepath.Join("points.new", fn) if err := afero.WriteFile(s, tmpfn, []byte(a.String()), 0644); err != nil { return err } if err := s.Rename(tmpfn, newfn); err != nil { return err } // XXX: update everything return nil } // collectPoints gathers up files in points.new/ and appends their contents to points.log, // removing each points.new/ file as it goes. func (s *State) collectPoints() { files, err := afero.ReadDir(s, "points.new") if err != nil { log.Print(err) return } for _, f := range files { filename := filepath.Join("points.new", f.Name()) awardstr, err := afero.ReadFile(s, filename) if err != nil { log.Print("Opening new points: ", err) continue } award, err := ParseAward(string(awardstr)) if err != nil { log.Print("Can't parse award file ", filename, ": ", err) continue } duplicate := false for _, e := range s.PointsLog() { if award.Same(e) { duplicate = true break } } if duplicate { log.Print("Skipping duplicate points: ", award.String()) } else { log.Print("Award: ", award.String()) logf, err := s.OpenFile("points.log", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644) if err != nil { log.Print("Can't append to points log: ", err) return } fmt.Fprintln(logf, award.String()) logf.Close() } if err := s.Remove(filename); err != nil { log.Print("Unable to remove new points file: ", err) } } } func (s *State) maybeInitialize() { // Are we supposed to re-initialize? if _, err := s.Stat("initialized"); !os.IsNotExist(err) { return } now := time.Now().UTC().Format(time.RFC3339) log.Print("initialized file missing, re-initializing") // Remove any extant control and state files s.Remove("enabled") s.Remove("hours") s.Remove("points.log") s.Remove("messages.html") s.RemoveAll("points.tmp") s.RemoveAll("points.new") s.RemoveAll("teams") // Make sure various subdirectories exist s.Mkdir("points.tmp", 0755) s.Mkdir("points.new", 0755) s.Mkdir("teams", 0755) // Preseed available team ids if file doesn't exist if f, err := s.OpenFile("teamids.txt", os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0644); err == nil { id := make([]byte, 8) for i := 0; i < 100; i += 1 { for i := range id { char := rand.Intn(len(DistinguishableChars)) id[i] = DistinguishableChars[char] } fmt.Fprintln(f, string(id)) } f.Close() } // Create some files if f, err := s.Create("initialized"); err == nil { fmt.Fprintln(f, "initialized: remove to re-initialize the contest.") fmt.Fprintln(f) fmt.Fprintln(f, "This instance was initaliazed at", now) f.Close() } if f, err := s.Create("enabled"); err == nil { fmt.Fprintln(f, "enabled: remove or rename to suspend the contest.") f.Close() } if f, err := s.Create("hours"); err == nil { fmt.Fprintln(f, "# hours: when the contest is enabled") fmt.Fprintln(f, "#") fmt.Fprintln(f, "# Enable: + timestamp") fmt.Fprintln(f, "# Disable: - timestamp") fmt.Fprintln(f, "#") fmt.Fprintln(f, "# You can have multiple start/stop times.") fmt.Fprintln(f, "# Whatever time is the most recent, wins.") fmt.Fprintln(f, "# Times in the future are ignored.") fmt.Fprintln(f) fmt.Fprintln(f, "+", now) fmt.Fprintln(f, "- 3019-10-31T00:00:00Z") f.Close() } if f, err := s.Create("messages.html"); err == nil { fmt.Fprintln(f, "") f.Close() } if f, err := s.Create("points.log"); err == nil { f.Close() } } func (s *State) Update() { s.maybeInitialize() s.UpdateEnabled() if s.Enabled { s.collectPoints() } }