// HomeHandler is a http handler for the home page for logged in users.
func HomeHandler(w http.ResponseWriter, r *http.Request) {
	member, err := checkMemberApproval(w, r, true)
	if err != nil {
		return
	}

	view := HomeView{
		StdTemplate: StdTemplate{
			Member: member,
		},
		Teaching:  make(map[string]*git.Organization),
		Assisting: make(map[string]*git.Organization),
		Courses:   make(map[string]*git.Organization),
	}

	for key := range member.Teaching {
		view.Teaching[key], _ = git.NewOrganization(key, true)
	}
	for key := range member.AssistantCourses {
		view.Assisting[key], _ = git.NewOrganization(key, true)
	}
	for key := range member.Courses {
		view.Courses[key], _ = git.NewOrganization(key, true)
	}

	if !member.IsComplete() {
		http.Redirect(w, r, pages.REGISTER_REDIRECT, 307)
		return
	}

	execTemplate("home.html", w, view)
}

// RequestRandomGroupHandler is a http handler used by a student to request a random group assignment.
func RequestRandomGroupHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkMemberApproval(w, r, false)
	if err != nil {
		http.Error(w, err.Error(), 404)
		log.Println(err)
		return
	}

	orgname := r.FormValue("course")
	if !git.HasOrganization(orgname) {
		http.Error(w, "Does not have organization.", 404)
	}

	org, err := git.NewOrganization(orgname, false)
	if err != nil {
		http.Error(w, "Does not have organization.", 404)
	}
	defer func() {
		err := org.Save()
		if err != nil {
			org.Unlock()
			log.Println(err)
		}
	}()

	org.PendingRandomGroup[member.Username] = nil
}

// SlipdaysHandler is used to get used slipdays for a user in a course.
func SlipdaysHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkMemberApproval(w, r, false)
	if err != nil {
		http.Error(w, err.Error(), 404)
		log.Println(err)
		return
	}

	orgname := r.FormValue("Course")

	org, err := git.NewOrganization(orgname, true)
	if err != nil {
		log.Println(err)
		http.Error(w, err.Error(), 500)
		return
	}

	view := SlipdaysView{
		Course:      orgname,
		MaxSlipdays: org.SlipdaysMax,
	}

	if org.IsTeacher(member) {
		username := r.FormValue("Username")

		user, err := git.NewMemberFromUsername(username, true)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 404)
			return
		}

		if !org.IsMember(member) {
			http.Error(w, "Unknown member of course.", 404)
			return
		}

		courseopt := user.Courses[org.Name]

		view.UsedSlipdays = courseopt.UsedSlipDays
		view.Username = user.Username
	} else if org.IsMember(member) {
		courseopt := member.Courses[org.Name]

		view.UsedSlipdays = courseopt.UsedSlipDays
		view.Username = member.Username
	} else {
		http.Error(w, "Unknown member of course.", 404)
		return
	}

	enc := json.NewEncoder(w)
	err = enc.Encode(view)
	if err != nil {
		log.Println(err)
		http.Error(w, err.Error(), 404)
		return
	}
}

// RemoveUserHandler is http handler used to remove users from the list of students on a course.
func RemoveUserHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkTeacherApproval(w, r, true)
	if err != nil {
		http.Redirect(w, r, "/", 307)
		log.Println(err)
		return
	}

	username := r.FormValue("user")
	course := r.FormValue("course")

	if !git.HasOrganization(course) {
		http.Error(w, "Unknown course.", 404)
		return
	}

	org, err := git.NewOrganization(course, false)
	if err != nil {
		http.Error(w, "Not valid organization.", 404)
		return
	}

	defer func() {
		err := org.Save()
		if err != nil {
			org.Unlock()
			log.Println(err)
		}
	}()

	if !org.IsTeacher(member) {
		http.Error(w, "Is not a teacher or assistant for this course.", 404)
		return
	}

	user, err := git.NewMemberFromUsername(username, false)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	defer func() {
		err := user.Save()
		if err != nil {
			user.Unlock()
			log.Println(err)
		}
	}()

	if org.IsMember(user) {
		org.RemoveMembership(user)
		user.RemoveOrganization(org)
	} else {
		http.Error(w, "Couldn't find this user in this course. ", 404)
		return
	}
}

// AddAssistantHandler is a http handler used to add users as assistants on a course.
func AddAssistantHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkTeacherApproval(w, r, false)
	if err != nil {
		log.Println(err)
		return
	}

	username := r.FormValue("assistant")
	course := r.FormValue("course")

	if !git.HasOrganization(course) {
		http.Error(w, "Unknown course.", 404)
		return
	}

	if username == member.Username {
		return
	}

	assistant, err := git.NewMemberFromUsername(username, false)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	defer func() {
		if err := assistant.Save(); err != nil {
			assistant.Unlock()
			log.Println(err)
		}
	}()

	org, err := git.NewOrganization(course, false)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	defer func() {
		if err := org.Save(); err != nil {
			org.Unlock()
			log.Println(err)
		}
	}()

	if !org.IsTeacher(member) {
		http.Error(w, "User is not the teacher for this course.", 404)
		return
	}

	assistant.AddAssistingOrganization(org)

	org.AddTeacher(assistant)
	if _, ok := org.PendingUser[username]; ok {
		delete(org.PendingUser, username)
	}
}

// RegisterCourseMemberHandler is a http handler which register new students
// signing up for a course. After registering the student, this handler
// gives back a informal page about how to accept the invitation to the
// organization on github.
func RegisterCourseMemberHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkMemberApproval(w, r, true)
	if err != nil {
		log.Println(err)
		return
	}

	// Gets the org and check if valid
	orgname := ""
	if path := strings.Split(r.URL.Path, "/"); len(path) == 4 {
		if !git.HasOrganization(path[3]) {
			http.Redirect(w, r, "/course/register", 307)
			return
		}

		orgname = path[3]
	} else {
		http.Redirect(w, r, "/course/register", 307)
		return
	}

	org, err := git.NewOrganization(orgname, false)
	if err != nil {
		http.Redirect(w, r, "/course/register", 307)
		return
	}

	defer func() {
		err = org.Save()
		if err != nil {
			org.Unlock()
			log.Println(err)
		}
	}()

	if _, ok := org.Members[member.Username]; ok {
		http.Redirect(w, r, "/course/"+orgname, 307)
		return
	}

	err = org.AddMembership(member)
	if err != nil {
		log.Println("Error adding the student to course. Error msg:", err)
	}

	view := NewMemberView{
		StdTemplate: StdTemplate{
			Member: member,
		},
		Org: orgname,
	}
	execTemplate("course-registeredmemberinfo.html", w, view)
}

// ListReviewsHandler will write back a list of all the code reviews
// in a course, as json data.
//
// Expected input keys: course
func ListReviewsHandler(w http.ResponseWriter, r *http.Request) {
	view := ListReviewsView{
		Error: true,
	}

	enc := json.NewEncoder(w)

	// Checks if the user is signed in.
	member, err := checkMemberApproval(w, r, true)
	if err != nil {
		log.Println(err)
		return
	}

	if r.FormValue("course") == "" {
		view.Errormsg = "Missing required course field."
		enc.Encode(view)
		return
	}

	if !git.HasOrganization(r.FormValue("course")) {
		view.Errormsg = "Unknown course."
		enc.Encode(view)
		return
	}

	org, err := git.NewOrganization(r.FormValue("course"), true)
	if err != nil {
		view.Errormsg = "Unknown course."
		enc.Encode(view)
		return
	}

	if !org.IsMember(member) {
		view.Errormsg = "Not a member of this course."
		enc.Encode(view)
		return
	}

	crlist := []*git.CodeReview{}
	for _, crid := range org.CodeReviewlist {
		if cr, err := git.GetCodeReview(crid); err == nil {
			crlist = append(crlist, cr)
		}
	}

	view.Error = false
	view.Reviews = crlist
	enc.Encode(view)
}

// RemovePendingUserHandler is http handler used to remove users from the list of pending students on a course.
func RemovePendingUserHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkTeacherApproval(w, r, true)
	if err != nil {
		http.Redirect(w, r, "/", 307)
		log.Println(err)
		return
	}

	username := r.FormValue("user")
	course := r.FormValue("course")

	if !git.HasOrganization(course) {
		http.Error(w, "Unknown course.", 404)
		return
	}

	org, err := git.NewOrganization(course, false)
	if err != nil {
		http.Error(w, "Not valid organization.", 404)
		return
	}
	defer func() {
		err := org.Save()
		if err != nil {
			org.Unlock()
			log.Println(err)
		}
	}()

	org.Lock()
	defer org.Unlock()

	if !org.IsTeacher(member) {
		http.Error(w, "Is not a teacher or assistant for this course.", 404)
		return
	}

	if _, ok := org.PendingUser[username]; ok {
		delete(org.PendingUser, username)
	}
}

// ScoreboardHandler is a http handler to give the user a page
// showing the scoreboard for a course
func ScoreboardHandler(w http.ResponseWriter, r *http.Request) {
	member, err := checkMemberApproval(w, r, true)
	if err != nil {
		return
	}

	// Gets the org and check if valid
	orgname := ""
	if path := strings.Split(r.URL.Path, "/"); len(path) == 3 {
		if !git.HasOrganization(path[2]) {
			http.Redirect(w, r, HomeURL, 307)
			return
		}

		orgname = path[2]
	} else {
		http.Redirect(w, r, HomeURL, 307)
		return
	}

	org, err := git.NewOrganization(orgname, true)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	if !org.IsMember(member) {
		http.Redirect(w, r, HomeURL, 307)
		return
	}

	view := ScoreboardView{
		StdTemplate: StdTemplate{
			Member: member,
		},
		Org: org,
	}

	execTemplate("scoreboard.html", w, view)
}

// CIResultSummaryHandler is a http handler used to get a build summary
// of the build for a user or group. This handler writes back the summary
// as JSON data.
func CIResultSummaryHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	teacher, err := checkTeacherApproval(w, r, false)
	if err != nil {
		http.Error(w, err.Error(), 404)
		log.Println(err)
		return
	}

	orgname := r.FormValue("Course")
	username := r.FormValue("Username")

	if orgname == "" || username == "" {
		http.Error(w, "Empty request.", 404)
		return
	}

	org, err := git.NewOrganization(orgname, true)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	if !org.IsTeacher(teacher) {
		http.Error(w, "Not a teacher for this course.", 404)
		return
	}

	res := make(map[string]*ci.BuildResult)
	notes := make(map[string]string)
	//credit := make(map[string]score.Score)
	//if group ...
	if strings.HasPrefix(username, git.GroupRepoPrefix) {
		groupid, err := strconv.Atoi(username[len(git.GroupRepoPrefix):])
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 500)
			return
		}

		group, err := git.NewGroup(orgname, groupid, true)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 500)
			return
		}

		for labnum, lab := range group.Assignments {
			labname := org.GroupLabFolders[labnum]
			buildid := group.GetLastBuildID(labnum)
			if buildid < 0 {
				continue
			}

			build, err := ci.GetBuildResult(buildid)
			if err != nil {
				log.Println(err)
				continue
			}
			res[labname] = build
			notes[labname] = lab.Notes
			//credit[labname] = lab.ExtraCredit
		}
	} else {
		user, err := git.NewMemberFromUsername(username, true)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 500)
			return
		}

		courseopt, ok := user.Courses[orgname]
		if ok {
			for labnum, lab := range courseopt.Assignments {
				labname := org.IndividualLabFolders[labnum]
				buildid := user.GetLastBuildID(orgname, labnum)
				if buildid < 0 {
					continue
				}

				build, err := ci.GetBuildResult(buildid)
				if err != nil {
					log.Println(err)
					continue
				}
				res[labname] = build
				notes[labname] = lab.Notes
				//credit[labname] = lab.ExtraCredit
			}
		}
	}

	view := SummaryView{
		Course:  orgname,
		User:    username,
		Summary: res,
		Notes:   notes,
//.........这里部分代码省略.........

// ManualCITriggerHandler is a http handler for manually triggering test builds.
func ManualCITriggerHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkMemberApproval(w, r, false)
	if err != nil {
		http.Error(w, err.Error(), 404)
		log.Println(err)
		return
	}

	course := r.FormValue("course")
	user := r.FormValue("user")
	lab := r.FormValue("lab")

	if !git.HasOrganization(course) {
		http.Error(w, "Unknown organization", 404)
		return
	}

	org, err := git.NewOrganization(course, true)
	if err != nil {
		http.Error(w, "Organization Error", 404)
		return
	}

	// Defaults back to username or group name for the user if not a teacher.
	if !org.IsTeacher(member) {
		if org.IsMember(member) {
			if strings.Contains(user, "group") {
				if member.Courses[org.Name].IsGroupMember {
					user = "group" + strconv.Itoa(member.Courses[org.Name].GroupNum)
				} else {
					http.Error(w, "Not a group member", 404)
					return
				}
			} else {
				user = member.Username
			}
		} else {
			http.Error(w, "Not a member of the course", 404)
			return
		}
	}

	groupid := -1
	labnum := -1
	if strings.Contains(user, "group") {
		groupid, err = strconv.Atoi(user[len("group"):])
		if err != nil {
			http.Error(w, err.Error(), 500)
			return
		}

		for i, name := range org.GroupLabFolders {
			if name == lab {
				labnum = i
				break
			}
		}
	} else {
		for i, name := range org.IndividualLabFolders {
			if name == lab {
				labnum = i
				break
			}
		}
	}

	var repo string
	var destfolder string
	if _, ok := org.Members[user]; ok {
		repo = user + "-" + git.StandardRepoName
		destfolder = git.StandardRepoName
	} else if _, ok := org.Groups[user]; ok {
		repo = user
		destfolder = git.GroupsRepoName
	} else {
		http.Error(w, "Unknown user", 404)
		return
	}

	opt := ci.DaemonOptions{
		Org:   org.Name,
		User:  user,
		Group: groupid,

		Repo:       repo,
		BaseFolder: org.CI.Basepath,
		LabFolder:  lab,
		LabNumber:  labnum,
		AdminToken: org.AdminToken,
		DestFolder: destfolder,
		Secret:     org.CI.Secret,
		IsPush:     false,
	}

	log.Println(opt)

	ci.StartTesterDaemon(opt)
}

// CIResultHandler is a http handeler for getting results from
// a build. This handler writes back the results as JSON data.
func CIResultHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkMemberApproval(w, r, false)
	if err != nil {
		http.Error(w, err.Error(), 404)
		log.Println(err)
		return
	}

	// TODO: add more security
	orgname := r.FormValue("Course")
	username := r.FormValue("Username")
	labname := r.FormValue("Labname")

	org, err := git.NewOrganization(orgname, true)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	if !org.IsMember(member) {
		http.Error(w, "Not a member for this course.", 404)
		return
	}

	var res *ci.BuildResult

	if strings.HasPrefix(username, git.GroupRepoPrefix) {
		labnum := -1
		for i, name := range org.GroupLabFolders {
			if name == labname {
				labnum = i
				break
			}
		}

		if labnum < 0 {
			http.Error(w, "No lab with that name found.", 404)
			return
		}

		groupid, err := strconv.Atoi(username[len(git.GroupRepoPrefix):])
		if err != nil {
			http.Error(w, "Could not convert the group ID.", 404)
			return
		}

		group, err := git.NewGroup(orgname, groupid, true)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 404)
			return
		}

		buildid := group.GetLastBuildID(labnum)
		if buildid < 0 {
			http.Error(w, "Could not find the build.", 404)
			return
		}

		res, err = ci.GetBuildResult(buildid)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 404)
			return
		}
	} else {
		labnum := -1
		for i, name := range org.IndividualLabFolders {
			if name == labname {
				labnum = i
				break
			}
		}

		if labnum < 0 {
			http.Error(w, "No lab with that name found.", 404)
			return
		}

		user, err := git.NewMemberFromUsername(username, true)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 404)
			return
		}

		buildid := user.GetLastBuildID(orgname, labnum)
		if buildid < 0 {
			http.Error(w, "Could not find the build.", 404)
			return
		}

		res, err = ci.GetBuildResult(buildid)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 404)
			return
//.........这里部分代码省略.........

// AddGroupMemberHandler is a http handler adding an additional member to a active group.
func AddGroupMemberHandler(w http.ResponseWriter, r *http.Request) {
	view := AddGroupMemberView{}
	view.Error = true
	enc := json.NewEncoder(w)

	// Checks if the user is signed in and a teacher.
	member, err := checkTeacherApproval(w, r, true)
	if err != nil {
		err = enc.Encode(ErrSignIn)
		return
	}

	orgname := r.FormValue("course")
	if orgname == "" || !git.HasOrganization(orgname) {
		err = enc.Encode(ErrUnknownCourse)
		return
	}

	groupid, err := strconv.Atoi(r.FormValue("groupid"))
	if err != nil {
		view.ErrorMsg = err.Error()
		err = enc.Encode(view)
		return
	}

	if !git.HasGroup(groupid) {
		err = enc.Encode(ErrUnknownGroup)
		return
	}

	org, err := git.NewOrganization(orgname, false)
	if err != nil {
		view.ErrorMsg = err.Error()
		err = enc.Encode(view)
		return
	}

	defer func() {
		err := org.Save()
		if err != nil {
			org.Unlock()
			log.Println(err)
		}
	}()

	if !org.IsTeacher(member) {
		err = enc.Encode(ErrNotTeacher)
		return
	}

	group, err := git.NewGroup(orgname, groupid, false)
	if err != nil {
		view.ErrorMsg = err.Error()
		err = enc.Encode(view)
		return
	}

	defer func() {
		err := group.Save()
		if err != nil {
			group.Unlock()
			log.Println(err)
		}
	}()

	if group.TeamID == 0 {
		teams, err := org.ListTeams()
		if err != nil {
			view.ErrorMsg = err.Error()
			err = enc.Encode(view)
			return
		}

		if team, ok := teams[git.GroupRepoPrefix+strconv.Itoa(groupid)]; ok {
			group.TeamID = team.ID
		} else {
			view.ErrorMsg = "Error finding team on GitHub."
			err = enc.Encode(view)
			return
		}
	}

	r.ParseForm()
	members := r.PostForm["member"]

	for _, username := range members {
		if username == "" || !git.HasMember(username) {
			continue
		}

		group.AddMember(username)

		org.AddMemberToTeam(group.TeamID, username)
		delete(org.PendingRandomGroup, username)
	}

	group.Activate()

	view.Added = true
//.........这里部分代码省略.........

// TeachersPanelHandler is a http handler serving the Teacher panel.
// This page shows a summary of all the students and groups.
func TeachersPanelHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkTeacherApproval(w, r, true)
	if err != nil {
		log.Println(err)
		http.Redirect(w, r, pages.HOMEPAGE, 307)
		return
	}

	// Gets the org and check if valid
	orgname := ""
	if path := strings.Split(r.URL.Path, "/"); len(path) == 4 {
		if !git.HasOrganization(path[3]) {
			http.Redirect(w, r, pages.HOMEPAGE, 307)
			return
		}

		orgname = path[3]
	} else {
		http.Redirect(w, r, pages.HOMEPAGE, 307)
		return
	}

	org, err := git.NewOrganization(orgname, true)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	if !org.IsTeacher(member) {
		log.Println("User is not a teacher for this course.")
		http.Redirect(w, r, pages.HOMEPAGE, 307)
		return
	}

	// gets pending users
	users := org.PendingUser
	var status string
	for username := range users {
		// check status up against Github
		users[username], err = git.NewMemberFromUsername(username, true)
		if err != nil {
			continue
		}

		status, err = org.GetMembership(users[username].(*git.Member))
		if err != nil {
			log.Println(err)
			continue
		}

		if status == "active" {
			continue
			// TODO: what about group assignments?
		} else if status == "pending" {
			delete(users, username)
		} else {
			delete(users, username)
			log.Println("Got a unexpected status back from Github regarding Membership")
		}
	}

	// gets teachers
	for username := range org.Teachers {
		org.Teachers[username], _ = git.NewMemberFromUsername(username, true)
	}

	// gets users
	for username := range org.Members {
		org.Members[username], _ = git.NewMemberFromUsername(username, true)
	}

	// get pending groups
	pendinggroups := make(map[int]*git.Group)
	for groupID := range org.PendingGroup {
		group, err := git.NewGroup(org.Name, groupID, true)
		if err != nil {
			log.Println(err)
		}

		if group.Course != org.Name {
			org.Lock()
			delete(org.PendingGroup, groupID)
			err := org.Save()
			if err != nil {
				log.Println(err)
				org.Unlock()
			}
			continue
		}

		for key := range group.Members {
			groupmember, _ := git.NewMemberFromUsername(key, true)
			group.Members[key] = groupmember
		}

		pendinggroups[groupID] = group
	}
//.........这里部分代码省略.........

// ApUserResultsHandler is a http handeler for getting all results for a user
// from the latest anti-plagiarism test. This handler writes back the results as JSON data.
func ApUserResultsHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkMemberApproval(w, r, false)
	if err != nil {
		http.Error(w, err.Error(), 404)
		log.Println(err)
		return
	}

	// TODO: add more security
	orgname := r.FormValue("Course")
	username := r.FormValue("Username")

	org, err := git.NewOrganization(orgname, true)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	if !org.IsMember(member) {
		http.Error(w, "Not a member for this course.", 404)
		return
	}

	results := make(map[string]git.AntiPlagiarismResults)

	if strings.HasPrefix(username, git.GroupRepoPrefix) {
		// Get the group ID from the group name
		groupid, err := strconv.Atoi(username[len(git.GroupRepoPrefix):])
		if err != nil {
			http.Error(w, "Could not convert the group ID.", 404)
			return
		}

		// Get the group from the database
		group, err := git.NewGroup(orgname, groupid, true)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 404)
			return
		}

		// For each lab
		for i, name := range org.GroupLabFolders {
			// Get the results for the lab
			temp := group.GetAntiPlagiarismResults(org.Name, i)
			if temp != nil {
				results[name] = *temp
			}
		}
	} else {
		// Get user from the database
		user, err := git.NewMemberFromUsername(username, true)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 404)
			return
		}

		// For each lab
		for i, name := range org.IndividualLabFolders {
			// Get the results for the lab
			temp := user.GetAntiPlagiarismResults(org.Name, i)
			if temp != nil {
				results[name] = *temp
			}
		}
	}

	enc := json.NewEncoder(w)

	// Encode the results in JSON
	err = enc.Encode(results)
	if err != nil {
		http.Error(w, err.Error(), 404)
	}
}

// NotesHandler will add a note to a lab for a given user.
// Page requested with method GET will return latest note and POST will store a
// new note to the user or group.
// required input:
// - Course
// - Username //or
// - Group
// - labnum
// - Notes
func NotesHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	teacher, err := checkTeacherApproval(w, r, false)
	if err != nil {
		http.Error(w, err.Error(), 404)
		log.Println(err)
		return
	}

	course := r.FormValue("Course")
	username := r.FormValue("Username")
	notes := r.FormValue("Notes")
	groupid, _ := strconv.Atoi(r.FormValue("Group"))
	labnum, err := strconv.Atoi(r.FormValue("Labnum"))
	if err != nil {
		log.Println(err)
		http.Error(w, err.Error(), 404)
		return
	}

	org, err := git.NewOrganization(course, true)
	if err != nil {
		log.Println(err)
		http.Error(w, err.Error(), 500)
		return
	}

	if !org.IsTeacher(teacher) {
		log.Println(err)
		http.Error(w, "Not a teacher of this course", 404)
		return
	}

	if groupid > 0 {
		group, err := git.NewGroup(org.Name, groupid, false)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 500)
			return
		}

		if group.Course != org.Name {
			log.Println(err)
			http.Error(w, "Not a group in this course", 404)
			return
		}

		if r.Method == "POST" {
			group.AddNotes(labnum, notes)
		} else {
			view := &NotesView{
				Course: course,
				Group:  groupid,
				Labnum: labnum,
				Notes:  group.GetNotes(labnum),
			}

			enc := json.NewEncoder(w)
			if err = enc.Encode(view); err != nil {
				log.Println(err)
				http.Error(w, err.Error(), 500)
				return
			}
		}

		if err = group.Save(); err != nil {
			group.Unlock()
			log.Println(err)
			http.Error(w, err.Error(), 500)
			return
		}

	} else {
		user, err := git.NewMemberFromUsername(username, false)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 500)
			return
		}

		if !org.IsMember(user) {
			log.Println(err)
			http.Error(w, "Not a member of this course", 404)
			return
		}

		if r.Method == "POST" {
			user.AddNotes(org.Name, labnum, notes)
		} else {
			view := &NotesView{
				Course:   course,
//.........这里部分代码省略.........

// ApLabResultsHandler is a http handeler for getting results for one lab of a user
// from the latest anti-plagiarism test. This handler writes back the results as JSON data.
func ApLabResultsHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkMemberApproval(w, r, false)
	if err != nil {
		http.Error(w, err.Error(), 404)
		log.Println(err)
		return
	}

	// TODO: add more security
	orgname := r.FormValue("Course")
	username := r.FormValue("Username")
	labname := r.FormValue("Labname")

	org, err := git.NewOrganization(orgname, true)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	if !org.IsMember(member) {
		http.Error(w, "Not a member for this course.", 404)
		return
	}

	var results *git.AntiPlagiarismResults

	if strings.HasPrefix(username, git.GroupRepoPrefix) {
		labIndex := -1
		// Find the correct lab index
		for i, name := range org.GroupLabFolders {
			if name == labname {
				labIndex = i
				break
			}
		}

		if labIndex < 0 {
			http.Error(w, "No lab with that name found.", 404)
			return
		}

		// Get the group ID from the group name
		groupid, err := strconv.Atoi(username[len(git.GroupRepoPrefix):])
		if err != nil {
			http.Error(w, "Could not convert the group ID.", 404)
			return
		}

		// Get the group from the database
		group, err := git.NewGroup(orgname, groupid, true)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 404)
			return
		}

		// Get the results for the lab
		results = group.GetAntiPlagiarismResults(org.Name, labIndex)
	} else {
		labIndex := -1
		// Find the correct lab index
		for i, name := range org.IndividualLabFolders {
			if name == labname {
				labIndex = i
				break
			}
		}

		if labIndex < 0 {
			http.Error(w, "No lab with that name found.", 404)
			return
		}

		// Get the user from the database
		user, err := git.NewMemberFromUsername(username, true)
		if err != nil {
			log.Println(err)
			http.Error(w, err.Error(), 404)
			return
		}

		// Get the results for the lab
		results = user.GetAntiPlagiarismResults(org.Name, labIndex)
	}

	enc := json.NewEncoder(w)

	err = enc.Encode(results)
	if err != nil {
		http.Error(w, err.Error(), 404)
	}
}

// CreateOrgHandler is a http handler which will link a new course
// to a github organization. This function will make a new course
// in autograder and then create all needed repositories on github.
//
// Expected input: org, desc, groups, indv
// Optional input: private, template
func CreateOrgHandler(w http.ResponseWriter, r *http.Request) {
	// Checks if the user is signed in and a teacher.
	member, err := checkTeacherApproval(w, r, true)
	if err != nil {
		log.Println(err)
		return
	}

	member.Lock()

	org, err := git.NewOrganization(r.FormValue("org"), false)
	if err != nil {
		log.Println(err)
		return
	}

	defer func() {
		// Saved the new organization info
		err = org.Save()
		if err != nil {
			org.Unlock()
			member.Unlock()
			log.Println(err)
			return
		}

		err = member.Save()
		if err != nil {
			member.Unlock()
			log.Println(err)
			return
		}
	}()

	log.Println("Creating Course")

	org.AdminToken = member.GetToken()
	org.Private = r.FormValue("private") == "on"
	org.ScreenName = org.Name
	org.Description = r.FormValue("desc")
	groups, err := strconv.Atoi(r.FormValue("groups"))
	if err != nil {
		log.Println("Cannot convert number of groups assignments from string to int: ", err)
		groups = 0
	}
	org.GroupAssignments = groups
	indv, err := strconv.Atoi(r.FormValue("indv"))
	if err != nil {
		log.Println("Cannot convert number of individual assignments from string to int: ", err)
		http.Redirect(w, r, pages.HOMEPAGE, 307)
		return
	}
	org.IndividualAssignments = indv

	currepos, err := org.ListRepos()
	if err != nil {
		log.Println("Problem listing repos in the new course organization: ", err)
		http.Redirect(w, r, pages.HOMEPAGE, 307)
		return
	}

	templaterepos := make(map[string]git.Repo)
	if r.FormValue("template") != "" {
		templateorg, _ := git.NewOrganization(r.FormValue("template"), true)
		templaterepos, err = templateorg.ListRepos()
		if err != nil {
			log.Println("Problem listing repos in the template organization: ", err)
			http.Redirect(w, r, pages.HOMEPAGE, 307)
			return
		}
	}

	// creates the course info repo
	if _, ok := currepos[git.CourseInfoName]; !ok {
		if _, ok = templaterepos[git.CourseInfoName]; ok {
			err = org.Fork(r.FormValue("template"), git.CourseInfoName)
			if err != nil {
				log.Println("Couldn't fork the course info repo: ", err)
				http.Redirect(w, r, pages.HOMEPAGE, 307)
				return
			}
		} else {
			repo := git.RepositoryOptions{
				Name:     git.CourseInfoName,
				Private:  false,
				AutoInit: true,
			}
			err = org.CreateRepo(repo)
			if err != nil {
				log.Println(err)
				return
			}
		}
	}
//.........这里部分代码省略.........

// LeaderboardDataHandler is a http handler which return the leaderboard for a course in JSON format.
func LeaderboardDataHandler(w http.ResponseWriter, r *http.Request) {
	view := LeaderboardDataView{}
	view.Error = true
	enc := json.NewEncoder(w)

	member, err := checkMemberApproval(w, r, true)
	if err != nil {
		enc.Encode(ErrAccessToken)
		return
	}

	orgname := r.FormValue("course")
	period, err := strconv.Atoi(r.FormValue("period"))
	if err != nil {
		enc.Encode(ErrMissingField)
		return
	}

	if !git.HasOrganization(orgname) {
		enc.Encode(ErrUnknownCourse)
		return
	}

	org, err := git.NewOrganization(orgname, true)
	if err != nil {
		view.ErrorMsg = err.Error()
		enc.Encode(view)
		return
	}

	if !org.IsMember(member) {
		enc.Encode(ErrNotMember)
		return
	}

	var t time.Time
	if period == TotalScore {
		view.Error = false
		view.Leaderboard = org.GetTotalLeaderboard()
		view.Scores = org.TotalScore
	} else if period == MonthlyScore {
		t, err = time.Parse("1", r.FormValue("month"))
		if err != nil {
			t = time.Now()
		}
		month := t.Month()

		view.Error = false
		view.Leaderboard = org.GetMonthlyLeaderboard(month)
		view.Scores = org.MonthlyScore[month]
	} else if period == WeeklyScore {
		week, err := strconv.Atoi(r.FormValue("week"))
		if err != nil {
			_, week = time.Now().ISOWeek()
		}

		if week < 1 || week > 53 {
			view.ErrorMsg = "Week need to be between 1 and 53."
			enc.Encode(view)
			return
		}

		view.Error = false
		view.Leaderboard = org.GetWeeklyLeaderboard(week)
		view.Scores = org.WeeklyScore[week]
	}

	enc.Encode(view)
}

// PublishReviewHandler is a http handler which will publish a new
// code review to github. The function output json as the answer.
//
// Expected input keys: course, title, fileext, desc and code.
func PublishReviewHandler(w http.ResponseWriter, r *http.Request) {
	view := PublishReviewView{
		Error: true,
	}

	enc := json.NewEncoder(w)

	// Checks if the user is signed in.
	member, err := checkMemberApproval(w, r, true)
	if err != nil {
		view.Errormsg = "Not logged in."
		enc.Encode(view)
		return
	}

	if r.FormValue("course") == "" || r.FormValue("title") == "" ||
		r.FormValue("fileext") == "" || r.FormValue("desc") == "" ||
		r.FormValue("code") == "" {
		view.Errormsg = "Missing some required input data."
		enc.Encode(view)
		return
	}

	if !git.HasOrganization(r.FormValue("course")) {
		view.Errormsg = "Unknown course."
		enc.Encode(view)
		return
	}

	org, err := git.NewOrganization(r.FormValue("course"), false)
	if err != nil {
		view.Errormsg = "Error while getting orgaization data from storage."
		enc.Encode(view)
		return
	}

	defer func() {
		if err := org.Save(); err != nil {
			org.Unlock()
			log.Println(err)
		}
	}()

	if !org.IsMember(member) {
		view.Errormsg = "Not a member of this course."
		enc.Encode(view)
		return
	}

	alfanumreg, err := regexp.Compile("[^A-Za-z0-9]+")
	if err != nil {
		view.Errormsg = "Internal sanitazion error."
		enc.Encode(view)
		return
	}

	reg, err := regexp.Compile("[^A-Za-z0-9 -.]+")
	if err != nil {
		view.Errormsg = "Internal sanitazion error."
		enc.Encode(view)
		return
	}

	// removes illigal chars
	ext := r.FormValue("fileext")
	ext = alfanumreg.ReplaceAllString(ext, "")
	ext = strings.TrimSpace(ext)
	title := r.FormValue("title")
	title = reg.ReplaceAllString(title, "")
	title = strings.TrimSpace(title)

	cr, err := git.NewCodeReview()
	if err != nil {
		view.Errormsg = "Couldn't create code review: " + err.Error()
		enc.Encode(view)
		return
	}

	cr.Title = title
	cr.Ext = ext
	cr.Desc = r.FormValue("desc")
	cr.Code = r.FormValue("code")
	cr.User = member.Username

	err = org.AddCodeReview(cr)
	if err != nil {
		view.Errormsg = err.Error()
		enc.Encode(view)
		return
	}

	if err := cr.Save(); err != nil {
		view.Errormsg = err.Error()
		enc.Encode(view)
		return
	}
//.........这里部分代码省略.........