diff options
Diffstat (limited to 'endpoint_newcourses.go')
| -rw-r--r-- | endpoint_newcourses.go | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/endpoint_newcourses.go b/endpoint_newcourses.go new file mode 100644 index 0000000..5963e1b --- /dev/null +++ b/endpoint_newcourses.go @@ -0,0 +1,350 @@ +/* + * Overwrite courses with uploaded CSV + * + * Copyright (C) 2024 Runxi Yu <https://runxiyu.org> + * SPDX-License-Identifier: AGPL-3.0-or-later + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +package main + +import ( + "context" + "encoding/csv" + "errors" + "fmt" + "io" + "net/http" + "sync/atomic" + + "github.com/jackc/pgx/v5" +) + +func handleNewCourses(w http.ResponseWriter, req *http.Request) { + if req.Method != http.MethodPost { + wstr( + w, + http.StatusMethodNotAllowed, + "Only POST is allowed here", + ) + return + } + + sessionCookie, err := req.Cookie("session") + if errors.Is(err, http.ErrNoCookie) { + wstr( + w, + http.StatusUnauthorized, + "No session cookie, which is required for this endpoint", + ) + return + } else if err != nil { + wstr(w, http.StatusBadRequest, "Error: Unable to check cookie.") + return + } + + var userDepartment string + err = db.QueryRow( + req.Context(), + "SELECT department FROM users WHERE session = $1", + sessionCookie.Value, + ).Scan(&userDepartment) + if err != nil { + if errors.Is(err, pgx.ErrNoRows) { + wstr( + w, + http.StatusForbidden, + "Invalid session cookie", + ) + return + } + wstr( + w, + http.StatusInternalServerError, + fmt.Sprintf( + "Error: Unexpected database error: %s", + err, + ), + ) + return + } + + if userDepartment != staffDepartment { + wstr( + w, + http.StatusForbidden, + "You are not authorized to view this page", + ) + return + } + + if atomic.LoadUint32(&state) != 0 { + wstr( + w, + http.StatusBadRequest, + "Uploading the course table is only supported when student-access is disabled", + ) + return + } + /* TODO: Potential race. The global state may need to be write-locked. */ + + file, fileHeader, err := req.FormFile("coursecsv") + if err != nil { + wstr( + w, + http.StatusBadRequest, + "Failed loading file from request... did you select a file before hitting that red button?", + ) + return + } + + if fileHeader.Header.Get("Content-Type") != "text/csv" { + wstr( + w, + http.StatusBadRequest, + "Does not look like a proper CSV file", + ) + return + } + + csvReader := csv.NewReader(file) + titleLine, err := csvReader.Read() + if err != nil { + wstr( + w, + http.StatusBadRequest, + "Error reading CSV", + ) + return + } + if titleLine == nil { + wstr( + w, + http.StatusInternalServerError, + "Unexpected nil titleLine slice", + ) + return + } + if len(titleLine) != 6 { + wstr( + w, + http.StatusBadRequest, + "First line has more than 6 elements", + ) + return + } + var titleIndex, maxIndex, teacherIndex, locationIndex, + typeIndex, groupIndex int = -1, -1, -1, -1, -1, -1 + for i, v := range titleLine { + switch v { + case "Title": + titleIndex = i + case "Max": + maxIndex = i + case "Teacher": + teacherIndex = i + case "Location": + locationIndex = i + case "Type": + typeIndex = i + case "Group": + groupIndex = i + } + } + + { + check := func(indexName string, indexNum int) bool { + if indexNum == -1 { + wstr( + w, + http.StatusBadRequest, + fmt.Sprintf( + "Missing column \"%s\"", + indexName, + ), + ) + return true + } + return false + } + + if check("Title", titleIndex) { + return + } + if check("Max", maxIndex) { + return + } + if check("Teacher", teacherIndex) { + return + } + if check("Location", locationIndex) { + return + } + if check("Type", typeIndex) { + return + } + if check("Group", groupIndex) { + return + } + } + + lineNumber := 1 + ok := func(ctx context.Context) bool { + tx, err := db.Begin(ctx) + if err != nil { + wstr( + w, + http.StatusInternalServerError, + "Unexpected database error", + ) + } + defer func() { + err := tx.Rollback(ctx) + if err != nil && (!errors.Is(err, pgx.ErrTxClosed)) { + wstr( + w, + http.StatusInternalServerError, + "Unexpected database error", + ) + return + } + }() + _, err = tx.Exec( + ctx, + "DELETE FROM choices", + ) + if err != nil { + wstr( + w, + http.StatusInternalServerError, + "Unexpected database error", + ) + } + _, err = tx.Exec( + ctx, + "DELETE FROM courses", + ) + if err != nil { + wstr( + w, + http.StatusInternalServerError, + "Unexpected database error", + ) + } + + for { + lineNumber++ + line, err := csvReader.Read() + if err != nil { + if errors.Is(err, io.EOF) { + break + } + wstr( + w, + http.StatusInternalServerError, + "Error reading CSV", + ) + return false + } + if line == nil { + wstr( + w, + http.StatusInternalServerError, + "Unexpected nil line", + ) + return false + } + if len(line) != 6 { + wstr( + w, + http.StatusBadRequest, + fmt.Sprintf( + "Line %d has insufficient items", + lineNumber, + ), + ) + return false + } + if !checkCourseType(courseTypeT(line[typeIndex])) { + wstr( + w, + http.StatusBadRequest, + fmt.Sprintf( + "Line %d has invalid course type \"%s\"", + lineNumber, + line[typeIndex], + ), + ) + return false + } + if !checkCourseGroup(courseGroupT(line[groupIndex])) { + wstr( + w, + http.StatusBadRequest, + fmt.Sprintf( + "Line %d has invalid course group \"%s\"", + lineNumber, + line[groupIndex], + ), + ) + return false + } + _, err = tx.Exec( + ctx, + "INSERT INTO courses(nmax, title, teacher, location, ctype, cgroup) VALUES ($1, $2, $3, $4, $5, $6)", + line[maxIndex], + line[titleIndex], + line[teacherIndex], + line[locationIndex], + line[typeIndex], + line[groupIndex], + ) + if err != nil { + wstr( + w, + http.StatusInternalServerError, + "Unexpected database error", + ) + return false + } + } + err = tx.Commit(ctx) + if err != nil { + wstr( + w, + http.StatusInternalServerError, + "Unexpected database error", + ) + return false + } + return true + }(req.Context()) + if !ok { + return + } + + courses.Clear() + err = setupCourses(req.Context()) + if err != nil { + wstr( + w, + http.StatusInternalServerError, + "Error setting up course table again, the data might be corrupted!", + ) + return + } + + http.Redirect(w, req, "/", http.StatusSeeOther) +} |