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/*
* Index page
*
* 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 (
"errors"
"fmt"
"log"
"net/http"
"github.com/jackc/pgx/v5"
)
/*
* Serve the index page. Also handles the login page in case the user doesn't
* have any valid login cookies.
*/
func handleIndex(w http.ResponseWriter, req *http.Request) {
sessionCookie, err := req.Cookie("session")
if errors.Is(err, http.ErrNoCookie) {
authURL, err := generateAuthorizationURL()
if err != nil {
wstr(
w,
http.StatusInternalServerError,
"Cannot generate authorization URL",
)
return
}
err = tmpl.ExecuteTemplate(
w,
"login",
map[string]string{
"authURL": authURL,
/*
* We directly generate the login URL here
* instead of doing so in a redirect to save
* requests.
*/
},
)
if err != nil {
log.Println(err)
return
}
return
} else if err != nil {
wstr(w, http.StatusBadRequest, "Error: Unable to check cookie.")
return
}
var userID, userName, userDepartment string
err = db.QueryRow(
req.Context(),
"SELECT id, name, department FROM users WHERE session = $1",
sessionCookie.Value,
).Scan(&userID, &userName, &userDepartment)
if err != nil {
if errors.Is(err, pgx.ErrNoRows) {
authURL, err := generateAuthorizationURL()
if err != nil {
wstr(
w,
http.StatusInternalServerError,
"Cannot generate authorization URL",
)
return
}
err = tmpl.ExecuteTemplate(
w,
"login",
map[string]interface{}{
"authURL": authURL,
"notes": "Your session is invalid or has expired.",
},
)
if err != nil {
log.Println(err)
return
}
return
}
wstr(
w,
http.StatusInternalServerError,
fmt.Sprintf(
"Error: Unexpected database error: %s",
err,
),
)
return
}
err = func() error {
coursesLock.RLock()
defer coursesLock.RUnlock()
return tmpl.ExecuteTemplate(
w,
"student",
map[string]interface{}{
"open": true,
"user": map[string]interface{}{
"Name": userName,
"Department": userDepartment,
},
"courses": courses,
},
)
}()
if err != nil {
log.Println(err)
return
}
}
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