[Feature:System] Local CSV File (#27)

* Local CSV File

New helper script for retrieving CSV file on an accessible file system.

* Update config.php

student_auto_feed/config.php

@@ -129,10 +129,23 @@
 //Allows "\r" EOL encoding.  This is rare but exists (e.g. Excel for Macintosh).
 ini_set('auto_detect_line_endings', true);
 
+/* DATA SOURCING --------------------------------------------------------------
+ * The Student Autofeed provides helper scripts to retrieve the CSV file for
+ * processing.  Shell script ssaf.sh is used to invoke one of the helper
+ * scripts and then execute the autofeed.  Current options are csv_local.php,
+ * imap_remote.php, and json_remote.php
+ * ------------------------------------------------------------------------- */
+
+//Local CSV
+//This is used by csv_local.php to reference where the CSV file is provided.
+define('LOCAL_SOURCE_CSV', '/path/to/csv');
+
 //Remote IMAP
 //This is used by imap_remote.php to login and retrieve a student enrollment
 //datasheet, should datasheets be provided via an IMAP email box.  This also
-//works with exchange servers with IMAP enabled.
+//works with exchange servers (local network and cloud) with IMAP and basic
+//authentication enabled.
+//Note that this does NOT work should exchange require OAuth2.
 //IMAP_FOLDER is the folder where the data sheets can be found.
 //IMAP_OPTIONS: q.v. "Optional flags for names" at https://www.php.net/manual/en/function.imap-open.php
 //IMAP_FROM is for validation.  Make sure it matches the identity of who sends the data sheets
@@ -163,7 +176,8 @@
 define('JSON_REMOTE_PASSWORD',    'json_password'); //DO NOT USE IN PRODUCTION
 define('JSON_REMOTE_PATH',        '/path/to/files/');
 
-// Add/Drop Reporting
+/* ADD/DROP REPORTING ------------------------------------------------------ */
+
 // Where to email reports.  Set to null to disable sending email.
 // Sendmail (or equivalent) needs to be installed on the server and configured
 // in php.ini.  Reports are sent "unauthenticated".

student_auto_feed/csv_local.php

@@ -0,0 +1,91 @@
+#!/usr/bin/env php
+<?php
+require __DIR__ . "/config.php";
+
+new csv_local();
+exit(0);
+
+/**
+ * Validate and copy CSV data file via filesystem.
+ *
+ * This data source option has the CSV file provided to any filesystem the
+ * autofeed's server can access (local or mounted).  LOCAL_SOURCE_CSV must
+ * be defined in config.php, referencing the location of the CSV file upload.
+ *
+ * @author Peter Bailie, Rensselaer Polytechnic Institute
+ */
+class csv_local {
+    /** @static @property string */
+    private static $source_file = LOCAL_SOURCE_CSV;
+
+    /** @static @property string */
+    private static $dest_file = CSV_FILE;
+
+    /** @static @property string */
+    private static $err = "";
+
+    public function __construct() {
+        // Main process
+        switch(false) {
+        case $this->validate_csv():
+        case $this->copy_csv():
+            // If we wind up here, something went wrong in the main process.
+            fprintf(STDERR, "%s", self::$err);
+            exit(1);
+        }
+    }
+
+    /**
+     * Validate CSV file before copy.
+     *
+     * Check's for the file's existence and tries to check that the file was
+     * provided/refreshed on the same day as the autofeed was run.  The day
+     * check is to help prevent the auto feed from blindly running the same CSV
+     * multiple days in a row and alert the sysadmin that an expected file
+     * refresh did not happen.  $this->err is set with an error message when
+     * validation fails.
+     *
+     * @return boolean true when CSV is validated, false otherwise.
+     */
+    private function validate_csv() {
+        clearstatcache();
+
+        if (!file_exists(self::$source_file)) {
+            self::$err = sprintf("CSV upload missing: %s\n", self::$source_file);
+            return false;
+        }
+
+        $file_modified = filemtime(self::$source_file);
+        $today = time();
+        // There are 86400 seconds in a day.
+        if (intdiv($today, 86400) !== intdiv($file_modified, 86400)) {
+            $today = date("m-d-Y", $today);
+            $file_modified = date("m-d-Y", $file_modified);
+            $hash = md5(file_get_contents(self::$source_file));
+            self::$err = sprintf("CSV upload modified time mismatch.\nToday:         %s\nUploaded File: %s\nUploaded File Hash: %s\n", $today, $file_modified, $hash);
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Copy CSV file.
+     *
+     * $this->err is set with an error message when file copy fails.
+     *
+     * @return boolean true when copy is successful, false otherwise.
+     */
+    private function copy_csv() {
+        if (file_exists(self::$dest_file)) {
+            unlink(self::$dest_file);
+        }
+
+        if (!copy(self::$source_file, self::$dest_file)) {
+            self::$err = sprintf("Failed to copy file.\nSource: %s\nDest:   %s\n", self::$source_file, self::$dest_file);
+            return false;
+        }
+
+        return true;
+    }
+}

student_auto_feed/ssaf.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+# Use this bash script to run a data sourcing script before
+# submitty_student_auto_feed.php.  This is intended to be used with cron.
+#
+# Author: Peter Bailie, Rensselaer Polytechnic Institute
+
+display_usage() {
+    cat << EOM
+usage: ssaf.sh (data_source) (term) [DB_auth]
+
+data_source: csv_local|imap_remote|json_remote
+             Which data sourcing script to run first: csv_local.php,
+             imap_remote.php, or json_remote.php (required)
+term:        Term code to pass to submitty_student_auto_feed.php  (required)
+DB_auth:     DB auth string for submitty_student_auto_feed.php    [optional]
+EOM
+    exit 1
+}
+
+if [ $# -ne 2 ] && [ $# -ne 3 ]; then
+    display_usage
+fi
+
+CWD=$(dirname "$0")
+if [ "$1" = "csv_local" ] || [ "$1" = "imap_remote" ] || [ "$1" = "json_remote" ]; then
+    SOURCE="${CWD}/${1}.php"
+else
+    display_usage
+fi
+
+if $SOURCE; then
+    if [ "$3" != "" ]; then
+        DASH_A="-a$3"
+    fi
+
+    DASH_T="-t$2"
+    "$CWD"/submitty_student_auto_feed.php "$DASH_T" "$DASH_A"
+else
+    echo "${1}.php exited $?.  Auto feed not run."
+fi