Add Feedback domain module: public submission flow, admin CRUD, reporting (#7)

Co-authored-by: Patrick Müller <mail@pmueller.me>
Reviewed-on: #7
Co-authored-by: Patrick Mueller <patrick@mueller-patrick.tech>
Co-committed-by: Patrick Mueller <patrick@mueller-patrick.tech>

src/models/feedback/admin/csv.service.ts

@@ -0,0 +1,70 @@
+import {NachklangFeedbackDB} from '../Feedback.db';
+import {formatDatetime} from '../feedback.dates';
+
+const CSV_SEPARATOR = ';';
+const UTF8_BOM = '';
+
+/**
+ * RFC 4180 field escaping for a `;`-separated CSV, plus a formula-injection
+ * guard: a field starting with = + - @ gets a leading apostrophe so
+ * German-locale Excel never evaluates it as a formula.
+ */
+export const escapeCsvField = (value: string | number | null | undefined): string => {
+	let str = value === null || value === undefined ? '' : String(value);
+	str = str.replace(/\r\n|\r|\n/g, ' ');
+
+	if (/^[=+\-@]/.test(str)) {
+		str = `'${str}`;
+	}
+
+	if (str.includes(CSV_SEPARATOR) || str.includes('"')) {
+		str = `"${str.replace(/"/g, '""')}"`;
+	}
+
+	return str;
+};
+
+const buildCsv = (headers: string[], rows: (string | number | null | undefined)[][]): string => {
+	const lines = [headers.map(escapeCsvField).join(CSV_SEPARATOR)];
+	for (const row of rows) {
+		lines.push(row.map(escapeCsvField).join(CSV_SEPARATOR));
+	}
+	return UTF8_BOM + lines.join('\r\n');
+};
+
+export const buildResponsesCsv = async (eventId: number): Promise<string> => {
+	let conn = await NachklangFeedbackDB.getConnection();
+	try {
+		const rows = await conn.query(
+			`SELECT sa.submission_id, s.submitted_at, sa.question_label_snapshot, sa.question_type,
+				sa.song_title_snapshot, sa.rating, sa.text_answer
+			FROM submission_answers sa
+			INNER JOIN submissions s ON s.submission_id = sa.submission_id
+			WHERE sa.event_id = ?
+			ORDER BY sa.submission_id ASC`,
+			[eventId]
+		);
+		return buildCsv(
+			['submission_id', 'submitted_at', 'question_label', 'question_type', 'song_title', 'rating', 'text_answer'],
+			rows.map((r: any) => [r.submission_id, formatDatetime(r.submitted_at), r.question_label_snapshot, r.question_type, r.song_title_snapshot, r.rating, r.text_answer])
+		);
+	} finally {
+		await conn.end();
+	}
+};
+
+export const buildGuestBookCsv = async (eventId: number): Promise<string> => {
+	let conn = await NachklangFeedbackDB.getConnection();
+	try {
+		const rows = await conn.query(
+			'SELECT entry_id, created_at, display_name, message FROM guest_book_entries WHERE event_id = ? ORDER BY created_at ASC',
+			[eventId]
+		);
+		return buildCsv(
+			['entry_id', 'submitted_at', 'display_name', 'message'],
+			rows.map((r: any) => [r.entry_id, formatDatetime(r.created_at), r.display_name, r.message])
+		);
+	} finally {
+		await conn.end();
+	}
+};