Add configuration and database core

app/db.py

@@ -1 +1,87 @@
 """SQLite helpers."""
+
+from __future__ import annotations
+
+from collections.abc import AsyncIterator
+from contextlib import asynccontextmanager
+from pathlib import Path
+
+import aiosqlite
+
+SCHEMA = """
+CREATE TABLE IF NOT EXISTS quizzes (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    title TEXT NOT NULL,
+    pool_json TEXT NOT NULL,
+    time_limit_default INTEGER NOT NULL DEFAULT 60,
+    score_fn_name TEXT NOT NULL DEFAULT 'linear_decay',
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE IF NOT EXISTS quiz_sessions (
+    sid TEXT PRIMARY KEY,
+    quiz_id INTEGER NOT NULL REFERENCES quizzes(id),
+    title TEXT NOT NULL,
+    state TEXT NOT NULL DEFAULT 'lobby',
+    current_question_idx INTEGER,
+    started_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    finished_at TIMESTAMP
+);
+
+CREATE TABLE IF NOT EXISTS participants (
+    sid TEXT NOT NULL REFERENCES quiz_sessions(sid),
+    student_id TEXT NOT NULL,
+    name TEXT NOT NULL,
+    cookie_id TEXT NOT NULL,
+    joined_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    PRIMARY KEY (sid, student_id)
+);
+
+CREATE TABLE IF NOT EXISTS question_events (
+    sid TEXT NOT NULL REFERENCES quiz_sessions(sid),
+    question_idx INTEGER NOT NULL,
+    opened_at TIMESTAMP NOT NULL,
+    closed_at TIMESTAMP,
+    time_limit INTEGER NOT NULL,
+    PRIMARY KEY (sid, question_idx)
+);
+
+CREATE TABLE IF NOT EXISTS submissions (
+    sid TEXT NOT NULL REFERENCES quiz_sessions(sid),
+    student_id TEXT NOT NULL,
+    question_idx INTEGER NOT NULL,
+    answer TEXT,
+    submitted_at TIMESTAMP,
+    elapsed_ms INTEGER,
+    score INTEGER NOT NULL DEFAULT 0,
+    status TEXT NOT NULL DEFAULT 'submitted',
+    PRIMARY KEY (sid, student_id, question_idx)
+);
+
+CREATE INDEX IF NOT EXISTS idx_submissions_sid_qidx ON submissions(sid, question_idx);
+CREATE INDEX IF NOT EXISTS idx_participants_sid ON participants(sid);
+"""
+
+
+async def init_db(db_path: str) -> None:
+    if db_path != ":memory:":
+        Path(db_path).parent.mkdir(parents=True, exist_ok=True)
+    async with connect(db_path) as db:
+        await db.executescript(SCHEMA)
+        await db.commit()
+
+
+@asynccontextmanager
+async def connect(db_path: str) -> AsyncIterator[aiosqlite.Connection]:
+    db = await aiosqlite.connect(db_path)
+    db.row_factory = aiosqlite.Row
+    await db.execute("PRAGMA foreign_keys=ON")
+    await db.execute("PRAGMA journal_mode=WAL")
+    try:
+        yield db
+    finally:
+        await db.close()
+
+
+def row_to_dict(row: aiosqlite.Row | None) -> dict | None:
+    return dict(row) if row is not None else None