implement JellyStat API for watch history, genre summary, and user summary; add PostgreSQL connection pool and update requirements

gateway/jellystat/db.py

@@ -0,0 +1,130 @@
+"""PostgreSQL connection pool for the JellyStat database."""
+
+from __future__ import annotations
+
+import logging
+from pathlib import Path
+
+import asyncpg
+from fastapi import FastAPI, Request
+
+from src.config import get_config
+
+logger = logging.getLogger("gateway.jellystat")
+
+# ---------------------------------------------------------------------------
+# DSN builder
+# ---------------------------------------------------------------------------
+
+
+def _build_dsn() -> str:
+    """Build a PostgreSQL DSN from individual environment variables."""
+    host = get_config("JELLYSTAT_DB_HOST", "localhost")
+    port = get_config("JELLYSTAT_DB_PORT", "5432")
+    user = get_config("JELLYSTAT_DB_USER", "postgres")
+    password = get_config("JELLYSTAT_DB_PASSWORD", "")
+    dbname = get_config("JELLYSTAT_DB_NAME", "jfstat")
+    return f"postgresql://{user}:{password}@{host}:{port}/{dbname}"
+
+
+# ---------------------------------------------------------------------------
+# Pool lifecycle (called from main.py lifespan)
+# ---------------------------------------------------------------------------
+
+
+async def init_pool(app: FastAPI) -> None:
+    """Create the connection pool and store it on app.state."""
+    dsn = _build_dsn()
+    safe = dsn.split("@")[1] if "@" in dsn else dsn
+    logger.info("Connecting to JellyStat database at %s", safe)
+
+    pool = await asyncpg.create_pool(dsn, min_size=1, max_size=5)
+    app.state.jellystat_pool = pool
+
+    # Deploy functions on every startup (CREATE OR REPLACE is idempotent)
+    await _ensure_functions(pool)
+
+
+async def close_pool(app: FastAPI) -> None:
+    """Close the pool on shutdown."""
+    pool: asyncpg.Pool | None = getattr(app.state, "jellystat_pool", None)
+    if pool:
+        await pool.close()
+        logger.info("JellyStat pool closed")
+
+
+# ---------------------------------------------------------------------------
+# FastAPI dependency
+# ---------------------------------------------------------------------------
+
+
+async def get_pool(request: Request) -> asyncpg.Pool:
+    """Return the JellyStat connection pool from app state."""
+    return request.app.state.jellystat_pool
+
+
+# ---------------------------------------------------------------------------
+# Function deployment
+# ---------------------------------------------------------------------------
+
+
+async def _ensure_functions(pool: asyncpg.Pool) -> None:
+    """Run startup-functions.sql to create or replace all JellyStat functions."""
+    sql_path = Path(__file__).parent / "startup-functions.sql"
+    if not sql_path.exists():
+        logger.warning("startup-functions.sql not found — skipping function deployment")
+        return
+
+    sql = sql_path.read_text()
+    statements = _split_sql(sql)
+
+    async with pool.acquire() as conn:
+        for stmt in statements:
+            try:
+                await conn.execute(stmt)
+            except Exception:
+                # Log but don't crash — functions might already exist
+                logger.exception("Failed to deploy SQL statement — continuing")
+
+    logger.info("JellyStat functions deployed (%d statements)", len(statements))
+
+
+def _split_sql(sql: str) -> list[str]:
+    """
+    Split a multi-statement SQL string into individual statements.
+
+    Respects $$ dollar-quoting so that semicolons inside function bodies
+    don't cause premature splits.  Pure comment lines (starting with ``--``)
+    outside dollar-quoted blocks are stripped.
+    """
+    statements: list[str] = []
+    current: list[str] = []
+    in_dollar_quote = False
+
+    for line in sql.split("\n"):
+        stripped = line.strip()
+
+        # Skip pure comment lines outside of dollar-quoted blocks
+        if not in_dollar_quote and stripped.startswith("--"):
+            continue
+
+        # Toggle dollar-quote state whenever we see $$
+        if "$$" in line:
+            in_dollar_quote = not in_dollar_quote
+
+        current.append(line)
+
+        # Statement terminator: semicolon at end of line, outside $$ block
+        if not in_dollar_quote and line.rstrip().endswith(";"):
+            stmt = "\n".join(current).strip()
+            if stmt:
+                statements.append(stmt)
+            current = []
+
+    # Catch any trailing statement that wasn't terminated by a semicolon
+    if current:
+        stmt = "\n".join(current).strip()
+        if stmt:
+            statements.append(stmt)
+
+    return statements