import sqlite3
from pathlib import Path
from poller.sources.base import Reading


class Dedup:
    """SQLite-backed deduplication. Tracks which readings have been pushed."""

    def __init__(self, db_path: str = "dedup.db"):
        self.conn = sqlite3.connect(db_path)
        self.conn.execute("""
            CREATE TABLE IF NOT EXISTS seen (
                source_type TEXT,
                source_user_id TEXT,
                metric TEXT,
                timestamp INTEGER,
                PRIMARY KEY (source_type, source_user_id, metric, timestamp)
            )
        """)

    def filter_new(self, readings: list[Reading]) -> list[Reading]:
        """Return only readings not yet seen."""
        new = []
        for r in readings:
            cur = self.conn.execute(
                "SELECT 1 FROM seen WHERE source_type=? AND source_user_id=? AND metric=? AND timestamp=?",
                (r.source_type, r.source_user_id, r.metric, r.timestamp),
            )
            if not cur.fetchone():
                new.append(r)
        return new

    def mark_seen(self, readings: list[Reading]):
        """Mark readings as pushed."""
        self.conn.executemany(
            "INSERT OR IGNORE INTO seen (source_type, source_user_id, metric, timestamp) VALUES (?,?,?,?)",
            [(r.source_type, r.source_user_id, r.metric, r.timestamp) for r in readings],
        )
        self.conn.commit()