"""
db/database.py
--------------
SQLite initialization, schema creation, and default game seeding.
All table definitions live here. Call init_db() once on app startup.
"""

import sqlite3
import logging
import os

logger = logging.getLogger(__name__)

# DB file lives in lottosight/data/lottosight.db
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
DB_PATH = os.path.join(BASE_DIR, "data", "lottosight.db")


def get_connection():
    """Return a sqlite3 connection with foreign keys enabled."""
    conn = sqlite3.connect(DB_PATH)
    conn.execute("PRAGMA foreign_keys = ON")
    conn.row_factory = sqlite3.Row
    return conn


def init_db():
    """
    Initialize the database — create all tables if they don't exist,
    then seed default game configs.
    Safe to call on every app launch (uses IF NOT EXISTS).
    """
    logger.info("[DB] Initializing database at %s", DB_PATH)

    # Ensure data/ directory exists
    os.makedirs(os.path.dirname(DB_PATH), exist_ok=True)

    conn = get_connection()
    try:
        cursor = conn.cursor()

        # ── games ──────────────────────────────────────────────────────────
        cursor.execute("""
            CREATE TABLE IF NOT EXISTS games (
                id          INTEGER PRIMARY KEY AUTOINCREMENT,
                name        TEXT    NOT NULL UNIQUE,
                main_count  INTEGER NOT NULL,
                main_max    INTEGER NOT NULL,
                bonus_count INTEGER NOT NULL DEFAULT 0,
                bonus_max   INTEGER NOT NULL DEFAULT 0,
                active      INTEGER NOT NULL DEFAULT 1
            )
        """)

        # ── draws ──────────────────────────────────────────────────────────
        cursor.execute("""
            CREATE TABLE IF NOT EXISTS draws (
                id          INTEGER PRIMARY KEY AUTOINCREMENT,
                game_id     INTEGER NOT NULL REFERENCES games(id),
                draw_date   TEXT    NOT NULL,
                numbers     TEXT    NOT NULL,
                bonus       TEXT,
                multiplier  TEXT,
                source      TEXT,
                created_at  TEXT    NOT NULL DEFAULT (datetime('now'))
            )
        """)

        # Unique constraint: one record per game per draw date
        cursor.execute("""
            CREATE UNIQUE INDEX IF NOT EXISTS idx_draws_game_date
            ON draws (game_id, draw_date)
        """)

        # Index for fast date-range queries
        cursor.execute("""
            CREATE INDEX IF NOT EXISTS idx_draws_date
            ON draws (draw_date)
        """)

        # ── predictions ────────────────────────────────────────────────────
        cursor.execute("""
            CREATE TABLE IF NOT EXISTS predictions (
                id          INTEGER PRIMARY KEY AUTOINCREMENT,
                game_id     INTEGER NOT NULL REFERENCES games(id),
                strategy    TEXT    NOT NULL,
                numbers     TEXT    NOT NULL,
                bonus       TEXT,
                created_at  TEXT    NOT NULL DEFAULT (datetime('now'))
            )
        """)

        # ── fetch_log ──────────────────────────────────────────────────────
        cursor.execute("""
            CREATE TABLE IF NOT EXISTS fetch_log (
                id          INTEGER PRIMARY KEY AUTOINCREMENT,
                source      TEXT    NOT NULL,
                fetched_at  TEXT    NOT NULL DEFAULT (datetime('now')),
                added       INTEGER NOT NULL DEFAULT 0,
                skipped     INTEGER NOT NULL DEFAULT 0,
                status      TEXT    NOT NULL DEFAULT 'success',
                message     TEXT
            )
        """)

        conn.commit()
        logger.info("[DB] Tables created/verified OK")

        _seed_games(cursor, conn)

    except Exception as e:
        conn.rollback()
        logger.error("[ERROR] DB init failed: %s", e, exc_info=True)
        raise
    finally:
        conn.close()


def _seed_games(cursor, conn):
    """
    Insert default game configs if they don't already exist.
    Uses INSERT OR IGNORE to be idempotent on every launch.
    """
    defaults = [
        # name            main_count  main_max  bonus_count  bonus_max  active
        ("Powerball",     5,          69,        1,           26,        1),
        ("Mega Millions", 5,          70,        1,           25,        1),
    ]

    for row in defaults:
        cursor.execute("""
            INSERT OR IGNORE INTO games
                (name, main_count, main_max, bonus_count, bonus_max, active)
            VALUES (?, ?, ?, ?, ?, ?)
        """, row)

    inserted = conn.total_changes
    conn.commit()

    if inserted > 0:
        logger.info("[DB] Seeded %d default game(s)", inserted)
    else:
        logger.info("[DB] Default games already seeded — skipped")


def get_db_stats():
    """
    Return a dict of basic DB stats for display in Settings screen.
    {game_name: draw_count, ...}
    """
    conn = get_connection()
    try:
        cursor = conn.cursor()
        cursor.execute("""
            SELECT g.name, COUNT(d.id) as draw_count
            FROM games g
            LEFT JOIN draws d ON d.game_id = g.id
            GROUP BY g.id
            ORDER BY g.name
        """)
        rows = cursor.fetchall()
        return {row["name"]: row["draw_count"] for row in rows}
    finally:
        conn.close()