"""
SQLite database for tracking daily usage
"""

import sqlite3
from datetime import datetime, timezone, timedelta
from config import settings
import threading

_local = threading.local()


def get_db():
    """Get thread-local database connection"""
    if not hasattr(_local, "connection"):
        _local.connection = sqlite3.connect(
            settings.database_path,
            check_same_thread=False
        )
        _local.connection.row_factory = sqlite3.Row
    return _local.connection


def init_db():
    """Initialize database schema"""
    conn = get_db()
    cursor = conn.cursor()

    cursor.execute("""
        CREATE TABLE IF NOT EXISTS usage (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id TEXT NOT NULL,
            date TEXT NOT NULL,
            count INTEGER DEFAULT 0,
            created_at TEXT DEFAULT CURRENT_TIMESTAMP,
            updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
            UNIQUE(user_id, date)
        )
    """)

    cursor.execute("""
        CREATE INDEX IF NOT EXISTS idx_usage_user_date 
        ON usage(user_id, date)
    """)

    cursor.execute("""
        CREATE TABLE IF NOT EXISTS extraction_log (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id TEXT NOT NULL,
            tier TEXT,
            timestamp TEXT DEFAULT CURRENT_TIMESTAMP,
            success INTEGER DEFAULT 1,
            processing_time_ms INTEGER
        )
    """)

    conn.commit()
    cleanup_old_records()


def get_today_utc() -> str:
    """Get today's date in UTC as string"""
    return datetime.now(timezone.utc).strftime("%Y-%m-%d")


def get_usage_today(user_id: str) -> int:
    """Get number of extractions used today for a user"""
    conn = get_db()
    cursor = conn.cursor()

    today = get_today_utc()
    cursor.execute(
        "SELECT count FROM usage WHERE user_id = ? AND date = ?",
        (user_id, today)
    )

    row = cursor.fetchone()
    return row["count"] if row else 0


def increment_usage(user_id: str) -> int:
    """Increment usage count for today. Returns new count."""
    conn = get_db()
    cursor = conn.cursor()

    today = get_today_utc()
    now = datetime.now(timezone.utc).isoformat()

    cursor.execute("""
        INSERT INTO usage (user_id, date, count, updated_at)
        VALUES (?, ?, 1, ?)
        ON CONFLICT(user_id, date) 
        DO UPDATE SET 
            count = count + 1,
            updated_at = ?
    """, (user_id, today, now, now))

    conn.commit()
    return get_usage_today(user_id)


def cleanup_old_records(days_to_keep: int = 30):
    """Remove usage records older than specified days"""
    conn = get_db()
    cursor = conn.cursor()

    cutoff = (datetime.now(timezone.utc) - timedelta(days=days_to_keep)).strftime("%Y-%m-%d")

    cursor.execute("DELETE FROM usage WHERE date < ?", (cutoff,))
    cursor.execute("DELETE FROM extraction_log WHERE date(timestamp) < ?", (cutoff,))

    conn.commit()


def get_usage_stats(user_id: str, days: int = 7) -> list:
    """Get usage history for a user"""
    conn = get_db()
    cursor = conn.cursor()

    cutoff = (datetime.now(timezone.utc) - timedelta(days=days)).strftime("%Y-%m-%d")

    cursor.execute("""
        SELECT date, count 
        FROM usage 
        WHERE user_id = ? AND date >= ?
        ORDER BY date DESC
    """, (user_id, cutoff))

    return [dict(row) for row in cursor.fetchall()]