"""
FocusTrack - Database Layer
SQLite-based local storage. Zero cloud, zero accounts.
"""

import sqlite3
import json
import logging
from pathlib import Path
from datetime import datetime, date
from typing import Optional, List, Dict, Any
import threading

logger = logging.getLogger("focustrack.database")

DB_PATH = Path(__file__).parent / "data" / "activity.db"


class Database:
    """Thread-safe SQLite database manager for FocusTrack."""

    def __init__(self, db_path: Path = DB_PATH):
        self.db_path = db_path
        self.db_path.parent.mkdir(exist_ok=True)
        self._local = threading.local()

    def _get_conn(self) -> sqlite3.Connection:
        """Get thread-local database connection."""
        if not hasattr(self._local, "conn") or self._local.conn is None:
            self._local.conn = sqlite3.connect(
                str(self.db_path),
                detect_types=sqlite3.PARSE_DECLTYPES | sqlite3.PARSE_COLNAMES,
                check_same_thread=False,
            )
            self._local.conn.row_factory = sqlite3.Row
            self._local.conn.execute("PRAGMA journal_mode=WAL")
            self._local.conn.execute("PRAGMA synchronous=NORMAL")
        return self._local.conn

    @property
    def conn(self) -> sqlite3.Connection:
        return self._get_conn()

    def initialize(self):
        """Create tables and default data."""
        self.conn.executescript("""
            CREATE TABLE IF NOT EXISTS activities (
                id          INTEGER PRIMARY KEY AUTOINCREMENT,
                timestamp   DATETIME NOT NULL,
                app_name    TEXT NOT NULL,
                window_title TEXT NOT NULL,
                duration_seconds INTEGER DEFAULT 0,
                category    TEXT DEFAULT 'uncategorized',
                is_idle     BOOLEAN DEFAULT 0
            );

            CREATE INDEX IF NOT EXISTS idx_activities_timestamp
                ON activities(timestamp);
            CREATE INDEX IF NOT EXISTS idx_activities_app
                ON activities(app_name);

            CREATE TABLE IF NOT EXISTS settings (
                key   TEXT PRIMARY KEY,
                value TEXT NOT NULL
            );

            CREATE TABLE IF NOT EXISTS categories (
                id      INTEGER PRIMARY KEY AUTOINCREMENT,
                name    TEXT UNIQUE NOT NULL,
                color   TEXT DEFAULT '#6366f1',
                keywords TEXT DEFAULT '[]',
                apps    TEXT DEFAULT '[]'
            );
        """)
        self.conn.commit()
        self._seed_defaults()
        logger.info(f"Database ready at {self.db_path}")

    def _seed_defaults(self):
        """Insert default settings and categories if not present."""
        defaults = {
            "idle_threshold_seconds": "300",
            "heartbeat_interval": "5",
            "theme": "dark",
            "auto_start": "false",
            "ignored_apps": '["Finder", "explorer.exe"]',
            "tracker_running": "true",
        }
        for key, value in defaults.items():
            self.conn.execute(
                "INSERT OR IGNORE INTO settings (key, value) VALUES (?, ?)",
                (key, value)
            )

        default_categories = [
            ("coding",        "#22d3ee", '["code", "terminal", "vim", "emacs", "debug"]',  '["code", "cursor", "vscode", "pycharm", "intellij", "xcode", "terminal", "iterm", "warp", "alacritty", "sublime", "atom", "neovim"]'),
            ("browsing",      "#f59e0b", '["http", "www", "chrome", "firefox", "safari"]', '["chrome", "firefox", "safari", "edge", "brave", "opera"]'),
            ("communication", "#10b981", '["mail", "slack", "teams", "discord", "zoom"]',  '["slack", "discord", "teams", "zoom", "meet", "mail", "outlook", "telegram", "whatsapp"]'),
            ("design",        "#a78bfa", '["figma", "sketch", "photoshop", "illustrator"]','["figma", "sketch", "photoshop", "illustrator", "xd", "canva", "affinity"]'),
            ("documents",     "#fb923c", '["word", "excel", "sheets", "docs", "notion"]',  '["word", "excel", "notion", "obsidian", "pages", "numbers", "libreoffice"]'),
            ("media",         "#f43f5e", '["youtube", "spotify", "vlc", "netflix"]',        '["spotify", "vlc", "quicktime", "itunes", "music"]'),
            ("system",        "#64748b", '["settings", "finder", "explorer"]',              '["finder", "explorer", "systempreferences", "taskmanager"]'),
            ("idle",          "#374151", '[]',                                              '[]'),
        ]
        for cat in default_categories:
            self.conn.execute(
                "INSERT OR IGNORE INTO categories (name, color, keywords, apps) VALUES (?,?,?,?)",
                cat
            )
        self.conn.commit()

    # ─── Activity CRUD ───────────────────────────────────────────────────────

    def log_activity(self, timestamp: datetime, app_name: str, window_title: str,
                     duration_seconds: int, category: str, is_idle: bool):
        self.conn.execute(
            """INSERT INTO activities
               (timestamp, app_name, window_title, duration_seconds, category, is_idle)
               VALUES (?,?,?,?,?,?)""",
            (timestamp.isoformat(), app_name, window_title,
             duration_seconds, category, int(is_idle))
        )
        self.conn.commit()

    def get_activities(self, start: datetime, end: datetime,
                       search: str = "", limit: int = 500, offset: int = 0) -> List[Dict]:
        query = """
            SELECT * FROM activities
            WHERE timestamp BETWEEN ? AND ?
        """
        params: list = [start.isoformat(), end.isoformat()]
        if search:
            query += " AND (app_name LIKE ? OR window_title LIKE ? OR category LIKE ?)"
            params += [f"%{search}%", f"%{search}%", f"%{search}%"]
        query += " ORDER BY timestamp DESC LIMIT ? OFFSET ?"
        params += [limit, offset]
        rows = self.conn.execute(query, params).fetchall()
        return [dict(r) for r in rows]

    def get_activity_count(self, start: datetime, end: datetime, search: str = "") -> int:
        query = "SELECT COUNT(*) FROM activities WHERE timestamp BETWEEN ? AND ?"
        params: list = [start.isoformat(), end.isoformat()]
        if search:
            query += " AND (app_name LIKE ? OR window_title LIKE ? OR category LIKE ?)"
            params += [f"%{search}%", f"%{search}%", f"%{search}%"]
        return self.conn.execute(query, params).fetchone()[0]

    def get_summary(self, start: datetime, end: datetime) -> Dict[str, Any]:
        """Aggregate stats for dashboard cards."""
        row = self.conn.execute("""
            SELECT
                SUM(CASE WHEN is_idle=0 THEN duration_seconds ELSE 0 END) as focus_seconds,
                SUM(CASE WHEN is_idle=1 THEN duration_seconds ELSE 0 END) as idle_seconds,
                SUM(duration_seconds) as total_seconds,
                COUNT(DISTINCT app_name) as unique_apps
            FROM activities
            WHERE timestamp BETWEEN ? AND ?
        """, (start.isoformat(), end.isoformat())).fetchone()
        return dict(row) if row else {}

    def get_by_category(self, start: datetime, end: datetime) -> List[Dict]:
        rows = self.conn.execute("""
            SELECT category,
                   SUM(duration_seconds) as total_seconds,
                   COUNT(*) as sessions
            FROM activities
            WHERE timestamp BETWEEN ? AND ? AND is_idle=0
            GROUP BY category
            ORDER BY total_seconds DESC
        """, (start.isoformat(), end.isoformat())).fetchall()
        return [dict(r) for r in rows]

    def get_by_app(self, start: datetime, end: datetime, limit: int = 10) -> List[Dict]:
        rows = self.conn.execute("""
            SELECT app_name, category,
                   SUM(duration_seconds) as total_seconds,
                   COUNT(*) as sessions
            FROM activities
            WHERE timestamp BETWEEN ? AND ? AND is_idle=0
            GROUP BY app_name
            ORDER BY total_seconds DESC
            LIMIT ?
        """, (start.isoformat(), end.isoformat(), limit)).fetchall()
        return [dict(r) for r in rows]

    def get_hourly_timeline(self, target_date: date) -> List[Dict]:
        start = datetime.combine(target_date, datetime.min.time())
        end   = datetime.combine(target_date, datetime.max.time())
        rows = self.conn.execute("""
            SELECT strftime('%H', timestamp) as hour,
                   category,
                   SUM(duration_seconds) as total_seconds
            FROM activities
            WHERE timestamp BETWEEN ? AND ? AND is_idle=0
            GROUP BY hour, category
            ORDER BY hour
        """, (start.isoformat(), end.isoformat())).fetchall()
        return [dict(r) for r in rows]

    def get_daily_totals(self, start: datetime, end: datetime) -> List[Dict]:
        rows = self.conn.execute("""
            SELECT date(timestamp) as day,
                   SUM(CASE WHEN is_idle=0 THEN duration_seconds ELSE 0 END) as focus_seconds,
                   SUM(CASE WHEN is_idle=1 THEN duration_seconds ELSE 0 END) as idle_seconds
            FROM activities
            WHERE timestamp BETWEEN ? AND ?
            GROUP BY day
            ORDER BY day
        """, (start.isoformat(), end.isoformat())).fetchall()
        return [dict(r) for r in rows]

    def get_latest_activity(self) -> Optional[Dict]:
        row = self.conn.execute(
            "SELECT * FROM activities ORDER BY timestamp DESC LIMIT 1"
        ).fetchone()
        return dict(row) if row else None

    # ─── Settings ────────────────────────────────────────────────────────────

    def get_setting(self, key: str, default: Any = None) -> Any:
        row = self.conn.execute(
            "SELECT value FROM settings WHERE key=?", (key,)
        ).fetchone()
        return row[0] if row else default

    def set_setting(self, key: str, value: Any):
        self.conn.execute(
            "INSERT OR REPLACE INTO settings (key, value) VALUES (?,?)",
            (key, str(value))
        )
        self.conn.commit()

    def get_all_settings(self) -> Dict[str, str]:
        rows = self.conn.execute("SELECT key, value FROM settings").fetchall()
        return {r[0]: r[1] for r in rows}

    # ─── Categories ──────────────────────────────────────────────────────────

    def get_categories(self) -> List[Dict]:
        rows = self.conn.execute("SELECT * FROM categories ORDER BY name").fetchall()
        return [dict(r) for r in rows]

    def upsert_category(self, name: str, color: str, keywords: list, apps: list):
        self.conn.execute("""
            INSERT OR REPLACE INTO categories (name, color, keywords, apps)
            VALUES (?,?,?,?)
        """, (name, color, json.dumps(keywords), json.dumps(apps)))
        self.conn.commit()

    def delete_category(self, name: str):
        self.conn.execute("DELETE FROM categories WHERE name=?", (name,))
        self.conn.commit()

    # ─── Maintenance ─────────────────────────────────────────────────────────

    def clear_all_data(self):
        self.conn.execute("DELETE FROM activities")
        self.conn.commit()
        logger.warning("All activity data cleared")

    def get_db_size_mb(self) -> float:
        try:
            return self.db_path.stat().st_size / (1024 * 1024)
        except Exception:
            return 0.0