import sqlite3
import hashlib
import ipaddress
from typing import Dict, List, Optional, Tuple

DATABASE = 'data/auction.db'


def get_db():
    return sqlite3.connect(DATABASE)


def _table_has_column(cursor, table, column):
    cursor.execute(f"PRAGMA table_info({table})")
    return any(row[1] == column for row in cursor.fetchall())


def _ensure_created_at(conn, table, backfill_age_minutes=None):
    c = conn.cursor()
    if not _table_has_column(c, table, "created_at"):
        c.execute(
            f"ALTER TABLE {table} ADD COLUMN created_at TIMESTAMP"
        )
        if backfill_age_minutes is None:
            c.execute(
                f"UPDATE {table} SET created_at = CURRENT_TIMESTAMP WHERE created_at IS NULL"
            )
        else:
            c.execute(
                f"UPDATE {table} SET created_at = datetime('now', ?) WHERE created_at IS NULL",
                (f"-{backfill_age_minutes} minutes",),
            )
        conn.commit()
        return True
    return False


def _delete_by_age(cursor, table, column, max_age_minutes, extra_where=None):
    cutoff_delta = f"-{max_age_minutes} minutes"
    extra = f" AND {extra_where}" if extra_where else ""
    cursor.execute(
        f"DELETE FROM {table} WHERE datetime({column}) < datetime('now', ?){extra}",
        (cutoff_delta,),
    )
    return cursor.rowcount


def cleanup_expired_records(max_age_minutes=7):
    conn = get_db()
    c = conn.cursor()

    try:
        for table in ("users", "artworks", "transactions", "artwork_settings"):
            # Backfill to "old enough" so legacy rows get cleaned on the next cycle.
            _ensure_created_at(conn, table, backfill_age_minutes=max_age_minutes + 1)

        deletions = {}
        for table in ("artworks", "transactions", "artwork_settings", "users"):
            if _table_has_column(c, table, "created_at"):
                extra_where = "username != 'admin'" if table == "users" else None
                deletions[table] = _delete_by_age(
                    c,
                    table=table,
                    column="created_at",
                    max_age_minutes=max_age_minutes,
                    extra_where=extra_where,
                )
            else:
                deletions[table] = 0

        c.execute(
            "DELETE FROM artwork_settings WHERE artwork_id NOT IN (SELECT id FROM artworks)"
        )
        deleted_settings = c.rowcount

        conn.commit()
        return {
            "artworks": deletions.get("artworks", 0),
            "transactions": deletions.get("transactions", 0),
            "artwork_settings": deletions.get("artwork_settings", 0)
            + deleted_settings,
            "users": deletions.get("users", 0),
        }
    finally:
        conn.close()


def init_db():
    conn = get_db()
    c = conn.cursor()
    
    c.execute('''CREATE TABLE IF NOT EXISTS users
                 (id INTEGER PRIMARY KEY, username TEXT UNIQUE, password TEXT, balance INTEGER DEFAULT 1000,
                  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP)''')
    
    c.execute('''CREATE TABLE IF NOT EXISTS artworks
                 (id INTEGER PRIMARY KEY, title TEXT, data TEXT, price INTEGER, 
                  owner_id INTEGER, is_private INTEGER DEFAULT 0, signature TEXT,
                  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP)''')
    
    c.execute('''CREATE TABLE IF NOT EXISTS transactions
                 (id INTEGER PRIMARY KEY, artwork_id INTEGER, buyer_id INTEGER, 
                  seller_id INTEGER, amount INTEGER, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP)''')
    
    c.execute('''CREATE TABLE IF NOT EXISTS artwork_settings
                 (id INTEGER PRIMARY KEY, artwork_id INTEGER, settings_data TEXT,
                  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP)''')

    # Schema guards for older databases
    for table in ("users", "artworks", "transactions", "artwork_settings"):
        _ensure_created_at(conn, table)
    
    c.execute("INSERT OR IGNORE INTO users (username, password, balance) VALUES (?, ?, ?)",
              ('admin', hashlib.md5('MFKJGOIH3249738547IJTIRTJHOIJJ'.encode()).hexdigest(), 999999))
    
    conn.commit()
    conn.close()


def get_user_balance(user_id):
    conn = get_db()
    c = conn.cursor()
    c.execute("SELECT balance FROM users WHERE id = ?", (user_id,))
    result = c.fetchone()
    conn.close()
    return result[0] if result else 0


def fetch_recent_artworks_for_user(user_id: int, limit: int = 20) -> List[Dict]:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute(
            """
            SELECT a.id, a.title, a.data, a.price, a.owner_id, a.is_private,
                   a.signature, a.created_at, u.username
            FROM artworks a
            LEFT JOIN users u ON a.owner_id = u.id
            WHERE a.is_private = 0 OR a.owner_id = ?
            ORDER BY a.created_at DESC
            LIMIT ?
            """,
            (user_id, limit),
        )
        artworks_data = c.fetchall()
        return [
            {
                "id": art[0],
                "title": art[1],
                "data": art[2],
                "price": art[3],
                "owner_id": art[4],
                "is_private": art[5],
                "signature": art[6] or "",
                "created_at": art[7],
                "owner_name": art[8],
            }
            for art in artworks_data
        ]
    finally:
        conn.close()


def authenticate_user(username: str, password: str) -> Optional[Dict]:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute(
            "SELECT id, username, balance FROM users WHERE username = ? AND password = ?",
            (username, hashlib.md5(password.encode()).hexdigest()),
        )
        user = c.fetchone()
        if user:
            return {"id": user[0], "username": user[1], "balance": user[2]}
        return None
    finally:
        conn.close()

def session_user(username: str) -> Optional[Dict]:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute(
            "SELECT id, username, balance FROM users WHERE username = ?",
            [username],
        )
        user = c.fetchone()
        if user:
            return None
        return True
    finally:
        conn.close()


def create_user(username: str, password: str) -> Tuple[bool, Optional[int]]:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute("SELECT id FROM users WHERE username = ?", (username,))
        if c.fetchone():
            return False, None
        c.execute(
            "INSERT INTO users (username, password) VALUES (?, ?)",
            (username, hashlib.md5(password.encode()).hexdigest()),
        )
        conn.commit()
        return True, c.lastrowid
    finally:
        conn.close()


def create_artwork_record(
    owner_id: int,
    title: str,
    data: str,
    price: int,
    is_private: int,
    signature: str,
    settings_data: Optional[str] = None,
    created_at: Optional[str] = None,
) -> int:
    conn = get_db()
    c = conn.cursor()
    try:
        if created_at:
            c.execute(
                """
                INSERT INTO artworks (title, data, price, owner_id, is_private, signature, created_at)
                VALUES (?, ?, ?, ?, ?, ?, ?)
                """,
                (title, data, price, owner_id, is_private, signature, created_at),
            )
        else:
            c.execute(
                """
                INSERT INTO artworks (title, data, price, owner_id, is_private, signature)
                VALUES (?, ?, ?, ?, ?, ?)
                """,
                (title, data, price, owner_id, is_private, signature),
            )

        artwork_id = c.lastrowid

        if settings_data:
            c.execute(
                "INSERT INTO artwork_settings (artwork_id, settings_data) VALUES (?, ?)",
                (artwork_id, settings_data),
            )

        conn.commit()
        return artwork_id
    finally:
        conn.close()


def get_user_profile(user_id: int) -> Tuple[Optional[Dict], List[Dict]]:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute("SELECT id, username, balance FROM users WHERE id = ?", (user_id,))
        user_data = c.fetchone()
        if not user_data:
            return None, []

        c.execute(
            """
            SELECT id, title, data, price, owner_id, is_private, signature, created_at
            FROM artworks
            WHERE owner_id = ?
            ORDER BY created_at DESC
            """,
            (user_id,),
        )
        artworks_data = c.fetchall()
        artworks = [
            {
                "id": art[0],
                "title": art[1],
                "data": art[2],
                "price": art[3],
                "owner_id": art[4],
                "is_private": art[5],
                "signature": art[6] or "",
                "created_at": art[7],
            }
            for art in artworks_data
        ]
        user = {"id": user_data[0], "username": user_data[1], "balance": user_data[2]}
        return user, artworks
    finally:
        conn.close()


def get_artwork_with_settings(artwork_id: int) -> Optional[Tuple[Dict, Optional[str]]]:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute(
            """
            SELECT a.id, a.title, a.data, a.price, a.owner_id, a.is_private,
                   a.signature, a.created_at, s.settings_data
            FROM artworks a
            LEFT JOIN artwork_settings s ON a.id = s.artwork_id
            WHERE a.id = ?
            """,
            (artwork_id,),
        )
        row = c.fetchone()
        if not row:
            return None

        artwork = {
            "id": row[0],
            "title": row[1],
            "data": row[2],
            "price": row[3],
            "owner_id": row[4],
            "is_private": row[5],
            "signature": row[6] or "",
            "created_at": row[7],
        }
        return artwork, row[8]
    finally:
        conn.close()


def save_artwork_settings(artwork_id: int, settings_data: str) -> None:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute("SELECT id FROM artwork_settings WHERE artwork_id = ?", (artwork_id,))
        existing = c.fetchone()
        if existing:
            c.execute(
                "UPDATE artwork_settings SET settings_data = ? WHERE artwork_id = ?",
                (settings_data, artwork_id),
            )
        else:
            c.execute(
                "INSERT INTO artwork_settings (artwork_id, settings_data) VALUES (?, ?)",
                (artwork_id, settings_data),
            )
        conn.commit()
    finally:
        conn.close()


def get_artwork_owner_id(artwork_id: int) -> Optional[int]:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute("SELECT owner_id FROM artworks WHERE id = ?", (artwork_id,))
        row = c.fetchone()
        return row[0] if row else None
    finally:
        conn.close()


def purchase_artwork(buyer_id: int, artwork_id: int) -> Tuple[bool, str]:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute("SELECT * FROM artworks WHERE id = ?", (artwork_id,))
        artwork = c.fetchone()
        if not artwork:
            return False, "not_found"

        price = artwork[3]
        owner_id = artwork[4]

        if owner_id == buyer_id:
            return False, "same_owner"

        c.execute("SELECT balance FROM users WHERE id = ?", (buyer_id,))
        buyer = c.fetchone()
        if not buyer:
            return False, "buyer_missing"

        buyer_balance = buyer[0]
        if buyer_balance < price:
            return False, "insufficient"

        c.execute(
            "UPDATE users SET balance = balance - ? WHERE id = ?",
            (price, buyer_id),
        )
        c.execute(
            "UPDATE users SET balance = balance + ? WHERE id = ?",
            (price, owner_id),
        )
        c.execute(
            "UPDATE artworks SET owner_id = ? WHERE id = ?",
            (buyer_id, artwork_id),
        )
        c.execute(
            "INSERT INTO transactions (artwork_id, buyer_id, seller_id, amount) VALUES (?, ?, ?, ?)",
            (artwork_id, buyer_id, owner_id, price),
        )
        conn.commit()
        return True, "ok"
    finally:
        conn.close()


def search_artworks(query: str) -> List[Dict]:
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute(
            "SELECT * FROM artworks WHERE title LIKE ? OR data LIKE ?",
            (f"%{query}%", f"%{query}%")
        )
        results_data = c.fetchall()
        return [
            {
                "id": art[0],
                "title": art[1],
                "data": art[2],
                "price": art[3],
                "owner_id": art[4],
                "created_at": art[5],
            }
            for art in results_data
        ]
    finally:
        conn.close()


def import_artwork_record(
    owner_id: int, title: str, shapes_json: str, price: int, signature: str = ""
) -> int:
    return create_artwork_record(
        owner_id=owner_id,
        title=title,
        data=shapes_json,
        price=price,
        is_private=0,
        signature=signature,
    )


def check_connect(ip):
    conn = get_db()
    c = conn.cursor()
    try:
        c.execute("SELECT COUNT(*) FROM users")
        users_count = c.fetchone()[0]

        c.execute("SELECT COUNT(*) FROM artworks")
        artworks_count = c.fetchone()[0]

        c.execute(
            """
            SELECT a.id, a.title, a.signature, a.is_private, u.username, a.created_at
            FROM artworks a
            JOIN users u ON a.owner_id = u.id
            ORDER BY a.created_at DESC
            """,
        )
        recent_data = c.fetchall()
        recent = [
            {
                "id": art[0],
                "title": art[1],
                "signature": art[2] or "",
                "is_private": art[3],
                "owner": art[4],
                "created_at": art[5],
            }
            for art in recent_data
        ]
        parts = ["OK"]
        if ipaddress.ip_address(ip).is_loopback:
            parts.append(recent)
        return parts
    finally:
        conn.close()