import sqlite3
import threading

class RAMController:
    def __init__(self, size_bytes, db_path='ram_storage.db'):
        self.size_bytes = size_bytes
        self.conn = sqlite3.connect(db_path, check_same_thread=False)
        self.db_lock = threading.Lock()
        with self.db_lock:
            self.conn.execute('''CREATE TABLE IF NOT EXISTS ram_cells (
                address INTEGER PRIMARY KEY,
                data BLOB
            )''')
            self.conn.commit()

    def read(self, address, length):
        if address < 0 or address + length > self.size_bytes:
            raise IndexError("Memory access out of bounds")
        with self.db_lock:
            cur = self.conn.execute(
                "SELECT address, data FROM ram_cells WHERE address >= ? AND address < ? ORDER BY address ASC",
                (address, address + length)
            )
            # Build a bytearray of the requested range
            result = bytearray([0] * length)
            for row in cur:
                addr = row[0]
                data = row[1]
                if address <= addr < address + length:
                    result[addr - address] = data[0] if isinstance(data, (bytes, bytearray)) else data
            return result

    def write(self, address, data):
        if address < 0 or address + len(data) > self.size_bytes:
            raise IndexError("Memory access out of bounds")
        with self.db_lock:
            for offset, value in enumerate(data):
                self.conn.execute(
                    "INSERT OR REPLACE INTO ram_cells (address, data) VALUES (?, ?)",
                    (address + offset, sqlite3.Binary(bytes([value])))
                )
            self.conn.commit()

    def close(self):
        with self.db_lock:
            if self.conn:
                self.conn.close()
                self.conn = None