[WIP] Flipper Devtool (#113)

* FLPv0.1 on Python; File transfer is working.
* FLPv0.1 on Python; .gitignore fixes.
* Update protocol to latest version; change interface to OOP

Co-authored-by: Daniel Solmann <DanGSun@yandex.ru>
Co-authored-by: coreglitch <mail@s3f.ru>

flp/flipper/file.py

@@ -0,0 +1,122 @@
+from enum import Enum
+
+import serial
+
+
+class RemoteIOError(IOError):
+    pass
+
+
+class UnsupportedOperation(RemoteIOError):
+    # TODO: Tell more on error
+    pass
+
+
+class ReadWriteError(RemoteIOError):
+    pass
+
+
+class FileMode(Enum):
+    READ = "r"
+    WRITE = "w"
+    # APPEND = "a" - Not Impl
+    # READ_WRITE = "w+"
+    # READ_APPEND = "a+"
+
+
+class File:
+    opened: bool = False
+    filename: str
+    conn: serial.Serial
+    mode = FileMode.READ
+
+    def _open(self):
+        # Opening file on Flipper's end
+        self.conn.write(f"f_open {self.filename} {self.mode}\n".encode())
+
+        # Checking, if everything is OK.
+        self.conn.write(b"f_valid\n")
+        return bool(int(self.conn.read_until().decode()))
+
+    def __init__(self, conn: serial.Serial, filename: str, mode=FileMode.READ):
+        self.conn = conn
+        self.mode = mode
+        self.filename = filename
+
+        if not self._open():
+            raise RemoteIOError
+        self.opened = True
+
+    def lseek(self, size: int):
+        self.conn.write(f"f_lseek {size}\n".encode())
+
+    def tell(self):
+        self.conn.write(b"f_tell\n")
+        return int(self.conn.read_until().decode())
+
+    def size(self):
+        self.conn.write(b"f_size\n")
+        return int(self.conn.read_until().decode())
+
+    def write(self, data: bytes):
+        if self.mode != FileMode.WRITE:
+            raise UnsupportedOperation
+        self.conn.write(f"f_write {len(data)}\n".encode())
+        self.conn.write(data)
+        self.conn.write(b"\n")
+
+        if self.conn.read_until().decode().strip() != "OK":
+            raise ReadWriteError
+
+    def read(self, size: int) -> bytes:
+        self.conn.write(f"f_read {size}\n".encode())
+        return self.conn.read(size)
+
+    def _close(self):
+        self.conn.write(b"f_close\n")
+
+    def close(self):
+        self._close()
+        # TODO: Add termination of remote file process.
+        del self
+
+    def read_all(self, block_size=128) -> bytes:
+        """
+        Function to simplify reading of file over serial.
+
+        :return: content of file represented in `bytes`
+        """
+        size = self.size()
+        a = bytearray()
+        seek = 0
+        # Reading in blocks of block_size
+        while seek < block_size * (size // block_size - 1):
+            seek += block_size
+            self.lseek(seek)
+            a.extend(self.read(block_size))
+
+        seek += block_size
+        self.lseek(seek)
+        a.extend(self.read(size - seek))  # Appending mod
+
+        self.lseek(0)  # Resetting seek to default-position
+
+        return bytes(a)
+
+
+def push(ser: serial.Serial, local_path, remote_path):
+    with open(local_path, "rb") as local_f:  # Reading local file
+        a = local_f.read()
+
+    remote_f = File(ser, remote_path, FileMode.WRITE)
+    remote_f.write(a)
+    remote_f.close()
+
+
+def pull(ser: serial.Serial, remote_path, local_path):
+    remote_f = File(ser, remote_path, FileMode.READ)
+
+    with open(local_path, "wb") as f:
+        f.write(remote_f.read_all())
+
+    remote_f.close()