1 files changed, 57 insertions, 0 deletions
diff --git a/tasd/file.py b/tasd/file.py
new file mode 100644
index 0000000..53d4f74
--- /dev/null
+++ b/tasd/file.py
@@ -0,0 +1,57 @@
+import tasd.packets as packets
+import tasd.constants as constants
+import tasd.utils as utils
+from tasd.packet import lookup_packet, _TASDPacket
+from typing import List
+
+class TASD():
+    MAGIC = b"TASD"
+    def __init__(self, version = 1, g_keylen = 2):
+        self.version = version
+        self.g_keylen = g_keylen
+        self.packets: List[_TASDPacket] = []
+    @classmethod
+    def from_bytes(cls, buffer: bytes, *, bypass_errors = False):
+        magic = utils.readBytes(buffer, 0, 4)
+        if magic != cls.MAGIC:
+            raise ValueError("Invalid TASD File, Missing Magic")
+        version = utils.readUint16(buffer, 4)
+        if version != 1 and not bypass_errors:
+            raise ValueError("Unsupported TASD File, Version Unsupported", version)
+        g_keylen = utils.readUint8(buffer, 6)
+        if g_keylen != 2:
+            raise ValueError("Unsupported TASD File, Unknown G_KEYLEN", g_keylen)
+        self = cls(version, g_keylen)
+        index = 7
+        while index < len(buffer):
+            key = utils.readUintN(buffer, index, self.g_keylen)
+            index += self.g_keylen
+            packet_cls = lookup_packet(key)
+            pexp = utils.readUint8(buffer, index)
+            index += 1
+            plen = utils.readUintN(buffer, index, pexp)
+            index += pexp
+            data = utils.readBytes(buffer, index, plen)
+            index += plen
+            packet = packet_cls.from_bytes(data)
+            self.packets.append(packet)
+        return self
+    def to_bytes(self):
+        header = bytearray(7)
+        header[0:4] = self.MAGIC
+        utils.writeUint16(self.version, header, 4)
+        utils.writeUint8(self.g_keylen, header, 6)
+        packets = [ header ]
+        for packet in self.packets:
+            plen = packet.size()
+            pexp = utils.minUint(plen)
+            size = self.g_keylen + 1 + pexp
+            buffer = bytearray(size)
+            utils.writeUintN(packet._key, buffer, 0, self.g_keylen)
+            utils.writeUint8(pexp, buffer, self.g_keylen)
+            utils.writeUintN(plen, buffer, self.g_keylen + 1, pexp)
+            payload = packet.to_bytes()
+            packets.append(buffer + payload)
+        return b"".join(packets)
+    def __repr__(self):
+        return f"TASD(version={self.version}, g_keylen={self.g_keylen})"