"""Support for remote Python debugging.

Some ASCII art to describe the structure:

 IN PYTHON SUBPROCESS # IN IDLE PROCESS
 #
 # oid='gui_adapter'
 +----------+ # +------------+ +-----+
 | GUIProxy |--remote#call-->| GUIAdapter |--calls-->| GUI |
+-----+--calls-->+----------+ # +------------+ +-----+
| Idb | # /
+-----+<-calls--+------------+ # +----------+<--calls-/
 | IdbAdapter |<--remote#call--| IdbProxy |
 +------------+ # +----------+
 oid='idb_adapter' #

The purpose of the Proxy and Adapter classes is to translate certain
arguments and return values that cannot be transported through the RPC
barrier, in particular frame and traceback objects.

"""

import types
from idlelib import debugger

debugging = 0

idb_adap_oid = "idb_adapter"
gui_adap_oid = "gui_adapter"

#=======================================
#
# In the PYTHON subprocess:

frametable = {}
dicttable = {}
codetable = {}
tracebacktable = {}

def wrap_frame(frame):
 fid = id(frame)
 frametable[fid] = frame
 return fid

def wrap_info(info):
 "replace info[2], a traceback instance, by its ID"
 if info is None:
 return None
 else:
 traceback = info[2]
 assert isinstance(traceback, types.TracebackType)
 traceback_id = id(traceback)
 tracebacktable[traceback_id] = traceback
 modified_info = (info[0], info[1], traceback_id)
 return modified_info

class GUIProxy:

 def __init__(self, conn, gui_adap_oid):
 self.conn = conn
 self.oid = gui_adap_oid

 def interaction(self, message, frame, info=None):
 # calls rpc.SocketIO.remotecall() via run.MyHandler instance
 # pass frame and traceback object IDs instead of the objects themselves
 self.conn.remotecall(self.oid, "interaction",
 (message, wrap_frame(frame), wrap_info(info)),
 {})

class IdbAdapter:

 def __init__(self, idb):
 self.idb = idb

 #----------called by an IdbProxy----------

 def set_step(self):
 self.idb.set_step()

 def set_quit(self):
 self.idb.set_quit()

 def set_continue(self):
 self.idb.set_continue()

 def set_next(self, fid):
 frame = frametable[fid]
 self.idb.set_next(frame)

 def set_return(self, fid):
 frame = frametable[fid]
 self.idb.set_return(frame)

 def get_stack(self, fid, tbid):
 frame = frametable[fid]
 if tbid is None:
 tb = None
 else:
 tb = tracebacktable[tbid]
 stack, i = self.idb.get_stack(frame, tb)
 stack = [(wrap_frame(frame2), k) for frame2, k in stack]
 return stack, i

 def run(self, cmd):
 import __main__
 self.idb.run(cmd, __main__.__dict__)

 def set_break(self, filename, lineno):
 msg = self.idb.set_break(filename, lineno)
 return msg

 def clear_break(self, filename, lineno):
 msg = self.idb.clear_break(filename, lineno)
 return msg

 def clear_all_file_breaks(self, filename):
 msg = self.idb.clear_all_file_breaks(filename)
 return msg

 #----------called by a FrameProxy----------

 def frame_attr(self, fid, name):
 frame = frametable[fid]
 return getattr(frame, name)

 def frame_globals(self, fid):
 frame = frametable[fid]
 dict = frame.f_globals
 did = id(dict)
 dicttable[did] = dict
 return did

 def frame_locals(self, fid):
 frame = frametable[fid]
 dict = frame.f_locals
 did = id(dict)
 dicttable[did] = dict
 return did

 def frame_code(self, fid):
 frame = frametable[fid]
 code = frame.f_code
 cid = id(code)
 codetable[cid] = code
 return cid

 #----------called by a CodeProxy----------

 def code_name(self, cid):
 code = codetable[cid]
 return code.co_name

 def code_filename(self, cid):
 code = codetable[cid]
 return code.co_filename

 #----------called by a DictProxy----------

 def dict_keys(self, did):
 raise NotImplementedError("dict_keys not public or pickleable")
## dict = dicttable[did]
## return dict.keys()

 ### Needed until dict_keys is type is finished and pickealable.
 ### Will probably need to extend rpc.py:SocketIO._proxify at that time.
 def dict_keys_list(self, did):
 dict = dicttable[did]
 return list(dict.keys())

 def dict_item(self, did, key):
 dict = dicttable[did]
 value = dict[key]
 value = repr(value) ### can't pickle module 'builtins'
 return value

#----------end class IdbAdapter----------


def start_debugger(rpchandler, gui_adap_oid):
 """Start the debugger and its RPC link in the Python subprocess

 Start the subprocess side of the split debugger and set up that side of the
 RPC link by instantiating the GUIProxy, Idb debugger, and IdbAdapter
 objects and linking them together. Register the IdbAdapter with the
 RPCServer to handle RPC requests from the split debugger GUI via the
 IdbProxy.

 """
 gui_proxy = GUIProxy(rpchandler, gui_adap_oid)
 idb = debugger.Idb(gui_proxy)
 idb_adap = IdbAdapter(idb)
 rpchandler.register(idb_adap_oid, idb_adap)
 return idb_adap_oid


#=======================================
#
# In the IDLE process:


class FrameProxy:

 def __init__(self, conn, fid):
 self._conn = conn
 self._fid = fid
 self._oid = "idb_adapter"
 self._dictcache = {}

 def __getattr__(self, name):
 if name[:1] == "_":
 raise AttributeError(name)
 if name == "f_code":
 return self._get_f_code()
 if name == "f_globals":
 return self._get_f_globals()
 if name == "f_locals":
 return self._get_f_locals()
 return self._conn.remotecall(self._oid, "frame_attr",
 (self._fid, name), {})

 def _get_f_code(self):
 cid = self._conn.remotecall(self._oid, "frame_code", (self._fid,), {})
 return CodeProxy(self._conn, self._oid, cid)

 def _get_f_globals(self):
 did = self._conn.remotecall(self._oid, "frame_globals",
 (self._fid,), {})
 return self._get_dict_proxy(did)

 def _get_f_locals(self):
 did = self._conn.remotecall(self._oid, "frame_locals",
 (self._fid,), {})
 return self._get_dict_proxy(did)

 def _get_dict_proxy(self, did):
 if did in self._dictcache:
 return self._dictcache[did]
 dp = DictProxy(self._conn, self._oid, did)
 self._dictcache[did] = dp
 return dp


class CodeProxy:

 def __init__(self, conn, oid, cid):
 self._conn = conn
 self._oid = oid
 self._cid = cid

 def __getattr__(self, name):
 if name == "co_name":
 return self._conn.remotecall(self._oid, "code_name",
 (self._cid,), {})
 if name == "co_filename":
 return self._conn.remotecall(self._oid, "code_filename",
 (self._cid,), {})


class DictProxy:

 def __init__(self, conn, oid, did):
 self._conn = conn
 self._oid = oid
 self._did = did

## def keys(self):
## return self._conn.remotecall(self._oid, "dict_keys", (self._did,), {})

 # 'temporary' until dict_keys is a pickleable built-in type
 def keys(self):
 return self._conn.remotecall(self._oid,
 "dict_keys_list", (self._did,), {})

 def __getitem__(self, key):
 return self._conn.remotecall(self._oid, "dict_item",
 (self._did, key), {})

 def __getattr__(self, name):
 ##print("*** Failed DictProxy.__getattr__:", name)
 raise AttributeError(name)


class GUIAdapter:

 def __init__(self, conn, gui):
 self.conn = conn
 self.gui = gui

 def interaction(self, message, fid, modified_info):
 ##print("*** Interaction: (%s, %s, %s)" % (message, fid, modified_info))
 frame = FrameProxy(self.conn, fid)
 self.gui.interaction(message, frame, modified_info)


class IdbProxy:

 def __init__(self, conn, shell, oid):
 self.oid = oid
 self.conn = conn
 self.shell = shell

 def call(self, methodname, *args, **kwargs):
 ##print("*** IdbProxy.call %s %s %s" % (methodname, args, kwargs))
 value = self.conn.remotecall(self.oid, methodname, args, kwargs)
 ##print("*** IdbProxy.call %s returns %r" % (methodname, value))
 return value

 def run(self, cmd, locals):
 # Ignores locals on purpose!
 seq = self.conn.asyncqueue(self.oid, "run", (cmd,), {})
 self.shell.interp.active_seq = seq

 def get_stack(self, frame, tbid):
 # passing frame and traceback IDs, not the objects themselves
 stack, i = self.call("get_stack", frame._fid, tbid)
 stack = [(FrameProxy(self.conn, fid), k) for fid, k in stack]
 return stack, i

 def set_continue(self):
 self.call("set_continue")

 def set_step(self):
 self.call("set_step")

 def set_next(self, frame):
 self.call("set_next", frame._fid)

 def set_return(self, frame):
 self.call("set_return", frame._fid)

 def set_quit(self):
 self.call("set_quit")

 def set_break(self, filename, lineno):
 msg = self.call("set_break", filename, lineno)
 return msg

 def clear_break(self, filename, lineno):
 msg = self.call("clear_break", filename, lineno)
 return msg

 def clear_all_file_breaks(self, filename):
 msg = self.call("clear_all_file_breaks", filename)
 return msg

def start_remote_debugger(rpcclt, pyshell):
 """Start the subprocess debugger, initialize the debugger GUI and RPC link

 Request the RPCServer start the Python subprocess debugger and link. Set
 up the Idle side of the split debugger by instantiating the IdbProxy,
 debugger GUI, and debugger GUIAdapter objects and linking them together.

 Register the GUIAdapter with the RPCClient to handle debugger GUI
 interaction requests coming from the subprocess debugger via the GUIProxy.

 The IdbAdapter will pass execution and environment requests coming from the
 Idle debugger GUI to the subprocess debugger via the IdbProxy.

 """
 global idb_adap_oid

 idb_adap_oid = rpcclt.remotecall("exec", "start_the_debugger",\
 (gui_adap_oid,), {})
 idb_proxy = IdbProxy(rpcclt, pyshell, idb_adap_oid)
 gui = debugger.Debugger(pyshell, idb_proxy)
 gui_adap = GUIAdapter(rpcclt, gui)
 rpcclt.register(gui_adap_oid, gui_adap)
 return gui

def close_remote_debugger(rpcclt):
 """Shut down subprocess debugger and Idle side of debugger RPC link

 Request that the RPCServer shut down the subprocess debugger and link.
 Unregister the GUIAdapter, which will cause a GC on the Idle process
 debugger and RPC link objects. (The second reference to the debugger GUI
 is deleted in pyshell.close_remote_debugger().)

 """
 close_subprocess_debugger(rpcclt)
 rpcclt.unregister(gui_adap_oid)

def close_subprocess_debugger(rpcclt):
 rpcclt.remotecall("exec", "stop_the_debugger", (idb_adap_oid,), {})

def restart_subprocess_debugger(rpcclt):
 idb_adap_oid_ret = rpcclt.remotecall("exec", "start_the_debugger",\
 (gui_adap_oid,), {})
 assert idb_adap_oid_ret == idb_adap_oid, 'Idb restarted with different oid'


if __name__ == "__main__":
 from unittest import main
 main('idlelib.idle_test.test_debugger', verbosity=2, exit=False)