# LLDB UI state in the Vim user interface.

import os, re, sys
import lldb
import vim
from vim_panes import *
from vim_signs import *

def is_same_file(a, b):
  """ returns true if paths a and b are the same file """
  a = os.path.realpath(a)
  b = os.path.realpath(b)
  return a in b or b in a

class UI:
  def __init__(self):
    """ Declare UI state variables """

    # Default panes to display
    self.defaultPanes = ['breakpoints', 'backtrace', 'locals', 'threads', 'registers', 'disassembly']

    # map of tuples (filename, line) --> SBBreakpoint
    self.markedBreakpoints = {}

    # Currently shown signs
    self.breakpointSigns = {}
    self.pcSigns = []

    # Container for panes
    self.paneCol = PaneLayout()

    # All possible LLDB panes
    self.backtracePane = BacktracePane(self.paneCol)
    self.threadPane = ThreadPane(self.paneCol)
    self.disassemblyPane = DisassemblyPane(self.paneCol)
    self.localsPane = LocalsPane(self.paneCol)
    self.registersPane = RegistersPane(self.paneCol)
    self.breakPane = BreakpointsPane(self.paneCol)

  def activate(self):
    """ Activate UI: display default set of panes """
    self.paneCol.prepare(self.defaultPanes)

  def get_user_buffers(self, filter_name=None):
    """ Returns a list of buffers that are not a part of the LLDB UI. That is, they
        are not contained in the PaneLayout object self.paneCol.
    """
    ret = []
    for w in vim.windows:
      b = w.buffer
      if not self.paneCol.contains(b.name):
        if filter_name is None or filter_name in b.name:
          ret.append(b) 
    return ret

  def update_pc(self, process, buffers, goto_file):
    """ Place the PC sign on the PC location of each thread's selected frame """

    def GetPCSourceLocation(thread):
      """ Returns a tuple (thread_index, file, line, column) that represents where
          the PC sign should be placed for a thread.
      """

      frame = thread.GetSelectedFrame()
      frame_num = frame.GetFrameID()
      le = frame.GetLineEntry()
      while not le.IsValid() and frame_num < thread.GetNumFrames():
        frame_num += 1
        le = thread.GetFrameAtIndex(frame_num).GetLineEntry()

      if le.IsValid():
        path = os.path.join(le.GetFileSpec().GetDirectory(), le.GetFileSpec().GetFilename())
        return (thread.GetIndexID(), path, le.GetLine(), le.GetColumn())
      return None


    # Clear all existing PC signs
    del_list = []
    for sign in self.pcSigns:
      sign.hide()
      del_list.append(sign)
    for sign in del_list:
      self.pcSigns.remove(sign)
      del sign

    # Select a user (non-lldb) window 
    if not self.paneCol.selectWindow(False):
      # No user window found; avoid clobbering by splitting
      vim.command(":vsp")

    # Show a PC marker for each thread
    for thread in process:
      loc = GetPCSourceLocation(thread)
      if not loc:
        # no valid source locations for PCs. hide all existing PC markers
        continue

      buf = None
      (tid, fname, line, col) = loc
      buffers = self.get_user_buffers(fname)
      is_selected = thread.GetIndexID() == process.GetSelectedThread().GetIndexID()
      if len(buffers) == 1:
        buf = buffers[0]
        if buf != vim.current.buffer:
          # Vim has an open buffer to the required file: select it
          vim.command('execute ":%db"' % buf.number)
      elif is_selected and vim.current.buffer.name not in fname and os.path.exists(fname) and goto_file:
        # FIXME: If current buffer is modified, vim will complain when we try to switch away.
        #        Find a way to detect if the current buffer is modified, and...warn instead?
        vim.command('execute ":e %s"' % fname)
        buf = vim.current.buffer
      elif len(buffers) > 1 and goto_file:
        #FIXME: multiple open buffers match PC location
        continue
      else:
        continue

      self.pcSigns.append(PCSign(buf, line, is_selected))

      if is_selected and goto_file:
        # if the selected file has a PC marker, move the cursor there too
        curname = vim.current.buffer.name
        if curname is not None and is_same_file(curname, fname):
          move_cursor(line, 0)
        elif move_cursor:
          print "FIXME: not sure where to move cursor because %s != %s " % (vim.current.buffer.name, fname)

  def update_breakpoints(self, target, buffers):
    """ Decorates buffer with signs corresponding to breakpoints in target. """

    def GetBreakpointLocations(bp):
      """ Returns a list of tuples (resolved, filename, line) where a breakpoint was resolved. """
      if not bp.IsValid():
        sys.stderr.write("breakpoint is invalid, no locations")
        return []

      ret = []
      numLocs = bp.GetNumLocations()
      for i in range(numLocs):
        loc = bp.GetLocationAtIndex(i)
        desc = get_description(loc, lldb.eDescriptionLevelFull)
        match = re.search('at\ ([^:]+):([\d]+)', desc)
        try:
          lineNum = int(match.group(2).strip())
          ret.append((loc.IsResolved(), match.group(1), lineNum))
        except ValueError as e:
          sys.stderr.write("unable to parse breakpoint location line number: '%s'" % match.group(2))
          sys.stderr.write(str(e))

      return ret


    if target is None or not target.IsValid():
      return

    needed_bps = {}
    for bp_index in range(target.GetNumBreakpoints()):
      bp = target.GetBreakpointAtIndex(bp_index)
      locations = GetBreakpointLocations(bp)
      for (is_resolved, file, line) in GetBreakpointLocations(bp):
        for buf in buffers:
          if file in buf.name:
            needed_bps[(buf, line, is_resolved)] = bp

    # Hide any signs that correspond with disabled breakpoints
    del_list = []
    for (b, l, r) in self.breakpointSigns:
      if (b, l, r) not in needed_bps:
        self.breakpointSigns[(b, l, r)].hide()
        del_list.append((b, l, r))
    for d in del_list:
      del self.breakpointSigns[d]
      
    # Show any signs for new breakpoints
    for (b, l, r) in needed_bps:
      bp = needed_bps[(b, l, r)]
      if self.haveBreakpoint(b.name, l):
        self.markedBreakpoints[(b.name, l)].append(bp)
      else:
        self.markedBreakpoints[(b.name, l)] = [bp]

      if (b, l, r) not in self.breakpointSigns:
        s = BreakpointSign(b, l, r)
        self.breakpointSigns[(b, l, r)] = s

  def update(self, target, status, controller, goto_file=False):
    """ Updates debugger info panels and breakpoint/pc marks and prints
        status to the vim status line. If goto_file is True, the user's
        cursor is moved to the source PC location in the selected frame.
    """

    self.paneCol.update(target, controller)
    self.update_breakpoints(target, self.get_user_buffers())

    if target is not None and target.IsValid():
      process = target.GetProcess()
      if process is not None and process.IsValid():
        self.update_pc(process, self.get_user_buffers, goto_file)

    if status is not None and len(status) > 0:
      print status 

  def haveBreakpoint(self, file, line):
    """ Returns True if we have a breakpoint at file:line, False otherwise  """
    return (file, line) in self.markedBreakpoints

  def getBreakpoints(self, fname, line):
    """ Returns the LLDB SBBreakpoint object at fname:line """
    if self.haveBreakpoint(fname, line):
      return self.markedBreakpoints[(fname, line)]
    else:
      return None

  def deleteBreakpoints(self, name, line):
    del self.markedBreakpoints[(name, line)]

  def showWindow(self, name):
    """ Shows (un-hides) window pane specified by name """
    if not self.paneCol.havePane(name):
      sys.stderr.write("unknown window: %s" % name)
      return False
    self.paneCol.prepare([name])
    return True

  def hideWindow(self, name):
    """ Hides window pane specified by name """
    if not self.paneCol.havePane(name):
      sys.stderr.write("unknown window: %s" % name)
      return False
    self.paneCol.hide([name])
    return True

global ui
ui = UI()