From 733843a6d47ef6f17166d59e6f50d3abc66f9a9b Mon Sep 17 00:00:00 2001
From: Ben Jackson <puremourning@gmail.com>
Date: Thu, 3 Sep 2020 17:46:06 +0100
Subject: [PATCH] Support completion for console and watches.

Add omnifunc for prompt buffers

This synchronous completion can be used with any completion system
including built-in CTRL-X CTRL-O.

The filetype of the prompt buffers is set to VimspectorPrompt so that it
can be identified by completion systems. For example, this works well
with YCM:

let g:ycm_semantic_triggers =  {
  \   'VimspectorPrompt': [ '.', '->', ':', '<' ]
  \ }
---
 autoload/vimspector.vim             | 103 +++++++++++++++++++++++++++-
 python3/vimspector/debug_session.py |   3 +-
 python3/vimspector/output.py        |   3 +-
 python3/vimspector/utils.py         |   9 ++-
 python3/vimspector/variables.py     |   3 +-
 5 files changed, 113 insertions(+), 8 deletions(-)

diff --git a/autoload/vimspector.vim b/autoload/vimspector.vim
index 302b34d..df0b6a9 100644
--- a/autoload/vimspector.vim
+++ b/autoload/vimspector.vim
@@ -232,17 +232,114 @@ function! vimspector#CompleteOutput( ArgLead, CmdLine, CursorPos ) abort
   return join( buffers, "\n" )
 endfunction
 
+py3 <<EOF
+def _vimspector_GetExprCompletions( CmdLine, CursorPos ):
+  if not _vimspector_session:
+    return []
+
+  # FIXME
+  # Curiously, it seems that CursorPos is 0-based here and that's actually what
+  # the servers want/need ?
+  return [ i.get( 'text' ) or i[ 'label' ]
+           for i in _vimspector_session.GetCompletionsSync( CmdLine,
+                                                            CursorPos ) ]
+EOF
+
 function! vimspector#CompleteExpr( ArgLead, CmdLine, CursorPos ) abort
   if !s:enabled
     return
   endif
-  return join( py3eval( '_vimspector_session.GetCompletionsSync( '
+  return join( py3eval( '_vimspector_GetExprCompletions( '
                       \.'  vim.eval( "a:CmdLine" ),'
-                      \.'  int( vim.eval( "a:CursorPos" ) ) )'
-                      \. '   if _vimspector_session else []' ),
+                      \.'  int( vim.eval( "a:CursorPos" ) ) + 1 )' ),
              \ "\n" )
 endfunction
 
+let s:latest_completion_request = {}
+
+function! vimspector#CompleteFuncSync( prompt, find_start, query ) abort
+  if py3eval( 'not _vimspector_session' )
+    return []
+  endif
+
+  if a:find_start
+
+    " We're busy
+    if !empty( s:latest_completion_request )
+      return -1
+    endif
+
+    let line = getline( line( '.' ) )[ len( a:prompt ) : ]
+    let col = col( '.' ) - len( a:prompt )
+    let s:latest_completion_request.items =
+          \ py3eval( '_vimspector_session.GetCompletionsSync( '
+                   \.'  vim.eval( "line" ), '
+                   \.'  int( vim.eval( "col" ) ) )' )
+    let s:latest_completion_request.line = line
+    let s:latest_completion_request.col = col
+
+    let start_pos = col
+    for item in s:latest_completion_request.items
+      if !has_key( item, 'start' )
+        let item.start = col
+      else
+        " For some reason, the returned start value is 0-indexed even though we
+        " use columnsStartAt1
+        " TODO need to check this with the other servers that exist
+        let item.start += 1
+      endif
+      " TODO/FIXME. I don't think it's possible to implement the 'length'
+      " parameter, using vim's completion system
+      " if !has_key( item, 'length' )
+      "   let item.length = 0
+      " endif
+      if !has_key( item, 'text' )
+        let item.text = item.label
+      endif
+
+      if item.start < start_pos
+        let start_pos = item.start
+      endif
+    endfor
+
+    let s:latest_completion_request.start_pos = start_pos
+    let s:latest_completion_request.prompt = a:prompt
+
+    " start_pos is 1-based and the return of findstart is 0-based
+    return ( start_pos + len( a:prompt ) ) - 1
+  else
+    let items = []
+    let pfxlen = len( s:latest_completion_request.prompt )
+    for item in s:latest_completion_request.items
+      if item.start > s:latest_completion_request.start_pos
+        " fix up the text (insert anything that is already present in the line
+        " that would be erased by the fixed-up earlier start position)
+        "
+        " both start_pos and item.start are 1-based
+        let item.text = s:latest_completion_request.text[
+              \ s:latest_completion_request.start_pos + pfxlen - 1 :
+              \  item.start + pfxlen - 1 ] . item.text
+      endif
+
+      call add( items, { 'word': item.text,
+                       \ 'abbr': item.label,
+                       \ 'menu': get( item, 'type', '' ),
+                       \ 'icase': 1,
+                       \ } )
+    endfor
+    let s:latest_completion_request = {}
+    return { 'words': items, 'refresh': 'always' }
+  endif
+endfunction
+
+function! vimspector#OmniFuncWatch( find_start, query ) abort
+  return vimspector#CompleteFuncSync( 'Expression: ', a:find_start, a:query )
+endfunction
+
+function! vimspector#OmniFuncConsole( find_start, query ) abort
+  return vimspector#CompleteFuncSync( '> ', a:find_start, a:query )
+endfunction
+
 function! vimspector#Install( bang, ... ) abort
   if !s:enabled
     return
diff --git a/python3/vimspector/debug_session.py b/python3/vimspector/debug_session.py
index 5a542c6..6a40294 100644
--- a/python3/vimspector/debug_session.py
+++ b/python3/vimspector/debug_session.py
@@ -554,8 +554,7 @@ class DebugSession( object ):
     # TODO:
     #  - start / length
     #  - sortText
-    return [ i.get( 'text' ) or i[ 'label' ]
-             for i in response[ 'body' ][ 'targets' ] ]
+    return response[ 'body' ][ 'targets' ]
 
 
   def _SetUpUI( self ):
diff --git a/python3/vimspector/output.py b/python3/vimspector/output.py
index 90df09d..71c81e9 100644
--- a/python3/vimspector/output.py
+++ b/python3/vimspector/output.py
@@ -192,7 +192,8 @@ class OutputView( object ):
         utils.SetUpPromptBuffer( tab_buffer.buf,
                                  name,
                                  '> ',
-                                 'vimspector#EvaluateConsole' )
+                                 'vimspector#EvaluateConsole',
+                                 'vimspector#OmniFuncConsole' )
       else:
         utils.SetUpHiddenBuffer( tab_buffer.buf, name )
 
diff --git a/python3/vimspector/utils.py b/python3/vimspector/utils.py
index 17c8166..2874635 100644
--- a/python3/vimspector/utils.py
+++ b/python3/vimspector/utils.py
@@ -135,7 +135,7 @@ def SetUpHiddenBuffer( buf, name ):
   buf.name = name
 
 
-def SetUpPromptBuffer( buf, name, prompt, callback ):
+def SetUpPromptBuffer( buf, name, prompt, callback, omnifunc ):
   # This feature is _super_ new, so only enable when available
   if not Exists( '*prompt_setprompt' ):
     return SetUpHiddenBuffer( buf, name )
@@ -148,6 +148,7 @@ def SetUpPromptBuffer( buf, name, prompt, callback ):
   buf.options[ 'buflisted' ] = False
   buf.options[ 'bufhidden' ] = 'hide'
   buf.options[ 'textwidth' ] = 0
+  buf.options[ 'omnifunc' ] = omnifunc
   buf.name = name
 
   vim.eval( "prompt_setprompt( {0}, '{1}' )".format( buf.number,
@@ -156,6 +157,12 @@ def SetUpPromptBuffer( buf, name, prompt, callback ):
     buf.number,
     Escape( callback ) ) )
 
+  # This serves a few purposes, mainly to ensure that completion systems have
+  # something to work with. In particular it makes YCM use its identifier engine
+  # and you can config ycm to trigger semantic (annoyingly, synchronously) using
+  # some let g:ycm_auto_trggier
+  Call( 'setbufvar', buf.number, '&filetype', 'VimspectorPrompt' )
+
 
 def SetUpUIWindow( win ):
   win.options[ 'wrap' ] = False
diff --git a/python3/vimspector/variables.py b/python3/vimspector/variables.py
index d82090a..5694e46 100644
--- a/python3/vimspector/variables.py
+++ b/python3/vimspector/variables.py
@@ -147,7 +147,8 @@ class VariablesView( object ):
     utils.SetUpPromptBuffer( self._watch.buf,
                              'vimspector.Watches',
                              'Expression: ',
-                             'vimspector#AddWatchPrompt' )
+                             'vimspector#AddWatchPrompt',
+                             'vimspector#OmniFuncWatch' )
     with utils.LetCurrentWindow( watches_win ):
       vim.command(
         'nnoremap <buffer> <CR> :call vimspector#ExpandVariable()<CR>' )