fix(chat): simplify chat window reuse and command handling

Avoid toggling chat buffers through a separate entry point and fix
tab-local chat reuse when buffers are hidden or visible elsewhere.
Reuse or create chat windows in one code path, track tab chat buffers
consistently, and open escaped scratch buffer names safely.

- Removed the unused `force_new` parameter from `s:OpenChatWindow()`.
- Removed the forwarding-only `vim_ai#AIChatToggleRun()`.
- Removed the duplicate `settabvar()` from `vim_ai#AIChatRun()`.
- Added `abort` to `s:ReuseOrCreateChatWindow()`.
- Kept tab ownership based on `bufnr`, not scratch names.
- Escaped scratch names with `fnameescape()` when calling `:file`.
- Inlined trivial one-use window visibility logic into `s:ReuseOrCreateChatWindow()`.

Author: Konfekt

autoload/vim_ai.vim

@@ -25,69 +25,42 @@ function! vim_ai#ImportPythonModules() abort
   call s:ImportPythonModules()
 endfunction
 
-function! s:GetBufferWinIdInTab(bufnr, tabnr) abort
-  for l:win_id in win_findbuf(a:bufnr)
-    if win_id2tabwin(l:win_id)[0] == a:tabnr
-      return l:win_id
-    endif
-  endfor
-  return -1
-endfunction
-
 function! s:GetTabChatBuffer(tabnr) abort
   let l:chat_bufnr = gettabvar(a:tabnr, 'vim_ai_chat_bufnr', -1)
   if l:chat_bufnr == -1 || !bufexists(l:chat_bufnr)
     return -1
   endif
-  if getbufvar(l:chat_bufnr, "&filetype") !=# "aichat"
+  if getbufvar(l:chat_bufnr, '&filetype') !=# 'aichat'
     return -1
   endif
   return l:chat_bufnr
 endfunction
 
-function! s:IsBufferVisibleOutsideTab(bufnr, tabnr) abort
-  for l:win_id in win_findbuf(a:bufnr)
-    if win_id2tabwin(l:win_id)[0] != a:tabnr
-      return 1
-    endif
-  endfor
-  return 0
-endfunction
-
 " Configures ai-chat scratch window.
 " - scratch_buffer_keep_open = 0
 "   - opens new ai-chat every time
 "   - excludes buffer from buffer list
 " - scratch_buffer_keep_open = 1
 "   - keeps hidden ai-chat buffer for later reuse in the same tab
 "   - keeps the buffer in the buffer list
-function! s:OpenChatWindow(open_conf, force_new) abort
-  " open new buffer that will be used as a chat
-  let l:open_cmd = has_key(g:vim_ai_open_chat_presets, a:open_conf)
-        \ ? g:vim_ai_open_chat_presets[a:open_conf]
-        \ : a:open_conf
+function! s:OpenChatWindow(open_conf) abort
+  let l:open_cmd = get(g:vim_ai_open_chat_presets, a:open_conf, a:open_conf)
   execute l:open_cmd
 
-  let l:keep_open = g:vim_ai_chat['ui']['scratch_buffer_keep_open'] == '1'
+  let l:keep_open = g:vim_ai_chat['ui']['scratch_buffer_keep_open'] ==# '1'
 
   setlocal buftype=nofile
   setlocal noswapfile
-  setlocal ft=aichat
-  if l:keep_open
-    setlocal bufhidden=hide
-  else
-    setlocal bufhidden=wipe
-  endif
-  if bufexists(s:scratch_buffer_name)
-    " spawn another window if chat already exist
-    let l:index = 2
-    while bufexists(s:scratch_buffer_name . " " . l:index)
-      let l:index += 1
-    endwhile
-    execute "file " . s:scratch_buffer_name . " " . l:index
-  else
-    execute "file " . s:scratch_buffer_name
-  endif
+  setlocal filetype=aichat
+  execute 'setlocal bufhidden=' . (l:keep_open ? 'hide' : 'wipe')
+
+  let l:buffer_name = s:scratch_buffer_name
+  let l:index = 2
+  while bufexists(l:buffer_name)
+    let l:buffer_name = s:scratch_buffer_name . ' ' . l:index
+    let l:index += 1
+  endwhile
+  execute 'file ' . fnameescape(l:buffer_name)
 endfunction
 
 let s:is_handling_paste_mode = 0
@@ -249,56 +222,59 @@ function! vim_ai#AIImageRun(uses_range, config, ...) range abort
   py3 run_ai_image(unwrap('l:context'))
 endfunction
 
-function! s:ReuseOrCreateChatWindow(config)
-  let l:open_conf = a:config['ui']['open_chat_command']
+function! s:ReuseOrCreateChatWindow(config) abort
   let l:tabnr = tabpagenr()
-  let l:chat_bufnr = s:GetTabChatBuffer(l:tabnr)
-  let l:force_new = a:config['ui']['force_new_chat'] == '1'
+  let l:force_new = a:config['ui']['force_new_chat'] ==# '1'
 
-  if &filetype != 'aichat'
-    if l:chat_bufnr != -1
-      if s:IsBufferVisibleOutsideTab(l:chat_bufnr, l:tabnr)
-        let l:chat_bufnr = -1
-      endif
-    endif
+  if &filetype ==# 'aichat'
+    call settabvar(l:tabnr, 'vim_ai_chat_bufnr', bufnr('%'))
+    return
+  endif
 
-    if l:force_new
-      call s:OpenChatWindow(l:open_conf, 1)
-      let l:new_tabnr = tabpagenr()
-      let l:new_chat_bufnr = bufnr('%')
-      call settabvar(l:new_tabnr, 'vim_ai_chat_bufnr', l:new_chat_bufnr)
-      if l:new_tabnr == l:tabnr
-            \ && l:chat_bufnr != -1
-            \ && l:chat_bufnr != l:new_chat_bufnr
-            \ && !s:IsBufferVisibleOutsideTab(l:chat_bufnr, l:tabnr)
-        execute "bwipeout " . l:chat_bufnr
+  let l:chat_bufnr = s:GetTabChatBuffer(l:tabnr)
+  let l:chat_win_id = -1
+  let l:is_visible_outside_tab = 0
+
+  if l:chat_bufnr != -1
+    for l:win_id in win_findbuf(l:chat_bufnr)
+      let l:win_tabnr = win_id2tabwin(l:win_id)[0]
+      if l:win_tabnr == l:tabnr
+        let l:chat_win_id = l:win_id
+      else
+        let l:is_visible_outside_tab = 1
       endif
-      return
-    endif
+    endfor
 
-    if l:chat_bufnr != -1
-      let l:chat_win_id = s:GetBufferWinIdInTab(l:chat_bufnr, l:tabnr)
-      if l:chat_win_id != -1
-        call win_gotoid(l:chat_win_id)
-        return
-      endif
-      call s:OpenChatWindow(l:open_conf, 1)
-      let l:new_buffer = bufnr('%')
-      execute "buffer " . l:chat_bufnr
-      execute "bd " . l:new_buffer
-      return
+    if l:is_visible_outside_tab
+      let l:chat_bufnr = -1
+      let l:chat_win_id = -1
     endif
+  endif
 
-    call s:OpenChatWindow(l:open_conf, 0)
+  if !l:force_new && l:chat_win_id != -1
+    call win_gotoid(l:chat_win_id)
     call settabvar(tabpagenr(), 'vim_ai_chat_bufnr', bufnr('%'))
+    return
   endif
-endfunction
 
-function! vim_ai#AIChatToggleRun(uses_range, config, ...) range abort
-  if a:0 > 0
-    execute a:firstline . "," . a:lastline . "call vim_ai#AIChatRun(" . a:uses_range . ", " . string(a:config) . ", " . string(a:1) . ")"
-  else
-    execute a:firstline . "," . a:lastline . "call vim_ai#AIChatRun(" . a:uses_range . ", " . string(a:config) . ")"
+  call s:OpenChatWindow(a:config['ui']['open_chat_command'])
+  let l:new_tabnr = tabpagenr()
+  let l:new_chat_bufnr = bufnr('%')
+
+  if !l:force_new && l:chat_bufnr != -1
+    execute 'buffer ' . l:chat_bufnr
+    execute 'bwipeout ' . l:new_chat_bufnr
+    call settabvar(tabpagenr(), 'vim_ai_chat_bufnr', bufnr('%'))
+    return
+  endif
+
+  call settabvar(l:new_tabnr, 'vim_ai_chat_bufnr', l:new_chat_bufnr)
+
+  if l:force_new
+        \ && l:new_tabnr == l:tabnr
+        \ && l:chat_bufnr != -1
+        \ && l:chat_bufnr != l:new_chat_bufnr
+    execute 'bwipeout ' . l:chat_bufnr
   endif
 endfunction
 
@@ -343,12 +319,12 @@ function! vim_ai#AIChatRun(uses_range, config, ...) range abort
   let l:started_from_chat = &filetype == 'aichat'
 
   let l:config_input = {
-  \  "config_default": g:vim_ai_chat,
-  \  "config_extension": a:config,
-  \  "user_instruction": l:instruction,
-  \  "user_selection": l:selection,
-  \  "is_selection": l:is_selection,
-  \  "command_type": 'chat',
+  \  'config_default': g:vim_ai_chat,
+  \  'config_extension': a:config,
+  \  'user_instruction': l:instruction,
+  \  'user_selection': l:selection,
+  \  'is_selection': l:is_selection,
+  \  'command_type': 'chat',
   \}
   let l:context = py3eval("make_ai_context(unwrap('l:config_input'))")
   let l:config = l:context['config']
@@ -358,7 +334,6 @@ function! vim_ai#AIChatRun(uses_range, config, ...) range abort
   try
     call s:set_paste(l:config)
     call s:ReuseOrCreateChatWindow(l:config)
-    call settabvar(tabpagenr(), 'vim_ai_chat_bufnr', bufnr('%'))
 
     let l:context['bufnr'] = bufnr()
     let l:bufnr = bufnr()
@@ -368,15 +343,12 @@ function! vim_ai#AIChatRun(uses_range, config, ...) range abort
       return
     endif
 
-    let s:last_command = "chat"
+    let s:last_command = 'chat'
     let s:last_config = a:config
 
     if py3eval("run_ai_chat(unwrap('l:context'))")
       if g:vim_ai_async_chat == 1
-
         call setbufvar(l:bufnr, 'vim_ai_chat_start_last_line', line('$'))
-        " if user switches to a different buffer, setup autocommand that
-        " will clean undo history after returning back
         augroup AichatUndo
           au!
           autocmd BufEnter <buffer> call s:AIChatUndoCleanup()
@@ -402,7 +374,6 @@ function! vim_ai#AIChatStopRun() abort
   call s:AIChatUndoCleanup()
 endfunction
 
-
 " Function called in a timer that check if there are new lines from AI and
 " appned them in a buffer. It ends when AI thread is finished (or when
 " stopped).

plugin/vim-ai.vim

@@ -13,7 +13,7 @@ cal vim_ai_provider#Register('openai', {
 
 command! -range -nargs=? -complete=customlist,vim_ai#RoleCompletionComplete AI <line1>,<line2>call vim_ai#AIRun(<range>, {}, <q-args>)
 command! -range -nargs=? -complete=customlist,vim_ai#RoleCompletionEdit AIEdit <line1>,<line2>call vim_ai#AIEditRun(<range>, {}, <q-args>)
-command! -range -nargs=? -complete=customlist,vim_ai#RoleCompletionChat AIChat <line1>,<line2>call vim_ai#AIChatToggleRun(<range>, {}, <q-args>)
+command! -range -nargs=? -complete=customlist,vim_ai#RoleCompletionChat AIChat <line1>,<line2>call vim_ai#AIChatRun(<range>, {}, <q-args>)
 command! -range -nargs=? -complete=customlist,vim_ai#RoleCompletionImage AIImage <line1>,<line2>call vim_ai#AIImageRun(<range>, {}, <q-args>)
 command! -nargs=? AINewChat call vim_ai#AINewChatDeprecatedRun(<f-args>)
 command! AIRedo call vim_ai#AIRedoRun()