feat/client/undo

lua/opencode/commands/handlers/session.lua

@@ -452,6 +452,13 @@ end
 ---@param message_id? string
 function M.actions.undo(message_id)
   return with_active_session('No active session to undo', function(state_obj)
+    local queue = require('opencode.services.client_queue')
+    local queued = queue.undo_last()
+    if queued then
+      vim.notify(('Removed from client queue: ' .. queued.prompt):sub(vim.v.echospace), vim.log.levels.INFO)
+      return
+    end
+
     local target = message_id and find_message_in_state(state_obj, message_id) or find_last_user_message(state_obj)
     if not target then
       vim.notify('No user message to undo', vim.log.levels.WARN)

lua/opencode/services/client_queue.lua

@@ -0,0 +1,147 @@
+local state = require('opencode.state')
+local loading_animation = require('opencode.ui.loading_animation')
+local messaging = require('opencode.services.messaging')
+
+local M = {}
+
+---@class OpencodeClientQueueItem
+---@field prompt string
+---@field opts? SendMessageOpts
+---@field enqueued_at integer
+
+---@type OpencodeClientQueueItem[]
+local _queue = {}
+
+local tool_call_is_running = {}
+
+local _setup_done = false
+
+---@return string|nil
+local function current_session_id()
+  local s = state.active_session
+  return s and s.id or nil
+end
+
+---@param session_id string
+---@return boolean
+local function is_session_idle(session_id)
+  local status = loading_animation.get_status(session_id)
+  return not status or status.type == 'idle'
+end
+
+local function refresh_hint()
+  local ok, input_window = pcall(require, 'opencode.ui.input_window')
+  if not ok or not input_window or not input_window.render_queue_hint then
+    return
+  end
+  input_window.render_queue_hint(#_queue)
+end
+
+---Drain one item from the queue, but only when the active session is
+---idle. Returns true if an item was drained.
+---@return boolean drained_one
+function M.flush_one_if_idle()
+  if #_queue == 0 then
+    return false
+  end
+  local sid = current_session_id()
+  if not sid then
+    return false
+  end
+  local messages = state.messages or {}
+  if not is_session_idle(sid) and not tool_call_is_running[sid] then
+    return false
+  end
+  local item = table.remove(_queue, 1)
+  refresh_hint()
+  messaging.send_message(item.prompt, item.opts or {})
+  return true
+end
+
+---Drain one item unconditionally (no status check). Used by the tool-call
+---completion listener, which knows the server's runLoop is about to read
+---store for the next step.
+---@return boolean drained_one
+function M.flush_one_now()
+  if #_queue == 0 then
+    return false
+  end
+  local sid = current_session_id()
+  if not sid then
+    return false
+  end
+  local item = table.remove(_queue, 1)
+  refresh_hint()
+  messaging.send_message(item.prompt, item.opts or {})
+  return true
+end
+
+---Submit a prompt to the active session.
+---Drains immediately if the session is idle; otherwise holds in queue and
+---lets the tool-call completion listener pick it up.
+---@param prompt string
+---@param opts? SendMessageOpts
+function M.submit(prompt, opts)
+  if not prompt or prompt == '' then
+    return
+  end
+  M.setup()
+  table.insert(_queue, {
+    prompt = prompt,
+    opts = opts,
+    enqueued_at = os.time(),
+  })
+  refresh_hint()
+  while M.flush_one_if_idle() do
+  end
+end
+
+---@return integer
+function M.size()
+  return #_queue
+end
+
+---@return OpencodeClientQueueItem|nil
+function M.undo_last()
+  if #_queue == 0 then
+    return nil
+  end
+  local item = table.remove(_queue)
+  refresh_hint()
+  return item
+end
+
+function M.clear()
+  _queue = {}
+  refresh_hint()
+end
+
+---@param properties EventMessagePartUpdated['properties']
+local function on_part_updated(properties)
+  local part = properties.part
+  local sid = current_session_id()
+  if not sid or part.sessionID and part.sessionID ~= sid or part.type ~= 'tool' then
+    return
+  end
+  if part.state.status == 'completed' then
+    tool_call_is_running[sid] = nil
+    return
+  end
+  tool_call_is_running[sid] = true
+  while M.flush_one_now() do
+  end
+end
+
+function M.setup()
+  if _setup_done then
+    return
+  end
+  _setup_done = true
+  local mgr = state.event_manager
+  if not mgr or type(mgr.subscribe) ~= 'function' then
+    return
+  end
+  mgr:subscribe('message.part.updated', on_part_updated)
+end
+
+return M

lua/opencode/ui/footer.lua

@@ -167,6 +167,7 @@ function M.setup(windows)
   })
 
   loading_animation.setup()
+  require('opencode.services.client_queue').setup()
 end
 
 ---@param preserve_buffer? boolean

lua/opencode/ui/input_window.lua

@@ -153,7 +153,7 @@ function M.handle_submit()
     return false
   end
 
-  require('opencode.services.messaging').send_message(input_content)
+  require('opencode.services.client_queue').submit(input_content)
   return true
 end
 
@@ -726,4 +726,33 @@ function M.is_hidden()
   return M._hidden
 end
 
+local _queue_hint_ns = vim.api.nvim_create_namespace('opencode_queue_hint')
+local _queue_hint_extmark_id = nil
+
+---Render a small "[N queued]" hint at the end of the input line when the
+---client queue has pending items. Called by services/client_queue.
+---@param size integer
+function M.render_queue_hint(size)
+  local windows = state.windows
+  if not windows or not windows.input_buf or not vim.api.nvim_buf_is_valid(windows.input_buf) then
+    return
+  end
+  local input_buf = windows.input_buf
+  local cleared = pcall(vim.api.nvim_buf_clear_namespace, input_buf, _queue_hint_ns, 0, -1)
+  if not cleared then
+    return
+  end
+  _queue_hint_extmark_id = nil
+  if not size or size <= 0 then
+    return
+  end
+  local last_line = vim.api.nvim_buf_line_count(input_buf) - 1
+  local last_col = #(vim.api.nvim_buf_get_lines(input_buf, last_line, last_line + 1, false)[1] or '')
+  _queue_hint_extmark_id = vim.api.nvim_buf_set_extmark(input_buf, _queue_hint_ns, last_line, last_col, {
+    virt_text = { { string.format(' [%d queued]', size), 'Comment' } },
+    virt_text_pos = 'eol',
+    hl_mode = 'combine',
+  })
+end
+
 return M

lua/opencode/ui/loading_animation.lua

@@ -275,6 +275,12 @@ function M.is_running()
   return M._animation.timer ~= nil
 end
 
+---@param session_id string
+---@return OpencodeSessionStatusInfo['type']|nil
+function M.get_status(session_id)
+  return M._animation.last_status_map[session_id]
+end
+
 function M.refresh()
   if not state.windows then
     return