refactor(picker): merge history_picker into timeline_picker

Problem: After dropping the local history.txt, history_picker and
timeline_picker rendered the same data through the same base_picker with
nearly identical format functions, only differing by title, time
display,
and the post-selection action.

Solution: Extend timeline_picker.pick(messages, opts) with a { title,
callback } shape so the caller picks what happens on selection. Move
workflow.select_history to feed the timeline picker and refill the input
in the callback, then delete history_picker along with its keymap, type,
doc snippet, and topology reference.

Author: phanen

README.md

@@ -206,10 +206,6 @@ require('opencode').setup({
       undo = { '<C-u>', mode = { 'i', 'n' } }, -- Undo to selected message in timeline picker
       fork = { '<C-f>', mode = { 'i', 'n' } }, -- Fork from selected message in timeline picker
     },
-    history_picker = {
-      delete_entry = { '<C-d>', mode = { 'i', 'n' } }, -- Delete selected entry in the history picker
-      clear_all = { '<C-X>', mode = { 'i', 'n' } }, -- Clear all entries in the history picker
-    },
     model_picker = {
       toggle_favorite = { '<C-f>', mode = { 'i', 'n' } },
     },

lua/opencode/commands/handlers/session.lua

@@ -536,12 +536,13 @@ function M.actions.timeline()
     return
   end
 
-  local timeline_picker = require('opencode.ui.timeline_picker')
-  timeline_picker.pick(user_messages, function(selected_msg)
-    if selected_msg then
-      require('opencode.ui.navigation').goto_message_by_id(selected_msg.info.id)
-    end
-  end)
+  require('opencode.ui.timeline_picker').pick(user_messages, {
+    callback = function(selected_msg)
+      if selected_msg then
+        require('opencode.ui.navigation').goto_message_by_id(selected_msg.info.id)
+      end
+    end,
+  })
 end
 
 ---@param message_id? string

lua/opencode/commands/handlers/workflow.lua

@@ -106,8 +106,46 @@ function M.actions.quick_chat(message, range)
   quick_chat.quick_chat(prompt, { context_config = ctx }, range)
 end
 
+---Refill the input buffer from a user message returned by the timeline picker.
+---Open the opencode UI first when the input window is not mounted yet.
+---@param message OpencodeMessage
+local function refill_input_from_message(message)
+  local windows = state.windows
+  if not input_window.mounted(windows) then
+    session_runtime.open({ focus = 'input' })
+    windows = state.windows
+  end
+  if not input_window.mounted(windows) then
+    return
+  end
+  ---@cast windows { input_win: integer, input_buf: integer }
+  if input_window.refill_prompt_from_message(message) then
+    input_window.focus_input()
+  end
+end
+
+---@param entries OpencodeHistoryEntry[]
+local function pick_history_with(entries)
+  local messages = vim.tbl_map(function(entry)
+    return entry.message
+  end, entries)
+  require('opencode.ui.timeline_picker').pick(messages, {
+    title = 'Select History Entry',
+    callback = function(selected_msg)
+      if selected_msg then
+        refill_input_from_message(selected_msg)
+      end
+    end,
+  })
+end
+
 function M.actions.select_history()
-  require('opencode.ui.history_picker').pick()
+  local entries = history.read()
+  if #entries == 0 then
+    vim.notify('No history entries found', vim.log.levels.INFO)
+    return false
+  end
+  return pick_history_with(entries)
 end
 
 ---Refill the input buffer from a history entry reconstructed from the active

lua/opencode/config.lua

@@ -120,10 +120,6 @@ M.defaults = {
       undo = { '<C-u>',                                   mode = { 'i', 'n' }, desc = 'Undo to selected message' },
       fork = { '<C-f>',                                   mode = { 'i', 'n' }, desc = 'Fork from selected message' },
     },
-    history_picker = {
-      delete_entry = { '<C-d>',                           mode = { 'i', 'n' }, desc = 'Delete selected history entries' },
-      clear_all =    { '<C-X>',                           mode = { 'i', 'n' }, desc = 'Clear all history entries' },
-    },
     model_picker = {
       toggle_favorite = { '<C-f>',                        mode = { 'i', 'n' }, desc = 'Toggle model favorite' },
     },

lua/opencode/history.lua

@@ -1,7 +1,5 @@
 local state = require('opencode.state')
-local session_module = require('opencode.session')
 local input_window = require('opencode.ui.input_window')
-local Promise = require('opencode.promise')
 
 ---@class OpencodeHistoryEntry
 ---@field id string Message ID from the server
@@ -21,8 +19,7 @@ local cached_session_id = nil
 local prompt_before_history = nil
 
 local function active_session_id()
-  local session = state.active_session
-  return session and session.id or nil
+  return state.active_session and state.active_session.id
 end
 
 local function maybe_reset_for_new_session()
@@ -54,7 +51,9 @@ local function entry_has_content(entry)
 end
 
 --- Read user-message prompt history for the active session, newest first.
---- Empty list when there is no active session or no user messages yet.
+--- Pure read against `state.messages`; if no entry has been populated yet
+--- (e.g. right after switching sessions before SSE catches up) the result is
+--- an empty list. Populating `state.messages` is the renderer's job.
 ---@return OpencodeHistoryEntry[]
 function M.read()
   maybe_reset_for_new_session()
@@ -134,35 +133,6 @@ function M.reset()
   prompt_before_history = nil
 end
 
---- Force a fresh fetch from the server for the active session. Used by
---- callers (e.g. the history picker) that want guaranteed-fresh data and
---- don't want to wait for SSE to repopulate state.messages.
----@return Promise<OpencodeHistoryEntry[]>
-function M.refresh()
-  local active = state.active_session
-  if not active or not active.id then
-    return Promise.new():resolve({})
-  end
-  return session_module
-    .get_messages(active)
-    :and_then(function(messages)
-      local entries = {}
-      for _, msg in ipairs(messages or {}) do
-        if msg.info and msg.info.role == 'user' then
-          local prompt = input_window.build_prompt_from_message(msg)
-          local entry = { id = msg.info.id, message = msg, prompt = prompt }
-          if entry_has_content(entry) then
-            table.insert(entries, entry)
-          end
-        end
-      end
-      return Promise.new():resolve(entries)
-    end)
-    :catch(function()
-      return Promise.new():resolve({})
-    end)
-end
-
 -- Reset on session changes too. Subscribers react synchronously, so the next
 -- read() call sees the new active_session and clears state via
 -- maybe_reset_for_new_session.

lua/opencode/types.lua

@@ -162,7 +162,6 @@
 ---@field output_window OpencodeKeymapOutputWindow
 ---@field session_picker OpencodeSessionPickerKeymap
 ---@field timeline_picker OpencodeTimelinePickerKeymap
----@field history_picker OpencodeHistoryPickerKeymap
 ---@field quick_chat OpencodeQuickChatKeymap
 
 ---@class OpencodeSessionPickerKeymap
@@ -176,10 +175,6 @@
 ---@field undo OpencodeKeymapEntry
 ---@field fork OpencodeKeymapEntry
 
----@class OpencodeHistoryPickerKeymap
----@field delete_entry OpencodeKeymapEntry
----@field clear_all OpencodeKeymapEntry
-
 ---@class OpencodeQuickChatKeymap
 ---@field cancel OpencodeKeymapEntry
 

lua/opencode/ui/history_picker.lua

@@ -3,8 +3,13 @@ local config = require('opencode.config')
 local api = require('opencode.api')
 local base_picker = require('opencode.ui.base_picker')
 
+---@class OpencodeTimelinePickerOpts
+---@field title? string Picker title (defaults to 'Timeline')
+---@field callback fun(msg: OpencodeMessage|nil) Invoked with the selected message
+
 ---Format message parts for timeline picker
 ---@param msg OpencodeMessage Message object
+---@param width number
 ---@return PickerItem
 local function format_message_item(msg, width)
   local preview = msg.parts and msg.parts[1] and msg.parts[1].text or ''
@@ -14,21 +19,26 @@ local function format_message_item(msg, width)
   return base_picker.create_time_picker_item(vim.trim(preview), msg.info.time.created, debug_text, width)
 end
 
-function M.pick(messages, callback)
+---Open a picker over the given user messages. The shared undo/fork actions
+---always operate on the selected message via the server APIs; the caller
+---decides what to do on plain selection by passing `opts.callback`.
+---@param messages OpencodeMessage[]
+---@param opts OpencodeTimelinePickerOpts
+function M.pick(messages, opts)
   local keymap = config.keymap.timeline_picker
   local actions = {
     undo = {
       key = keymap.undo,
       label = 'undo',
-      fn = function(selected, opts)
+      fn = function(selected, _opts)
         api.undo(selected.info.id)
       end,
       reload = false,
     },
     fork = {
       key = keymap.fork,
       label = 'fork',
-      fn = function(selected, opts)
+      fn = function(selected, _opts)
         api.fork_session(selected.info.id)
       end,
       reload = false,
@@ -39,8 +49,8 @@ function M.pick(messages, callback)
     items = messages,
     format_fn = format_message_item,
     actions = actions,
-    callback = callback,
-    title = 'Timeline',
+    callback = opts.callback,
+    title = opts.title or 'Timeline',
     width = config.ui.picker_width,
     layout_opts = config.ui.picker,
   })

lua/opencode/ui/timeline_picker.lua

@@ -132,7 +132,6 @@
         "opencode.ui.mention",             // @mention UI
         "opencode.ui.file_picker",         // file browser
         "opencode.ui.picker",              // generic picker
-        "opencode.ui.history_picker",      // history browser
         "opencode.ui.mcp_picker",          // MCP tool browser
         "opencode.ui.permission.permission" // permission display
       ]