fix: re-implement prompt logger (#2574)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

lua/avante/config.lua

@@ -459,8 +459,7 @@ M._defaults = {
   },
   prompt_logger = { -- logs prompts to disk (timestamped, for replay/debugging)
     enabled = true, -- toggle logging entirely
-    log_dir = Utils.join_paths(vim.fn.stdpath("cache"), "avante_prompts"), -- directory where logs are saved
-    fortune_cookie_on_success = false, -- shows a random fortune after each logged prompt (requires `fortune` installed)
+    log_dir = vim.fn.stdpath("cache"), -- directory where logs are saved
     next_prompt = {
       normal = "<C-n>", -- load the next (newer) prompt log in normal mode
       insert = "<C-n>",

lua/avante/sidebar.lua

@@ -2674,6 +2674,7 @@ function Sidebar:create_input_container()
   self.handle_submit = handle_submit
 
   self.containers.input:mount()
+  PromptLogger.init()
 
   local function place_sign_at_first_line(bufnr)
     local group = "avante_input_prompt_group"
@@ -2739,6 +2740,11 @@ function Sidebar:create_input_container()
       place_sign_at_first_line(self.containers.input.bufnr)
     end,
   })
+  api.nvim_create_autocmd({ "TextChanged", "TextChangedI" }, {
+    group = self.augroup,
+    buffer = self.containers.input.bufnr,
+    callback = function() PromptLogger.update_current_input() end,
+  })
 
   api.nvim_create_autocmd("QuitPre", {
     group = self.augroup,

lua/avante/utils/promptLogger.lua

@@ -1,98 +1,92 @@
 local Config = require("avante.config")
 local Utils = require("avante.utils")
 
+-- last one in entries is always to hold current input
+local entries, idx = {}, 0
+
 ---@class avante.utils.promptLogger
 local M = {}
 
+function M.init()
+  entries = {}
+  local dir = Config.prompt_logger.log_dir
+  local log_file = Utils.join_paths(dir, "avante_prompts.log")
+  local file = io.open(log_file, "r")
+  if file then
+    local content = file:read("*a"):gsub("\n$", "")
+    file:close()
+
+    local lines = vim.split(content, "\n", { plain = true })
+    for _, line in ipairs(lines) do
+      local ok, entry = pcall(vim.fn.json_decode, line)
+      if ok and entry and entry.time and entry.input then table.insert(entries, entry) end
+    end
+  end
+  table.insert(entries, { input = "" })
+  idx = #entries - 1
+end
+
 function M.log_prompt(request)
   local log_dir = Config.prompt_logger.log_dir
-  local log_file = Utils.join_paths(log_dir, "avante_prompt_" .. os.date("%Y%m%d_%H%M%S") .. ".log")
+  local log_file = Utils.join_paths(log_dir, "avante_prompts.log")
 
   if vim.fn.isdirectory(log_dir) == 0 then vim.fn.mkdir(log_dir, "p") end
 
+  local entry = {
+    time = Utils.get_timestamp(),
+    input = request,
+  }
+
+  -- Remove any existing entries with the same input
+  if #entries > 1 then
+    for i = #entries - 1, 1, -1 do
+      if entries[i].input == entry.input then table.remove(entries, i) end
+    end
+    -- Add the new entry
+    table.insert(entries, #entries, entry)
+    idx = #entries - 1
+  else
+    table.insert(entries, entry)
+  end
+
   local file = io.open(log_file, "w")
   if file then
-    file:write(request)
-    file:close()
-    if Config.prompt_logger and Config.prompt_logger.fortune_cookie_on_success then
-      local handle = io.popen("fortune -s -n 100")
-      if handle then
-        local fortune_msg = handle:read("*a")
-        handle:close()
-        if fortune_msg and #fortune_msg > 0 then vim.notify(fortune_msg, vim.log.levels.INFO, { title = "" }) end
-      end
+    -- Write all entries to the log file, except the last one
+    for i = 1, #entries - 1, 1 do
+      file:write(vim.fn.json_encode(entries[i]) .. "\n")
     end
+    file:close()
   else
     vim.notify("Failed to log prompt", vim.log.levels.ERROR)
   end
 end
 
--- Cache + helper
-local logs, idx = {}, 0
-
-local function refresh_logs()
-  local dir = Config.prompt_logger.log_dir
-  logs = vim.fn.glob(Utils.join_paths(dir, "avante_prompt_*.log"), false, true)
-  table.sort(logs, function(a, b) -- newest first
-    return a > b
-  end)
-end
-
----@param step integer 0 = keep | 1 = newer | -1 = older
-local function load_log(step)
-  if #logs == 0 then refresh_logs() end
-  if #logs == 0 then
-    vim.notify("No prompt logs found 🤷", vim.log.levels.WARN)
-    return
-  end
-  idx = (idx + step) -- turn wheel
-  if idx < 1 then idx = #logs end -- wrap around
-  if idx > #logs then idx = 1 end
-
-  local fp = io.open(logs[idx], "r")
-  if not fp then
-    vim.notify("Could not open " .. logs[idx], vim.log.levels.ERROR)
-    return
-  end
-  local content = fp:read("*a")
-  fp:close()
-
-  local buf = vim.api.nvim_get_current_buf()
-  vim.api.nvim_buf_set_lines(buf, 0, -1, false, vim.split(content, "\n", { plain = true }))
-  vim.bo[buf].modifiable = true
-  vim.b[buf].avante_logpath = logs[idx]
-end
-
-function M.next_log() load_log(1) end
-
-function M.prev_log() load_log(-1) end
-
 local function _read_log(delta)
-  if #logs == 0 then refresh_logs() end
-  if #logs == 0 then return nil end
+  -- index of array starts from 1 in lua, while this idx starts from 0
+  idx = ((idx - delta) % #entries + #entries) % #entries
 
-  local target = idx + delta
-  if target < 1 then target = 1 end
-  if target > #logs then target = #logs end
-
-  idx = target
-
-  local fp = io.open(logs[idx], "r")
-  if not fp then return nil end
-  local txt = fp:read("*a")
-  fp:close()
-  return { txt = txt, path = logs[idx] }
+  return entries[idx + 1]
 end
 
 function M.on_log_retrieve(delta)
   return function()
     local res = _read_log(delta)
-    if not res then
-      vim.notify("No logs available", vim.log.levels.WARN)
+    if not res or not res.input then
+      vim.notify("No log entry found.", vim.log.levels.WARN)
       return
     end
-    vim.api.nvim_buf_set_lines(0, 0, -1, false, vim.split(res.txt, "\n", { plain = true }))
-    vim.api.nvim_win_set_cursor(0, { 1, 0 })
+    vim.api.nvim_buf_set_lines(0, 0, -1, false, vim.split(res.input, "\n", { plain = true }))
+    vim.api.nvim_win_set_cursor(
+      0,
+      { vim.api.nvim_buf_line_count(0), #vim.api.nvim_buf_get_lines(0, -2, -1, false)[1] }
+    )
+  end
+end
+
+function M.update_current_input()
+  if idx == #entries - 1 then
+    local lines = vim.api.nvim_buf_get_lines(0, 0, -1, false)
+    entries[#entries].input = table.concat(lines, "\n")
   end
 end