feat: Make question/answer/error headers configurable (#236)

Example of python version format config:
```
{
    question_header = '## User ',
    answer_header = '## Copilot ',
    error_header = '## Error ',
}
```

Closes #233

Signed-off-by: Tomas Slusny <[email protected]>

MIGRATION.md

@@ -55,6 +55,10 @@ local select = require('CopilotChat.select')
 chat.setup {
     -- Restore the behaviour for CopilotChat to use unnamed register by default
     selection = select.unnamed,
+    -- Restore the format with ## headers as prefixes,
+    question_header = '## User ',
+    answer_header = '## Copilot ',
+    error_header = '## Error ',
 }
 
 -- Restore CopilotChatVisual

README.md

@@ -198,8 +198,11 @@ Also see [here](/lua/CopilotChat/config.lua):
   model = 'gpt-4', -- GPT model to use, 'gpt-3.5-turbo' or 'gpt-4'
   temperature = 0.1, -- GPT temperature
 
-  name = 'CopilotChat', -- Name to use in chat
+  question_header = '', -- Header to use for user questions
+  answer_header = '**Copilot** ', -- Header to use for AI answers
+  error_header = '**Error** ', -- Header to use for errors
   separator = '---', -- Separator to use in chat
+
   show_folds = true, -- Shows folds for sections in chat
   show_help = true, -- Shows help message as virtual lines when waiting for user input
   auto_follow_cursor = true, -- Auto-follow cursor in chat

lua/CopilotChat/chat.lua

@@ -215,9 +215,10 @@ function Chat:finish(msg)
   else
     msg = self.help
   end
+  msg = vim.trim(msg)
 
   if msg and msg ~= '' then
-    local line = vim.api.nvim_buf_line_count(self.bufnr) - 1
+    local line = vim.api.nvim_buf_line_count(self.bufnr) - 2
     show_virt_line(msg, math.max(0, line - 1), self.bufnr, self.mark_ns)
   end
 end

lua/CopilotChat/config.lua

@@ -59,7 +59,9 @@ local select = require('CopilotChat.select')
 ---@field system_prompt string?
 ---@field model string?
 ---@field temperature number?
----@field name string?
+---@field question_header string?
+---@field answer_header string?
+---@field error_header string?
 ---@field separator string?
 ---@field show_folds boolean?
 ---@field show_help boolean?
@@ -82,8 +84,11 @@ return {
   model = 'gpt-4', -- GPT model to use, 'gpt-3.5-turbo' or 'gpt-4'
   temperature = 0.1, -- GPT temperature
 
-  name = 'CopilotChat', -- Name to use in chat
+  question_header = '', -- Header to use for user questions
+  answer_header = '**Copilot** ', -- Header to use for AI answers
+  error_header = '**Error** ', -- Header to use for errors
   separator = '---', -- Separator to use in chat
+
   show_folds = true, -- Shows folds for sections in chat
   show_help = true, -- Shows help message as virtual lines when waiting for user input
   auto_follow_cursor = true, -- Auto-follow cursor in chat

lua/CopilotChat/init.lua

@@ -356,11 +356,11 @@ function M.ask(prompt, config, source)
   end
 
   if state.copilot:stop() then
-    append('\n\n' .. config.separator .. '\n\n')
+    append('\n\n' .. config.question_header .. config.separator .. '\n\n')
   end
 
   append(updated_prompt)
-  append('\n\n**' .. config.name .. '** ' .. config.separator .. '\n\n')
+  append('\n\n' .. config.answer_header .. config.separator .. '\n\n')
   state.chat:follow()
 
   local selected_context = config.context
@@ -373,9 +373,9 @@ function M.ask(prompt, config, source)
 
   local function on_error(err)
     vim.schedule(function()
-      append('\n\n**Error** ' .. config.separator .. '\n\n')
+      append('\n\n' .. config.error_header .. config.separator .. '\n\n')
       append('```\n' .. err .. '\n```')
-      append('\n\n' .. config.separator .. '\n\n')
+      append('\n\n' .. config.question_header .. config.separator .. '\n\n')
       state.chat:finish()
       if M.config.auto_follow_cursor and M.config.auto_insert_mode and state.chat:active() then
         vim.cmd('startinsert')
@@ -405,7 +405,7 @@ function M.ask(prompt, config, source)
         on_error = on_error,
         on_done = function(response, token_count)
           vim.schedule(function()
-            append('\n\n' .. config.separator .. '\n\n')
+            append('\n\n' .. config.question_header .. config.separator .. '\n\n')
             state.response = response
             if tiktoken.available() and token_count and token_count > 0 then
               state.chat:finish(token_count .. ' tokens used')
@@ -443,7 +443,7 @@ function M.reset(no_insert)
 
   wrap(function()
     state.chat:clear()
-    append('\n')
+    append(M.config.question_header .. M.config.separator .. '\n\n')
     state.chat:finish()
     state.chat:follow()
 
@@ -491,22 +491,20 @@ function M.load(name, history_path)
   for i, message in ipairs(history) do
     if message.role == 'user' then
       if i > 1 then
-        append('\n\n' .. M.config.separator .. '\n\n')
-      else
-        append('\n')
+        append('\n\n')
       end
+      append(M.config.question_header .. M.config.separator .. '\n\n')
       append(message.content)
     elseif message.role == 'assistant' then
-      append('\n\n**' .. M.config.name .. '** ' .. M.config.separator .. '\n\n')
+      append('\n\n' .. M.config.answer_header .. M.config.separator .. '\n\n')
       append(message.content)
     end
   end
 
-  if #history == 0 then
-    append('\n')
-  else
-    append('\n\n' .. M.config.separator .. '\n')
+  if #history > 0 then
+    append('\n\n')
   end
+  append(M.config.question_header .. M.config.separator .. '\n\n')
 
   state.chat:finish()
   M.open()
@@ -733,7 +731,7 @@ function M.setup(config)
       end
     end)
 
-    append('\n')
+    append(M.config.question_header .. M.config.separator .. '\n\n')
     state.chat:finish()
   end)