feat: memory 🧠 (#793)

lua/avante/llm.lua

@@ -28,7 +28,7 @@ local group = api.nvim_create_augroup("avante_llm", { clear = true })
 ---@field file_content string
 ---@field selected_code string | nil
 ---@field project_context string | nil
----@field memory_context string | nil
+---@field history_messages AvanteLLMMessage[]
 ---
 ---@class StreamOptions: TemplateOptions
 ---@field ask boolean
@@ -44,10 +44,12 @@ M.stream = function(opts)
   local mode = opts.mode or "planning"
   ---@type AvanteProviderFunctor
   local Provider = opts.provider or P[Config.provider]
+  local _, body_opts = P.parse_config(Provider)
+  local max_tokens = body_opts.max_tokens or 4096
 
   -- Check if the instructions contains an image path
   local image_paths = {}
-  local original_instructions = opts.instructions
+  local instructions = opts.instructions
   if opts.instructions:match("image: ") then
     local lines = vim.split(opts.instructions, "\n")
     for i, line in ipairs(lines) do
@@ -57,7 +59,7 @@ M.stream = function(opts)
         table.remove(lines, i)
       end
     end
-    original_instructions = table.concat(lines, "\n")
+    instructions = table.concat(lines, "\n")
   end
 
   Path.prompts.initialize(Path.prompts.get(opts.bufnr))
@@ -67,29 +69,61 @@ M.stream = function(opts)
   local template_opts = {
     use_xml_format = Provider.use_xml_format,
     ask = opts.ask, -- TODO: add mode without ask instruction
-    question = original_instructions,
     code_lang = opts.code_lang,
     filepath = filepath,
     file_content = opts.file_content,
     selected_code = opts.selected_code,
     project_context = opts.project_context,
-    memory_context = opts.memory_context,
   }
 
-  local user_prompts = vim
-    .iter({
-      Path.prompts.render_file("_project.avanterules", template_opts),
-      Path.prompts.render_file("_memory.avanterules", template_opts),
-      Path.prompts.render_file("_context.avanterules", template_opts),
-      Path.prompts.render_mode(mode, template_opts),
-    })
-    :filter(function(k) return k ~= "" end)
-    :totable()
+  local system_prompt = Path.prompts.render_mode(mode, template_opts)
+
+  ---@type AvanteLLMMessage[]
+  local messages = {}
+
+  if opts.project_context ~= nil and opts.project_context ~= "" and opts.project_context ~= "null" then
+    local project_context = Path.prompts.render_file("_project.avanterules", template_opts)
+    if project_context ~= "" then table.insert(messages, { role = "user", content = project_context }) end
+  end
+
+  local code_context = Path.prompts.render_file("_context.avanterules", template_opts)
+  if code_context ~= "" then table.insert(messages, { role = "user", content = code_context }) end
+
+  if opts.use_xml_format then
+    table.insert(messages, { role = "user", content = string.format("<question>%s</question>", instructions) })
+  else
+    table.insert(messages, { role = "user", content = string.format("QUESTION:\n%s", instructions) })
+  end
+
+  local remaining_tokens = max_tokens - Utils.tokens.calculate_tokens(system_prompt)
+
+  for _, message in ipairs(messages) do
+    remaining_tokens = remaining_tokens - Utils.tokens.calculate_tokens(message.content)
+  end
+
+  if opts.history_messages then
+    if Config.history.max_tokens > 0 then remaining_tokens = math.min(Config.history.max_tokens, remaining_tokens) end
+    -- Traverse the history in reverse, keeping only the latest history until the remaining tokens are exhausted and the first message role is "user"
+    local history_messages = {}
+    for i = #opts.history_messages, 1, -1 do
+      local message = opts.history_messages[i]
+      local tokens = Utils.tokens.calculate_tokens(message.content)
+      remaining_tokens = remaining_tokens - tokens
+      if remaining_tokens > 0 then
+        table.insert(history_messages, message)
+      else
+        break
+      end
+    end
+    if #history_messages > 0 and history_messages[1].role == "assistant" then table.remove(history_messages, 1) end
+    -- prepend the history messages to the messages table
+    vim.iter(history_messages):each(function(msg) table.insert(messages, 1, msg) end)
+  end
 
   ---@type AvantePromptOptions
   local code_opts = {
-    system_prompt = Config.system_prompt,
-    user_prompts = user_prompts,
+    system_prompt = system_prompt,
+    messages = messages,
     image_paths = image_paths,
   }
 
@@ -164,7 +198,7 @@ M.stream = function(opts)
     on_error = function(err)
       if err.exit == 23 then
         local xdg_runtime_dir = os.getenv("XDG_RUNTIME_DIR")
-        if fn.isdirectory(xdg_runtime_dir) == 0 then
+        if not xdg_runtime_dir or fn.isdirectory(xdg_runtime_dir) == 0 then
           Utils.error(
             "$XDG_RUNTIME_DIR="
               .. xdg_runtime_dir