feat: implement a more flexible custom prompts solution (#1390)

lua/avante/path.lua

@@ -79,20 +79,29 @@ local Prompt = {}
 
 -- Given a mode, return the file name for the custom prompt.
 ---@param mode AvanteLlmMode
-function Prompt.get_mode_file(mode) return string.format("custom.%s.avanterules", mode) end
+---@return string
+function Prompt.get_custom_prompts_filepath(mode) return string.format("custom.%s.avanterules", mode) end
+
+function Prompt.get_builtin_prompts_filepath(mode) return string.format("%s.avanterules", mode) end
 
 ---@class AvanteTemplates
 ---@field initialize fun(directory: string): nil
 ---@field render fun(template: string, context: AvanteTemplateOptions): string
-local templates = nil
+local _templates_lib = nil
 
-Prompt.templates = { planning = nil, editing = nil, suggesting = nil }
+Prompt.custom_modes = {
+  planning = true,
+  editing = true,
+  suggesting = true,
+  ["cursor-planning"] = true,
+  ["cursor-applying"] = true,
+}
+
+Prompt.custom_prompts_contents = {}
 
--- We need to do this beacuse the prompt template engine requires a given directory to load all required files.
--- PERF: Hmm instead of copy to cache, we can also load in globals context, but it requires some work on bindings. (eh maybe?)
 ---@param project_root string
----@return string the resulted cache_directory to be loaded with avante_templates
-function Prompt.get(project_root)
+---@return string templates_dir
+function Prompt.get_templates_dir(project_root)
   if not P.available() then error("Make sure to build avante (missing avante_templates)", 2) end
 
   -- get root directory of given bufnr
@@ -107,16 +116,13 @@ function Prompt.get(project_root)
   for _, entry in ipairs(scanner) do
     local file = Path:new(entry)
     if file:is_file() then
-      if not entry:match("%.avanterules$") then goto continue end
-      if entry:find("planning") and Prompt.templates.planning == nil then
-        Utils.info(string.format("Using %s as planning system prompt", entry))
-        Prompt.templates.planning = file:read()
-      elseif entry:find("editing") and Prompt.templates.editing == nil then
-        Utils.info(string.format("Using %s as editing system prompt", entry))
-        Prompt.templates.editing = file:read()
-      elseif entry:find("suggesting") and Prompt.templates.suggesting == nil then
-        Utils.info(string.format("Using %s as suggesting system prompt", entry))
-        Prompt.templates.suggesting = file:read()
+      local pieces = vim.split(entry, "/")
+      local piece = pieces[#pieces]
+      local mode = piece:match("([^.]+)%.avanterules$")
+      if not mode or not Prompt.custom_modes[mode] then goto continue end
+      if Prompt.custom_prompts_contents[mode] == nil then
+        Utils.info(string.format("Using %s as %s system prompt", entry, mode))
+        Prompt.custom_prompts_contents[mode] = file:read()
       end
     end
     ::continue::
@@ -125,29 +131,41 @@ function Prompt.get(project_root)
   Path:new(debug.getinfo(1).source:match("@?(.*/)"):gsub("/lua/avante/path.lua$", "") .. "templates")
     :copy({ destination = cache_prompt_dir, recursive = true })
 
-  vim.iter(Prompt.templates):filter(function(_, v) return v ~= nil end):each(function(k, v)
-    local f = cache_prompt_dir:joinpath(Prompt.get_mode_file(k))
-    f:write(v, "w")
+  vim.iter(Prompt.custom_prompts_contents):filter(function(_, v) return v ~= nil end):each(function(k, v)
+    local orig_file = cache_prompt_dir:joinpath(Prompt.get_builtin_prompts_filepath(k))
+    local orig_content = orig_file:read()
+    local f = cache_prompt_dir:joinpath(Prompt.get_custom_prompts_filepath(k))
+    f:write(orig_content, "w")
+    f:write("{% block custom_prompt -%}\n", "a")
+    f:write(v, "a")
+    f:write("\n{%- endblock %}", "a")
   end)
 
-  return cache_prompt_dir:absolute()
+  local dir = cache_prompt_dir:absolute()
+  Utils.debug("Prompt cache directory:", dir)
+  return dir
 end
 
 ---@param mode AvanteLlmMode
-function Prompt.get_file(mode)
-  if Prompt.templates[mode] ~= nil then return Prompt.get_mode_file(mode) end
-  return string.format("%s.avanterules", mode)
+---@return string
+function Prompt.get_filepath(mode)
+  if Prompt.custom_prompts_contents[mode] ~= nil then return Prompt.get_custom_prompts_filepath(mode) end
+  return Prompt.get_builtin_prompts_filepath(mode)
 end
 
 ---@param path string
 ---@param opts AvanteTemplateOptions
-function Prompt.render_file(path, opts) return templates.render(path, opts) end
+function Prompt.render_file(path, opts) return _templates_lib.render(path, opts) end
 
 ---@param mode AvanteLlmMode
 ---@param opts AvanteTemplateOptions
-function Prompt.render_mode(mode, opts) return templates.render(Prompt.get_file(mode), opts) end
+function Prompt.render_mode(mode, opts)
+  local filepath = Prompt.get_filepath(mode)
+  Utils.debug("Prompt filepath:", filepath)
+  return _templates_lib.render(filepath, opts)
+end
 
-function Prompt.initialize(directory) templates.initialize(directory) end
+function Prompt.initialize(directory) _templates_lib.initialize(directory) end
 
 P.prompts = Prompt
 
@@ -184,14 +202,14 @@ P.repo_map = RepoMap
 
 ---@return AvanteTemplates|nil
 function P._init_templates_lib()
-  if templates ~= nil then return templates end
+  if _templates_lib ~= nil then return _templates_lib end
   local ok, module = pcall(require, "avante_templates")
   ---@cast module AvanteTemplates
   ---@cast ok boolean
   if not ok then return nil end
-  templates = module
+  _templates_lib = module
 
-  return templates
+  return _templates_lib
 end
 
 function P.setup()