feat: support apply current code snippet (#391)

lua/avante/sidebar.lua

@@ -183,15 +183,26 @@ local function realign_line_numbers(code_lines, snippet)
   return snippet
 end
 
+---@class AvanteCodeSnippet
+---@field range integer[]
+---@field content string
+---@field lang string
+---@field explanation string
+---@field start_line_in_response_buf integer
+---@field end_line_in_response_buf integer
+
+---@param code_content string
+---@param response_content string
+---@return AvanteCodeSnippet[]
 local function extract_code_snippets(code_content, response_content)
   local code_lines = vim.split(code_content, "\n")
   local snippets = {}
   local current_snippet = {}
   local in_code_block = false
-  local lang, start_line, end_line
+  local lang, start_line, end_line, start_line_in_response_buf
   local explanation = ""
 
-  for _, line in ipairs(vim.split(response_content, "\n")) do
+  for idx, line in ipairs(vim.split(response_content, "\n")) do
     local start_line_str, end_line_str = line:match("^Replace lines: (%d+)-(%d+)")
     if start_line_str ~= nil and end_line_str ~= nil then
       start_line = tonumber(start_line_str)
@@ -205,6 +216,8 @@ local function extract_code_snippets(code_content, response_content)
             content = table.concat(current_snippet, "\n"),
             lang = lang,
             explanation = explanation,
+            start_line_in_response_buf = start_line_in_response_buf,
+            end_line_in_response_buf = idx,
           }
           snippet = realign_line_numbers(code_lines, snippet)
           table.insert(snippets, snippet)
@@ -219,6 +232,7 @@ local function extract_code_snippets(code_content, response_content)
           lang = "text"
         end
         in_code_block = true
+        start_line_in_response_buf = idx
       end
     elseif in_code_block then
       table.insert(current_snippet, line)
@@ -318,10 +332,26 @@ local function parse_codeblocks(buf)
   return codeblocks
 end
 
-function Sidebar:apply()
+---@param current_cursor boolean
+function Sidebar:apply(current_cursor)
   local content = table.concat(Utils.get_buf_lines(0, -1, self.code.bufnr), "\n")
-  local response = self:get_content_between_separators()
+  local response, response_start_line = self:get_content_between_separators()
   local snippets = extract_code_snippets(content, response)
+  if current_cursor then
+    if self.result and self.result.winid then
+      local cursor_line = Utils.get_cursor_pos(self.result.winid)
+      for _, snippet in ipairs(snippets) do
+        if
+          cursor_line >= snippet.start_line_in_response_buf + response_start_line
+          and cursor_line <= snippet.end_line_in_response_buf + response_start_line
+        then
+          snippets = { snippet }
+          break
+        end
+      end
+    end
+  end
+
   local conflict_content = get_conflict_content(content, snippets)
 
   vim.defer_fn(function()
@@ -501,7 +531,7 @@ function Sidebar:on_mount()
 
     current_apply_extmark_id =
       api.nvim_buf_set_extmark(self.result.bufnr, CODEBLOCK_KEYBINDING_NAMESPACE, block.start_line, -1, {
-        virt_text = { { " [<A>: apply patch] ", "Keyword" } },
+        virt_text = { { " [<a>: apply this, <A>: apply all] ", "Keyword" } },
         virt_text_pos = "right_align",
         hl_group = "Keyword",
         priority = PRIORITY,
@@ -509,8 +539,11 @@ function Sidebar:on_mount()
   end
 
   local function bind_apply_key()
+    vim.keymap.set("n", "a", function()
+      self:apply(true)
+    end, { buffer = self.result.bufnr, noremap = true, silent = true })
     vim.keymap.set("n", "A", function()
-      self:apply()
+      self:apply(false)
     end, { buffer = self.result.bufnr, noremap = true, silent = true })
   end
 
@@ -878,7 +911,7 @@ function Sidebar:update_content_with_history(history)
   self:update_content(content)
 end
 
----@return string
+---@return string, integer
 function Sidebar:get_content_between_separators()
   local separator = "---"
   local cursor_line, _ = Utils.get_cursor_pos()
@@ -910,7 +943,7 @@ function Sidebar:get_content_between_separators()
   end
 
   local content = table.concat(vim.list_slice(lines, start_line, end_line), "\n")
-  return content
+  return content, start_line
 end
 
 ---@alias AvanteSlashCommands "clear" | "help" | "lines"
@@ -1150,7 +1183,7 @@ function Sidebar:create_input()
     )
 
     if Config.behaviour.auto_apply_diff_after_generation then
-      self:apply()
+      self:apply(false)
     end
   end