feat(mention): highlight mention in user prompt

Author: sudo-tee

lua/opencode/types.lua

@@ -238,7 +238,8 @@
 ---@field display_line number Line number to display the action
 ---@field range? { from: number, to: number } Optional range for the action
 
----@alias OutputExtmark vim.api.keyset.set_extmark|fun():vim.api.keyset.set_extmark
+---@alias OutputExtmarkType vim.api.keyset.set_extmark & {start_col:0}
+---@alias OutputExtmark OutputExtmarkType|fun():OutputExtmarkType
 
 ---@class OpencodeMessage
 ---@field info MessageInfo Metadata about the message

lua/opencode/ui/formatter.lua

@@ -320,7 +320,7 @@ function M._format_user_prompt(output, text)
   output:add_lines(vim.split(text, '\n'))
 
   local end_line = output:get_line_count()
-
+  require('opencode.ui.mention').highlight_mention(output)
   M._add_vertical_border(output, start_line, end_line, 'OpencodeMessageRoleUser', -3)
 end
 

lua/opencode/ui/mention.lua

@@ -40,6 +40,24 @@ function M.highlight_all_mentions(buf, callback)
   end
 end
 
+---@param output Output
+function M.highlight_mention(output)
+  local mention_pattern = '@[%w_%-%./][%w_%-%./]*'
+  for i, line in pairs(output:get_lines()) do
+    for mention in line:gmatch(mention_pattern) do
+      local col_start, col_end = line:find(mention, 1)
+      if col_start and col_end then
+        output:add_extmark(i, {
+          start_col = col_start - 1,
+          end_col = col_end,
+          hl_group = 'OpencodeMention',
+          priority = 1000,
+        })
+      end
+    end
+  end
+end
+
 local function insert_mention(windows, row, col, name)
   local current_line = vim.api.nvim_buf_get_lines(windows.input_buf, row - 1, row, false)[1]
 

lua/opencode/ui/output_window.lua

@@ -123,7 +123,11 @@ function M.set_extmarks(extmarks, line_offset)
       if actual_mark.end_row then
         actual_mark.end_row = actual_mark.end_row + line_offset
       end
-      pcall(vim.api.nvim_buf_set_extmark, output_buf, M.namespace, target_line, 0, actual_mark)
+      local start_col = actual_mark.start_col
+      if actual_mark.start_col then
+        actual_mark.start_col = nil
+      end
+      pcall(vim.api.nvim_buf_set_extmark, output_buf, M.namespace, target_line, start_col or 0, actual_mark)
     end
   end
 end