feat: custom documentation highlighting

closes #113

lua/blink/cmp/utils.lua

@@ -36,4 +36,98 @@ function utils.is_special_buffer()
   return buftype ~= ''
 end
 
+function utils.split_lines(text)
+  local lines = {}
+  for s in text:gmatch('[^\r\n]+') do
+    table.insert(lines, s)
+  end
+  return lines
+end
+
+--- Combines adjacent paragraph lines together
+--- @param lines string[]
+--- @return string[]
+--- TODO: Likely buggy
+function utils.combine_markdown_lines(lines)
+  local combined_lines = {}
+
+  local special_starting_chars = { '#', '>', '-', '|' }
+  local in_code_block = false
+  local prev_is_special = false
+  for _, line in ipairs(lines) do
+    if line:match('^%s*```') then in_code_block = not in_code_block end
+
+    local is_special = line:match('^%s*[' .. table.concat(special_starting_chars) .. ']') or line:match('^%s*%d\\.$')
+    local is_empty = line:match('^%s*$')
+    local has_linebreak = line:match('%s%s$')
+
+    if #combined_lines == 0 or in_code_block or is_special or prev_is_special or is_empty or has_linebreak then
+      table.insert(combined_lines, line)
+    elseif line:match('^%s*$') then
+      table.insert(combined_lines, '')
+    else
+      combined_lines[#combined_lines] = combined_lines[#combined_lines] .. '' .. line
+    end
+
+    prev_is_special = is_special
+  end
+
+  return combined_lines
+end
+
+function utils.highlight_with_treesitter(bufnr, root_lang, start_line, end_line)
+  local Range = require('vim.treesitter._range')
+
+  local trees = vim.treesitter.get_parser(bufnr, root_lang)
+  trees:parse({ start_line, end_line })
+  if not trees then return end
+
+  trees:for_each_tree(function(tree, tstree)
+    local lang = tstree:lang()
+    local highlighter_query = vim.treesitter.query.get(lang, 'highlights')
+    if not highlighter_query then return end
+
+    local root_node = tree:root()
+    local _, _, root_end_row, _ = root_node:range()
+
+    local iter = highlighter_query:iter_captures(tree:root(), bufnr, start_line, end_line)
+    local line = start_line
+    while line < end_line do
+      local capture, node, metadata, _ = iter(line)
+      if capture == nil then break end
+
+      local range = { root_end_row + 1, 0, root_end_row + 1, 0 }
+      if node then range = vim.treesitter.get_range(node, bufnr, metadata and metadata[capture]) end
+      local start_row, start_col, end_row, end_col = Range.unpack4(range)
+
+      if capture then
+        local name = highlighter_query.captures[capture]
+        local hl = 0
+        if not vim.startswith(name, '_') then hl = vim.api.nvim_get_hl_id_by_name('@' .. name .. '.' .. lang) end
+
+        -- The "priority" attribute can be set at the pattern level or on a particular capture
+        local priority = (
+          tonumber(metadata.priority or metadata[capture] and metadata[capture].priority)
+          or vim.highlight.priorities.treesitter
+        )
+
+        -- The "conceal" attribute can be set at the pattern level or on a particular capture
+        local conceal = metadata.conceal or metadata[capture] and metadata[capture].conceal
+
+        if hl and end_row >= line then
+          vim.api.nvim_buf_set_extmark(bufnr, require('blink.cmp.config').highlight.ns, start_row, start_col, {
+            end_line = end_row,
+            end_col = end_col,
+            hl_group = hl,
+            priority = priority,
+            conceal = conceal,
+          })
+        end
+      end
+
+      if start_row > line then line = start_row end
+    end
+  end)
+end
+
 return utils

lua/blink/cmp/windows/documentation.lua

@@ -1,4 +1,5 @@
 local config = require('blink.cmp.config').windows.documentation
+local utils = require('blink.cmp.utils')
 local sources = require('blink.cmp.sources.lib')
 local autocomplete = require('blink.cmp.windows.autocomplete')
 local docs = {}
@@ -11,7 +12,6 @@ function docs.setup()
     border = config.border,
     winhighlight = config.winhighlight,
     wrap = true,
-    filetype = 'markdown',
   })
 
   autocomplete.listen_on_position_update(function()
@@ -54,39 +54,40 @@ function docs.show_item(item)
       return
     end
 
-    local doc_lines = {}
-    if item.detail and item.detail ~= '' then
-      table.insert(doc_lines, '```' .. vim.bo.filetype)
-      for s in item.detail:gmatch('[^\r\n]+') do
-        table.insert(doc_lines, s)
-      end
-      table.insert(doc_lines, '```')
-      table.insert(doc_lines, '---')
-    end
+    local detail_lines = {}
+    if item.detail and item.detail ~= '' then detail_lines = utils.split_lines(item.detail) end
 
     local doc = type(item.documentation) == 'string' and item.documentation or item.documentation.value
-    for s in doc:gmatch('[^\r\n]+') do
-      table.insert(doc_lines, s)
+    local doc_lines = utils.split_lines(doc)
+    if type(item.documentation) ~= 'string' and item.documentation.kind == 'markdown' then
+      -- if the rendering seems bugged, it's likely due to this function
+      doc_lines = utils.combine_markdown_lines(doc_lines)
     end
-    vim.api.nvim_buf_set_lines(docs.win:get_buf(), 0, -1, true, doc_lines)
+
+    local combined_lines = vim.list_extend({}, detail_lines)
+    -- add a blank line for the --- separator
+    if #detail_lines > 0 then table.insert(combined_lines, '') end
+    vim.list_extend(combined_lines, doc_lines)
+
+    vim.api.nvim_buf_set_lines(docs.win:get_buf(), 0, -1, true, combined_lines)
     vim.api.nvim_set_option_value('modified', false, { buf = docs.win:get_buf() })
 
+    vim.api.nvim_buf_clear_namespace(docs.win:get_buf(), require('blink.cmp.config').highlight.ns, 0, -1)
+    if #detail_lines > 0 then
+      utils.highlight_with_treesitter(docs.win:get_buf(), vim.bo.filetype, 0, #detail_lines)
+      vim.api.nvim_buf_set_extmark(docs.win:get_buf(), require('blink.cmp.config').highlight.ns, #detail_lines, 0, {
+        virt_text = { { string.rep('─', docs.win.config.max_width) } },
+        virt_text_pos = 'overlay',
+        hl_eol = true,
+        hl_group = 'BlinkCmpDocDetail',
+      })
+    end
+    utils.highlight_with_treesitter(docs.win:get_buf(), 'markdown', #detail_lines + 1, #detail_lines + 1 + #doc_lines)
+
     if autocomplete.win:get_win() then
       docs.win:open()
       docs.update_position()
     end
-
-    -- use the built-in markdown styling
-    -- NOTE: according to https://github.com/Saghen/blink.cmp/pull/33#issuecomment-2400195950
-    -- it's possible for this to fail so we call it safely
-    pcall(
-      function()
-        vim.lsp.util.stylize_markdown(docs.win:get_buf(), doc_lines, {
-          height = vim.api.nvim_win_get_height(docs.win:get_win()),
-          width = vim.api.nvim_win_get_width(docs.win:get_win()),
-        })
-      end
-    )
   end)
 end
 

lua/blink/cmp/windows/lib/init.lua

@@ -69,7 +69,7 @@ function win:open()
     col = 1,
     focusable = false,
     zindex = 1001,
-    border = self.config.border == 'padded' and { ' ', '', '', '', '', '', ' ', ' ' } or self.config.border,
+    border = self.config.border == 'padded' and { ' ', '', '', ' ', '', '', ' ', ' ' } or self.config.border,
   })
   vim.api.nvim_set_option_value('winhighlight', self.config.winhighlight, { win = self.id })
   vim.api.nvim_set_option_value('wrap', self.config.wrap, { win = self.id })