feat: highlights

lua/fugitive-ts/highlight.lua

@@ -55,26 +55,30 @@ local function highlight_text(bufnr, ns, hunk, col_offset, text, lang, debug)
   return extmark_count
 end
 
+---@class fugitive-ts.HunkOpts
+---@field max_lines integer
+---@field conceal_prefixes boolean
+---@field highlights fugitive-ts.Highlights
+---@field debug boolean
+
 ---@param bufnr integer
 ---@param ns integer
 ---@param hunk fugitive-ts.Hunk
----@param max_lines integer
----@param highlight_headers boolean
----@param debug? boolean
-function M.highlight_hunk(bufnr, ns, hunk, max_lines, highlight_headers, debug)
+---@param opts fugitive-ts.HunkOpts
+function M.highlight_hunk(bufnr, ns, hunk, opts)
   local lang = hunk.lang
   if not lang then
     return
   end
 
-  if #hunk.lines > max_lines then
-    if debug then
+  if #hunk.lines > opts.max_lines then
+    if opts.debug then
       dbg(
         'skipping hunk %s:%d (%d lines > %d max)',
         hunk.filename,
         hunk.start_line,
         #hunk.lines,
-        max_lines
+        opts.max_lines
       )
     end
     return
@@ -93,7 +97,7 @@ function M.highlight_hunk(bufnr, ns, hunk, max_lines, highlight_headers, debug)
 
   local ok, parser_obj = pcall(vim.treesitter.get_string_parser, code, lang)
   if not ok or not parser_obj then
-    if debug then
+    if opts.debug then
       dbg('failed to create parser for lang: %s', lang)
     end
     return
@@ -101,7 +105,7 @@ function M.highlight_hunk(bufnr, ns, hunk, max_lines, highlight_headers, debug)
 
   local trees = parser_obj:parse()
   if not trees or #trees == 0 then
-    if debug then
+    if opts.debug then
       dbg('parse returned no trees for lang: %s', lang)
     end
     return
@@ -109,22 +113,29 @@ function M.highlight_hunk(bufnr, ns, hunk, max_lines, highlight_headers, debug)
 
   local query = vim.treesitter.query.get(lang, 'highlights')
   if not query then
-    if debug then
+    if opts.debug then
       dbg('no highlights query for lang: %s', lang)
     end
     return
   end
 
-  if highlight_headers and hunk.header_context and hunk.header_context_col then
+  if opts.highlights.headers and hunk.header_context and hunk.header_context_col then
     local header_line = hunk.start_line - 1
     pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, header_line, hunk.header_context_col, {
       end_col = hunk.header_context_col + #hunk.header_context,
       hl_group = 'Normal',
       priority = 199,
     })
-    local header_extmarks =
-      highlight_text(bufnr, ns, hunk, hunk.header_context_col, hunk.header_context, lang, debug)
-    if debug and header_extmarks > 0 then
+    local header_extmarks = highlight_text(
+      bufnr,
+      ns,
+      hunk,
+      hunk.header_context_col,
+      hunk.header_context,
+      lang,
+      opts.debug
+    )
+    if opts.debug and header_extmarks > 0 then
       dbg('header %s:%d applied %d extmarks', hunk.filename, hunk.start_line, header_extmarks)
     end
   end
@@ -132,7 +143,28 @@ function M.highlight_hunk(bufnr, ns, hunk, max_lines, highlight_headers, debug)
   for i, line in ipairs(hunk.lines) do
     local buf_line = hunk.start_line + i - 1
     local line_len = #line
-    if line_len > 1 then
+    local prefix = line:sub(1, 1)
+
+    if opts.conceal_prefixes then
+      pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 0, {
+        end_col = 1,
+        conceal = '',
+      })
+    end
+
+    if opts.highlights.background and (prefix == '+' or prefix == '-') then
+      local line_hl = prefix == '+' and 'DiffAdd' or 'DiffDelete'
+      local extmark_opts = {
+        line_hl_group = line_hl,
+        priority = 198,
+      }
+      if opts.highlights.linenr then
+        extmark_opts.number_hl_group = line_hl
+      end
+      pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 0, extmark_opts)
+    end
+
+    if line_len > 1 and opts.highlights.treesitter then
       pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 1, {
         end_col = line_len,
         hl_group = 'Normal',
@@ -141,6 +173,10 @@ function M.highlight_hunk(bufnr, ns, hunk, max_lines, highlight_headers, debug)
     end
   end
 
+  if not opts.highlights.treesitter then
+    return
+  end
+
   local extmark_count = 0
   for id, node, _ in query:iter_captures(trees[1]:root(), code) do
     local capture_name = '@' .. query.captures[id]
@@ -160,7 +196,7 @@ function M.highlight_hunk(bufnr, ns, hunk, max_lines, highlight_headers, debug)
     extmark_count = extmark_count + 1
   end
 
-  if debug then
+  if opts.debug then
     dbg('hunk %s:%d applied %d extmarks', hunk.filename, hunk.start_line, extmark_count)
   end
 end