feat(test): test panel

lua/cp/highlight.lua

@@ -0,0 +1,164 @@
+---@class DiffHighlight
+---@field line number
+---@field col_start number
+---@field col_end number
+---@field highlight_group string
+
+---@class ParsedDiff
+---@field content string[]
+---@field highlights DiffHighlight[]
+
+local M = {}
+
+---Parse git diff markers and extract highlight information
+---@param text string Raw git diff output line
+---@return string cleaned_text, DiffHighlight[]
+local function parse_diff_line(text)
+  local highlights = {}
+  local cleaned_text = text
+  local offset = 0
+
+  -- Pattern for removed text: [-removed text-]
+  for removed_text in text:gmatch('%[%-(.-)%-%]') do
+    local start_pos = text:find('%[%-' .. vim.pesc(removed_text) .. '%-%]', 1, false)
+    if start_pos then
+      -- Remove the marker and adjust positions
+      local marker_len = #('[-%-%]') + #removed_text
+      cleaned_text = cleaned_text:gsub('%[%-' .. vim.pesc(removed_text) .. '%-%]', '', 1)
+
+      -- Since we're removing text, we don't add highlights for removed content in the actual pane
+      -- This is handled by showing removed content in the expected pane
+    end
+  end
+
+  -- Reset for added text parsing on the cleaned text
+  local final_text = cleaned_text
+  local final_highlights = {}
+  offset = 0
+
+  -- Pattern for added text: {+added text+}
+  for added_text in cleaned_text:gmatch('{%+(.-)%+}') do
+    local start_pos = final_text:find('{%+' .. vim.pesc(added_text) .. '%+}', 1, false)
+    if start_pos then
+      -- Calculate position after previous highlights
+      local highlight_start = start_pos - offset - 1  -- 0-based for extmarks
+      local highlight_end = highlight_start + #added_text
+
+      table.insert(final_highlights, {
+        line = 0, -- Will be set by caller
+        col_start = highlight_start,
+        col_end = highlight_end,
+        highlight_group = 'CpDiffAdded'
+      })
+
+      -- Remove the marker
+      local marker_len = #{'{+'} + #{'+}'} + #added_text
+      final_text = final_text:gsub('{%+' .. vim.pesc(added_text) .. '%+}', added_text, 1)
+      offset = offset + #{'{+'} + #{'+}'}
+    end
+  end
+
+  return final_text, final_highlights
+end
+
+---Parse complete git diff output
+---@param diff_output string
+---@return ParsedDiff
+function M.parse_git_diff(diff_output)
+  local lines = vim.split(diff_output, '\n', { plain = true })
+  local content_lines = {}
+  local all_highlights = {}
+
+  -- Skip git diff header lines
+  local content_started = false
+  for _, line in ipairs(lines) do
+    -- Skip header lines (@@, +++, ---, index, etc.)
+    if content_started or (
+      not line:match('^@@') and
+      not line:match('^%+%+%+') and
+      not line:match('^%-%-%-') and
+      not line:match('^index') and
+      not line:match('^diff %-%-git')
+    ) then
+      content_started = true
+
+      -- Process content lines
+      if line:match('^%+') then
+        -- Added line - remove + prefix and parse highlights
+        local clean_line = line:sub(2) -- Remove + prefix
+        local parsed_line, line_highlights = parse_diff_line(clean_line)
+
+        table.insert(content_lines, parsed_line)
+
+        -- Set line numbers for highlights
+        local line_num = #content_lines
+        for _, highlight in ipairs(line_highlights) do
+          highlight.line = line_num - 1 -- 0-based for extmarks
+          table.insert(all_highlights, highlight)
+        end
+      elseif line:match('^%-') then
+        -- Removed line - we handle this in the expected pane, skip for actual
+      elseif not line:match('^\\') then -- Skip "\ No newline" messages
+        -- Unchanged line
+        local parsed_line, line_highlights = parse_diff_line(line)
+        table.insert(content_lines, parsed_line)
+
+        -- Set line numbers for any highlights (shouldn't be any for unchanged lines)
+        local line_num = #content_lines
+        for _, highlight in ipairs(line_highlights) do
+          highlight.line = line_num - 1 -- 0-based for extmarks
+          table.insert(all_highlights, highlight)
+        end
+      end
+    end
+  end
+
+  return {
+    content = content_lines,
+    highlights = all_highlights
+  }
+end
+
+---Apply highlights to a buffer using extmarks
+---@param bufnr number
+---@param highlights DiffHighlight[]
+---@param namespace number
+function M.apply_highlights(bufnr, highlights, namespace)
+  -- Clear existing highlights in this namespace
+  vim.api.nvim_buf_clear_namespace(bufnr, namespace, 0, -1)
+
+  for _, highlight in ipairs(highlights) do
+    if highlight.col_start < highlight.col_end then
+      vim.api.nvim_buf_set_extmark(bufnr, namespace, highlight.line, highlight.col_start, {
+        end_col = highlight.col_end,
+        hl_group = highlight.highlight_group,
+        priority = 100,
+      })
+    end
+  end
+end
+
+---Create namespace for diff highlights
+---@return number
+function M.create_namespace()
+  return vim.api.nvim_create_namespace('cp_diff_highlights')
+end
+
+---Parse and apply git diff to buffer
+---@param bufnr number
+---@param diff_output string
+---@param namespace number
+---@return string[] content_lines
+function M.parse_and_apply_diff(bufnr, diff_output, namespace)
+  local parsed = M.parse_git_diff(diff_output)
+
+  -- Set buffer content
+  vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, parsed.content)
+
+  -- Apply highlights
+  M.apply_highlights(bufnr, parsed.highlights, namespace)
+
+  return parsed.content
+end
+
+return M