[FEAT] Diffview extension: context in winbar

lua/lualine/extensions/git_diffview.lua

@@ -0,0 +1,344 @@
+-- README:
+-- Diffview buffers do not provide api for their info on the native winbar
+-- These fn achieve a similar functionality
+
+-- INFO: Functions and library to retrieve diffview info on buffers
+
+local function in_git_repo()
+  local handle = io.popen("git rev-parse --is-inside-work-tree 2>/dev/null")
+  if not handle then
+    return false
+  end
+  local output = handle:read("*a"):gsub("%s+", "")
+  handle:close()
+  return output == "true"
+end
+
+local function basename(path)
+  return path:match("[^/]+$") or path
+end
+
+local function resolve_git_reference(ref)
+  local handle = io.popen(string.format("git rev-parse --short %s 2>/dev/null", ref))
+  if not handle then
+    return nil
+  end
+  local resolved = handle:read("*a"):gsub("%s+", "")
+  handle:close()
+  return resolved ~= "" and resolved or nil
+end
+
+local function get_relative_to_head(hash)
+  local handle = io.popen(string.format("git rev-list --count --first-parent %s..HEAD 2>/dev/null", hash))
+  if not handle then
+    return nil
+  end
+  local count = handle:read("*a"):gsub("%s+", "")
+  handle:close()
+  return tonumber(count) and string.format("HEAD~%s", count) or hash
+end
+
+local function get_git_branch()
+  local handle = io.popen("git symbolic-ref --short HEAD 2>/dev/null || git rev-parse --short HEAD")
+  if not handle then
+    return "HEAD"
+  end
+  local branch = handle:read("*a"):gsub("%s+", "")
+  handle:close()
+  return branch ~= "" and branch or "HEAD"
+end
+
+-- Optional
+-- local function is_remote_branch(ref)
+--   local handle = io.popen(string.format("git branch -r --contains %s 2>/dev/null", ref))
+--   if not handle then
+--     return false
+--   end
+--   local remote = handle:read("*a"):match("%S+")
+--   handle:close()
+--   return remote and remote or false
+-- end
+
+local function get_all_branches_pointing_to(commit)
+  local handle = io.popen(string.format("git branch -a --points-at %s 2>/dev/null", commit))
+  if not handle then
+    return {}
+  end
+  local output = handle:read("*a")
+  handle:close()
+
+  local branches = {}
+  for line in output:gmatch("[^\r\n]+") do
+    -- Remove leading '*', spaces, etc.
+    line = line:gsub("^%*", ""):gsub("^%s+", ""):gsub("%s+$", "")
+    if line ~= "" then
+      table.insert(branches, line)
+    end
+  end
+  return branches
+end
+
+local function get_tag_for_commit(hash)
+  local handle = io.popen(string.format("git tag --points-at %s 2>/dev/null", hash))
+  if not handle then
+    return nil
+  end
+  local tag = handle:read("*a"):gsub("%s+", "")
+  handle:close()
+  return tag ~= "" and tag or nil
+end
+
+local function get_diffview_buffer_info(commit, filename, show_filename)
+  local inside_repo = in_git_repo()
+  local base = basename(filename)
+
+  -- If no commit given:
+  if not commit or commit == "" then
+    if inside_repo then
+      if show_filename then
+        return "WORKING TREE " .. base
+      else
+        return "WORKING TREE"
+      end
+    else
+      return base
+    end
+  end
+
+  -- print('DEBUG: commit: ' .. commit .. ' , filename: ', filename)
+  -- Handle .git/-style commit references (index/stages)
+  if commit:match("^%.git") then
+    -- Check if filename starts with :0, :1, :2, or :3
+    -- Pattern: :<stage>[:optional/path/to/file]
+    -- local stage, rest = filename:match("^:(%d+)(:(.*))?$")
+    local stage, rest = filename:match("^:(%d+):?(.*)$")
+    if stage then
+      stage = tonumber(stage)
+      local label
+      if stage == 0 then
+        label = "INDEX"
+      elseif stage == 1 then
+        label = "Base"
+      elseif stage == 2 then
+        label = "OURS"
+      elseif stage == 3 then
+        label = "THEIRS"
+      end
+
+      if show_filename and rest and rest ~= "" then
+        -- rest is the path after the stage, show basename of that path
+        local rest_base = basename(rest)
+        return label .. " " .. rest_base
+      else
+        -- no further path, just show the label
+        return label
+      end
+    else
+      -- If no stage detected, just show the filename as is
+      -- Or you could return something else if desired.
+      return inside_repo and ("WORKING TREE " .. base) or base
+    end
+  end
+
+  -- If we have a normal commit reference:
+  local short = resolve_git_reference(commit)
+  if not short then
+    -- Couldn't resolve commit, fallback
+    if inside_repo then
+      return "ERROR (No Short) for commit " .. commit .. base
+    else
+      return base
+    end
+  end
+
+
+  local head_short = resolve_git_reference("HEAD")
+  local branch = get_git_branch()
+  local branch_short = resolve_git_reference(branch)
+
+  -- Collect all possible matches
+  local matches = {}
+
+  -- If commit is HEAD
+  if short == head_short then
+    table.insert(matches, "HEAD")
+  end
+
+  -- If commit matches the current local branch
+  if branch_short and short == branch_short then
+    table.insert(matches, branch)
+  end
+
+  -- All branches (including remote) pointing exactly to this commit
+  local pointing_branches = get_all_branches_pointing_to(short)
+  for _, br in ipairs(pointing_branches) do
+    local already_in = false
+    for _, m in ipairs(matches) do
+      if m == br then
+        already_in = true
+        break
+      end
+    end
+    if not already_in then
+      table.insert(matches, br)
+    end
+  end
+
+  -- HEAD~N format
+  local relative = get_relative_to_head(short)
+  if relative and relative ~= short then
+    table.insert(matches, relative)
+  end
+
+  -- If there's a tag
+  local tag = get_tag_for_commit(short)
+  if tag then
+    table.insert(matches, tag)
+  end
+
+  -- If we found no special references, just use the short commit hash
+  -- if #matches == 0 then
+  table.insert(matches, short)
+  -- end
+
+  -- Format matches {ref} {ref2} ...
+  local formatted = {}
+  for _, m in ipairs(matches) do
+    formatted[#formatted+1] = "{" .. m .. "}"
+  end
+
+  local result = table.concat(formatted, " ")
+  if show_filename and base and base ~= "" then
+    result = result .. ": " .. base
+  end
+
+  return result
+end
+
+
+local function parse_diffview_buffer_name(bufname)
+  local git_part = bufname:match("%.git/(.*)$")
+  if git_part then
+    -- Check for staging syntax like :0, :1, :2, :3
+    -- local stage, rest = git_part:match("^:(%d+)(:(.*))?$")
+    local stage, rest = git_part:match("^:(%d+):?(.*)$")
+    if stage then
+      -- This is a staged scenario, commit = ".git"
+      -- rest is optional path after :N
+      -- INFO: Avoiding rest
+      if rest and rest ~= "" then
+        return ".git", ":"..stage..":"..rest
+      else
+        return ".git", ":"..stage
+      end
+    end
+
+    -- Otherwise, try to parse a commit (assuming anything up to next slash is commit)
+    local commit, path_after = git_part:match("^([^/]+)/(.+)$")
+    if commit and path_after then
+      return commit, path_after
+    elseif commit then
+      -- commit but no further path
+      return commit, commit
+    else
+      -- .git present but no recognizable commit or stage pattern
+      -- Just treat the remainder as filename
+      return nil, basename(bufname)
+    end
+  else
+    -- No .git in the name, no commit
+    return nil, basename(bufname)
+  end
+end
+
+-- INFO: lualine extension definition
+
+local M = {}
+
+-- INFO add filename to the returned string
+M.show_filename = false
+-- The function that derives commit and filename from the active buffer:
+M.get_current_diffview_buffer_info = function()
+  local bufname = vim.api.nvim_buf_get_name(0) -- current buffer's name
+  local commit, filename = parse_diffview_buffer_name(bufname)
+  if not commit then
+    -- no commit found, treat entire bufname as filename
+    filename = bufname
+    commit = nil
+  end
+  return get_diffview_buffer_info(commit, filename, M.show_filename)
+end
+
+M.winbar = {
+  lualine_a = {
+    {
+      'filename',
+    },
+  },
+  lualine_b = {
+    {M.get_current_diffview_buffer_info, },
+  },
+}
+M.inactive_winbar = {
+  lualine_a = {
+    {
+      'filename',
+    },
+  },
+  lualine_b = {
+    {M.get_current_diffview_buffer_info, },
+  },
+}
+
+-- Restrict to Diffview buffers
+-- M.buftypes = {''}
+M.filetypes = {
+  -- Null
+  'null',
+
+  -- Programming Languages
+  'lua', 'python', 'javascript', 'typescript', 'html', 'css', 'json', 'yaml', 'yml',
+  'markdown', 'md', 'c', 'cpp', 'cxx', 'h', 'hpp', 'java', 'ruby', 'go', 'php', 'rust',
+  'sh', 'bash', 'vim', 'toml', 'systemverilog', 'verilog', 'perl', 'swift', 'kotlin',
+  'scala', 'dart', 'r', 'sas', 'pascal', 'fortran', 'cobol', 'vhdl', 'assembly', 'asm',
+  'typescriptreact', 'javascriptreact', 'clojure', 'elixir', 'erlang', 'scheme', 'fsharp',
+
+  -- Scripting and Config Files
+  'ini', 'conf', 'env', 'config', 'properties', 'rc', 'toml', 'plist', 'bat', 'cmd', 'ps1',
+
+  -- Markup and Documentation
+  'xml', 'tex', 'latex', 'asciidoc', 'rst', 'csv', 'tsv', 'docbook', 'jsonnet', 'dita',
+  'org', 'textile',
+
+  -- Specialized Hardware and Electronics
+  'systemverilog', 'verilog', 'spectre', 'spice', 'veriloga',
+
+  -- Plugin/Framework Specific
+  'NvimTree', 'dashboard', 'packer', 'quickfix', 'help', 'terminal', 'diff', 'TelescopePrompt',
+
+  -- Build and Packaging Files
+  'make', 'cmake', 'ninja', 'dockerfile', 'gradle', 'maven', 'build', 'bazel',
+
+  -- Text and No Filetype
+  'text', 'plain', 'txt', 'log', 'unknown', 'none',
+
+  -- Git Related
+  'gitcommit', 'gitrebase', 'gitignore', 'gitattributes',
+
+  -- Shells and Terminals
+  'fish', 'zsh', 'csh', 'tcsh', 'ksh', 'ash', 'dash',
+
+  -- Other Formats
+  'sql', 'sqlite', 'protobuf', 'hcl', 'terraform', 'graphql', 'dot', 'plantuml', 'mermaid',
+  'lua', 'vimscript',
+
+  -- Graphics and Visual
+  'svg', 'eps', 'ai', 'psd', 'blend', 'obj', 'mtl', 'stl', 'fbx', 'gltf',
+
+  -- Archives and Compressed
+  'zip', 'tar', 'gz', 'bz2', 'xz', '7z', 'rar',
+
+  -- Miscellaneous
+  'ics', 'ical', 'vcard', 'yaml.sample', 'json.sample',
+}
+return M