new builtin - autocommands (#302)

* feat: new builtin - Autocommands finder

* fix: remove decorators to avoid confusion.

* make preview split same hl-group as border

* use highlight instead of marker character for preview selection hl

lua/telescope/builtin/init.lua

@@ -58,6 +58,7 @@ builtin.registers = require('telescope.builtin.internal').registers
 builtin.keymaps = require('telescope.builtin.internal').keymaps
 builtin.filetypes = require('telescope.builtin.internal').filetypes
 builtin.highlights = require('telescope.builtin.internal').highlights
+builtin.autocommands = require('telescope.builtin.internal').autocommands
 
 builtin.lsp_references = require('telescope.builtin.lsp').references
 builtin.lsp_document_symbols = require('telescope.builtin.lsp').document_symbols

lua/telescope/builtin/internal.lua

@@ -569,6 +569,96 @@ internal.highlights = function(opts)
   }):find()
 end
 
+internal.autocommands = function(opts)
+  local autocmd_table = {}
+
+  local pattern  = {}
+  pattern.BUFFER = "<buffer=%d+>"
+  pattern.EVENT  = "[%a]+"
+  pattern.GROUP  = "[%a%d_:]+"
+  pattern.INDENT = "^%s%s%s%s" -- match indentation of 4 spaces
+
+  local event, group, ft_pat, cmd, source_file, source_lnum
+  local current_event, current_group, current_ft
+
+  local cmd_output = vim.fn.execute("verb autocmd *", "silent")
+  for line in cmd_output:gmatch("[^\r\n]+") do
+    -- capture group and event
+    group, event = line:match("^(" .. pattern.GROUP .. ")%s+(" .. pattern.EVENT .. ")")
+    -- ..or just an event
+    if event == nil then
+      event = line:match("^(" .. pattern.EVENT .. ")")
+    end
+
+    if event then
+      group = group or "<anonymous>"
+      if event ~= current_event or group ~= current_group then
+        current_event = event
+        current_group = group
+      end
+      goto line_parsed
+    end
+
+    -- non event/group lines
+    ft_pat = line:match(pattern.INDENT .. "(%S+)")
+    if ft_pat then
+      if ft_pat:match("^%d+") then
+        ft_pat = "<buffer=" .. ft_pat .. ">"
+      end
+      current_ft = ft_pat
+
+      -- is there a command on the same line?
+      cmd = line:match(pattern.INDENT .. "%S+%s+(.+)")
+
+      goto line_parsed
+    end
+
+    if current_ft and cmd == nil then
+      -- trim leading spaces
+      cmd = line:gsub("^%s+", "")
+      goto line_parsed
+    end
+
+    if current_ft and cmd then
+      source_file, source_lnum = line:match("Last set from (.*) line (.*)")
+      if source_file then
+        local autocmd = {}
+        autocmd.event       = current_event
+        autocmd.group       = current_group
+        autocmd.ft_pattern  = current_ft
+        autocmd.command     = cmd
+        autocmd.source_file = source_file
+        autocmd.source_lnum = source_lnum
+        table.insert(autocmd_table, autocmd)
+
+        cmd = nil
+      end
+    end
+
+    ::line_parsed::
+  end
+
+  -- print(vim.inspect(autocmd_table))
+
+  pickers.new(opts,{
+    prompt_title = 'autocommands',
+    finder = finders.new_table {
+      results = autocmd_table,
+      entry_maker = make_entry.gen_from_autocommands(opts),
+    },
+    previewer = previewers.autocommands.new(opts),
+    sorter = conf.generic_sorter(opts),
+    attach_mappings = function(prompt_bufnr)
+      actions._goto_file_selection:replace(function(_, cmd)
+        local selection = actions.get_selected_entry()
+        actions.close(prompt_bufnr)
+        vim.cmd(cmd .. ' ' .. selection.value)
+      end)
+
+      return true
+    end
+  }):find()
+end
 
 local function apply_checks(mod)
   for k, v in pairs(mod) do

lua/telescope/make_entry.lua

@@ -682,4 +682,42 @@ function make_entry.gen_from_ctags(opts)
   end
 end
 
+function make_entry.gen_from_autocommands(_)
+  local displayer = entry_display.create {
+    separator = "▏",
+    items = {
+      { width = 14 },
+      { width = 18 },
+      { width = 16 },
+      { remaining = true },
+    },
+  }
+
+  local make_display = function(entry)
+    return displayer {
+      entry.event,
+      entry.group,
+      entry.ft_pattern,
+      entry.command
+    }
+  end
+
+  -- TODO: <action> dump current filtered items to buffer
+  return function(entry)
+    return {
+      event      = entry.event,
+      group      = entry.group,
+      ft_pattern = entry.ft_pattern,
+      command    = entry.command,
+      value      = string.format("+%d %s", entry.source_lnum, entry.source_file),
+      source_file = entry.source_file,
+      source_lnum = entry.source_lnum,
+      --
+      valid = true,
+      ordinal = entry.event .. " "  .. entry.group .. " " .. entry.ft_pattern .. " " .. entry.command,
+      display = make_display,
+    }
+  end
+end
+
 return make_entry

lua/telescope/previewers.lua

@@ -770,6 +770,51 @@ previewers.man = defaulter(function(_)
   }
 end)
 
+previewers.autocommands = defaulter(function(_)
+return previewers.new_buffer_previewer {
+  setup = function()
+    return {}
+  end,
+
+  teardown = function(self)
+    if self.state and self.state.hl_id then
+      pcall(vim.fn.matchdelete, self.state.hl_id, self.state.hl_win)
+      self.state.hl_id = nil
+    end
+  end,
+
+  preview_fn = function(self, entry, status)
+    local results = vim.tbl_filter(
+      function (x) return x.group == entry.group end,
+      status.picker.finder.results
+      )
+    local display = {}
+    table.insert(display, string.format(" augroup: %s - [ %d entries ]", entry.group, #results))
+    -- TODO: calculate banner width/string in setup()
+    -- TODO: get column characters to be the same HL group as border
+    table.insert(display, string.rep("─", vim.fn.getwininfo(status.preview_win)[1].width))
+
+    local selected_row
+    for idx, item in ipairs(results) do
+      if item == entry then
+        selected_row = idx
+      end
+      table.insert(display,
+        string.format("  %-14s▏%-08s %s", item.event, item.ft_pattern, item.command)
+      )
+    end
+
+    with_preview_window(status, nil, function()
+      -- TODO: set filetype in setup()
+      vim.api.nvim_buf_set_option(status.preview_bufnr, "filetype", "vim")
+      vim.api.nvim_buf_set_lines(status.preview_bufnr, 0, -1, false, display)
+      vim.api.nvim_buf_add_highlight(status.preview_bufnr, 0, "TelescopeBorder", 1, 0, -1)
+      vim.api.nvim_buf_add_highlight(status.preview_bufnr, 0, "TelescopeSelection", selected_row + 1, 0, -1)
+    end)
+  end,
+}
+end, {})
+
 previewers.display_content = defaulter(function(_)
   return previewers.new_buffer_previewer {
     preview_fn = function(self, entry, status)