Neovim commands to simplify context creation in markdown files

context.lua

-----------------------------------------------------------------
-- Neovim commands to simplify context creation in markdown files
--
-- Save as: lua/context.lua
--
-- How to use: require("_context").setup()
--
-----------------------------------------------------------------

local M = {}

--------------------------------
-- Copy quickfix files to clipboard
--------------------------------
local function copy_quickfix_files()
  -- Get all quickfix entries
  local qf_list = vim.fn.getqflist()

  -- Use table as set to store unique filenames
  local files = {}
  for _, item in ipairs(qf_list) do
    -- Get buffer name for each quickfix entry
    local filename = vim.fn.bufname(item.bufnr)
    if filename ~= "" then
      files[filename] = true
    end
  end

  -- Convert table keys to array and join with newlines
  local file_list = {}
  for filename, _ in pairs(files) do
    table.insert(file_list, filename)
  end

  -- Copy to system clipboard and show message
  vim.fn.setreg("+", table.concat(file_list, "\n"))
  print("Copied " .. #file_list .. " files to clipboard")
end

-- Create user command
vim.api.nvim_create_user_command("CopyQuickFixFiles", copy_quickfix_files, { desc = "Copy all unique files from quickfix list to clipboard" })

--------------------------------
-- Copy list of open buffers to clipboard
--------------------------------
local function list_of_open_buffers()
  local buffers = vim.api.nvim_list_bufs()
  local cwd = vim.fn.getcwd()
  local file_list = {}

  for _, bufnr in ipairs(buffers) do
    -- Only process loaded buffers
    if vim.api.nvim_buf_is_loaded(bufnr) then
      local bufname = vim.api.nvim_buf_get_name(bufnr)

      -- Skip empty buffers, NvimTree, and non-existent files
      if bufname ~= "" and not bufname:match("NvimTree") and vim.fn.filereadable(bufname) == 1 then
        -- Convert to relative path
        local relpath = vim.fn.substitute(bufname, cwd .. "/", "", "")
        table.insert(file_list, relpath)
      end
    end
  end

  return file_list
end

local function copy_list_of_open_buffers()
  local file_list = list_of_open_buffers()

  -- Copy to clipboard
  vim.fn.setreg("+", table.concat(file_list, "\n"))
  vim.notify(string.format("Copied %d open buffers to clipboard", #file_list), vim.log.levels.INFO)
end

--------------------------------
-- Copy code snippet
--
-- this function copies selection and adds line number in markdown format, example:
--
-- dir/filename.abc:293
-- ```lua
-- (selection here)
-- ```
--------------------------------
local function get_code_snippet(start_line, end_line)
  local file_name = vim.fn.expand("%:.")
  local lines = vim.api.nvim_buf_get_lines(0, start_line, end_line, false)
  local file_type = vim.api.nvim_get_option_value("filetype", { buf = 0 })

  -- get total line count to detect if entire buffer is selected
  local total_lines = vim.api.nvim_buf_line_count(0)

  -- only add line number if not selecting entire buffer
  local header = file_name
  if not (start_line == 0 and end_line == total_lines) then
    header = file_name .. ":" .. (start_line + 1)
  end

  return header .. "\n\n```" .. file_type .. "\n" .. table.concat(lines, "\n") .. "\n```\n\n"
end

------------------------
-- Commands and mappings
------------------------
function M.setup()
  -- commands
  vim.api.nvim_create_user_command("CopyListOfOpenBuffers", copy_list_of_open_buffers, { bang = true, desc = "Copy list of open buffers to clipboard" })

  -- Copy filename and line number
  -- example: src/filename.js:123
  vim.api.nvim_create_user_command("CopyPathLine", function()
    local value = vim.fn.expand("%:.") .. ":" .. vim.api.nvim_win_get_cursor(0)[1]
    vim.fn.setreg("*", value)
    vim.notify("Copied " .. value, vim.log.levels.INFO)
  end, { bang = true, desc = "Copy filename and current line number" })
  -- Copy filename path
  vim.api.nvim_create_user_command("CopyFullPath", function()
    local value = vim.fn.expand("%:p")
    vim.fn.setreg("*", value)
    vim.notify("Copied " .. value, vim.log.levels.INFO)
  end, { bang = true, desc = "Copy absolute file path" })
  -- Copy relative file path
  vim.api.nvim_create_user_command("CopyPath", function()
    local value = vim.fn.expand("%:.")
    vim.fn.setreg("*", value)
    vim.notify("Copied " .. value, vim.log.levels.INFO)
  end, { bang = true, desc = "Copy relative file path <F6>" })
  -- Copy file name with extension
  vim.api.nvim_create_user_command("CopyFileNameWithExtension", function()
    local value = vim.fn.expand("%:t")
    vim.fn.setreg("*", value)
    vim.notify("Copied " .. value, vim.log.levels.INFO)
  end, { bang = true, desc = "Copy filename with extension" })
  -- Copy file name without extension
  vim.api.nvim_create_user_command("CopyFileName", function()
    local value = vim.fn.expand("%:t:r")
    vim.fn.setreg("*", value)
    vim.notify("Copied " .. value, vim.log.levels.INFO)
  end, { bang = true, desc = "Copy filename without extension" })

  -- Copy code snippet
  vim.api.nvim_create_user_command("CopyCodeSnippet", function(opts)
    local start_line = vim.fn.line("'<") - 1
    local end_line = vim.fn.line("'>")
    vim.fn.setreg("*", get_code_snippet(start_line, end_line))
    vim.notify("Added code snippet to clipboard", vim.log.levels.INFO)
  end, { range = true, bang = true, desc = "Copy selection as markdown code snippet <F6>" })

  -- F6 copies relative file path
  vim.api.nvim_set_keymap("n", "<F6>", ":CopyPath<CR>", { noremap = true, desc = "Copy relative file path" })

  -- map it to F6 on visual mode
  vim.api.nvim_set_keymap("v", "<F6>", ":CopyCodeSnippet<CR>", { noremap = true, desc = "Copy selection as markdown code snippet" })
end

return M