-- core/autocmds.lua
local aug = vim.api.nvim_create_augroup
local au = vim.api.nvim_create_autocmd

-- highlight yanked text briefly
au("TextYankPost", {
  group = aug("highlight_yank", { clear = true }),
  callback = function() vim.highlight.on_yank({ timeout = 150 }) end,
})

-- restore last cursor position when reopening a file
au("BufReadPost", {
  group = aug("last_loc", { clear = true }),
  callback = function(ev)
    local mark = vim.api.nvim_buf_get_mark(ev.buf, '"')
    local lines = vim.api.nvim_buf_line_count(ev.buf)
    if mark[1] > 0 and mark[1] <= lines then
      pcall(vim.api.nvim_win_set_cursor, 0, mark)
    end
  end,
})

-- trim trailing whitespace on save (skip filetypes where it matters)
au("BufWritePre", {
  group = aug("trim_ws", { clear = true }),
  callback = function()
    if vim.bo.filetype == "diff" or vim.bo.filetype == "markdown" then return end
    local view = vim.fn.winsaveview()
    vim.cmd([[silent! keeppatterns %s/\s\+$//e]])
    vim.fn.winrestview(view)
  end,
})

-- auto-create parent dirs on save
au("BufWritePre", {
  group = aug("mkdir_on_save", { clear = true }),
  callback = function(ev)
    if ev.match:match("^%w+://") then return end
    local dir = vim.fn.fnamemodify(ev.file, ":p:h")
    if vim.fn.isdirectory(dir) == 0 then vim.fn.mkdir(dir, "p") end
  end,
})