-- Terminals should open with insert mode
vim.api.nvim_create_autocmd("BufEnter", { pattern = "term://*", callback = function() vim.cmd("startinsert") end })

-- Start treesitter
vim.api.nvim_create_autocmd('FileType', {
    pattern = '*',
    callback = function()
        pcall(vim.treesitter.start)
        vim.bo.indentexpr = "v:lua.require'nvim-treesitter'.indentexpr()"
    end,
})

-- highlights yanked text
vim.api.nvim_create_autocmd("TextYankPost", {
    callback = function()
        vim.highlight.on_yank({
            higroup = "IncSearch",
            timeout = 200,
        })
    end,
})

-- Set absolute numbers when in insert mode otherwise relativenumbers
local nums = vim.api.nvim_create_augroup('smart_numbers', {})
vim.api.nvim_create_autocmd('InsertEnter', {
    group = nums,
    callback = function()
        vim.opt.relativenumber = false
    end,
})
vim.api.nvim_create_autocmd('InsertLeave', {
    group = nums,
    callback = function()
        vim.opt.relativenumber = true
    end,
})

-- removes trailing whitespace on save
vim.api.nvim_create_autocmd("BufWritePre", {
    callback = function()
        local save_cursor = vim.fn.getpos(".")
        vim.cmd([[%s/\s\+$//e]])
        vim.fn.setpos(".", save_cursor)
    end,
})

-- Lsp autocomplete
vim.api.nvim_create_autocmd('LspAttach', {
    group = vim.api.nvim_create_augroup('my.lsp', {}),
    callback = function(ev)
        local client = vim.lsp.get_client_by_id(ev.data.client_id)
        if not client then return end

        -- Set completeopt for a better experience
        vim.opt.completeopt = { 'menu', 'menuone', 'noinsert', 'noselect' }

        -- Enable completion if the server supports it
        if client:supports_method('textDocument/completion') then
          vim.lsp.completion.enable(true, client.id, ev.buf, {
            autotrigger = true,   -- false = manual trigger only
          })
        end
    end,
})

-- Format: whole file or visual selection via :Fc
local function smart_format()
  local mode = vim.fn.mode()
  local in_visual = mode == "v" or mode == "V" or mode == "\22"

  local clients = vim.lsp.get_clients({ bufnr = 0 })
  local has_formatter = false
  for _, client in ipairs(clients) do
    if client.supports_method("textDocument/formatting") then
      has_formatter = true
      break
    end
  end

  if in_visual then
    if has_formatter then
      vim.lsp.buf.format({
        range = {
          start = vim.api.nvim_buf_get_mark(0, "<"),
          ["end"] = vim.api.nvim_buf_get_mark(0, ">"),
        },
      })
    else
      vim.cmd("normal! gv=")
    end
  else
    if has_formatter then
      vim.lsp.buf.format({ async = false })
    else
      local view = vim.fn.winsaveview()
      vim.cmd("normal! gg=G")
      vim.fn.winrestview(view)
    end
  end
end
vim.api.nvim_create_user_command("FF", smart_format, { range = true })