local plug_dir = vim.fn.stdpath('config') .. '/lua'
local M = {}

function M.packer_compile()
    local file = vim.fn.expand('%:p')
    if file:match(plug_dir) then
        vim.api.nvim_command('PackerCompile')
    end
end

function M.nvim_create_augroups(definitions)
  for group_name, definition in pairs(definitions) do
    vim.api.nvim_command('augroup '..group_name)
    vim.api.nvim_command('autocmd!')
    for _, def in ipairs(definition) do
      local command = table.concat(vim.tbl_flatten{'autocmd', def}, ' ')
      vim.api.nvim_command(command)
    end
    vim.api.nvim_command('augroup END')
  end
end

function M.load_autocmds()
    local definitions = {
        packer = {
            {"BufWritePost", "*.lua", "lua require('events').packer_compile()"};
        };

        -- Edit binary files in hex with xxd (:%!xxd and :%!xxd -r)
        -- or using nvim -b to edit files using xxd-format
        binary = {
            {"BufReadPre"  , "*.bin,*.exe", "let &bin=1"};
            {"BufReadPost" , "*.bin,*.exe", "if &bin | %!xxd"};
            {"BufReadPost" , "*.bin,*.exe", "set ft=xxd | endif"};
            {"BufWritePre" , "*.bin,*.exe", "if &bin | %!xxd -r"};
            {"BufWritePre" , "*.bin,*.exe", "endif"};
            {"BufWritePost", "*.bin,*.exe", "if &bin | %!xxd"};
            {"BufWritePost", "*.bin,*.exe", "set nomod | endif"};
        };

        document = {
            {"BufNewFile,BufEnter,BufRead", "*.md,*.mkd", "setfiletype markdown"};
            {"BufNewFile,BufEnter,BufRead", "*.tex", "setfiletype tex"};
            {"BufNewFile,BufRead", "*.md,*.mkd", "setlocal spell"};
            {"BufNewFile,BufRead", "*.tex", "setlocal spell"};
        };

        wins = {
            -- Equalize window dimensions when resizing vim window
            {"VimResized", "*", [[tabdo wincmd =]]};
            -- Force write shada on leaving nvim
            {"VimLeave", "*", [[if has('nvim') | wshada! | else | wviminfo! | endif]]};
            -- Check if file changed when its window is focus, more eager than 'autoread'
            {"FocusGained", "* checktime"};
        };

        yank = {
            {"TextYankPost", [[* silent! lua vim.highlight.on_yank({higroup="IncSearch", timeout=300})]]};
        };
    }

    M.nvim_create_augroups(definitions)
end

return M