-- install packer if not already there
local install_path = vim.fn.stdpath 'data' .. '/site/pack/packer/start/packer.nvim'
if vim.fn.empty(vim.fn.glob(install_path)) > 0 then
  is_bootstrap = true
  vim.fn.system{'git', 'clone', '--depth', '1', 'https://github.com/wbthomason/packer.nvim', install_path }
  vim.cmd [[packadd packer.nvim]]
end

-- Install Plugins
require('packer').startup(function(use)
  use 'wbthomason/packer.nvim'
  use 'neovim/nvim-lspconfig'
  use 'nvim-treesitter/nvim-treesitter'
  use {
    'hrsh7th/nvim-cmp',
    requires = { 'hrsh7th/cmp-nvim-lsp', 'hrsh7th/cmp-buffer', 'hrsh7th/cmp-cmdline', 'hrsh7th/cmp-path', 'hrsh7th/cmp-nvim-lua', 'onsails/lspkind.nvim' }
  }
  if is_bootstrap then
    require('packer').sync()
  end
end)

-- Don't run additional config if installing packer
if is_bootstrap then
  print '=================================='
  print '    Plugins are being installed'
  print '    Wait until Packer completes,'
  print '       then restart nvim'
  print '=================================='
  return
end

-- Some basic settings
vim.wo.number = true
vim.wo.relativenumber = true
vim.o.pumheight = 20

-- Additional keybinds if lsp running
local on_attach = function(client, bufnr)
  local bufopts = { noremap=true, silent=true, buffer=bufnr }
  vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, bufopts)
  vim.keymap.set('n', 'gd', vim.lsp.buf.definition, bufopts)
end

local lsp_flags = {
  
}

-- lsp configs
require('lspconfig')['tsserver'].setup{
  on_attach = on_attach,
  flags = lsp_flags
}

require('lspconfig')['lua_ls'].setup{
  on_attach = on_attach,
  flags = lsp_flags
}

require('lspconfig')['gopls'].setup{
  on_attach = on_attach,
  flags = lsp_flags
}

-- TreeSitter Config
require('nvim-treesitter.configs').setup{
  ensure_installed = {'go', 'vim', 'typescript', 'help', 'lua', 'javascript', 'python'},
  highlight = {
    enable = true
  }
}

-- autocompletion
local cmp = require 'cmp'
local lspkind = require 'lspkind'
cmp.setup {
  sources = {
    { name = 'nvim_lsp' },
    { name = 'buffer' },
    { name = 'cmdline' },
    { name = 'path' },
    { name = 'nvim-lua' }
  },
  formatting = {
    format = lspkind.cmp_format()
  },
  mapping = cmp.mapping.preset.insert {
    ['<Tab>'] = cmp.mapping(function(fallback)
      if cmp.visible() then
        cmp.select_next_item()
      else
        fallback()
      end
    end, {'i', 's'})
  }
}