local ensure_packer = function()
	local fn = vim.fn
	local install_path = fn.stdpath('data')..'/site/pack/packer/start/packer.nvim'
	if fn.empty(fn.glob(install_path)) > 0 then
		fn.system({'git', 'clone', '--depth', '1', 'https://github.com/wbthomason/packer.nvim', install_path})
		vim.cmd [[packadd packer.nvim]]
		return true
	end
	return false
end

local packer_bootstrap = ensure_packer()

return require('packer').startup(function(use)
	use 'wbthomason/packer.nvim'

	use {
		'rose-pine/neovim',
		as = 'rose-pine',
		config = function()
			vim.cmd('colorscheme rose-pine')
		end
	}

	use {
		"SmiteshP/nvim-navic",
		requires = "neovim/nvim-lspconfig"
	}

	use {
		"folke/which-key.nvim",
		config = function()
			require("which-key").setup {
				-- your configuration comes here
				-- or leave it empty to use the default settings
				-- refer to the configuration section below
			}
		end
	}

	use {
		'neovim/nvim-lspconfig',
		config = function()
			local lspconfig = require('lspconfig')
			local capabilities = require('cmp_nvim_lsp').default_capabilities(vim.lsp.protocol.make_client_capabilities())
			local cache = os.getenv("XDG_RUNTIME_DIR") or "/tmp/"

			local on_attach = function(client, bufnr)
				vim.api.nvim_exec_autocmds('User', {pattern = 'LspAttached'})
				require('nvim-navic').attach(client, bufnr)
			end

			lspconfig.ccls.setup {
				on_attach = on_attach,
				capabilities = capabilities,
				single_file_support = true,
				init_options = {
					cache = {
						directory = cache .. "/ccls"
					}
				}
			}

			lspconfig.phpactor.setup {
				on_attach = on_attach,
				capabilities = capabilities
			}

			lspconfig.bashls.setup {
				on_attach = on_attach,
				capabilities = capabilities
			}

			lspconfig.rust_analyzer.setup {
				on_attach = on_attach,
				capabilities = capabilities
			}

			lspconfig.lua_ls.setup {
				on_attach = on_attach,
				capabilities = capabilities,
				settings = {
					Lua = {
						runtime = {
							version = 'LuaJIT',
						},

						diagnostics = {
							globals = {'vim'},
						},

						workspace = {
							library = vim.api.nvim_get_runtime_file("", true),
						},

						telemetry = {
							enable = false,
						}
					}
				}
			}
		end
	}

	use {
		'nvim-treesitter/nvim-treesitter',
		run = ':TSUpdate',
		config = function()
			require'nvim-treesitter.configs'.setup {
				ensure_installed = { "c", "cpp", "php", "lua" },
				sync_install = false,
				auto_install = true,
				highlight = {
					enable = true,
					additional_vim_regex_highlighting = false,
				}
			}
		end
	}

	use {
		'hrsh7th/nvim-cmp',
		requires = {
			'hrsh7th/cmp-nvim-lsp',
			'hrsh7th/cmp-vsnip',
			'hrsh7th/vim-vsnip',
			'hrsh7th/cmp-nvim-lsp-signature-help',
			'hrsh7th/cmp-nvim-lsp-document-symbol',
		},
		config = function()
			-- Setup nvim-cmp.
			local cmp = require'cmp'
			local has_words_before = function()
				local line, col = unpack(vim.api.nvim_win_get_cursor(0))
				return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
			end

			local feedkey = function(key, mode)
				vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes(key, true, true, true), mode, true)
			end

			cmp.setup({
				snippet = {
					-- REQUIRED - you must specify a snippet engine
					expand = function(args)
						vim.fn["vsnip#anonymous"](args.body) -- For `vsnip` users.
						-- require('luasnip').lsp_expand(args.body) -- For `luasnip` users.
						-- require('snippy').expand_snippet(args.body) -- For `snippy` users.
						-- vim.fn["UltiSnips#Anon"](args.body) -- For `ultisnips` users.
					end,
				},
				window = {
					completion = cmp.config.window.bordered(),
					documentation = cmp.config.window.bordered(),
				},
				mapping = cmp.mapping.preset.insert({
					['<C-b>'] = cmp.mapping.scroll_docs(-4),
					['<C-f>'] = cmp.mapping.scroll_docs(4),
					['<C-Space>'] = cmp.mapping.complete(),
					['<C-e>'] = cmp.mapping.abort(),
					['<CR>'] = cmp.mapping.confirm({ select = false }), -- Accept currently selected item. Set `select` to `false` to only confirm explicitly selected items.
					['<Tab>'] = cmp.mapping(function(fallback)
						if cmp.visible() then
							cmp.select_next_item()
						elseif vim.fn["vsnip#available"](1) == 1 then
							feedkey("<Plug>(vsnip-expand-or-jump)", "")
						elseif has_words_before() then
							cmp.complete()
						else
							fallback() -- The fallback function sends a already mapped key. In this case, it's probably `<Tab>`.
						end
					end, { "i", "s" }),
					['<S-Tab>'] = cmp.mapping(function()
						if cmp.visible() then
							cmp.select_prev_item()
						elseif vim.fn["vsnip#jumpable"](-1) == 1 then
							feedkey("<Plug>(vsnip-jump-prev)", "")
						end
					end, { "i", "s" }),
				}),
				sources = cmp.config.sources({
					{ name = 'nvim_lsp' },
					{ name = 'vsnip' }, -- For vsnip users.
					-- { name = 'luasnip' }, -- For luasnip users.
					-- { name = 'ultisnips' }, -- For ultisnips users.
					-- { name = 'snippy' }, -- For snippy users.
					{ name = 'nvim_lsp_signature_help' }
				}, {
					{ name = 'buffer' },
				})
			})
		end
	}

	if packer_bootstrap then
		require('packer').sync()
	end
end)