local luasnip = require('luasnip')
local cmp = require'cmp'

local has_words_before = function()
	unpack = unpack or table.unpack
	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 kind_icons = {
	Text = "",
	Method = "",
	Function = "",
	Constructor = "",
	Field = "",
	Variable = "",
	Class = "ﴯ",
	Interface = "",
	Module = "",
	Property = "ﰠ",
	Unit = "",
	Value = "",
	Enum = "",
	Keyword = "",
	Snippet = "",
	Color = "",
	File = "",
	Reference = "",
	Folder = "",
	EnumMember = "",
	Constant = "",
	Struct = "",
	Event = "",
	Operator = "",
	TypeParameter = ""
}

cmp.setup({
	snippet = {
		expand = function(args)
			require('luasnip').lsp_expand(args.body)
		end,
	},
	window = {
	},
	mapping = cmp.mapping.preset.insert({
		['<Tab>'] = cmp.mapping(function(fallback)
			if cmp.visible() then
				cmp.select_next_item()
			elseif luasnip.expand_or_jumpable() then
				luasnip.expand_or_jump()
			elseif has_words_before() then
				cmp.complete()
			else
				fallback()
			end
		end, { 'i', 's' }),

		['<S-Tab>'] = cmp.mapping(function(fallback)
			if cmp.visible() then
				cmp.select_prev_item()
			elseif luasnip.jumpable(-1) then
				luasnip.jump(-1)
			else
				fallback()
			end
		end, { 'i', 's' }),
	}),
	sources = cmp.config.sources({
		{ name = 'nvim_lsp' },
		{ name = 'luasnip' },
		{ name = 'omni' },
		{ name = 'buffer' },
	}),
	formatting = {
		format = function(entry, vim_item)
			vim_item.kind = string.format('%s %s', kind_icons[vim_item.kind], vim_item.kind)
			vim_item.menu = ({
				buffer = "[Buffer]",
				nvim_lsp = "[LSP]",
				luasnip = "[LuaSnip]",
				nvim_lua = "[Lua]",
				latex_symbols = "[LaTeX]",
			})[entry.source.name]
			return vim_item
		end
	},
})