local has_words_before = function()
    if vim.api.nvim_buf_get_option(0, "buftype") == "prompt" then
        return false
    end
    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

local lsp_symbols = {
    Text = "   (Text) ",
    Method = "   (Method)",
    Function = "   (Function)",
    Constructor = "   (Constructor)",
    Field = " ﴲ  (Field)",
    Variable = "[] (Variable)",
    Class = "   (Class)",
    Interface = " ﰮ  (Interface)",
    Module = "   (Module)",
    Property = " 襁 (Property)",
    Unit = "   (Unit)",
    Value = "   (Value)",
    Enum = " 練 (Enum)",
    Keyword = "   (Keyword)",
    Snippet = "   (Snippet)",
    Color = "   (Color)",
    File = "   (File)",
    Reference = "   (Reference)",
    Folder = "   (Folder)",
    EnumMember = "   (EnumMember)",
    Constant = " ﲀ  (Constant)",
    Struct = " ﳤ  (Struct)",
    Event = "   (Event)",
    Operator = "   (Operator)",
    TypeParameter = "   (TypeParameter)",
}

local status, cmp = pcall(require, "cmp")
if (not status) then return end

cmp.setup {
    completion = {
        completeopt = 'menuone,noinsert,noselect',
    },
    formatting = {
        format = function(entry, vim_item)
            -- fancy icons and a name of kind
            vim_item.kind = lsp_symbols[vim_item.kind]
            -- set a name for each source
            vim_item.menu = ({
                buffer = "[Buffer]",
                nvim_lsp = "[LSP]",
                vsnip = "[vSnip]",
                path = "[Path]",
                spell = "[Spell]",
            })[entry.source.name]
            return vim_item
        end,
    },
    snippet = {
        expand = function(args)
            vim.fn["vsnip#anonymous"](args.body)
        end,
    },
    mapping = {
        ["<cr>"] = cmp.mapping.confirm({ select = false, behavior = cmp.ConfirmBehavior.Replace }),
        -- ["<Tab>"] = cmp.mapping.confirm({select = true, behavior = cmp.ConfirmBehavior.Insert}),
        ["<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 = {
        { name = 'vsnip' },
        { name = 'nvim_lsp' },
        { name = 'path' },
        {
            name = 'buffer',
            keyword_length = 4,
            keyword_pattern = [[\d\@!\k\k*]],
            options = {
                -- keyword_pattern = [[\k\+]]-- for non ascii caracters
                keyword_pattern = [[\d\@!\k\k*]],
            }
        },
        -- { name = 'spell', keyword_length = 4 },
    },
    experimental = {
        -- I like the new menu better! Nice work hrsh7th
        native_menu = false,

        -- Let's play with this for a day or two
        ghost_text = true,
    },
}

-- Use buffer source for `/` (if you enabled `native_menu`, this won't work anymore).
cmp.setup.cmdline('/', {
    mapping = cmp.mapping.preset.cmdline(),
    sources = {
        { name = 'buffer' }
    }
})

cmp.setup.cmdline(':', {
    mapping = cmp.mapping.preset.cmdline(),
    sources = cmp.config.sources({
        { name = 'path' },
        { name = 'cmdline' }
    })
})


vim.cmd [[autocmd FileType TelescopePrompt lua require('cmp').setup.buffer { enabled = false }]]
vim.g.vsnip_snippet_dir = '~/.config/nvim/vsnips'