nvim/lua/config/nvim-cmp.lua

--[[
    Copyright 2023 Oscar Wallberg

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        https://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
]]

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

cmp.setup({
    enabled = function()
        -- disable completion in comments
        local context = require 'cmp.config.context'
        -- keep command mode completion enabled when cursor is in a comment
        if vim.api.nvim_get_mode().mode == 'c' then
            return true
        else
            return not context.in_treesitter_capture('comment') and
                not context.in_syntax_group('Comment')
        end
    end,
    completion = { keyword_length = 3 },
    snippet = {
        expand = function(args)
            -- vim.fn["vsnip#anonymous"](args.body) -- For `vsnip` users.
            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
    },
    formatting = {
        format = function(entry, vim_item)
            vim_item = lspkind.cmp_format({
                mode = 'text',     -- show only symbol annotations
                maxwidth = 50,     -- prevent the popup from showing more than provided characters (e.g 50 will not show more than 50 characters)
                ellipsis_char =
                '...'              -- when popup menu exceed maxwidth, the truncated part would show ellipsis_char instead (must define maxwidth first)

                -- The function below will be called before any actual modifications from lspkind
                -- so that you can provide more controls on popup customization. (See [#30](https://github.com/onsails/lspkind-nvim/pull/30))
                --[[ before = function(entry, vim_item)
                        ...
                        return vim_item
                    end ]]
            })(entry, vim_item)

            vim_item.dup = 0

            return vim_item
        end
    },
    experimental = { ghost_text = true },
    mapping = {
        ['<C-p>'] = cmp.mapping.select_prev_item(),
        ['<C-n>'] = cmp.mapping.select_next_item(),
        ['<C-d>'] = cmp.mapping.scroll_docs(-4),
        ['<C-f>'] = cmp.mapping.scroll_docs(4),
        ['<C-Space>'] = cmp.mapping.complete(),
        ['<C-e>'] = cmp.mapping.close(),
        ['<CR>'] = cmp.mapping(
            function(fallback)
                if cmp.visible() then
                    cmp.confirm(
                        {
                            behavior = cmp.ConfirmBehavior.Replace,
                            select = true
                        }
                    )
                    -- vim.api.nvim_feedkeys('(', 'i', true)
                else
                    fallback()
                end
            end, { 'i', 's' }
        ),
        -- ['<Down>'] = cmp.mapping(
        --     function(fallback)
        --         if cmp.visible() then
        --             cmp.select_next_item()
        --         elseif luasnip.expand_or_jumpable() then
        --             luasnip.expand_or_jump()
        --         else
        --             fallback()
        --         end
        --     end, { 'i', 's' }
        -- ),

        -- ['<Up>'] = 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' }
        -- ),
        ['<Tab>'] = cmp.mapping(
            function(fallback)
                if cmp.visible() then
                    cmp.select_next_item()
                    -- You could replace the expand_or_jumpable() calls within expand_or_locally_jumpable()
                    -- they way you will only jump inside the snippet region
                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 = {
        -- { name = 'buffer' },
        { name = 'path' },
        { name = 'nvim_lsp' },
        -- { name = 'nvim_lsp_signature_help' },
        -- { name = 'nvim_lua' },
        -- { name = 'vsnip' }, -- For vsnip users.
        { name = 'luasnip' } -- For luasnip users.
        -- { name = 'ultisnips' }, -- For ultisnips users.
        -- { name = 'snippy' }, -- For snippy users.
    }
})
--  see https://github.com/hrsh7th/nvim-cmp/wiki/Menu-Appearance#how-to-add-visual-studio-code-dark-theme-colors-to-the-menu
-- -- gray
-- vim.fn.execute("highlight! CmpItemAbbrDeprecated guibg=NONE gui=strikethrough guifg=#808080")
-- -- blue
-- vim.fn.execute("highlight! CmpItemAbbrMatch guibg=NONE guifg=#569CD6")
-- vim.fn.execute("highlight! CmpItemAbbrMatchFuzzy guibg=NONE guifg=#569CD6")
-- -- light blue
-- vim.fn.execute("highlight! CmpItemKindVariable guibg=NONE guifg=#9CDCFE")
-- vim.fn.execute("highlight! CmpItemKindInterface guibg=NONE guifg=#9CDCFE")
-- vim.fn.execute("highlight! CmpItemKindText guibg=NONE guifg=#9CDCFE")
-- -- pink
-- vim.fn.execute("highlight! CmpItemKindFunction guibg=NONE guifg=#C586C0")
-- vim.fn.execute("highlight! CmpItemKindMethod guibg=NONE guifg=#C586C0")
-- -- front
-- vim.fn.execute("highlight! CmpItemKindKeyword guibg=NONE guifg=#D4D4D4")
-- vim.fn.execute("highlight! CmpItemKindProperty guibg=NONE guifg=#D4D4D4")
-- vim.fn.execute("highlight! CmpItemKindUnit guibg=NONE guifg=#D4D4D4")

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', option = { ignore_cmds = { 'Man', '!' } } } }
        )
    }
)

local cmp_autopairs = require('nvim-autopairs.completion.cmp')
cmp.event:on(
    'confirm_done',
    cmp_autopairs.on_confirm_done()
)