.dotfiles/nvim/lua/autocompletion.lua

-- Setup nvim-cmp.
local cmp = require 'cmp'

cmp.setup({
  snippet = {
    expand = function(args)
      require('luasnip').lsp_expand(args.body)
    end,
  },
  mapping = {
    ['<C-b>'] = cmp.mapping(cmp.mapping.scroll_docs(-4), { 'i', 'c' }),
    ['<C-f>'] = cmp.mapping(cmp.mapping.scroll_docs(4), { 'i', 'c' }),
    ['<C-n>'] = cmp.mapping(cmp.mapping.select_next_item(), { 'i', 'c' }),
    ['<C-p>'] = cmp.mapping(cmp.mapping.select_prev_item(), { 'i', 'c' }),
    ['<C-Space>'] = cmp.mapping(cmp.mapping.complete(), { 'i', 'c' }),
    ['<C-y>'] = cmp.config.disable, -- Specify `cmp.config.disable` if you want to remove the default `<C-y>` mapping.
    ['<C-e>'] = cmp.mapping({
      i = cmp.mapping.abort(),
      c = cmp.mapping.close(),
    }),
    -- Accept currently selected item. If none selected, `select` first item.
    -- Set `select` to `false` to only confirm explicitly selected items.
    ['<CR>'] = cmp.mapping.confirm({ select = true }),
  },
  sources = cmp.config.sources({
    { name = 'nvim_lsp',
      entry_filter = function(entry, ctx)
        return require('cmp.types').lsp.CompletionItemKind[entry:get_kind()] ~= 'Text'
      end,
    },
    { name = 'luasnip' },
    { name = 'buffer', keyword_length = 5 },
  }),
  experimental = {
    native_menu = false,
    ghost_text = true,
  }
})

-- Use cmdline & path source for ':'
cmp.setup.cmdline(':', {
  sources = cmp.config.sources({
    { name = 'path' }
  }, {
    { name = 'cmdline' }
  })
})

local on_attach = function(client, bufnr)
  local function buf_set_keymap(...)
    vim.api.nvim_buf_set_keymap(bufnr, ...)
  end

  local opts = { noremap = true, silent = true, buffer=0 }
  vim.keymap.set("n", "gd", "<cmd>Telescope lsp_definitions<CR>", opts)
  vim.keymap.set("n", "gD", "<cmd>Telescope lsp_implementations<CR>", opts)
  vim.keymap.set("n", "gf", function() vim.lsp.buf.format {async = true} end, opts)
  vim.keymap.set("n", "K", vim.lsp.buf.hover, opts)
  vim.keymap.set("n", "ge", vim.diagnostic.open_float, opts)
  vim.keymap.set("n", "gs", vim.lsp.buf.signature_help, opts)
  vim.keymap.set("n", "gR", vim.lsp.buf.rename, opts)
  vim.keymap.set("n", "gH", vim.lsp.buf.code_action, opts)
end

-- LSP INSTALLER
require("mason").setup()
require("mason-lspconfig").setup()


require("mason-lspconfig").setup_handlers {
    -- The first entry (without a key) will be the default handler
    -- and will be called for each installed server that doesn't have
    -- a dedicated handler.
    function (server_name) -- default handler (optional)
        require("lspconfig")[server_name].setup {
            on_attach = on_attach,
            capabilities = require("cmp_nvim_lsp").default_capabilities(vim.lsp.protocol.make_client_capabilities())
    }
    end,
    -- Next, you can provide a dedicated handler for specific servers.
    -- For example, a handler override for the `rust_analyzer`:
    ["rust_analyzer"] = function ()
        require("rust-tools").setup {}
    end
}


-- EXTRA SETUP
require'lspconfig'.lua_ls.setup {
  settings = {
    Lua = {
      runtime = {
        -- Tell the language server which version of Lua you're using (most likely LuaJIT in the case of Neovim)
        version = 'LuaJIT',
      },
      diagnostics = {
        -- Get the language server to recognize the `vim` global
        globals = {'vim'},
      },
      workspace = {
        -- Make the server aware of Neovim runtime files
        library = vim.api.nvim_get_runtime_file("", true),
      },
      -- Do not send telemetry data containing a randomized but unique identifier
      telemetry = {
        enable = false,
      },
    },
  },
}


-- LSP SIGNATURE
require "lsp_signature".setup {
  handler_opts = {
    border = "rounded"
  },
  toggle_key = "<M-r>",
}