lsp.lua

-- [[ Configure LSP ]]
--  This function gets run when an LSP connects to a particular buffer.
local on_attach = function(_, bufnr)
  local signs = { Error = "", Warn = "", Hint = "", Info = "" }
  for type, icon in pairs(signs) do
    local hl = "DiagnosticSign" .. type
    vim.fn.sign_define(hl, { text = icon, texthl = hl, numhl = "" })
  end
  -- NOTE: Remember that lua is a real programming language, and as such it is possible
  -- to define small helper and utility functions so you don't have to repeat yourself
  -- many times.
  --
  -- In this case, we create a function that lets us more easily define mappings specific
  -- for LSP related items. It sets the mode, buffer and description for us each time.
  local nmap = function(keys, func, desc)
    if desc then
      desc = 'LSP: ' .. desc
    end

    vim.keymap.set('n', keys, func, { buffer = bufnr, desc = desc })
  end

  nmap('<leader>rn', vim.lsp.buf.rename, '[R]e[n]ame')
  nmap('<leader>ca', vim.lsp.buf.code_action, '[C]ode [A]ction')

  nmap('gd', vim.lsp.buf.definition, '[G]oto [D]efinition')
  nmap('gr', require('telescope.builtin').lsp_references, '[G]oto [R]eferences')
  nmap('gI', require('telescope.builtin').lsp_implementations, '[G]oto [I]mplementation')
  nmap('<leader>D', vim.lsp.buf.type_definition, 'Type [D]efinition')
  nmap('<leader>ds', require('telescope.builtin').lsp_document_symbols, '[D]ocument [S]ymbols')
  nmap('<leader>ws', require('telescope.builtin').lsp_dynamic_workspace_symbols, '[W]orkspace [S]ymbols')

  -- See `:help K` for why this keymap
  nmap('K', vim.lsp.buf.hover, 'Hover Documentation')
  nmap('<C-k>', vim.lsp.buf.signature_help, 'Signature Documentation')

  -- Lesser used LSP functionality
  nmap('gD', vim.lsp.buf.declaration, '[G]oto [D]eclaration')
  nmap('<leader>wa', vim.lsp.buf.add_workspace_folder, '[W]orkspace [A]dd Folder')
  nmap('<leader>wr', vim.lsp.buf.remove_workspace_folder, '[W]orkspace [R]emove Folder')
  nmap('<leader>wl', function()
    print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
  end, '[W]orkspace [L]ist Folders')

  -- Create a command `:Format` local to the LSP buffer
  vim.api.nvim_buf_create_user_command(bufnr, 'Format', function(_)
    vim.lsp.buf.format()
  end, { desc = 'Format current buffer with LSP' })
end

-- document existing key chains
-- require('which-key').register({
--   ['<leader>c'] = { name = '[C]ode', _ = 'which_key_ignore' },
--   ['<leader>d'] = { name = '[D]ocument', _ = 'which_key_ignore' },
--   ['<leader>g'] = { name = '[G]it', _ = 'which_key_ignore' },
--   ['<leader>h'] = { name = 'More git', _ = 'which_key_ignore' },
--   ['<leader>r'] = { name = '[R]ename', _ = 'which_key_ignore' },
--   ['<leader>s'] = { name = '[S]earch', _ = 'which_key_ignore' },
--   ['<leader>w'] = { name = '[W]orkspace', _ = 'which_key_ignore' },
-- })

-- Enable the following language servers
--  Feel free to add/remove any LSPs that you want here. They will automatically be installed.
--
--  Add any additional override configuration in the following tables. They will be passed to
--  the `settings` field of the server config. You must look up that documentation yourself.
--
--  If you want to override the default filetypes that your language server will attach to you can
--  define the property 'filetypes' to the map in question.
local servers = {
  -- clangd = {},
  -- gopls = {},
  -- pyright = {},
  -- rust_analyzer = {},
  -- tsserver = {},
  -- html = { filetypes = { 'html', 'twig', 'hbs'} },

  lua_ls = {
    Lua = {
      workspace = { checkThirdParty = false },
      telemetry = { enable = false },
    },
  },
}

-- Setup neovim lua configuration
require('neodev').setup()

-- nvim-cmp supports additional completion capabilities, so broadcast that to servers
local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities = require('cmp_nvim_lsp').default_capabilities(capabilities)

-- Ensure the servers above are installed
local mason_lspconfig = require 'mason-lspconfig'

mason_lspconfig.setup {
  ensure_installed = vim.tbl_keys(servers),
}

mason_lspconfig.setup_handlers {
  function(server_name)
    require('lspconfig')[server_name].setup {
      capabilities = capabilities,
      on_attach = on_attach,
      settings = servers[server_name],
      filetypes = (servers[server_name] or {}).filetypes,
    }
  end
}

-- [[ Configure nvim-cmp ]]
-- See `:help cmp`
local cmp = require 'cmp'
local luasnip = require 'luasnip'
require('luasnip.loaders.from_vscode').lazy_load()
luasnip.config.setup {}

cmp.setup {
  snippet = {
    expand = function(args)
      luasnip.lsp_expand(args.body)
    end,
  },
  mapping = cmp.mapping.preset.insert {
    ['<C-n>'] = cmp.mapping.select_next_item(),
    ['<C-p>'] = cmp.mapping.select_prev_item(),
    ['<C-d>'] = cmp.mapping.scroll_docs(-4),
    ['<C-f>'] = cmp.mapping.scroll_docs(4),
    ['<C-Space>'] = cmp.mapping.complete {},
    ['<CR>'] = cmp.mapping.confirm {
      behavior = cmp.ConfirmBehavior.Replace,
      select = true,
    },
    ['<Tab>'] = cmp.mapping(function(fallback)
      if cmp.visible() then
        cmp.select_next_item()
      elseif luasnip.expand_or_locally_jumpable() then
        luasnip.expand_or_jump()
      else
        fallback()
      end
    end, { 'i', 's' }),
    ['<S-Tab>'] = cmp.mapping(function(fallback)
      if cmp.visible() then
        cmp.select_prev_item()
      elseif luasnip.locally_jumpable(-1) then
        luasnip.jump(-1)
      else
        fallback()
      end
    end, { 'i', 's' }),
  },
  sources = {
    { name = 'nvim_lsp' },
    { name = 'luasnip' },
  },
}