return {
  'nvim-lspconfig',
  event = { 'BufReadPost', 'BufWritePost', 'BufNewFile' },
  before = function()
    require('lz.n').trigger_load('blink.cmp')
  end,
  after = function()
    local i = require('icons')

    local opts = {
      ---@class vim.diagnostic.Opts
      diagnostics = {
        underline = true,
        update_in_insert = false,
        virtual_text = {
          spacing = 4,
          source = 'if_many',
          prefix = function(diagnostic)
            for d, icon in pairs(i.diagnostics) do
              if diagnostic.severity == vim.diagnostic.severity[d:upper()] then
                return icon
              end
            end

            return '●'
          end,
        },
        severity_sort = true,
        signs = {
          text = {
            [vim.diagnostic.severity.ERROR] = i.diagnostics.Error,
            [vim.diagnostic.severity.WARN] = i.diagnostics.Warn,
            [vim.diagnostic.severity.HINT] = i.diagnostics.Hint,
            [vim.diagnostic.severity.INFO] = i.diagnostics.Info,
          },
        },
      },

      capabilities = {
        workspace = {
          fileOperations = {
            didRename = true,
            willRename = true,
          },
        },
      },

      servers = {
        lua_ls = {
          settings = {
            Lua = {
              workspace = { checkThirdParty = false },
              codeLens = { enable = true },
              completion = { callSnippet = 'Replace' },
              doc = { privateName = { '^_' } },
              hint = {
                enable = true,
                setType = false,
                paramType = true,
                paramName = 'Disable',
                semicolon = 'Disable',
                arrayIndex = 'Disable',
              },
            },
          },
        },
      },
    }

    -- Codelens.
    vim.api.nvim_create_autocmd('User', {
      pattern = 'LspSupportsMethod',
      callback = function(args)
        local client = vim.lsp.get_client_by_id(args.data.client_id)
        local buffer = args.data.buffer

        if client and args.data.method == 'textDocument/codeLens' then
          vim.lsp.codelens.refresh()

          vim.api.nvim_create_autocmd(
            { 'BufEnter', 'CursorHold', 'InsertLeave' },
            {
              buffer = buffer,
              callback = vim.lsp.codelens.refresh,
            }
          )
        end
      end,
    })

    -- Diagnostics.
    vim.diagnostic.config(vim.deepcopy(opts.diagnostics))

    -- Server setup.
    local has_blink, blink = pcall(require, 'blink.cmp')
    local capabilities = vim.tbl_deep_extend(
      'force',
      {},
      vim.lsp.protocol.make_client_capabilities(),
      has_blink and blink.get_lsp_capabilities() or {},
      opts.capabilities
    )

    local function setup(server)
      local server_opts = vim.tbl_deep_extend('force', {
        capabilities = vim.deepcopy(capabilities),
      }, opts.servers[server] or {})

      if server_opts.enabled == false then
        return
      end

      if opts.setup and opts.setup[server] then
        if opts.setup[server](server, server_opts) then
          return
        end
      end

      require('lspconfig')[server].setup(server_opts)
    end

    for server, server_opts in pairs(opts.servers) do
      if server_opts.enabled ~= false then
        setup(server)
      end
    end

    -- Set keymaps.
    vim.api.nvim_create_autocmd('LspAttach', {
      callback = function(args)
        local client = vim.lsp.get_client_by_id(args.data.client_id)

        if not client then
          return
        end

        local set = vim.keymap.set

        set('n', '<LEADER>cl', '<CMD>LspInfo<CR>', { desc = 'lsp info' })
        set('n', 'gD', vim.lsp.buf.declaration, { desc = 'declaration' })
        set('n', 'gI', vim.lsp.buf.implementation, { desc = 'implementation' })

        set(
          'n',
          'gr',
          vim.lsp.buf.references,
          { desc = 'references', nowait = true }
        )

        set(
          'n',
          'gy',
          vim.lsp.buf.type_definition,
          { desc = 'type definition' }
        )

        set('n', 'K', function()
          return vim.lsp.buf.hover()
        end, { desc = 'hover' })

        if client.supports_method('textDocument/codeAction') then
          set(
            { 'n', 'v' },
            '<LEADER>ca',
            vim.lsp.buf.code_action,
            { desc = 'code action' }
          )
        end

        if client.supports_method('textDocument/codeLens') then
          set(
            { 'n', 'v' },
            '<LEADER>cc',
            vim.lsp.codelens.run,
            { desc = 'run codelens' }
          )

          set(
            'n',
            '<LEADER>cC',
            vim.lsp.codelens.refresh,
            { desc = 'refresh & display codelens' }
          )
        end

        if client.supports_method('textDocument/definition') then
          set('n', 'gd', vim.lsp.buf.definition, { desc = 'definition' })
        end

        if client.supports_method('textDocument/documentHighlight') then
          if Snacks.words.is_enabled() then
            set('n', '<A-n>', function()
              Snacks.words.jump(vim.v.count1, true)
            end, { desc = 'next reference' })

            set('n', '<A-p>', function()
              Snacks.words.jump(-vim.v.count1, true)
            end, { desc = 'prev reference' })

            set('n', ']]', function()
              Snacks.words.jump(vim.v.count1)
            end, { desc = 'next reference' })

            set('n', '[[', function()
              Snacks.words.jump(-vim.v.count1)
            end, { desc = 'prev reference' })
          end
        end

        if client.supports_method('textDocument/rename') then
          set('n', '<LEADER>cr', vim.lsp.buf.rename, { desc = 'rename' })
        end

        if client.supports_method('textDocument/signatureHelp') then
          set('i', '<C-k>', function()
            return vim.lsp.buf.signature_help()
          end, { desc = 'signature help' })

          set('n', 'gK', function()
            vim.lsp.buf.signature_help()
          end, { desc = 'signature help' })
        end

        if
          client.supports_method('workspace/didRenameFiles')
          or client.supports_method('workspace/willRenameFiles')
        then
          set('n', '<LEADER>cR', function()
            Snacks.rename.rename_file()
          end, { desc = 'rename file' })
        end
      end,
    })
  end,
}