local status_ok, lspconfig = pcall(require, "lspconfig")
if not status_ok then
	return
end

-- configure lsp when attached
local function lsp_attach(client, bufnr)
  -- helper functions
  local function set_lsp_sign(name, text)
    vim.fn.sign_define(name, { text = text, texthl = name })
  end

  local map = function(m, lhs, rhs)
    local opts = { remap = false, silent = true, buffer = bufnr }
    vim.keymap.set(m, lhs, rhs, opts)
  end
  set_lsp_sign("DiagnosticSignError", "x")
  set_lsp_sign("DiagnosticSignWarn" , "!")
  set_lsp_sign("DiagnosticSignInfo" , "i")
  set_lsp_sign("DiagnosticSignHint" , "h")

  -- LSP actions
  map('n', 'K', '<cmd>lua vim.lsp.buf.hover()<cr>')
  map('n', 'gD', '<cmd>lua vim.lsp.buf.definition()<cr>')
  -- map('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>')
  map('n', 'gI', '<cmd>lua vim.lsp.buf.implementation()<cr>')
  map('n', 'gY', '<cmd>lua vim.lsp.buf.type_definition()<cr>')
  map('n', 'gR', '<cmd>lua vim.lsp.buf.references()<cr>')
  map('n', '<S-Tab>', '<cmd>lua vim.lsp.buf.signature_help()<cr>')
  map('n', '<leader>lr', '<cmd>lua vim.lsp.buf.rename()<cr>')
  map('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>')

  -- Diagnostics
  map('n', '[d', '<cmd>lua vim.diagnostic.goto_prev()<cr>')
  map('n', ']d', '<cmd>lua vim.diagnostic.goto_next()<cr>')

  vim.api.nvim_buf_create_user_command(bufnr, 'LspFormat', function()
    vim.lsp.buf.format()
  end, {desc = 'Format buffer with language server'})
  vim.api.nvim_buf_create_user_command('LspWorkspaceAdd', function()
    vim.lsp.buf.add_workspace_folder()
    end, { desc = 'Add folder to workspace' })
  vim.api.nvim_buf_create_user_command('LspWorkspaceList', function()
      vim.notify(vim.inspect(vim.lsp.buf.list_workspace_folders()))
    end, { desc = 'List workspace folders' })
  vim.api.nvim_buf_create_user_command('LspWorkspaceRemove', function()
    vim.lsp.buf.remove_workspace_folder()
    end, { desc = 'Remove folder from workspace' })
end

vim.diagnostic.config({
  virtual_text = false,
  signs = true,
  update_in_insert = false,
  underline = true,
  severity_sort = true,
})

vim.lsp.handlers['textDocument/hover'] = vim.lsp.with(vim.lsp.handlers.hover,
  { border = 'shadow', })
vim.lsp.handlers['textDocument/signatureHelp'] = vim.lsp.with(
  vim.lsp.handlers.signature_help, { border = 'shadow' })

-- get servers and attach to them
require('mason').setup {}
require('mason-lspconfig').setup {}

local get_servers = require('mason-lspconfig').get_installed_servers
for _, server_name in ipairs(get_servers()) do
  lspconfig[server_name].setup({ on_attach = lsp_attach, })
end