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

local function lsp_keymaps(bufnr)
  local map = function(m, lhs, rhs)
    local opts = {remap = false, silent = true, buffer = bufnr}
    vim.keymap.set(m, lhs, rhs, opts)
  end

  -- 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', 'go', '<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', '<F2>', '<cmd>lua vim.lsp.buf.rename()<cr>')
  map('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>')

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

local function set_lsp_sign(name, text)
  vim.fn.sign_define(name, {text = text, texthl = name})
end
set_lsp_sign("DiagnosticSignError", "x")
set_lsp_sign("DiagnosticSignWarn" , "!")
set_lsp_sign("DiagnosticSignInfo" , "i")
set_lsp_sign("DiagnosticSignHint" , "h")

local function lsp_settings()
  local sign = function(opts)
    vim.fn.sign_define(opts.name, {
      texthl = opts.name,
      text = opts.text,
      numhl = ''
    })
  end

  vim.diagnostic.config({
    virtual_text = false,
    signs = true,
    update_in_insert = false,
    underline = true,
    severity_sort = true,
    float = {
      focusable = false,
      show_header = true,
      style = 'minimal',
      border = 'shadow',
      source = 'always',
      header = '',
      prefix = '* ',
    },
  })

  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'}
  )
  local command = vim.api.nvim_create_user_command
  command('LspWorkspaceAdd', function()
    vim.lsp.buf.add_workspace_folder()
  end, {desc = 'Add folder to workspace'})
  command('LspWorkspaceList', function()
    vim.notify(vim.inspect(vim.lsp.buf.list_workspace_folders()))
  end, {desc = 'List workspace folders'})
  command('LspWorkspaceRemove', function()
    vim.lsp.buf.remove_workspace_folder()
  end, {desc = 'Remove folder from workspace'})
end

local function lsp_attach(client, bufnr)
  local buf_command = vim.api.nvim_buf_create_user_command

  lsp_keymaps(bufnr)

  buf_command(bufnr, 'LspFormat', function()
    vim.lsp.buf.format()
  end, {desc = 'Format buffer with language server'})
end

lsp_settings()

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,
    capabilities = require('cmp_nvim_lsp').default_capabilities(),
  })
end