local nvim_lsp = require('lspconfig')
local cmp = require'cmp'

cmp.setup({
  sources = {
    {name = 'buffer'},
    {name = 'nvim_lsp'},
    {name = 'vsnip'},
  },
  snippet = {
    expand = function(args)
      vim.fn["vsnip#anonymous"](args.body)
    end,
  },
  mapping = {
    ['<C-Space>'] = cmp.mapping.complete(),
    ['<C-e>'] = cmp.mapping.close(),
    ['<CR>'] = cmp.mapping.confirm({ select = true }),
  },
  documentation = {
    border = 'rounded',
  },
})

-- Use an on_attach function to only map the following keys
-- after the language server attaches to the current buffer

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

  -- Mappings.
  local opts = { noremap=true, silent=true }

  -- See `:help vim.lsp.*` for documentation on any of the below functions
  buf_set_keymap('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<CR>', opts)
  buf_set_keymap('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<CR>', opts)
  buf_set_keymap('n', 'K', '<cmd>lua vim.lsp.buf.hover()<CR>', opts)
  buf_set_keymap('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<CR>', opts)
  buf_set_keymap('n', 'gr', '<cmd>lua vim.lsp.buf.references()<CR>', opts)
  buf_set_keymap('n', '<space>e', '<cmd>lua vim.lsp.diagnostic.show_line_diagnostics()<CR>', opts)
  buf_set_keymap('n', '[d', '<cmd>lua vim.lsp.diagnostic.goto_prev()<CR>', opts)
  buf_set_keymap('n', ']d', '<cmd>lua vim.lsp.diagnostic.goto_next()<CR>', opts)
end

-- Setup lspconfig. 
 
--- Use a loop to conveniently call 'setup' on multiple servers and
-- map buffer local keybindings when the language server attaches
local servers = { 'jedi_language_server', 'rust_analyzer', 'tsserver', 'clangd' }
for _, lsp in ipairs(servers) do
  nvim_lsp[lsp].setup {
    capabilities = capabilities,
    on_attach = on_attach,
    flags = {
      debounce_text_changes = 150,
    }
  }
end