vim.diagnostic.config({
  -- only show virtual text for WARN and higher
  virtual_text = { severity = { min = vim.diagnostic.severity.WARN } },
})

local capabilities = require('cmp_nvim_lsp').default_capabilities()

local nvim_lsp = require('lspconfig')

nvim_lsp.bashls.setup({
  capabilities = capabilities,
  on_attach = on_attach,
});

if vim.fn.executable("node_modules/.bin/eslint") == 1 then
  local options = {}
  -- some projects have local rules, this isn't exactly generic but is good
  -- enough
  if vim.fn.isdirectory("lint-rules") == 1 then
    options.rulePaths = { "./lint-rules" }
  end

  nvim_lsp.eslint.setup({
    settings = {
      options = options,
    },
    on_attach = function(client, bufnr)
      -- add formatting capability, the language server registers this
      -- dynamically but neovim does not support that yet
      -- https://github.com/microsoft/vscode-eslint/pull/1307
      client.server_capabilities.documentFormattingProvider = true
      client.server_capabilities.documentRangeFormattingProvider = true

      -- mappings should have been attached by typescript and re-attaching can
      -- overwrite the typescript specific overrides
    end,
  })
end

if vim.fn.executable("dprint") == 1 then
  local version = vim.version.parse(vim.fn.system("dprint --version"))
  if vim.version.cmp(version, {0,45,0}) >= 0 then
    nvim_lsp.dprint.setup({})
  end
end

if vim.fn.executable("deno") == 1 then
  nvim_lsp.denols.setup({
    capabilities = capabilities,
    on_attach = on_attach,
  });
else
  require('typescript').setup({
    server = {
      init_options = {
        completionDisableFilterText = true,
        preferences = {
          importModuleSpecifierPreference = 'non-relative',
        },
      },
      capabilities = capabilities,
      handlers = {
        ['$/typescriptVersion'] = function(err, result, ctx, config)
          vim.notify(string.format('Typescript %s', result.version))
        end
      },
      flags = {
        debounce_text_changes = 150,
      },
      on_attach = function(client, bufnr)
        -- mark tsserver as not having formatting available as we rely on
        -- eslint for that
        client.server_capabilities.documentFormattingProvider = false
        client.server_capabilities.documentRangeFormattingProvider = false

        on_attach(client, bufnr)

        -- override mappings for typescript
        local opts = { silent = true, buffer = bufnr }
        -- exclude import statements from reference search (may have false positives)
        vim.keymap.set('n', 'gr', '<cmd>Telescope lsp_references default_text=!import\\ <CR>', opts)
        vim.keymap.set('n', 'gD', '<cmd>Telescope lsp_definitions<CR>', opts)
        vim.keymap.set('n', 'gd', '<cmd>TypescriptGoToSourceDefinition<CR>', opts)
      end
    }
  })
end

if vim.fn.executable("gopls") == 1 then
  nvim_lsp.gopls.setup({
    capabilities = capabilities,
    on_attach = on_attach,
  });
end

if vim.fn.executable("solargraph") == 1 then
  nvim_lsp.solargraph.setup({
    capabilities = capabilities,
    on_attach = on_attach,
    init_options = {
      formatting = false,
    }
  })
end

if vim.fn.executable("nil") == 1 then
  nvim_lsp.nil_ls.setup({
    on_attach = on_attach,
  });
end

-- format on save
local group = vim.api.nvim_create_augroup('LspFormatting', { clear = false })

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

    if client.server_capabilities.documentFormattingProvider then
      for key, cmd in pairs(vim.api.nvim_get_autocmds({ group = group, buffer = bufnr })) do
        vim.api.nvim_del_autocmd(cmd.id)
      end
      vim.api.nvim_create_autocmd('BufWritePre', {
        group = group,
        buffer = bufnr,
        callback = function()
          vim.lsp.buf.format()
        end,
      })
    end
  end,
})

-- custom LSP servers
local configs = require('lspconfig.configs')

if not configs.elvish then
  configs.elvish = {
    default_config = {
      cmd = {'elvish', '--lsp'},
      filetypes = {'elvish'},
      root_dir = nvim_lsp.util.root_pattern('*.elv'),
      settings = {},
    },
  }
end

nvim_lsp.elvish.setup({
  capabilities = capabilities,
  on_attach = on_attach,
})