local function reload_workspace(bufnr)
   local clients = vim.lsp.get_clients { bufnr = bufnr, name = 'rust_analyzer' }
   for _, client in ipairs(clients) do
      vim.notify 'Reloading Cargo Workspace'
      client.request('rust-analyzer/reloadWorkspace', nil, function(err)
         if err then
            error(tostring(err))
         end
         vim.notify 'Cargo workspace reloaded'
      end, 0)
   end
end

local function is_library(fname)
   local user_home = vim.fs.normalize(vim.env.HOME)
   local cargo_home = os.getenv 'CARGO_HOME' or user_home .. '/.cargo'
   local registry = cargo_home .. '/registry/src'
   local git_registry = cargo_home .. '/git/checkouts'

   local rustup_home = os.getenv 'RUSTUP_HOME' or user_home .. '/.rustup'
   local toolchains = rustup_home .. '/toolchains'

   for _, item in ipairs { toolchains, registry, git_registry } do
      if vim.fs.relpath(item, fname) then
         local clients = vim.lsp.get_clients { name = 'rust_analyzer' }
         return #clients > 0 and clients[#clients].config.root_dir or nil
      end
   end
end

return {
   cmd = { 'rust-analyzer' },
   filetypes = { 'rust' },
   root_dir = function(bufnr, on_dir)
      local fname = vim.api.nvim_buf_get_name(bufnr)
      local reused_dir = is_library(fname)
      if reused_dir then
         on_dir(reused_dir)
         return
      end

      local cargo_crate_dir = vim.fs.root(fname, { 'Cargo.toml' })
      local cargo_workspace_root

      if cargo_crate_dir == nil then
         on_dir(
            vim.fs.root(fname, { 'rust-project.json' })
            or vim.fs.dirname(vim.fs.find('.git', { path = fname, upward = true })[1])
         )
         return
      end

      local cmd = {
         'cargo',
         'metadata',
         '--no-deps',
         '--format-version',
         '1',
         '--manifest-path',
         cargo_crate_dir .. '/Cargo.toml',
      }

      vim.system(cmd, { text = true }, function(output)
         if output.code == 0 then
            if output.stdout then
               local result = vim.json.decode(output.stdout)
               if result['workspace_root'] then
                  cargo_workspace_root = vim.fs.normalize(result['workspace_root'])
               end
            end

            on_dir(cargo_workspace_root or cargo_crate_dir)
         else
            vim.schedule(function()
               vim.notify(('[rust_analyzer] cmd failed with code %d: %s\n%s'):format(output.code, cmd, output.stderr))
            end)
         end
      end)
   end,
   capabilities = {
      experimental = {
         serverStatusNotification = true,
      },
   },
   before_init = function(init_params, config)
      -- See https://github.com/rust-lang/rust-analyzer/blob/eb5da56d839ae0a9e9f50774fa3eb78eb0964550/docs/dev/lsp-extensions.md?plain=1#L26
      if config.settings and config.settings['rust-analyzer'] then
         init_params.initializationOptions = config.settings['rust-analyzer']
      end
   end,
   on_attach = function()
      vim.api.nvim_buf_create_user_command(0, 'LspCargoReload', function()
         reload_workspace(0)
      end, { desc = 'Reload current cargo workspace' })
   end,

   settings = {
      ["rust-analyzer"] = {
         -- Other Settings ...
         procMacro = {
            ignored = {
               leptos_macro = {
                  -- optional: --
                  -- "component",
                  "server",
               },
            },
         },
      },
   },
}
