From b141ee78162af525b6c7e085f907add41f536896 Mon Sep 17 00:00:00 2001
From: Carsten <carsten@ravensburg.it>
Date: Tue, 21 Apr 2026 22:02:24 +0200
Subject: [PATCH] feat(server): host schema, context, auth, status transitions

---
 server/config/test.exs                        |  2 +
 server/lib/server/hosts.ex                    | 66 +++++++++++++++++++
 server/lib/server/schema/host.ex              | 32 +++++++++
 .../20260421200116_create_hosts.exs           | 19 ++++++
 server/test/server/hosts_test.exs             | 55 ++++++++++++++++
 5 files changed, 174 insertions(+)
 create mode 100644 server/lib/server/hosts.ex
 create mode 100644 server/lib/server/schema/host.ex
 create mode 100644 server/priv/repo/migrations/20260421200116_create_hosts.exs
 create mode 100644 server/test/server/hosts_test.exs

diff --git a/server/config/test.exs b/server/config/test.exs
index 70f1b90..91ee1f4 100644
--- a/server/config/test.exs
+++ b/server/config/test.exs
@@ -26,3 +26,5 @@ config :phoenix, :plug_init_mode, :runtime
 # Enable helpful, but potentially expensive runtime checks
 config :phoenix_live_view,
   enable_expensive_runtime_checks: true
+
+config :bcrypt_elixir, :log_rounds, 4
diff --git a/server/lib/server/hosts.ex b/server/lib/server/hosts.ex
new file mode 100644
index 0000000..b08135f
--- /dev/null
+++ b/server/lib/server/hosts.ex
@@ -0,0 +1,66 @@
+defmodule Server.Hosts do
+  @moduledoc "Host registration, authentication, status tracking."
+
+  alias Server.Repo
+  alias Server.Schema.Host
+
+  @spec create_host(String.t()) :: {:ok, {Host.t(), String.t()}} | {:error, Ecto.Changeset.t()}
+  def create_host(name) do
+    token = generate_token()
+    hash = Bcrypt.hash_pwd_salt(token)
+
+    %Host{}
+    |> Host.create_changeset(%{name: name, token_hash: hash})
+    |> Repo.insert()
+    |> case do
+      {:ok, host} -> {:ok, {host, token}}
+      {:error, cs} -> {:error, cs}
+    end
+  end
+
+  @spec authenticate(String.t(), String.t()) ::
+          {:ok, Host.t()} | {:error, :unknown_host | :invalid_token}
+  def authenticate(name, token) when is_binary(name) and is_binary(token) do
+    case Repo.get_by(Host, name: name) do
+      nil ->
+        Bcrypt.no_user_verify()
+        {:error, :unknown_host}
+
+      host ->
+        if Bcrypt.verify_pass(token, host.token_hash) do
+          {:ok, host}
+        else
+          {:error, :invalid_token}
+        end
+    end
+  end
+
+  @spec mark_online(Host.t(), String.t() | nil) :: {:ok, Host.t()} | {:error, Ecto.Changeset.t()}
+  def mark_online(%Host{} = host, agent_version) do
+    host
+    |> Host.status_changeset(%{
+      status: "online",
+      last_seen_at: DateTime.utc_now(),
+      agent_version: agent_version
+    })
+    |> Repo.update()
+  end
+
+  @spec mark_offline(Host.t()) :: {:ok, Host.t()} | {:error, Ecto.Changeset.t()}
+  def mark_offline(%Host{} = host) do
+    host
+    |> Host.status_changeset(%{status: "offline"})
+    |> Repo.update()
+  end
+
+  @doc "Mark every host offline — called on server boot to clear stale online flags."
+  @spec mark_all_offline() :: {integer(), nil}
+  def mark_all_offline do
+    import Ecto.Query
+    Repo.update_all(from(h in Host), set: [status: "offline", updated_at: DateTime.utc_now()])
+  end
+
+  defp generate_token do
+    :crypto.strong_rand_bytes(32) |> Base.url_encode64(padding: false)
+  end
+end
diff --git a/server/lib/server/schema/host.ex b/server/lib/server/schema/host.ex
new file mode 100644
index 0000000..a2bd68f
--- /dev/null
+++ b/server/lib/server/schema/host.ex
@@ -0,0 +1,32 @@
+defmodule Server.Schema.Host do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  @statuses ~w(never_connected online offline)
+
+  schema "hosts" do
+    field :name, :string
+    field :token_hash, :string
+    field :agent_version, :string
+    field :proxmox_version, :string
+    field :zfs_version, :string
+    field :status, :string, default: "never_connected"
+    field :last_seen_at, :utc_datetime_usec
+
+    timestamps(type: :utc_datetime_usec)
+  end
+
+  def create_changeset(host, attrs) do
+    host
+    |> cast(attrs, [:name, :token_hash])
+    |> validate_required([:name, :token_hash])
+    |> validate_length(:name, min: 1, max: 100)
+    |> unique_constraint(:name)
+  end
+
+  def status_changeset(host, attrs) do
+    host
+    |> cast(attrs, [:status, :last_seen_at, :agent_version])
+    |> validate_inclusion(:status, @statuses)
+  end
+end
diff --git a/server/priv/repo/migrations/20260421200116_create_hosts.exs b/server/priv/repo/migrations/20260421200116_create_hosts.exs
new file mode 100644
index 0000000..1b35a89
--- /dev/null
+++ b/server/priv/repo/migrations/20260421200116_create_hosts.exs
@@ -0,0 +1,19 @@
+defmodule Server.Repo.Migrations.CreateHosts do
+  use Ecto.Migration
+
+  def change do
+    create table(:hosts) do
+      add :name, :string, null: false
+      add :token_hash, :string, null: false
+      add :agent_version, :string
+      add :proxmox_version, :string
+      add :zfs_version, :string
+      add :status, :string, null: false, default: "never_connected"
+      add :last_seen_at, :utc_datetime_usec
+
+      timestamps(type: :utc_datetime_usec)
+    end
+
+    create unique_index(:hosts, [:name])
+  end
+end
diff --git a/server/test/server/hosts_test.exs b/server/test/server/hosts_test.exs
new file mode 100644
index 0000000..7c542aa
--- /dev/null
+++ b/server/test/server/hosts_test.exs
@@ -0,0 +1,55 @@
+defmodule Server.HostsTest do
+  use Server.DataCase, async: true
+
+  alias Server.Hosts
+
+  describe "create_host/1" do
+    test "returns host and a plaintext token on success" do
+      assert {:ok, {host, token}} = Hosts.create_host("pve-01")
+      assert host.name == "pve-01"
+      assert host.status == "never_connected"
+      assert is_binary(token) and byte_size(token) >= 32
+      refute host.token_hash == token
+    end
+
+    test "rejects duplicate names" do
+      {:ok, _} = Hosts.create_host("pve-01")
+      assert {:error, changeset} = Hosts.create_host("pve-01")
+      assert %{name: ["has already been taken"]} = errors_on(changeset)
+    end
+  end
+
+  describe "authenticate/2" do
+    test "returns host for valid name+token" do
+      {:ok, {host, token}} = Hosts.create_host("pve-01")
+      assert {:ok, found} = Hosts.authenticate("pve-01", token)
+      assert found.id == host.id
+    end
+
+    test "returns :invalid_token for wrong token" do
+      {:ok, {_host, _token}} = Hosts.create_host("pve-01")
+      assert {:error, :invalid_token} = Hosts.authenticate("pve-01", "wrong")
+    end
+
+    test "returns :unknown_host when name does not exist" do
+      assert {:error, :unknown_host} = Hosts.authenticate("nope", "whatever")
+    end
+  end
+
+  describe "mark_online/2 and mark_offline/1" do
+    test "mark_online stamps status, last_seen_at, agent_version" do
+      {:ok, {host, _}} = Hosts.create_host("pve-01")
+      assert {:ok, updated} = Hosts.mark_online(host, "0.1.0")
+      assert updated.status == "online"
+      assert updated.agent_version == "0.1.0"
+      assert updated.last_seen_at != nil
+    end
+
+    test "mark_offline sets status to offline" do
+      {:ok, {host, _}} = Hosts.create_host("pve-01")
+      {:ok, online} = Hosts.mark_online(host, "0.1.0")
+      assert {:ok, offline} = Hosts.mark_offline(online)
+      assert offline.status == "offline"
+    end
+  end
+end