# `checks.vm-hive-squid`: runs ../host-modules/hive-squid.nix in a VM, which
# the module-eval suite can only read. Three nodes on two networks:
#
#   agent (vlan 1) --> proxy (vlan 1 = the stand-in bridge, vlan 2 = uplink) --> web (vlan 2)
#
# `proxy` imports the squid module against stub options for the few hive
# options it reads, so no hive-c0re build is pulled in; the module-eval suite
# covers the real option wiring.
{ pkgs }:
let
  bridgeIp = "192.168.1.1";

  hiveStubs =
    { lib, config, ... }:
    {
      options.services.hyperhive = {
        deploy.hive-controller.enable = lib.mkOption {
          type = lib.types.bool;
          default = true;
        };
        swarm.serviceDomains = lib.mkOption {
          type = lib.types.listOf lib.types.str;
          default = [ "forge.t.local" ];
        };
        swarm.forge.domain = lib.mkOption {
          type = lib.types.str;
          default = "forge.t.local";
        };
        network = {
          bridgeIp = lib.mkOption {
            type = lib.types.str;
            default = bridgeIp;
          };
          networkCidr = lib.mkOption {
            type = lib.types.str;
            default = "192.168.1.0/24";
          };
          exposeHostPorts = lib.mkOption {
            type = lib.types.listOf lib.types.port;
            default = [ ];
          };
          enable = lib.mkOption {
            type = lib.types.bool;
            default = true;
          };
        };
        otel = {
          scrapeTargets = lib.mkOption {
            type = lib.types.attrsOf lib.types.str;
            default = { };
          };
          journalUnits = lib.mkOption {
            type = lib.types.listOf lib.types.str;
            default = [ ];
          };
        };
      };
      # The firewall hole hive-network.nix opens for `exposeHostPorts`.
      config.networking.firewall.interfaces.eth1.allowedTCPPorts =
        config.services.hyperhive.network.exposeHostPorts;
    };

  # Plain TCP on 443: a CONNECT is answered before any TLS, which is all the
  # test reads.
  listen443 = addrs: {
    services.nginx = {
      enable = true;
      virtualHosts.default.listen = map (addr: {
        inherit addr;
        port = 443;
      }) addrs;
    };
  };
in
pkgs.testers.runNixOSTest {
  name = "hive-squid";

  nodes = {
    proxy =
      { lib, ... }:
      {
        imports = [
          hiveStubs
          ../host-modules/hive-squid.nix
          # Listeners a leaked destination would reach: loopback and the bridge.
          (listen443 [
            "127.0.0.1"
            bridgeIp
          ])
        ];
        virtualisation.vlans = [
          1
          2
        ];
        networking.interfaces.eth1.ipv4.addresses = lib.mkForce [
          {
            address = bridgeIp;
            prefixLength = 24;
          }
        ];
        networking.interfaces.eth2.ipv4.addresses = lib.mkForce [
          {
            address = "192.168.2.1";
            prefixLength = 24;
          }
        ];
        # Names the proxy resolves, each a different destination class.
        networking.hosts = {
          "192.168.2.2" = [ "forge.t.local" ];
          "127.0.0.1" = [ "loop.t.local" ];
          ${bridgeIp} = [ "bridge.t.local" ];
          "169.254.169.254" = [ "meta.t.local" ];
        };
        services.hyperhive.squid.allowedDomains = [
          "forge.t.local"
          "loop.t.local"
          "bridge.t.local"
          "meta.t.local"
        ];
      };

    web =
      { lib, ... }:
      {
        imports = [ (listen443 [ "0.0.0.0" ]) ];
        virtualisation.vlans = [ 2 ];
        networking.interfaces.eth1.ipv4.addresses = lib.mkForce [
          {
            address = "192.168.2.2";
            prefixLength = 24;
          }
        ];
        networking.firewall.allowedTCPPorts = [ 443 ];
      };

    agent =
      { lib, ... }:
      {
        virtualisation.vlans = [ 1 ];
        networking.interfaces.eth1.ipv4.addresses = lib.mkForce [
          {
            address = "192.168.1.3";
            prefixLength = 24;
          }
        ];
      };
  };

  testScript = ''
    import re

    start_all()
    proxy.wait_for_unit("squid.service")
    proxy.wait_for_unit("squid-exporter.service")
    proxy.wait_for_unit("nginx.service")
    web.wait_for_unit("nginx.service")
    proxy.wait_for_open_port(3128, "${bridgeIp}")

    def connect(host):
        # The status squid answered the CONNECT with; 000 when none came back.
        return agent.succeed(
            "curl -sS -m 15 -p -x http://${bridgeIp}:3128 -o /dev/null "
            f"-w '%{{http_connect}}' https://{host}/ 2>/dev/null || true"
        ).strip()

    with subtest("an allowed name is tunnelled and an unlisted one is refused"):
        assert connect("forge.t.local") == "200", "allow canary"
        assert connect("deny-canary.invalid") == "403", "deny canary"

    with subtest("a name resolving to a host-local destination is refused"):
        assert connect("loop.t.local") == "403", "loopback"
        assert connect("bridge.t.local") == "403", "bridge address"
        assert connect("meta.t.local") == "403", "link-local"

    with subtest("IP literals are refused even when the address is reachable"):
        assert connect("127.0.0.1") == "403"
        assert connect("192.168.2.2") == "403"

    with subtest("only a port-443 CONNECT is allowed"):
        assert connect("forge.t.local:22") == "403"
        assert connect("forge.t.local:80") == "403"

    with subtest("an agent cannot read cachemgr"):
        agent.succeed(
            "test $(curl -s -m 15 -o /dev/null -w '%{http_code}' "
            "http://${bridgeIp}:3128/squid-internal-mgr/counters) = 403"
        )

    with subtest("the self-check passes against the same squid"):
        proxy.succeed("systemctl start squid-selfcheck.service")
        proxy.succeed(
            "journalctl -u squid-selfcheck.service -o cat | "
            "grep -F 'squid-selfcheck ok=true allow_canary=forge.t.local "
            "allow_status=200 deny_canary=deny-canary.invalid deny_status=403'"
        )

    with subtest("squid's access log reaches the journal under squid.service"):
        log = proxy.succeed("journalctl -u squid.service -o cat")
        assert re.search(r"192\.168\.1\.3 TCP_TUNNEL/200 .* CONNECT forge\.t\.local:443", log), log
        assert re.search(r"192\.168\.1\.3 TCP_DENIED/403 .* CONNECT deny-canary\.invalid:443", log), log
        assert re.search(r"192\.168\.1\.3 TCP_DENIED/403 .* CONNECT loop\.t\.local:443", log), log
        # Exporter scrapes are cachemgr requests and stay out of the log.
        assert "squid-internal-mgr" not in log, log

    with subtest("the exporter serves squid's counters on loopback"):
        metrics = proxy.succeed("curl -sf http://127.0.0.1:9301/metrics")
        print("\n".join(l for l in metrics.splitlines() if l.startswith(("squid_up", "squid_client_http"))))
        assert 'squid_up{host="${bridgeIp}"} 1' in metrics
        m = re.search(r"^squid_client_http_requests_total (\S+)$", metrics, re.M)
        assert m and float(m.group(1)) >= 9, metrics
        m = re.search(r"^squid_client_http_errors_total (\S+)$", metrics, re.M)
        assert m and float(m.group(1)) >= 1, metrics
        proxy.fail("curl -sf -m 5 http://${bridgeIp}:9301/metrics")

    with subtest("squid survives a reload"):
        proxy.succeed("systemctl reload squid.service")
        proxy.wait_for_unit("squid.service")
        assert connect("forge.t.local") == "200"
  '';
}