import ./make-test-python.nix (
  { lib, pkgs, ... }:

  # This nixosTest is supposed to check the following:
  #
  # - Whether syncthing's API handles multiple requests for many devices, see
  #   https://github.com/NixOS/nixpkgs/issues/260262
  #
  # - Whether syncthing-init.service generated bash script removes devices and
  #   folders that are not present in the user's configuration, which is partly
  #   injected into the script. See also:
  #   https://github.com/NixOS/nixpkgs/issues/259256
  #

  let
    # Just a long path not to copy paste
    configPath = "/var/lib/syncthing/.config/syncthing/config.xml";

    # We will iterate this and more attribute sets defined here, later in the
    # testScript. Start with this, and distinguish these settings from other
    # settings, as we check these differently with xmllint, due to the ID.
    settingsWithId = {
      devices = {
        # All of the device IDs used here were generated by the following command:
        #
        #    (${pkgs.syncthing}/bin/syncthing generate --home /tmp/foo\
        #       | grep ID: | sed 's/.*ID: *//') && rm -rf /tmp/foo
        #
        # See also discussion at:
        # https://forum.syncthing.net/t/how-to-generate-dummy-device-ids/20927/8
        test_device1.id = "IVTZ5XF-EF3GKFT-GS4AZLG-IT6H2ZP-6WK75SF-AFXQXJJ-BNRZ4N6-XPDKVAU";
        test_device2.id = "5C35H56-Z2GFF4F-F3IVD4B-GJYVWIE-SMDBJZN-GI66KWP-52JIQGN-4AVLYAM";
        test_device3.id = "XKLSKHE-BZOHV7B-WQZACEF-GTH36NP-6JSBB6L-RXS3M7C-EEVWO2L-C5B4OAJ";
        test_device4.id = "APN5Q7J-35GZETO-5KCLF35-ZA7KBWK-HGWPBNG-FERF24R-UTLGMEX-4VJ6PQX";
        test_device5.id = "D4YXQEE-5MK6LIK-BRU5QWM-ZRXJCK2-N3RQBJE-23JKTQQ-LYGDPHF-RFPZIQX";
        test_device6.id = "TKMCH64-T44VSLI-6FN2YLF-URBZOBR-ATO4DYX-GEDRIII-CSMRQAI-UAQMDQG";
        test_device7.id = "472EEBG-Q4PZCD4-4CX6PGF-XS3FSQ2-UFXBZVB-PGNXWLX-7FKBLER-NJ3EMAR";
        test_device8.id = "HW6KUMK-WTBG24L-2HZQXLO-TGJSG2M-2JG3FHX-5OGYRUJ-T6L5NN7-L364QAZ";
        test_device9.id = "YAE24AP-7LSVY4T-J74ZSEM-A2IK6RB-FGA35TP-AG4CSLU-ED4UYYY-2J2TDQU";
        test_device10.id = "277XFSB-OFMQOBI-3XGNGUE-Y7FWRV3-QQDADIY-QIIPQ26-EOGTYKW-JP2EXAI";
        test_device11.id = "2WWXVTN-Q3QWAAY-XFORMRM-2FDI5XZ-OGN33BD-XOLL42R-DHLT2ML-QYXDQAU";
      };
      # Generates a few folders with IDs and paths as written...
      folders = lib.pipe 6 [
        (builtins.genList (x: {
          name = "/var/lib/syncthing/test_folder${builtins.toString x}";
          value = {
            id = "DontDeleteMe${builtins.toString x}";
          };
        }))
        builtins.listToAttrs
      ];
    };
    # Non default options that we check later if were applied
    settingsWithoutId = {
      options = {
        autoUpgradeIntervalH = 0;
        urAccepted = -1;
      };
      gui = {
        theme = "dark";
      };
    };
    # Used later when checking whether settings were set in config.xml:
    checkSettingWithId =
      {
        t, # t for type
        id,
        not ? false,
      }:
      ''
        print("Searching for a ${t} with id ${id}")
        configVal_${t} = machine.succeed(
            "${pkgs.libxml2}/bin/xmllint "
            "--xpath 'string(//${t}[@id=\"${id}\"]/@id)' ${configPath}"
        )
        print("${t}.id = {}".format(configVal_${t}))
        assert "${id}" ${if not then "not" else ""} in configVal_${t}
      '';
    # Same as checkSettingWithId, but for 'options' and 'gui'
    checkSettingWithoutId =
      {
        t, # t for type
        n, # n for name
        v, # v for value
        not ? false,
      }:
      ''
        print("checking whether setting ${t}.${n} is set to ${v}")
        configVal_${t}_${n} = machine.succeed(
            "${pkgs.libxml2}/bin/xmllint "
            "--xpath 'string(/configuration/${t}/${n})' ${configPath}"
        )
        print("${t}.${n} = {}".format(configVal_${t}_${n}))
        assert "${v}" ${if not then "not" else ""} in configVal_${t}_${n}
      '';
    # Removes duplication a bit to define this function for the IDs to delete -
    # we check whether they were added after our script ran, and before the
    # systemd unit's bash script ran, and afterwards - whether the systemd unit
    # worked.
    checkSettingsToDelete =
      {
        not,
      }:
      lib.pipe IDsToDelete [
        (lib.mapAttrsToList (
          t: id:
          checkSettingWithId {
            inherit t id;
            inherit not;
          }
        ))
        lib.concatStrings
      ];
    # These IDs are added to syncthing using the API, similarly to how the
    # generated systemd unit's bash script does it. Only we add it and expect the
    # systemd unit bash script to remove them when executed.
    IDsToDelete = {
      # Also created using the syncthing generate command above
      device = "LZ2CTHT-3W2M7BC-CMKDFZL-DLUQJFS-WJR73PA-NZGODWG-DZBHCHI-OXTQXAK";
      # Intentionally this is a substring of the IDs of the 'test_folder's, as
      # explained in: https://github.com/NixOS/nixpkgs/issues/259256
      folder = "DeleteMe";
    };
    addDeviceToDeleteScript = pkgs.writers.writeBash "syncthing-add-device-to-delete.sh" ''
      set -euo pipefail

      export RUNTIME_DIRECTORY=/tmp

      curl() {
          # get the api key by parsing the config.xml
          while
              ! ${pkgs.libxml2}/bin/xmllint \
                  --xpath 'string(configuration/gui/apikey)' \
                  ${configPath} \
                  >"$RUNTIME_DIRECTORY/api_key"
          do sleep 1; done

          (printf "X-API-Key: "; cat "$RUNTIME_DIRECTORY/api_key") >"$RUNTIME_DIRECTORY/headers"

          ${pkgs.curl}/bin/curl -sSLk -H "@$RUNTIME_DIRECTORY/headers" \
              --retry 1000 --retry-delay 1 --retry-all-errors \
              "$@"
      }
      curl -d ${lib.escapeShellArg (builtins.toJSON { deviceID = IDsToDelete.device; })} \
          -X POST 127.0.0.1:8384/rest/config/devices
      curl -d ${lib.escapeShellArg (builtins.toJSON { id = IDsToDelete.folder; })} \
          -X POST 127.0.0.1:8384/rest/config/folders
    '';
  in
  {
    name = "syncthing-many-devices";
    meta.maintainers = with lib.maintainers; [ doronbehar ];

    nodes.machine = {
      services.syncthing = {
        enable = true;
        overrideDevices = true;
        overrideFolders = true;
        settings = settingsWithoutId // settingsWithId;
      };
    };
    testScript =
      ''
        machine.wait_for_unit("syncthing-init.service")
      ''
      + (lib.pipe settingsWithId [
        # Check that folders and devices were added properly and that all IDs exist
        (lib.mapAttrsRecursive (
          path: id:
          checkSettingWithId {
            # plural -> solitary
            t = (lib.removeSuffix "s" (builtins.elemAt path 0));
            inherit id;
          }
        ))
        # Get all the values we applied the above function upon
        (lib.collect builtins.isString)
        lib.concatStrings
      ])
      + (lib.pipe settingsWithoutId [
        # Check that all other syncthing.settings were added properly with correct
        # values
        (lib.mapAttrsRecursive (
          path: value:
          checkSettingWithoutId {
            t = (builtins.elemAt path 0);
            n = (builtins.elemAt path 1);
            v = (builtins.toString value);
          }
        ))
        # Get all the values we applied the above function upon
        (lib.collect builtins.isString)
        lib.concatStrings
      ])
      + ''
        # Run the script on the machine
        machine.succeed("${addDeviceToDeleteScript}")
      ''
      + (checkSettingsToDelete {
        not = false;
      })
      + ''
        # Useful for debugging later
        machine.copy_from_vm("${configPath}", "before")

        machine.systemctl("restart syncthing-init.service")
        machine.wait_for_unit("syncthing-init.service")
      ''
      + (checkSettingsToDelete {
        not = true;
      })
      + ''
        # Useful for debugging later
        machine.copy_from_vm("${configPath}", "after")

        # Copy the systemd unit's bash script, to inspect it for debugging.
        mergeScript = machine.succeed(
            "systemctl cat syncthing-init.service | "
            "${pkgs.initool}/bin/initool g - Service ExecStart --value-only"
        ).strip() # strip from new lines
        machine.copy_from_vm(mergeScript, "")
      '';
  }
)
