{ config, pkgs, lib, ... }:

with lib;

{
  options = {

    networking.interfaces = lib.mkOption {
      type = with types;
        attrsOf (submodule ({ ... }: {
          options.genode = {

            driver = mkOption { type = types.enum [ "ipxe" "virtio" ]; };

            stack = mkOption {
              type = with types; nullOr (enum [ "lwip" "lxip" ]);
              default = "lwip";
            };

          };
        }));
    };

    hardware.genode.platform.policies = lib.mkOption {
      type = with types; listOf path;
      default = [ ];
      description = ''
        List of policies to append to the Genode platform driver.
        Type is Init.Config.Policy.Type.
      '';
    };

    hardware.usb.genode.enable = lib.mkEnableOption "USB driver";

    hardware.usb.genode.storage.enable =
      lib.mkEnableOption "USB mass storage driver";

  };

  config = {

    assertions = with builtins;
      let
        addrCheck = name: interface: {
          assertion = lessThan (length interface.ipv4.addresses) 2;
          message = "Genode interfaces do not support multihoming.";
        };
        routeCheck = name: interface: {
          assertion = lessThan (length interface.ipv4.routes) 2;
          message = "Genode interfaces do not support multiple routes.";
        };
      in lib.mapAttrsToList addrCheck config.networking.interfaces
      ++ lib.mapAttrsToList routeCheck config.networking.interfaces;

    hardware.usb.genode.storage.enable = config.genode.boot.storeBackend
      == "usb";

    hardware.usb.genode.enable = config.hardware.usb.genode.storage.enable;

    hardware.genode.platform.policies = lib.lists.imap0 (i: name:
      builtins.toFile (name + ".platform-policy.dhall") ''
        let Genode = env:DHALL_GENODE

        in  Genode.Init.Config.Policy::{
            , service = "Platform"
            , label = Genode.Init.LabelSelector.prefix "nixos -> ${name}.driver"
            , content =
              [ Genode.Prelude.XML.leaf
                  { name = "pci"
                  , attributes = toMap {
                    , class = "ETHERNET"
                    , index = "${toString i}"
                    }
                  }
              ]
            }
      '') (builtins.attrNames config.networking.interfaces)
      ++ lib.optional config.hardware.usb.genode.enable
      (builtins.toFile ("usb.platform-policy.dhall") ''
        let Genode = env:DHALL_GENODE

        in  Genode.Init.Config.Policy::{
            , service = "Platform"
            , label = Genode.Init.LabelSelector.prefix "usb_drv"
            , content =
              [ Genode.Prelude.XML.leaf
                  { name = "pci", attributes = toMap { class = "USB" } }
              ]
            }
      '');

    genode.core.basePackages = with pkgs.genodePackages;
      [ acpi_drv platform_drv ]
      ++ lib.optional config.hardware.usb.genode.enable
      pkgs.genodePackages.usb_drv;

    genode.init.children = let

      nics = mapAttrs' (name: interface:
        let name' = name + ".driver";
        in {
          name = name';
          value = let
            binary = with pkgs.genodePackages;
              {
                ipxe = ipxe_nic_drv;
                virtio = virtio_nic_drv;
              }.${interface.genode.driver};
          in {
            inputs = [ binary ];
            configFile = let
              policies = if interface.genode.stack == null then
                "[] : List Init.Config.Policy.Type"
              else ''
                [ Init.Config.Policy::{
                  , service = "Nic"
                  , label = Init.LabelSelector.prefix "${name}.sockets"
                  }
                ]
              '';
            in pkgs.writeText "${name'}.dhall" ''
              let Genode = env:DHALL_GENODE

              let Init = Genode.Init

              in  Init.Child.flat
                    Init.Child.Attributes::{
                    , binary = "${binary.pname}"
                    , provides = [ "Nic" ]
                    , resources = Init.Resources::{
                      , caps = 128
                      , ram = Genode.units.MiB 4
                      }
                    , routes = [
                      , Init.ServiceRoute.parent "IO_MEM"
                      , Init.ServiceRoute.parent "Platform"
                      ]
                    , config = Init.Config::{
                      , attributes = toMap { verbose = "true" }
                      , policies = ${policies}
                      }
                    }
            '';
          };
        }) config.networking.interfaces;

      sockets = mapAttrs' (name: interface:
        let name' = name + ".sockets";
        in {
          name = name';
          value = if interface.genode.stack == null then
            null
          else {
            inputs = with pkgs.genodePackages;
              {
                lwip = [ vfs_lwip ];
                lxip = [ vfs_lxip ];
              }.${interface.genode.stack};
            configFile = let
              binary = "${pkgs.genodePackages.vfs}/bin/vfs";
              ram = {
                lwip = 16;
                lxip = 32;
              }.${interface.genode.stack};
              settings = with builtins;
                lib.optionals (interface.ipv4.addresses != [ ])
                (let addr = head interface.ipv4.addresses;
                in [
                  {
                    name = "ip_addr";
                    value = addr.address;
                  }
                  {
                    name = "netmask";
                    value = if addr.prefixLength == 24 then
                      "255.255.255.0"
                    else
                      throw "missing prefix to netmask conversion";
                  }
                ]) ++ lib.optional (interface.ipv4.routes != [ ])
                (let route = head interface.ipv4.routes;
                in {
                  name = "gateway";
                  value = route.address;
                }) ++ lib.optional (interface.useDHCP != null) {
                  name = "dhcp";
                  value = if interface.useDHCP then "true" else "false";
                };
              settingsMap = builtins.concatStringsSep ", " (map
                ({ name, value }:
                  ''{ mapKey = "${name}", mapValue = "${value}" }'') settings);
            in pkgs.writeText "${name'}.dhall" ''
              let Genode = env:DHALL_GENODE

              let Init = Genode.Init

              in  Init.Child.flat
                    Init.Child.Attributes::{
                    , binary = "${binary}"
                    , provides = [ "File_system" ]
                    , resources = Init.Resources::{
                      , caps = 128
                      , ram = Genode.units.MiB ${toString ram}
                      }
                    , config = Init.Config::{
                      , policies =
                        [ Init.Config.Policy::{
                          , service = "File_system"
                          , label = Init.LabelSelector.suffix "${name'}"
                          , attributes = toMap { root = "/", writeable="yes" }
                          }
                        ]
                      , content =
                          let VFS = Genode.VFS

                          in  [ VFS.vfs
                                  [ VFS.leafAttrs
                                      "${interface.genode.stack}"
                                      ([ ${settingsMap} ] : Genode.Prelude.Map.Type Text Text)
                                  ]
                              ]
                      }
                    }
            '';
          };
        }) config.networking.interfaces;

    in lib.filterAttrs (n: v: v != null) (nics // sockets);

    genode.core.children = {

      acpi_drv = {
        coreROMs = [ "acpi_drv" ];
        configFile = pkgs.writeText "acpi_drv.dhall" ''
          let Genode = env:DHALL_GENODE

          let Init = Genode.Init

          let label = λ(_ : Text) → { local = _, route = _ }

          in  Init.Child.flat
                Init.Child.Attributes::{
                , binary = "acpi_drv"
                , resources = Init.Resources::{
                  , caps = 400
                  , ram = Genode.units.MiB 4
                  , constrainPhys = True
                  }
                , romReports = [ label "acpi", label "smbios_table" ]
                , routes =
                  [ Init.ServiceRoute.parent "IRQ"
                  , Init.ServiceRoute.parent "IO_MEM"
                  , Init.ServiceRoute.parent "IO_PORT"
                  ]
                }
        '';
      };

      platform_drv = {
        coreROMs = [ "platform_drv" ];
        configFile = let
          policies = map (policy: ", ${policy}")
            config.hardware.genode.platform.policies;
        in pkgs.writeText "platform_drv.dhall" ''
          let Genode = env:DHALL_GENODE

          let Init = Genode.Init

          in  Init.Child.flat
                Init.Child.Attributes::{
                , binary = "platform_drv"
                , resources = Init.Resources::{
                  , caps = 800
                  , ram = Genode.units.MiB 4
                  , constrainPhys = True
                  }
                , reportRoms = let label = "acpi" in [ { local = label, route = label } ]
                , provides = [ "Platform" ]
                , routes =
                  [ Init.ServiceRoute.parent "IRQ"
                  , Init.ServiceRoute.parent "IO_MEM"
                  , Init.ServiceRoute.parent "IO_PORT"
                  ]
                , config = Init.Config::{
                  , policies = [ ${toString policies} ]
                  }
                }
        '';
      };
    } // (if config.hardware.usb.genode.enable then {

      usb_drv = {
        coreROMs = [ "usb_drv" ];
        configFile = builtins.toFile "usb_drv.dhall" ''
          let Genode = env:DHALL_GENODE

          let XML = Genode.Prelude.XML

          let Init = Genode.Init

          let storageEnable = ${
            if config.hardware.usb.genode.storage.enable then
              "True"
            else
              "False"
          }

          in  Init.Child.flat
                Init.Child.Attributes::{
                , binary = "usb_drv"
                , provides = [ "Block", "Usb" ]
                , resources = Init.Resources::{ caps = 256, ram = Genode.units.MiB 12 }
                , routes = [ Init.ServiceRoute.parent "IO_MEM" ]
                , config = Init.Config::{
                  , attributes = toMap { uhci = "yes", ehci = "yes", xhci = "yes" }
                  , content =
                      if    storageEnable
                      then  [ XML.leaf
                                { name = "storage", attributes = XML.emptyAttributes }
                            ]
                      else  [] : List XML.Type
                  , policies =
                      if    storageEnable
                      then  [ Init.Config.Policy::{
                              , service = "Block"
                              , label = Init.LabelSelector.prefix "store_fs"
                              }
                            ]
                      else  [] : List Init.Config.Policy.Type
                  }
                }
        '';
      };
    } else
      { });

  };

}