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

with lib;

let
  cfg = config.services.kioskEdid;

  overrideModule = types.submodule {
    options = {
      connector = mkOption {
        type = types.str;
        example = "HDMI-A-1";
        description = ''
          DRM connector name to apply the EDID override to.
          Check `ls /sys/class/drm/` on target hardware to confirm the
          exact name (e.g. HDMI-A-1, HDMI-A-2).
        '';
      };

      edidFile = mkOption {
        type = types.path;
        description = ''
          Path to the binary EDID file to force for this connector.
        '';
      };

      forceConnected = mkOption {
        type = types.bool;
        default = true;
        description = ''
          Also force this connector to be treated as connected
          (video=<connector>:e), in case the real link reports
          disconnected/garbled state through a splitter or wireless kit.
        '';
      };
    };
  };
in
{
  options.services.kioskEdid = {
    enable = mkEnableOption "forcing custom EDIDs on one or more display connectors";

    overrides = mkOption {
      type = types.listOf overrideModule;
      default = [ ];
      description = ''
        List of per-connector EDID overrides to apply. Each entry gets its
        own firmware file and its own drm.edid_firmware kernel param.
      '';
      example = literalExpression ''
        [
          { connector = "HDMI-A-1"; edidFile = ./android-4k30-edid.bin; }
          { connector = "HDMI-A-2"; edidFile = ./android-4k30-edid.bin; }
        ]
      '';
    };
  };

  config = mkIf cfg.enable {
    hardware.firmware = map
      (o: pkgs.runCommand "kiosk-edid-firmware-${o.connector}" { } ''
        mkdir -p $out/lib/firmware/edid
        cp ${o.edidFile} $out/lib/firmware/edid/${o.connector}.bin
      '')
      cfg.overrides;

    boot.kernelParams = flatten (map
      (o:
        [ "drm.edid_firmware=${o.connector}:edid/${o.connector}.bin" ]
        ++ optional o.forceConnected "video=${o.connector}:e"
      )
      cfg.overrides);
  };
}