# Save this as podman-pod.nix
{ config, lib, pkgs, ... }:

with lib;

let
  cfg = config.services.podmanPods;

  podOptions = { name, config, ... }: {
    options = {
      name = mkOption {
        type = types.str;
        description = "Name of the pod";
      };
      ports = mkOption {
        type = types.listOf types.str;
        default = [ ];
        description = "List of port mappings (e.g. ['8080:80'])";
      };
      containers = mkOption {
        type = types.attrsOf (types.submodule {
          options = {
            image = mkOption {
              type = types.str;
              description = "Docker image for the container";
            };
            extraOptions = mkOption {
              type = types.listOf types.str;
              default = [ ];
              description = "Additional options for the container";
            };
          };
        });
        default = { };
        description = "Containers to run in the pod";
      };
    };
  };

  createPodScript = name: podDef:
    let
      podDefinitionString = builtins.toJSON { inherit (podDef) ports; };
    in
    pkgs.writeScript "manage-pod-${name}.sh" ''
      #!/usr/bin/env nix-shell
      #!nix-shell -i bash -p htop curl

      set -e

      POD_NAME="${name}"
      POD_DEFINITION='${podDefinitionString}'

      create_pod() {
        podman pod create --name "$POD_NAME" \
          ${concatStringsSep " " (map (port: "--publish ${port}") podDef.ports)}
      }

      if podman pod exists "$POD_NAME"; then
        CURRENT_CONFIG=$(podman pod inspect "$POD_NAME" | jq -c '.[0] | {ports: [.PortMappings[].HostPort | tostring + ":" + (.ContainerPort | tostring)]}')
        if [ "$CURRENT_CONFIG" != "$POD_DEFINITION" ]; then
          echo "Pod configuration has changed. Recreating pod..."
          podman pod rm -f "$POD_NAME"
          create_pod
        else
          echo "Pod configuration unchanged."
        fi
      else
        echo "Pod does not exist. Creating..."
        create_pod
      fi
    '';
in
{
  options.services.podmanPods = mkOption {
    type = types.attrsOf (types.submodule podOptions);
    default = { };
    description = "Podman pods to create";
  };

  config = mkIf (cfg != { }) {
    virtualisation.podman.enable = true;
    virtualisation.oci-containers.backend = "podman";

    environment.systemPackages = [ pkgs.jq ];

    systemd.services = mapAttrs'
      (name: podDef:
        nameValuePair "podman-pod-${name}" {
          description = "Manage Podman pod: ${name}";
          serviceConfig = {
            Type = "oneshot";
            ExecStart = "${createPodScript name podDef}";
          };
          path = [ pkgs.podman ];
          wantedBy = [ "multi-user.target" ];
        }
      )
      cfg //
    mapAttrs'
      (podName: podDef:
        nameValuePair "podman-pod-${podName}" {
          after = [ "network.target" ];
          wantedBy = [ "multi-user.target" ];
        }
      )
      cfg //
    mapAttrs'
      (podName: podDef:
        nameValuePair "podman-${podName}" {
          after = [ "podman-pod-${podName}.service" ];
          requires = [ "podman-pod-${podName}.service" ];
          partOf = [ "podman-pod-${podName}.service" ];
        }
      )
      (flattenAttrs (mapAttrsToList
        (podName: podDef:
          mapAttrs'
            (containerName: containerDef:
              nameValuePair "${podName}-${containerName}" containerDef
            )
            podDef.containers
        )
        cfg));

    virtualisation.oci-containers.containers = flatten (mapAttrsToList
      (podName: podDef:
        mapAttrsToList
          (containerName: containerDef:
            nameValuePair "${podName}-${containerName}" ({
              inherit (containerDef) image;
              extraOptions = [ "--pod=${podName}" ] ++ containerDef.extraOptions;
            })
          )
          podDef.containers
      )
      cfg);

    networking.firewall.allowedTCPPorts = flatten (mapAttrsToList
      (name: podDef:
        map (portMapping: lib.toInt (lib.head (lib.splitString ":" portMapping))) podDef.ports
      )
      cfg);

    # systemd.services = mapAttrs'
    #   (podName: podDef:
    #     nameValuePair "podman-pod-${podName}" {
    #       after = [ "network.target" ];
    #       wantedBy = [ "multi-user.target" ];
    #     }
    #   )
    #   cfg //
    # mapAttrs'
    #   (podName: podDef:
    #     nameValuePair "podman-${podName}" {
    #       after = [ "podman-pod-${podName}.service" ];
    #       requires = [ "podman-pod-${podName}.service" ];
    #       partOf = [ "podman-pod-${podName}.service" ];
    #     }
    #   )
    #   (flattenAttrs (mapAttrsToList
    #     (podName: podDef:
    #       mapAttrs'
    #         (containerName: containerDef:
    #           nameValuePair "${podName}-${containerName}" containerDef
    #         )
    #         podDef.containers
    #     )
    #     cfg));
  };
}