{ config, lib, pkgs, ... }:
let
  # Provides a fake "docker" binary mapping to podman
  cfg = config.services.podman;
  podmanPackage = cfg.package;
  docker_host = "unix:///run/user/$UID/podman/podman.sock";

  fakeDockerBinary = pkgs.runCommand "${podmanPackage.pname}-docker-compat-${podmanPackage.version}"
    {
      outputs = [ "out" "man" ];
      inherit (podmanPackage) meta;
    } ''
    mkdir -p $out/bin
    ln -s ${podmanPackage}/bin/podman $out/bin/docker

    mkdir -p $man/share/man/man1
    for f in ${podmanPackage.man}/share/man/man1/*; do
      basename=$(basename $f | sed s/podman/docker/g)
      ln -s $f $man/share/man/man1/$basename
    done
  '';
  dockerComposeCompat = pkgs.runCommand "docker-compose-podman-compat"
    {
      buildInputs = [ pkgs.makeWrapper ];
    } ''
        mkdir -p $out/bin
        makeWrapper '${pkgs.docker-compose}/libexec/docker/cli-plugins/docker-compose' "$out/bin/docker-compose" \
    --set-default "DOCKER_HOST" 'unix:///run/user/$UID/podman/podman.sock' \
    --set-default DOCKER_BUILDKIT 0
  '';
in
with lib; {
  options.services.podman = {
    dockerCompat =
      {
        fakeDockerBinary.enable = mkEnableOption {
          description = ''
            Create an alias mapping <command>docker</command> to <command>podman</command>.
          '';
        };
        dockerSocket.enable = mkEnableOption {
          description = ''
            Set the DOCKER_HOST environment variable to make docker tools use the podman docker
          '';
        };
        dockerCompose.enable = mkEnableOption {
          description = ''
            Install a docker-compose binary that uses the podman socket
          '';
        };
      };
  };
  config = lib.mkIf cfg.enable (lib.mkMerge [
    (lib.mkIf cfg.dockerCompat.fakeDockerBinary.enable {
      home.packages = [ fakeDockerBinary ];
    })
    (lib.mkIf cfg.dockerCompat.dockerCompose.enable {
      home.packages = [ dockerComposeCompat ];
    })
    (lib.mkIf cfg.dockerCompat.dockerSocket.enable {
      home.sessionVariables."DOCKER_HOST" = "unix:///run/user/$UID/podman/podman.sock";
    })

  ]);
}