#!/bin/bash
# =============================================== #
# devc.sh v2.0; job79                             #
# Dev container enter script. Handles setting up  #
# different dev containers, resuming sessions and #
# automatic container updates.                    #
# =============================================== #
set -eu
log() { printf '\e[%sm%s\e[0m %s\n' "${3:-36}" "${2:-○}" "$1"; }
arg() { echo -n " $@"; }

# run_args returns the podman run arguments required for
# starting a new container.
default_args() {
  arg "--name $name"
  arg "--hostname $name"

  # Pull newer container image if available.
  arg "--pull=newer"

  # Use keep-id so the container user matches the host user.
  arg "--userns=keep-id"

  # Disable selinux labeling so unix sockets can be mounted
  # without problems.
  arg "--security-opt label=disable"

  # Mount the wayland socket. Required to get the system
  # clipboard (wl-copy) and gui applications working.
  [ -e "/run/user/$UID/wayland-0" ] && arg "-v /run/user/$UID/wayland-0:/run/user/1000/wayland-0"

  # Mount the ssh socket to get ssh working.
  [ -e "$SSH_AUTH_SOCK" ] && arg "-v $SSH_AUTH_SOCK:/run/user/1000/ssh-auth-sock"

  # Make the user home dir a volume so it survives container
  # restarts. Use copy to keep the homedir files from the image.
  arg "-v $name:/home/user:copy"

  # If there is custom configuration for the container, load
  # it here.
  config_file="$(dirname "$(realpath "$0")")/containers/$name/config.sh"
  [ -f "${config_file}" ] && source "${config_file}"
}

# param_args returns the podman run arguments based on the
# arguments provided to this script.
param_args() {
  while test $# -gt 0; do
    case "$1" in
    -gpu) # Enable gpu acceleration.
      arg "--device /dev/dri" ;;
    -host-spawn) # Enable spawning host commands from inside the container using host-spawn.
      arg "-v /run/user/$UID/bus:/tmp/bus"
      arg "-e HOST_HOME=$HOME" # Use to translate paths.
      arg "-e DBUS_SESSION_BUS_ADDRESS='unix:path=/tmp/bus'"
      ;;
    -x11) # Enable X11 support.
      arg "-e DISPLAY=$DISPLAY"
      arg "-v /tmp/.X11-unix:/tmp/.X11-unix"
      arg "-e XAUTHORITY=/run/user/1000/.Xauthority"
      arg "-v $XAUTHORITY:/run/user/1000/.Xauthority:ro"
      ;;
    *) # Use unknown arguments a podman arguments.
      arg "$1" ;;
    esac
    shift
  done
}

### MAIN ###
# Get container registry from DEVC_REGISTRY env variable.
if [ -n "${DEVC_REGISTRY:-}" ]; then
  registry="$DEVC_REGISTRY"
else
  log "registry unknown; set the DEVC_REGISTRY environment variable" 'x' 31
  exit 1
fi

# Get the devcontainer name from the first argument. If not
# provided, use the last used name when possible.
if [[ $# -gt 0 ]] && [[ ${1:-} != -* ]]; then
  image="$1"
  [[ "$image" != *:* ]] && image="$image:main"
  echo "$image" >"$HOME/.local/share/devc-previous-container"
  shift
elif [ -f "$HOME/.local/share/devc-previous-container" ]; then
  image=$(<"$HOME/.local/share/devc-previous-container")
else
  log "no container name specified" 'x' 31
  exit 1
fi
name="${image%:*}"

# Create a new container when the container is not running or
# when any arguments are provided.
if [ "$(podman container inspect "$name" -f {{.State.Running}} 2>&1)" != 'true' ] || [[ $# -gt 0 ]]; then
  log "starting devcontainer..."
  podman container rm -f -t 0 "$name" 1>/dev/null
  podman run -td $(default_args) $(param_args $@) "$registry/$image"
fi

podman exec -it "$name" bash -l