#!/usr/bin/env bash

function _exit() {
  if [[ "$#" -gt 1 ]]; then
    # When there are multiple args, the last arg is the exit code.
    echo "${@:1:($# - 1)}"
    exit "${@: -1}"
  fi
  echo "$1"
  exit 0
}

help_text="\
Start a docker dev container
Usage: start_docker.sh [OPTIONS] image container

Positionals:
  image             The image to instantiate
  container         The name for the container

Options:
  -u,--user USER      The user to add in the container (defaults to 'bts')
  -p,--pass PASS      The password for USER in the container (defaults to USER)
  -i,--image IMAGE    The image to instantiate (defaults to 'bluetradingsystems/sparkd-dev:latest')
  -c,--container CONT The name for the container
  -m,--mount MOUNT    The name for the folder (outside the container) to create/mount to the home
                      directory in the container. Mount folders are added here: $mount_prefix
  --mount-existing    Mount the specified dir even if it already exists
  --port <cont_port>:<host_port> OR [<cont_port>:<host_port>,...] Port mapping(s). May be
                      specified multiple times.
  -h,--help           Print this help message and exit

"

mount_prefix="$HOME/.sparkd-dev/mounts"
declare docker_user=""
declare docker_pass=""
declare image_name=""
declare cont_name=""
declare mount_name=""
declare -i mount_existing=0
declare -a port_mappings=()

while [[ $# -gt 0 ]]; do
  case "$1" in
    -u)
      ;&
    --user)
      if [[ -z "$2" ]]; then
        _exit "User (-u,--user) must be non-empty" 1
      fi
      docker_user="$2"
      shift 2
      ;;
    -p)
      ;&
    --pass)
      if [[ -z "$2" ]]; then
        _exit "Password (-p,--pass) must be non-empty" 1
      fi
      docker_pass="$2"
      shift 2
      ;;
    -i)
      ;&
    --image)
      if [[ -n "$image_name" ]]; then
        _exit "Unexpected argument '$1'" 1
      elif [[ -z "$2" ]]; then
        _exit "Image (-i,--image) must be non-empty" 1
      fi
      image_name="$2"
      shift 2
      ;;
    -c)
      ;&
    --container)
      if [[ -n "$cont_name" ]]; then
        _exit "Unexpected argument '$1'" 1
      elif [[ -z "$2" ]]; then
        _exit "Container (-c,--container) must be non-empty" 1
      fi
      cont_name="$2"
      shift 2
      ;;
    --port)
      # Parse port(s) arg, and append the result to 'port_mappings'
      # Note: port(s) may be specified in bracketed notation:
      #   [a:b,c:d,...,y:z]
      next_ports="$(echo "$2" | sed -e 's/\[//g' -e 's/\]//g' -e 's/,/ /g')"
      if [[ "${#port_mappings[@]}" -gt 0 ]]; then
        next_ports=" $next_ports"
      fi
      port_mappings+=("$next_ports")
      shift 2
      ;;
    -m)
      ;&
    --mount)
      if [[ -z "$2" ]]; then
        echo "Mount (-m,--mount) must be non-empty"
      fi
      mount_name="$2"
      shift 2
      ;;
    --mount-existing)
      mount_existing=1
      shift 1
      ;;
    -h)
      ;&
    --help)
      _exit "$help_text" 0
      ;;
    *)
      if [[ -z "$1" ]]; then
        _exit "Invalid positional argument '$1'" "$help_text" 1
      elif [[ -z "$image_name" ]]; then
        image_name="$1"
      elif [[ -z "$cont_name" ]]; then
        cont_name="$1"
      else
        _exit "Unexpected argument '$1'" "$help_text" 1
      fi
      shift 1
      ;;
  esac
done


if [[ -z "$image_name" ]]; then
  image_name="bluetradingsystems/sparkd-dev:latest"
fi

host_name="$(hostname)"
if [[ -n "$cont_name" ]]; then
  host_name="$host_name.$cont_name"
fi

if [[ -z "$mount_name" ]]; then
  mount_name="$cont_name"
fi

if [[ -z "$mount_name" && -z "$cont_name" ]]; then
  _exit "Please specify mount (-m,--mount) and/or container (-c,--container)" 1
fi

if [[ -z "$docker_user" ]]; then
  docker_user="bts"
fi

if [[ "$docker_user" = "root" ]]; then
  _exit "USER (--user) cannot be 'root'" 1
fi

cont_home="/home/$docker_user"
home_src="$mount_prefix/$mount_name"
home_tgt="$cont_home"
this_dir="$(dirname "$(realpath "${BASH_SOURCE[0]}")")"
repo_src="$(cd "$this_dir" && git rev-parse --show-toplevel)"
repo_tgt="$cont_home/spark"
working_dir="$cont_home"

if [[ $mount_existing -eq 0 && -e "$home_src" ]]; then
  # Don't overwrite existing dir (might be mounted in another container)
  _exit "Mount dir '$home_src' already exists (use --mount-existing to mount \
an existing directory)" 1
fi

mkdir -p "$home_src"

if [[ "${#port_mappings[@]}" -eq 0 ]]; then
  port_mappings=("8000:8000" "8001:8001" "8002:8002" "8003:8003")
fi

# Adapt port_mappings into args for `docker run` by prepending "-p " to each
# item
declare -a docker_port_args=()
for port_mapping in "${port_mappings[@]}"; do
  docker_port_args+=("-p $port_mapping")
done

echo "Starting container '$cont_name'
image_name  : $image_name
cont_name   : $cont_name
home_src    : $home_src
home_tgt    : $home_tgt
repo_src    : $repo_src
repo_tgt    : $repo_tgt
working dir : $working_dir
ports       : ${port_mappings[*]}
"

# DON'T wrap $docker_port_args in quotes. We want bash to split args by
# whitespace
docker run \
  --net bridge \
  -h "$host_name" \
  -e "TZ=America/New_York" \
  --cap-add=SYS_PTRACE \
  --security-opt seccomp=unconfined \
  --name "$cont_name" \
  -v "$home_src:$home_tgt" \
  -v "$repo_src:$repo_tgt" \
  -w "$working_dir" \
  ${docker_port_args[*]} \
  --shm-size=4024m \
  -t \
  -i \
  -d \
  -e DISPLAY="$DISPLAY" \
  "$image_name"

# Add user w/ same uid and gid as the current user outside of docker, so the
# user inside the docker has file permissions in the mounted dir.
docker_group="$docker_user"
docker_uid="$(id -u "$USER")"
docker_gid="$(id -g "$USER")"
if [[ -z "$docker_pass" ]]; then
  docker_pass="$docker_user"
fi
docker exec -u root -it "$cont_name" "$repo_tgt/docker/sparkd/dev/set_user.sh" \
--user "$docker_user" \
--uid "$docker_uid" \
--group "$docker_group" \
--gid "$docker_gid" \
--pass "$docker_pass"

# Run same script VS Code runs to initialize the container
docker exec -u "$docker_user" -it "$cont_name" "$repo_tgt/docker/sparkd/dev/devcontainer_post_create.sh"