#!/bin/bash

# "SoftPLC C++ Toolkit 5" startup script
# ======================================
# This script starts a Docker container running the docker image
# named: "softplc/toolkit".
# This image is found at hub.docker.com and will be automatically downloaded
# by a proper Docker installation as part of the first time of use.
#
# This script uses 2 directories:
#  BUILD_DIR and SOURCE_DIR
#
# It results in a Docker container which mounts those 2 host directories
# into the container's /build and /source directories.  The BUILD_DIR is provided
# to this script by way of your CWD (current working directory) at the time
# that you run the script.  The SOURCE_DIR is provided on the command line when
# you run this script.
#
# Each of the 2 fixed container directories can be mapped to any directory on
# your host build system. While the container is running, it will have the
# two mapped directories, and this is typically temporary and project or TLM specific.
# You will be running only build tools (cmake and make) from a shell within the
# container.  For source code text editing, use your normal text editor, and do
# it *outside* of the container as you normally do.
#
# The 2 host directories, BUILD_DIR and SOURCE_DIR will always be mapped into
# the container at /build and /source respectively.  These are bind mounts in
# the Docker vernacular.
# Think of those 2 bind mounts as two legs.  That makes for a memory
# aid for remembering the name of this script:  standup-toolkit.sh.
#
# Example:
# $ cd ~/tlms/mytlm
# $ mkdir build-arm64
# $ cd build-arm64			# CWD provides BUILD_DIR
# $ standup-toolkit.sh ~/tlms/mytlm	# SOURCE_DIR on command line
#
# The above starts a container running softplc/toolkit and opens up a terminal
# within it.  The container is focused on its /build and /source directories,
# which are identical to the host's ~/tlms/mytlm/build-arm64 and
# ~/tlms/mytlm respectively.
#
# If you need more VOLUME_MOUNTS, you may modify this script in your own
# copy.
#
# Using CMake and make are the same as prior SoftPLC Toolkits.  From the
# /build directory you run "makemake.sh".  Then you run "make".
# The only differences are that you do this from the container's bash terminal
# and that the host's BUILD_DIR and SOURCE_DIR will be mapped into the
# container's /build and /source.  Below is an example that would be done
# after the one time "standup-toolkit.sh".
#
# $ cd /build		# tooltkit bash starts here any way.
# now run makemake.sh found in this location:
# $ /opt/softplc/c++-toolkit-5/bin/makemake.sh ARCH /source  # always "/source"
# $ make
#
# Terminate the container by running exit from its terminal; because bash is the
# container's only job, the container stops and (with --rm) is removed:
# $ exit

# The container runs as YOUR host user id (see USER_RUN below), so files it
# writes into BUILD_DIR are owned by you, not root.  Running as your uid needs a
# writable HOME inside the container: the host uid has no passwd entry there, so
# HOME would otherwise default to "/" and any build step that touches $HOME fails
# with a permission error.  We set HOME=/tmp to solve that.  If some build step
# must write to a root-owned path inside the image, comment out USER_RUN to fall
# back to running as root (outputs are then root-owned, but you can copy them out).

# The version tag named "latest" is used by the toolkit maintainers to earmark
# the most recently released image.  You may want to pin DOCKER_IMAGE to a
# known stable numeric version, like "softplc/toolkit:1.9"

DOCKER_IMAGE="softplc/toolkit:trixie_latest"
#DOCKER_IMAGE="softplc/toolkit:bullseye_latest"

usage() {
	echo
	echo "Usage:"
	echo
	echo "$ cd BUILD_DIR"
	echo "$ $0 SOURCE_DIR"
	echo
	exit 1
}


if ! command -v docker >/dev/null 2>&1; then
	echo "You must have a recent version of Docker installed"
	exit 2
fi

# Portable daemon check: works on Linux, macOS/Windows Docker Desktop, and WSL.
# ('systemctl is-active docker' is Linux-systemd-only and wrongly fails elsewhere.)
if ! docker info >/dev/null 2>&1; then
	echo "Docker does not appear to be running; please start Docker and retry."
	exit 3
fi

# The documented, reserved first argument is SOURCE_DIR.  An undocumented second
# argument "-v" enables the maintainer-only extra mounts (the FOR_DICK block
# further down).  Deliberately not shown in usage().
if [[ $# -lt 1 || $# -gt 2 ]]; then
	usage
fi

EXTRA_VOLUMES=
if [[ $# -eq 2 ]]; then
	if [[ "$2" == "-v" ]]; then
		EXTRA_VOLUMES=1
	else
		usage
	fi
fi

echo "using image \"$DOCKER_IMAGE\""

# Resolve SOURCE_DIR to an absolute path portably (no realpath dependency) and
# validate that it exists.
SOURCE_DIR="$(cd "$1" 2>/dev/null && pwd)" || { echo "SOURCE_DIR \"$1\" not found"; usage; }
BUILD_DIR="$(pwd)"

echo "SOURCE_DIR=\"$SOURCE_DIR\"  BUILD_DIR=\"$BUILD_DIR\""

VOLUME_MOUNTS="$VOLUME_MOUNTS -v $SOURCE_DIR:/source"
VOLUME_MOUNTS="$VOLUME_MOUNTS -v $BUILD_DIR:/build"

# The image self-registers the running uid into /etc/passwd at startup (see its
# entrypoint), so getpwuid() resolves for scp/ssh/sudo without mounting the host
# /etc/passwd -- works on any OS.  We pass HOST_USER so the registered account
# (and your shell prompt) shows your real name instead of the generic "builder".
USER_ENV="-e HOST_USER=$(id -un)"

# --- Advanced / maintainer-only extra mounts --------------------------------
# The two mounts above are all a standard TLM build needs.  Add project-specific
# host directories below only if a particular TLM requires them, and keep them
# commented for normal distribution.  NOTE: Docker auto-creates a missing
# bind-mount source as a root-owned empty dir, so a stray mount is NOT harmless.
#
# Example -- a client project that needs an extra cloned repo:

# Enabled only by the undocumented "-v" second argument (see arg
# parsing near the top).  Extra volume mounts can be placed in here.
if [[ -n "$EXTRA_VOLUMES" ]]; then
	VOLUME_MOUNTS="$VOLUME_MOUNTS -v /i/git-repos/CIPster:/CIPster"
	VOLUME_MOUNTS="$VOLUME_MOUNTS -v /svn/softplc/h:/opt/softplc/c++-toolkit-5/h"
fi

# Maintainer overrides -- live-mount toolkit sources over the image's copies:
#VOLUME_MOUNTS="$VOLUME_MOUNTS -v /svn/softplc/h/tlm.h:/opt/softplc/c++-toolkit-5/h/tlm.h"
#VOLUME_MOUNTS="$VOLUME_MOUNTS -v /opt/softplc/c++-toolkit-5/h/dt_objects.h:/opt/softplc/c++-toolkit-5/h/dt_objects.h"
#VOLUME_MOUNTS="$VOLUME_MOUNTS -v /opt/softplc/c++-toolkit-5/cmake/tlm.cmake:/opt/softplc/c++-toolkit-5/cmake/tlm.cmake"

# Run as your host user so build outputs in BUILD_DIR are owned by you, not root.
# HOME=/tmp gives that uid a writable home inside the image (see the note near the
# top).  Comment this line out to run as root instead.
USER_RUN="--user $(id -u):$(id -g) -e HOME=/tmp"

#SET_CONTAINER_NAME="--name toolkit"

# keep this line if you want the newest image on each run:
docker pull $DOCKER_IMAGE

cat <<HINT

  Starting the SoftPLC Toolkit container; you will get a shell in /build.
  To build your TLM, run these two commands inside the container:

    /opt/softplc/c++-toolkit-5/bin/makemake.sh ARCH /source
    make

  (replace ARCH with your target, e.g. arm64).  Type 'exit' to leave.
  Need root? run 'sudo -i' (no password) to install packages or remove
  protected files; such changes vanish when the container exits.

HINT

docker run -it --rm --workdir /build \
	$SET_CONTAINER_NAME \
	--hostname toolkit \
	$VOLUME_MOUNTS \
	$USER_RUN \
	$USER_ENV \
	$DOCKER_IMAGE