#! /usr/bin/env bash

# Upgrade remote packages in a bdep-managed build2 toolchain build (default
# configurations), essentially as if by executing:
#
# bdep sync -fur && b
#
# In each project of the toolchain.
#
# Note that we can't just do that because as soon as we drop some dependency
# package, the tools (b, bpkg, etc) become non-runnable (missing shared
# libraries, etc).
#
# Finally, this script only upgrades the default configurations (including
# -libs, if present). To upgrade the rest you can use the normal way, for
# example:
#
# bdep sync -fur @<cfg>|-a
#
# If the -c option is specified, the configuration is upgraded and configured
# but only the build system is updated. This can be done at a later stage by
# running the build system in the configuration directory:
#
# BDEP_SYNC=0 b
#
owd="$(pwd)"
trap "{ cd '$owd'; exit 1; }" ERR
set -o errtrace # Trap in functions.

function info () { echo "$*" 1>&2; }
function error () { info "$*"; exit 1; }

# Run a command with tracing (similar to set -x).
#
# Note that this function will execute a command with arguments that contain
# spaces but it will not print them as quoted (and neither does set -x).
#
function run ()
{
  echo "+ $@" 1>&2
  "$@"
}

function run_no_sync ()
{
  echo "+ BDEP_SYNC=0 $@" 1>&2
  BDEP_SYNC=0 "$@"
}

# Make sure the build2 tools are runnable.
#
b    --version >/dev/null
bpkg --version >/dev/null
bdep --version >/dev/null

configure_only=

while [ $# -gt 0 ]; do
  case $1 in
    -c)
      configure_only=--configure-only
      shift
      ;;
    *)
      error "unexpected $1"
      ;;
  esac
done

# Get the configuration directories.
#
tcfg="$(b info: build2/  | sed -n -re 's/^out_root: (.+)$/\1/p')"
lcfg="$(b info: libbutl/ | sed -n -re 's/^out_root: (.+)$/\1/p')"

if [ -z "$tcfg" -o -z "$lcfg" ]; then
  error "unable to determine build configuration directories"
fi

tcfg="$(dirname "$tcfg")"
lcfg="$(dirname "$lcfg")"

if [ "$tcfg" = "$lcfg" ]; then
  lcfg=
fi

# The plan is as follows:
#
# 0. First, make backup copies of configurations. If something goes wrong,
#    it's likely the tools will be left in a non-runnable state.
#
# 1. Next, install the build tollchain on the side and then upgrade the
#    configurations using that.
#

# Step 0.
#
if test -e "$tcfg.bak"; then
  error "$tcfg.bak already exist"
fi

if [ -n "$lcfg" ]; then
  if test -e "$lcfg.bak"; then
    error "$lcfg.bak already exist"
  fi
fi

run cp -rp "$tcfg" "$tcfg.bak"

if [ -n "$lcfg" ]; then
  run cp -rp "$lcfg" "$lcfg.bak"
fi

# Step 1.
#

# @@ TMP: I don't see why we would need this.
#
#run_no_sync b "$tcfg"/libbutl/libbutl/hxx{version}
#run_no_sync b "$tcfg"/libbpkg/libbpkg/hxx{version}
#run_no_sync b "$tcfg"/build2/libbuild2/hxx{version}

run rm -rf /tmp/build2-install

run_no_sync bpkg install -d "$tcfg" \
  config.install.root=/tmp/build2-install \
  config.bin.rpath=/tmp/build2-install/lib \
  build2 bpkg bdep

opath="$PATH"
run export PATH="/tmp/build2-install/bin:$PATH"

run which b bpkg bdep

run b --version >/dev/null
run bpkg --version >/dev/null
run bdep --version >/dev/null

run bpkg fetch -d "$tcfg"
run_no_sync bpkg build -d "$tcfg" --keep-out -ur $configure_only

# In configure-only we update the build system manually.
#
if [ -n "$configure_only" ]; then
  run_no_sync b build2/
fi

if [ -n "$lcfg" ]; then
  run bpkg fetch -d "$lcfg"
  run_no_sync bpkg build -d "$lcfg" --keep-out -ur $configure_only
fi

run export PATH="$opath"

run b --version >/dev/null
run b build2/ # Should be a noop.

if [ -z "$configure_only" ]; then
  run bpkg --version >/dev/null
  run bdep --version >/dev/null
  run b bpkg/ bdep/ # Should be a noop.
fi

run rm -rf /tmp/build2-install

run rm -rf "$tcfg.bak"

if [ -n "$lcfg" ]; then
  run rm -rf "$lcfg.bak"
fi