#!/bin/sh
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This file is part of dobuild.
# Copyright (c) 2019 Contributors as noted in the AUTHORS file.
#
# SPDX-License-Identifier: MPL-2.0

set -e

physical_pwd() {
  pwd -P 2>/dev/null || pwd
}

try_canonicalize() {
  readlink -f "$@" 2>/dev/null || realpath "$@"
}

canonicalize() {
  if ! try_canonicalize "$1" 2>/dev/null; then
    echo "$(cd "$(dirname "$1")" && physical_pwd)/$(basename "$1")"
  fi
}

scriptdir() {
  dirname "$(canonicalize "${BASH_SOURCE:-$1}")"
}

template_subst() {
  sed \
    -e "s!%MARCH%!${MARCH}!g" \
    -e "s!%DISTRIB%!${DISTRIB}!g" \
    -e "s!%REGISTRY_PREFIX%!${REGISTRY_PREFIX}!g"
}

mktemp_dockerfile() {
  mkdir -p "$1"
  echo "$1/dobuild_generated.dockerfile"
}

findonly_file() {
  workingdir="$1"
  name="$2"
  filter="$3"
  
    find "$workingdir" -maxdepth 1 -type f -name "$name" \
  | grep "^${workingdir}/${filter}" \
  | {
      firstfound=
      lastfound=

      while IFS= read -r line; do
        firstfound="${firstfound:-$line}"
        lastfound="$line"
      done
      
      if [ "$firstfound" != "$lastfound" ]; then
        printf 'error: more than one match found for %s in %s using filter %s\n' "$name" "$workingdir" "$filter" 1>&2
        return 3
      fi
      
      echo "$firstfound"
    }
}

export LANG=C
export LC_ALL=C

DOBUILDDIR="${DOBUILDDIR:-"$(dirname "$(scriptdir "$0")")"}"
MAKE="${MAKE:-$(command -v make)}"
PATH="$DOBUILDDIR/bin:$PATH"

set -- "$@" --

FILTER="$DOBUILD_FILTER"
WORKINGDIR=
MAKEFILE=
DISTRIB=
MARCH=
IMAGE=

while :; do
  case $1 in
    -f|--file|--makefile)
      if [ "$2" != '--' ]; then
        MAKEFILE="${MAKEFILE:-$2}"
        set -- "$@" "$1" "$2"
        shift
      else
        printf 'error: "%s" requires a non-empty option argument.\n' "$1" >&2
        exit 3
      fi
      ;;
    --file=|--makefile=)
      printf 'error: "%s" requires a non-empty option argument.\n' "$1" >&2
      exit 3
      ;;
    --file=?*|--makefile=?*)
      MAKEFILE="${MAKEFILE:-${1#*=}}"
      set -- "$@" "$1"
      ;;
    -C|--directory)
      if [ "$2" != '--' ]; then
        WORKINGDIR="$2"
        shift
      else
        printf 'error: "%s" requires a non-empty option argument.\n' "$1" >&2
        exit 3
      fi
      ;;
    --directory=)
      printf 'error: "%s" requires a non-empty option argument.\n' "$1" >&2
      exit 3
      ;;
    --directory=?*)
      WORKINGDIR="${1#*=}"
      ;;
    --dockerfile)
      if [ "$2" != '--' ]; then
        DOCKERFILE="$2"
        shift
      else
        printf 'warning: "%s" ignored, requires a non-empty option argument.\n' "$1" >&2
      fi
      ;;
    --dockerfile=)
      printf 'warning: "%s" ignored, requires a non-empty option argument.\n' "$1" >&2
      ;;
    --dockerfile=?*|DOCKERFILE=?*)
      DOCKERFILE="${1#*=}"
      ;;
    --image)
      if [ "$2" != '--' ]; then
        IMAGE="$2"
        shift
      else
        printf 'error: "%s" requires a non-empty option argument.\n' "$1" >&2
        exit 3
      fi
      ;;
    --image=)
      printf 'error: "%s" requires a non-empty option argument.\n' "$1" >&2
      exit 3
      ;;
    --image=?*|IMAGE=?*)
      IMAGE="${1#*=}"
      ;;
    --filter)
      if [ "$2" != '--' ]; then
        FILTER="$2"
        set -- "$@" "FILTER=$FILTER"
        shift
      else
        printf 'warning: "%s" ignored, requires a non-empty option argument.\n' "$1" >&2
      fi
      ;;
    --filter=)
      printf 'warning: "%s" ignored, requires a non-empty option argument.\n' "$1" >&2
      ;;
    --filter=?*|FILTER=?*)
      FILTER="${1#*=}"
      set -- "$@" "FILTER=$FILTER"
      ;;
    MARCH=?*)
      MARCH="${1#*=}"
      ;;
    DISTRIB=?*)
      DISTRIB="${1#*=}"
      ;;
    PROJECTDIR=?*)
      PROJECTDIR="${1#*=}"
      ;;
    --)
      shift
      break
      ;;
    *)
      set -- "$@" "$1"
      ;;
  esac

  shift
done

if [ -n "$WORKINGDIR" ]; then
  cd "$WORKINGDIR"
fi

PROJECTDIR="${DOBUILD_PROJECTDIR:-.}"
OUTDIR="${DOBUILD_OUTDIR:-$PROJECTDIR/.build}"
DISTRIB_SUFFIX="${DISTRIB:+-${DISTRIB}}"
MARCH_DISTRIB="${MARCH:-[^-]*}${DISTRIB_SUFFIX}"
FILTER="${FILTER:-${MARCH_DISTRIB:+${MARCH_DISTRIB}-}[^.]*}"
BUILD_DOCKERFILE="${DOCKERFILE:-$(findonly_file "$PROJECTDIR" '*.dockerfile' "$FILTER")}"
BUILD_DOCKERFILE="${BUILD_DOCKERFILE:-$(find "$PROJECTDIR" -maxdepth 1 -type f -name 'Dockerfile')}" || true

if [ -z "$MAKEFILE" ]; then
  if [ -f "$PROJECTDIR/CMakeLists.txt" ]; then
    set -- --file="$DOBUILDDIR/examples/cmake-gtest-example/Makefile" "$@"
  elif [ -f "$PROJECTDIR/Makefile" ] || [ -f "$PROJECTDIR/makefile" ] || [ -f "$PROJECTDIR/GNUmakefile" ]; then
    printf 'error: makefile project support not implemented.\n' >&2
    exit 3
  else
    printf 'error: unknown project kind.\n' >&2
    exit 3
  fi
fi

set -- "$@" "PROJECTDIR=$PROJECTDIR" "DOBUILDDIR=$DOBUILDDIR" "OUTDIR=$OUTDIR"

if [ -n "$IMAGE" ]; then
  BUILD_DOCKERFILE="$(mktemp_dockerfile "$OUTDIR")"
  
  { \
    echo "FROM %REGISTRY_PREFIX%${IMAGE}"; \
    echo; \
  } | template_subst > "$BUILD_DOCKERFILE"
fi

if [ -n "$BUILD_DOCKERFILE" ]; then
  if [ "$BUILD_DOCKERFILE" = '-' ]; then
    BUILD_DOCKERFILE="$(mktemp_dockerfile "$OUTDIR")"
    template_subst > "$BUILD_DOCKERFILE"
  fi

  set -- "$@" "DOCKERFILE=$BUILD_DOCKERFILE"
fi

if [ -n "$MARCH" ]; then
  set -- "$@" "MARCH=$MARCH"
fi

if [ -n "$DISTRIB" ]; then
  set -- "$@" "DISTRIB=$DISTRIB"
fi

exec "$MAKE" "$@"