#!/bin/bash
#
# Build configuration utility for Serval DNA on Apple iOS.
#
# Copyright 2016-2017 Flinders University
#
# This script runs Serval DNA's main 'configure' script several times, once for
# each different target iOS target, and saves the Makefile that is generated by
# each run.  It then creates a top-level Makefile that:
# (1) invokes each of the saved Makefiles in turn to generate one static library
#     for each target, then
# (2) combines all these libraries into a single "multi slice" static library
#     that can be imported into an Xcode project.
#
# This allows the iOS development cycle to be similarly rapid as for platforms
# such as Linux or native Apple OS-X:
#  (1) a single 'configure' step adapts the Makefile(s) to the specific needs of
#      the target architecture(s), then
#  (2) the edit-make-test cycle can be repeated as often as desired:
#      (a) edit; make changes to source file(s)
#      (b) make; compile the changed source files into executable form using the
#          dependency rules in the Makefile(s), which avoids unnecessary
#          re-compilation, then re-build the app in Xcode, which links in the
#          new static library
#      (c) test; run the re-built app, either in an iOS simulator or by
#          side-loading into an iPhone
#

# Exit on error
set -e

usage() {
   echo "Usage: ${0##*/} [-f|--force]"
}

# Run the Serval DNA configure script once for each architecture, and save the
# files produced by each run.

main() {
   setup
   parse_command_line "$@"
   check
   exec 5>&1
   TARGETS=()
   configure iphoneos        armv7  /Library/Serval
   configure iphoneos        arm64  /Library/Serval
   configure iphonesimulator i386   /tmp/serval-dna
   configure iphonesimulator x86_64 /tmp/serval-dna
   create_makefile
}

# Trace and diagnostic functions.

run() {
   echo + "$@" >&5
   "$@"
}

usage_error() {
   echo "${0##*/}: $*" >&2
   usage >&2
   exit 1
}

fatal() {
   echo "${0##*/}: $1" >&2
   shift
   while [ $# -ne 0 ]; do
      echo "$1" >&2
      shift
   done
   exit 1
}

# Parse command-line options.

parse_command_line() {
   library=libservaldaemon.a
   swiftmodule=ServalDNA.swiftmodule
   opt_force_configure=false
   opt_force_config_status=false
   log_display_line_count=10
   while [ $# -ne 0 ]; do
      opt="$1"
      shift
      case "$opt" in
      -h | --help)
         usage
         exit 0
         ;;
      -f|--force-configure)
         opt_force_configure=true
         ;;
      --force-config-status)
         opt_force_config_status=true
         ;;
      -*)
         usage_error "Unknown option: $opt"
         ;;
      *)
         usage_error "Spurious argument: $opt"
         ;;
      esac
   done
}

# Work out the path of the directory containing this script relative to the
# current working directory (SCRIPT_DIR), the path of the Serval DNA repository
# root directory relative to the current working directory (SERVAL_DNA_DIR), and
# the path of these two directories relative to each other.

setup() {
   case "$0" in
   */?*/*) SCRIPT_DIR="${0%/*}"; SERVAL_DNA_DIR="${0%/?*/*}";;
   ./*)    SCRIPT_DIR=".";       SERVAL_DNA_DIR="..";;
   */*)    SCRIPT_DIR="${0%/*}"; SERVAL_DNA_DIR=".";;
   *)      SCRIPT_DIR=".";       SERVAL_DNA_DIR="..";;
   esac
   SCRIPT_DIR_RELATIVE_TO_SERVAL_DNA_DIR="$(cd "$SCRIPT_DIR" >/dev/null && echo "${PWD##*/}")"
   SERVAL_DNA_DIR_RELATIVE_TO_SCRIPT_DIR=".."
   SERVAL_DNA_CONFIGURE="$SERVAL_DNA_DIR/configure"
}

# Ensure that the Serval DNA 'configure' script exists and is executable.

check() {
   if [ ! -e "$SERVAL_DNA_CONFIGURE" ]; then
      fatal "missing script: $SERVAL_DNA_CONFIGURE" \
            "Run 'autoreconf -f -i -I m4' then run me again."
   fi
   if [ ! -x "$SERVAL_DNA_CONFIGURE" ]; then
      fatal "script is not executable: $SERVAL_DNA_CONFIGURE" \
            "Run 'autoreconf -f -i -I m4' then run me again."
   fi
   case "$("$SERVAL_DNA_CONFIGURE" --version)" in
   servald\ configure\ *) ;;
   *) fatal "malfunctioning script: $SERVAL_DNA_CONFIGURE" \
            "Run 'autoreconf -f -i -I m4' then run me again."
   esac
}

configure() {
   local platform="${1?}"
   local arch="${2?}"
   local prefix="${3?}"

   # Convert from the Xcode architecture name to the autoconf cpu name, so it
   # can be passed in the --host option to the configure script.
   local cpu
   case "$arch" in
   arm64) cpu=aarch64;;
   *)     cpu="$arch";;
   esac

   # A "target" is an architecture (aka, "slice" or "architecture", eg, armv7,
   # arm64, i386) and an Apple SDK (eg, iphoneos, iphonesimulator, macosx).
   local target="$arch-$platform"

   TARGETS+=("$arch-$platform")

   configure_script="$SERVAL_DNA_DIR_RELATIVE_TO_SCRIPT_DIR/configure"
   makefile_in="$SERVAL_DNA_DIR_RELATIVE_TO_SCRIPT_DIR/Makefile.in"

   # Path of the directory under which the files this script creates will be placed
   # relative to the directory containing this script.
   local target_build_dir="$SCRIPT_DIR/build/$target"
   target_build_dir="${target_build_dir#./}"
   script_dir_relative_to_target_build_dir="../.."

   if [ ! -d "$target_build_dir" ]; then
      run mkdir -p "$target_build_dir"
   fi

   # Note: the configure script created by autoconf places its output files in
   # the current working directory.
   if $opt_force_configure || $opt_force_config_status ||
      ! [ -e "$target_build_dir/.configured" ] ||
      [ "$target_build_dir/config.status" -ot "$configure_script" ] ||
      [ "$target_build_dir/Makefile" -ot "$configure_script" ] ||
      [ "$target_build_dir/Makefile" -ot "$makefile_in" ] ||
      [ "$target_build_dir/Makefile" -ot "$target_build_dir/config.status" ]
   then
      run pushd "$target_build_dir" >/dev/null

      rm -f .configured

      configure_script="$script_dir_relative_to_target_build_dir/$configure_script"
      makefile_in="$script_dir_relative_to_target_build_dir/$makefile_in"

      if $opt_force_configure ||
         ! [ -e ".configured" ] ||
         [ "config.status" -ot "$configure_script" ] ||
         [ "Makefile" -ot "$configure_script" ]
      then
         run rm -f config.status Makefile
         if ! run "$configure_script" \
               --host="$cpu-apple-darwin" \
               --enable-xcode-sdk="$platform" \
               --prefix "$prefix" \
               &>configure.out
         then
            fatal "configure failed; see $target_build_dir/configure.out for full log" \
                  "Last $log_display_line_count lines were:" \
                  "" \
                  "$(tail -n $log_display_line_count configure.out)"
         fi
         if [ ! -r config.status ]; then
            fatal "configure for $target did not produce config.status"
         fi
         if [ ! -r Makefile ]; then
            fatal "configure for $target did not produce Makefile"
         fi
      elif $opt_force_config_status ||
         [ "Makefile" -ot "$makefile_in" ] ||
         [ "Makefile" -ot "config.status" ]
      then
         run rm -f Makefile
         if ! run ./config.status &>config.status.out
         then
            fatal "./config.status failed; see $target_build_dir/config.status.out:" \
                  "$(cat config.status.out)"
         fi
      fi

      > .configured
      run popd >/dev/null
   fi
}

# Create a Serval DNA Makefile that creates an Apple framework bundle:
# - generates a modulemap file for the bundle
# - generates a Xcode config file
# - invokes all the per-target iOS makefiles to create one static library for
#   each target slice (arch-sdk)
# - merges all the static libraries into a single, multi-slice library
# - generates an Info.plist XML file describing the bundle
# - creates the correct directory structure and symbolic links for the bundle

foreach_target() {
   local target
   local target_dir
   for target in "${TARGETS[@]}"; do
      arch="${target%%-*}"
      sdk="${target#-*}"
      target_dir="build/$target"
      target_var=$(echo -n "$target" | tr -C a-zA-z0-9_ _)
      eval "$@"
   done
}

create_makefile() {
   echo "Creating $SCRIPT_DIR/Makefile"
   cat >"$SCRIPT_DIR/Makefile" <<EOF
# Makefile for Serval DNA on Apple iOS
# Copyright 2017 Flinders University
# This file was auto-generated by the ./${0##*/} script
# $(date)

srcdir=$SERVAL_DNA_DIR_RELATIVE_TO_SCRIPT_DIR
dstdir=frameworks
targets=${TARGETS[*]}

fw_name=ServalDNA
fw_version=A
fw_bundle_id=org.servalproject.serval-dna
fw_bundle_version=1.0

fw_dir=\$(dstdir)/\$(fw_name).framework
fw_dstdir=\$(fw_dir)/Versions/\$(fw_version)
fw_library=\$(fw_dstdir)/\$(fw_name)
fw_swiftmodule=\$(fw_dstdir)/Modules/\$(fw_name).swiftmodule
fw_info_plist=\$(fw_dstdir)/Resources/Info.plist
fw_config_headers=\$(targets:%=\$(fw_dstdir)/Headers/%/config.h)
fw_serval_headers=\$(addprefix \$(fw_dstdir)/Headers/, \$(LIB_HDRS) \$(PUBLIC_HDRS))
fw_sqlite3_headers=\$(addprefix \$(fw_dstdir)/Headers/, \$(notdir \$(SQLITE3_HDRS)))
fw_modulemap=\$(fw_dstdir)/Modules/module.modulemap
xcconfig=\$(dstdir)/\$(fw_name).xcconfig

include \$(srcdir)/headerfiles.mk

.PHONY: all \\
        clean\
$(foreach_target echo    '" \\"' \; \
                 echo    '"        install_${target_var}_sodium_headers \\"' \; \
                 echo    '"        $target_dir/$library \\"' \; \
                 echo    '"        $target_dir/$swiftmodule \\"' \; \
                 echo -n '"        clean-$target"')

all: \$(fw_library) \\
     \$(fw_info_plist) \\
     \$(fw_config_headers) \\
     \$(fw_serval_headers) \\
     \$(fw_sqlite3_headers) \\
     \$(fw_modulemap) \\
     \$(xcconfig)$(foreach_target echo '" \\"' \; \
                                  echo -n '"     install_${target_var}_sodium_headers"' \; \
                                  echo -n '"     \$(fw_swiftmodule)/$arch.swiftmodule"')
	cd \$(fw_dstdir)/.. && ln -snf \$(fw_version) Current
	cd \$(fw_dstdir)/../.. && ln -snf Versions/Current/* .

\$(fw_info_plist): ./info-plist.sh
	mkdir -p \$(dir \$@)
	./info-plist.sh \$(fw_name) \$(fw_bundle_id) \$(fw_bundle_version) >\$@

\$(fw_library):$(foreach_target echo '" \\"' \; \
                                echo -n '"		$target_dir/$library"')
	mkdir -p \$(dir \$@)
	lipo -create -output \$@ \$^

$(foreach_target echo '"\$(fw_swiftmodule)/$arch.swiftmodule: $target_dir/$swiftmodule"' \; \
                 echo '"	mkdir -p \$(dir \$@)"' \; \
                 echo '"	cp \$< \$@"' \; \
                 echo)

\$(fw_config_headers): \$(fw_dstdir)/Headers/%: build/%
	mkdir -p \$(dir \$@)
	cp \$< \$@

\$(fw_serval_headers): \$(fw_dstdir)/Headers/%: \$(srcdir)/%
	mkdir -p \$(dir \$@)
	cp \$< \$@

\$(fw_sqlite3_headers): \$(fw_dstdir)/Headers/%: \$(srcdir)/\$(SQLITE3_AMALGAMATION)/%
	mkdir -p \$(dir \$@)
	cp \$< \$@

\$(fw_modulemap):$(foreach_target echo '" \\"' \; \
                 echo -n '"        install_${target_var}_sodium_headers"') \\
        \$(srcdir)/headerfiles.mk Makefile
	mkdir -p \$(dir \$@)
	@{ \\
	   echo '/*' \\
	   echo 'module.modulemap for Serval DNA on Apple iOS' ;\\
	   echo 'Copyright 2017 Flinders University' ;\\
	   echo 'This file was auto-generated by \$(abspath Makefile)' ;\\
	   echo '\$(shell date)' ;\\
	   echo '*/' ;\\
	   echo 'framework module ServalDNA {' ;\\
	   echo '    requires tls // thread-local storage' ;\\
	   echo '    explicit module Daemon {' ;\\
	   echo '        export Sodium' ;\\
$(foreach_target echo '"	   echo '\''        header \"$target/config.h\"'\'' ;\\"')
           for header in \$(LIB_HDRS) \$(PUBLIC_HDRS) \$(notdir \$(SQLITE3_HDRS)); do \\
               echo "        header \"\$\$header\"" ;\\
           done ; \\
	   echo '    }' ;\\
	   echo '    explicit module Sodium {' ;\\
$(foreach_target echo '"	   echo '\''        header \"$target/sodium.h\"'\'' ;\\"' \; \
                 echo '"	   (cd $target_dir/libsodium-dev/include/; find . -type f -print | sed -e '\''s|^\./||'\'' -e '\''s|.*|        header \"$target/&\"|'\'' ) ;\\"')
	   echo '    }' ;\\
	   echo '}' ;\\
	   echo 'module ifaddrs [system] [extern_c] {' ;\\
           echo '    header "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator.sdk/usr/include/ifaddrs.h"' ;\\
           echo '    export *' ;\\
	   echo '}' ;\\
	   echo 'module inttypes [system] [extern_c] {' ;\\
           echo '    header "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/clang/include/inttypes.h"' ;\\
           echo '    export *' ;\\
	   echo '}' ;\\
	} >\$@

\$(xcconfig): Makefile
	mkdir -p \$(dir \$@)
	@{ \\
	   echo '// ServalDNA.xcconfig for Serval DNA on Apple iOS' ;\\
	   echo '// Copyright 2017 Flinders University' ;\\
           echo '// This file was auto-generated by \$(abspath Makefile)' ;\\
	   echo '// \$(shell date)' ;\\
	   echo 'SERVAL_DNA_FRAMEWORK_DIR = \$(abspath \$(fw_dir))' ;\\
	   echo 'FRAMEWORK_SEARCH_PATHS = \$\$(inherited) \$(abspath \$(dstdir))' ;\\
	   echo 'GCC_PREPROCESSOR_DEFINITIONS = \$\$(inherited) HAVE_CONFIG_H=1' ;\\
$(foreach_target echo '"	   echo '\''HEADER_SEARCH_PATHS[arch=$arch] = \$\$(inherited) \$\$(SERVAL_DNA_FRAMEWORK_DIR)/Headers/$target'\'' ;\\"')
	   echo 'SWIFT_INCLUDE_PATHS = \$\$(inherited) \$\$(SERVAL_DNA_FRAMEWORK_DIR)/Modules' ;\\
	   echo 'OTHER_SWIFT_FLAGS = \$\$(inherited) -Xcc -DHAVE_CONFIG_H=1' ;\\
	} >\$@

$(foreach_target echo \; \
                 echo '"install_${target_var}_sodium_headers: $target_dir/$library"' \; \
                 echo '"	cp -R $target_dir/libsodium-dev/include/ \$(fw_dstdir)/Headers/$target/"')

# If the source directory is already configured, then its config.h header
# file would interfere with these sub-makes, so delete it before invoking
# each sub-make.

$(foreach_target echo \; \
                 echo '"$target_dir/$library:"' \; \
                 echo '"	\$(RM) \$(srcdir)/config.h"' \; \
                 echo '"	\$(MAKE) -C $target_dir $library"')

$(foreach_target echo \; \
                 echo '"$target_dir/$swiftmodule:"' \; \
                 echo '"	\$(RM) \$(srcdir)/config.h"' \; \
                 echo '"	\$(MAKE) -C $target_dir $swiftmodule"')

clean: $(foreach_target echo -n '" clean-$target"')
	\$(RM) -r \$(dstdir)
$(foreach_target echo \; \
                 echo '"clean-$target:"' \; \
                 echo '"	\$(MAKE) -C $target_dir clean"')
EOF
}

main "$@"