#! /bin/sh

set -e
set -x

ARCH="$1"

SOURCE_DIR=$(echo "$(cd "$(dirname "$2")"; pwd -P)/$(basename "$2")")
BUILD_DIR=$(echo "$(cd "$(dirname "$3")"; pwd -P)/$(basename "$3")")

pushd "$BUILD_DIR"

set -e
devnull='> /dev/null 2>&1'

BUILD_ROOT="_iosbuild"
CONFIGURE_ARGS="--disable-docs
                --disable-examples
                --disable-libyuv
                --disable-unit-tests"
DIST_DIR="_dist"
FRAMEWORK_DIR="VPX.framework"
FRAMEWORK_LIB="VPX.framework/VPX"
HEADER_DIR="${FRAMEWORK_DIR}/Headers/vpx"
SCRIPT_DIR="$SOURCE_DIR"
LIBVPX_SOURCE_DIR="$SOURCE_DIR"


LIPO=$(xcrun -sdk iphoneos${SDK} -find lipo)

ORIG_PWD="$(pwd)"

if [ "$ARCH" = "armv7" ]; then
  TARGETS="armv7-darwin-gcc"
elif [ "$ARCH" = "arm64" ]; then
  TARGETS="arm64-darwin-gcc"
elif [ "$ARCH" = "x86_64" ]; then
  TARGETS="x86_64-iphonesimulator-gcc"
else
  echo "Unsupported architecture $ARCH"
  exit 1
fi

# Configures for the target specified by $1, and invokes make with the dist
# target using $DIST_DIR as the distribution output directory.
build_target() {
  local target="$1"
  local old_pwd="$(pwd)"
  local target_specific_flags=""

  case "${target}" in
    x86-*)
      target_specific_flags="--enable-pic"
      ;;
  esac

  mkdir "${target}"
  cd "${target}"
  eval "${LIBVPX_SOURCE_DIR}/configure" --target="${target}" \
    ${CONFIGURE_ARGS} ${EXTRA_CONFIGURE_ARGS} ${target_specific_flags} \
    ${devnull}
  export DIST_DIR
  eval make dist ${devnull}
  cd "${old_pwd}"
}

# Returns the preprocessor symbol for the target specified by $1.
target_to_preproc_symbol() {
  target="$1"
  case "${target}" in
    arm64-*)
      echo "__aarch64__"
      ;;
    armv7-*)
      echo "__ARM_ARCH_7A__"
      ;;
    x86_64-*)
      echo "__x86_64__"
      ;;
    *)
      echo "#error ${target} unknown/unsupported"
      return 1
      ;;
  esac
}

# Create a vpx_config.h shim that, based on preprocessor settings for the
# current target CPU, includes the real vpx_config.h for the current target.
# $1 is the list of targets.
create_vpx_framework_config_shim() {
  local targets="$1"
  local config_file="${HEADER_DIR}/vpx_config.h"
  local preproc_symbol=""
  local target=""
  local include_guard="VPX_FRAMEWORK_HEADERS_VPX_VPX_CONFIG_H_"

  local file_header="/*
 *  Copyright (c) The WebM project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
/* GENERATED FILE: DO NOT EDIT! */
#ifndef ${include_guard}
#define ${include_guard}
#if defined"

  printf "%s" "${file_header}" > "${config_file}"
  for target in ${targets}; do
    preproc_symbol=$(target_to_preproc_symbol "${target}")
    printf " ${preproc_symbol}\n" >> "${config_file}"
    printf "#define VPX_FRAMEWORK_TARGET \"${target}\"\n" >> "${config_file}"
    printf "#include \"VPX/vpx/${target}/vpx_config.h\"\n" >> "${config_file}"
    printf "#elif defined" >> "${config_file}"
    mkdir "${HEADER_DIR}/${target}"
    cp -p "${BUILD_ROOT}/${target}/vpx_config.h" "${HEADER_DIR}/${target}"
  done

  # Consume the last line of output from the loop: We don't want it.
  sed -i.bak -e '$d' "${config_file}"
  rm "${config_file}.bak"

  printf "#endif\n\n" >> "${config_file}"
  printf "#endif  // ${include_guard}" >> "${config_file}"
}

# Configures and builds each target specified by $1, and then builds
# VPX.framework.
build_framework() {
  local lib_list=""
  local targets="$1"
  local target=""
  local target_dist_dir=""

  # Clean up from previous build(s).
  rm -rf "${BUILD_ROOT}" "${FRAMEWORK_DIR}"

  # Create output dirs.
  mkdir -p "${BUILD_ROOT}"
  mkdir -p "${HEADER_DIR}"

  cd "${BUILD_ROOT}"

  for target in ${targets}; do
    build_target "${target}"
    target_dist_dir="${BUILD_ROOT}/${target}/${DIST_DIR}"
    local suffix="a"
    lib_list="${lib_list} ${target_dist_dir}/lib/libvpx.${suffix}"
  done

  cd "${ORIG_PWD}"

  # The basic libvpx API includes are all the same; just grab the most recent
  # set.
  cp -p "${target_dist_dir}"/include/vpx/* "${HEADER_DIR}"

  # Build the fat library.
  ${LIPO} -create ${lib_list} -output ${FRAMEWORK_DIR}/VPX

  # Create the vpx_config.h shim that allows usage of vpx_config.h from
  # within VPX.framework.
  create_vpx_framework_config_shim "${targets}"

  # Copy in vpx_version.h.
  cp -p "${BUILD_ROOT}/${target}/vpx_version.h" "${HEADER_DIR}"
}

build_framework "${TARGETS}"

popd