#!/bin/bash

# XCode will error during it's dependency graph construction (which happens before the build
# stage starts and any target "Run Script" phases are triggered)
#
# In order to avoid this error we need to build the framework before actually getting to the
# build stage so XCode is able to build the dependency graph
#
# XCode's Pre-action scripts don't output anything into XCode so the only way to emit a useful
# error is to **return a success status** and have the project detect and log the error itself
# then log it, stopping the build at that point
#
# The other step to get this to work properly is to ensure the framework in "Link Binary with
# Libraries" isn't using a relative directory, unfortunately there doesn't seem to be a good
# way to do this directly so we need to modify the '.pbxproj' file directly, updating the
# framework entry to have the following (on a single line):
# {
#   isa = PBXFileReference;
#   explicitFileType = wrapper.xcframework;
#   includeInIndex = 0;
#   path = "{FRAMEWORK NAME GOES HERE}";
#   sourceTree = BUILD_DIR;
# };
#
# Note: We might one day be able to replace this with a local podspec if this GitHub feature
# request ever gets implemented: https://github.com/CocoaPods/CocoaPods/issues/8464

# Need to set the path or we won't find cmake
PATH=${PATH}:/usr/local/bin:/opt/homebrew/bin:/sbin/md5
SHOULD_AUTO_INIT_SUBMODULES=${1:-false}

# Ensure the build directory exists (in case we need it before XCode creates it)
mkdir -p "${TARGET_BUILD_DIR}"

# Remove any old build errors
rm -rf "${TARGET_BUILD_DIR}/libsession_util_error.log"

# First ensure cmake is installed (store the error in a log and exit with a success status - xcode will output the error)
echo "info: Validating build requirements"

if ! which cmake > /dev/null; then
  touch "${TARGET_BUILD_DIR}/libsession_util_error.log"
  echo "error: cmake is required to build, please install (can install via homebrew with 'brew install cmake')."
  echo "error: cmake is required to build, please install (can install via homebrew with 'brew install cmake')." > "${TARGET_BUILD_DIR}/libsession_util_error.log"
  exit 0
fi

# Check if we have the `LibSession-Util` submodule checked out and if not (depending on the 'SHOULD_AUTO_INIT_SUBMODULES' argument) perform the checkout
if [ ! -d "${SRCROOT}/LibSession-Util" ] || [ ! -d "${SRCROOT}/LibSession-Util/src" ] || [ ! "$(ls -A "${SRCROOT}/LibSession-Util")" ]; then
  if [ "${SHOULD_AUTO_INIT_SUBMODULES}" != "false" ] & command -v git >/dev/null 2>&1; then
    echo "info: LibSession-Util submodule doesn't exist, resetting and checking out recusively now"
    git submodule foreach --recursive git reset --hard
    git submodule update --init --recursive
    echo "info: Checkout complete"
  else
    touch "${TARGET_BUILD_DIR}/libsession_util_error.log"
    echo "error: Need to fetch LibSession-Util submodule (git submodule update --init --recursive)."
    echo "error: Need to fetch LibSession-Util submodule (git submodule update --init --recursive)." > "${TARGET_BUILD_DIR}/libsession_util_error.log"
    exit 0
  fi
else
  are_submodules_valid() {
    local PARENT_PATH=$1
    
    # Change into the path to check for it's submodules
    cd "${PARENT_PATH}"
    local SUB_MODULE_PATHS=($(git config --file .gitmodules --get-regexp path | awk '{ print $2 }'))

    # If there are no submodules then return success based on whether the folder has any content
    if [ ${#SUB_MODULE_PATHS[@]} -eq 0 ]; then
      if [ "$(ls -A "${SRCROOT}/LibSession-Util")" ]; then
        return 1
      else
        return 0
      fi
    fi

    # Loop through the child submodules and check if they are valid
    for i in "${!SUB_MODULE_PATHS[@]}"; do
      local CHILD_PATH="${SUB_MODULE_PATHS[$i]}"
      
      # If the child path doesn't exist then it's invalid
      if [ ! -d "${CHILD_PATH}" ]; then
        return 1
      fi

      are_submodules_valid "${PARENT_PATH}/${CHILD_PATH}"
      local RESULT=$?

      if [ "${RESULT}" -eq 1 ]; then
        echo "info: Submodule ${CHILD_PATH} is in an invalid state."
        return 1
      fi
    done

    return 0
  }

  # Validate the state of the submodules
  are_submodules_valid "${SRCROOT}/LibSession-Util"

  HAS_INVALID_SUBMODULE=$?

  if [ "${HAS_INVALID_SUBMODULE}" -eq 1 ]; then
    if [ "${SHOULD_AUTO_INIT_SUBMODULES}" != "false" ] && command -v git >/dev/null 2>&1; then
      echo "info: Submodules are in an invalid state, resetting and checking out recusively now"
      cd "${SRCROOT}/LibSession-Util"
      git submodule foreach --recursive git reset --hard
      git submodule update --init --recursive
      echo "info: Checkout complete"
    else
      touch "${TARGET_BUILD_DIR}/libsession_util_error.log"
      echo "error: Submodules are in an invalid state, please delete 'LibSession-Util' and run 'git submodule update --init --recursive'."
      echo "error: Submodules are in an invalid state, please delete 'LibSession-Util' and run 'git submodule update --init --recursive'." > "${TARGET_BUILD_DIR}/libsession_util_error.log"
      exit 0
    fi
  fi
fi

# Generate a hash of the libSession-util source files and check if they differ from the last hash
echo "info: Checking for changes to source"

NEW_SOURCE_HASH=$(find "${SRCROOT}/LibSession-Util/src" -type f -exec md5 {} + | awk '{print $NF}' | sort | md5 | awk '{print $NF}')
NEW_HEADER_HASH=$(find "${SRCROOT}/LibSession-Util/include" -type f -exec md5 {} + | awk '{print $NF}' | sort | md5 | awk '{print $NF}')

if [ -f "${TARGET_BUILD_DIR}/libsession_util_source_hash.log" ]; then
    read -r OLD_SOURCE_HASH < "${TARGET_BUILD_DIR}/libsession_util_source_hash.log"
fi

if [ -f "${TARGET_BUILD_DIR}/libsession_util_header_hash.log" ]; then
    read -r OLD_HEADER_HASH < "${TARGET_BUILD_DIR}/libsession_util_header_hash.log"
fi

if [ -f "${TARGET_BUILD_DIR}/libsession_util_archs.log" ]; then
    read -r OLD_ARCHS < "${TARGET_BUILD_DIR}/libsession_util_archs.log"
fi

# Start the libSession-util build if it doesn't already exists
if [ "${NEW_SOURCE_HASH}" != "${OLD_SOURCE_HASH}" ] || [ "${NEW_HEADER_HASH}" != "${OLD_HEADER_HASH}" ] || [ "${ARCHS[*]}" != "${OLD_ARCHS}" ] || [ ! -d "${TARGET_BUILD_DIR}/libsession-util.xcframework" ]; then
  echo "info: Build is not up-to-date - creating new build"
  echo ""

  # Remove any existing build files (just to be safe)
  rm -rf "${TARGET_BUILD_DIR}/libsession-util.a"
  rm -rf "${TARGET_BUILD_DIR}/libsession-util.xcframework"
  rm -rf "${BUILD_DIR}/libsession-util.xcframework"

  # Trigger the new build
  cd "${SRCROOT}/LibSession-Util"
  result=$(./utils/ios.sh "libsession-util" false)

  if [ $? -ne 0 ]; then
    touch "${TARGET_BUILD_DIR}/libsession_util_error.log"
    echo "error: Failed to build libsession-util (See details in '${TARGET_BUILD_DIR}/pre-action-output.log')."
    echo "error: Failed to build libsession-util (See details in '${TARGET_BUILD_DIR}/pre-action-output.log')." > "${TARGET_BUILD_DIR}/libsession_util_error.log"
    exit 0
  fi

  # Save the updated source hash to disk to prevent rebuilds when there were no changes
  echo "${NEW_SOURCE_HASH}" > "${TARGET_BUILD_DIR}/libsession_util_source_hash.log"
  echo "${NEW_HEADER_HASH}" > "${TARGET_BUILD_DIR}/libsession_util_header_hash.log"
  echo "${ARCHS[*]}" > "${TARGET_BUILD_DIR}/libsession_util_archs.log"
  echo ""
  echo "info: Build complete"
else
  echo "info: Build is up-to-date"
fi

# Move the target-specific libSession-util build to the parent build directory (so XCode can have a reference to a single build)
rm -rf "${BUILD_DIR}/libsession-util.xcframework"
cp -r "${TARGET_BUILD_DIR}/libsession-util.xcframework" "${BUILD_DIR}/libsession-util.xcframework"