#!/bin/bash
# Copyright 2015 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

set -e

function follow_links() {
  cd -P "${1%/*}"
  file="$PWD/${1##*/}"
  while [ -h "$file" ]; do
    # On Mac OS, readlink -f doesn't work.
    cd -P "${file%/*}"
    file="$(readlink "$file")"
    cd -P "${file%/*}"
    file="$PWD/${file##*/}"
  done
  echo "$PWD/${file##*/}"
}

PROG_NAME="$(follow_links "$BASH_SOURCE")"
BIN_DIR="$(cd "${PROG_NAME%/*}" ; pwd -P)"
export FLUTTER_ROOT="$(cd "${BIN_DIR}/.." ; pwd -P)"

FLUTTER_TOOLS_DIR="$FLUTTER_ROOT/packages/flutter_tools"
SNAPSHOT_PATH="$FLUTTER_ROOT/bin/cache/flutter_tools.snapshot"
STAMP_PATH="$FLUTTER_ROOT/bin/cache/flutter_tools.stamp"
SCRIPT_PATH="$FLUTTER_TOOLS_DIR/bin/flutter_tools.dart"
DART_SDK_PATH="$FLUTTER_ROOT/bin/cache/dart-sdk"

DART="$DART_SDK_PATH/bin/dart"

REVISION=`(cd "$FLUTTER_ROOT"; git rev-parse HEAD)`
if [ ! -f "$SNAPSHOT_PATH" ] || [ ! -f "$STAMP_PATH" ] || [ `cat "$STAMP_PATH"` != "$REVISION" ] || [ "$FLUTTER_TOOLS_DIR/pubspec.yaml" -nt "$FLUTTER_TOOLS_DIR/pubspec.lock" ]; then
  "$FLUTTER_ROOT/bin/cache/update_dart_sdk.sh"

  echo Building flutter tool...
  FLUTTER_DIR="$FLUTTER_ROOT/packages/flutter"
  (cd "$FLUTTER_TOOLS_DIR"; "../../bin/cache/dart-sdk/bin/pub" get --verbosity=warning)
  "$DART" --snapshot="$SNAPSHOT_PATH" --packages="$FLUTTER_TOOLS_DIR/.packages" "$SCRIPT_PATH"
  echo $REVISION > "$STAMP_PATH"
fi

if [ $FLUTTER_DEV ]; then
  "$DART" --packages="$FLUTTER_TOOLS_DIR/.packages" -c "$SCRIPT_PATH" "$@"
else
  set +e
  "$DART" "$SNAPSHOT_PATH" "$@"

  # The VM exits with code 253 if the snapshot version is out-of-date.
  # If it is, we need to snapshot it again.
  EXIT_CODE=$?
  if [ $EXIT_CODE != 253 ]; then
    exit $EXIT_CODE
  fi

  set -e
  "$DART" --snapshot="$SNAPSHOT_PATH" --package="$FLUTTER_TOOLS_DIR/.packages" "$SCRIPT_PATH"
  "$DART" "$SNAPSHOT_PATH" "$@"
fi
