#!/usr/bin/env bash
# Copyright 2014 The Flutter Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# ---------------------------------- NOTE ---------------------------------- #
#
# Please keep the logic in this file consistent with the logic in the
# `flutter-dev.bat` script in the same directory to ensure that Flutter
# continues to work across all platforms!
#
# -------------------------------------------------------------------------- #

set -e

# This is a helper script for development purposes. It runs the Flutter tool
# from source code directly, without using the prebuilt snapshot. This is
# useful for development, as it allows you to make changes to the tool and see
# the effects immediately, but is much slower than using the prebuilt snapshot.

# To debug the tool, you can uncomment the following lines to enable debug
# mode and set an observatory port:
# FLUTTER_TOOL_ARGS="--enable-asserts $FLUTTER_TOOL_ARGS"
# FLUTTER_TOOL_ARGS="$FLUTTER_TOOL_ARGS --observe=65432"

# Needed because if it is set, cd may print the path it changed to.
unset CDPATH

# On Mac OS, readlink -f doesn't work, so follow_links traverses the path one
# link at a time, and then cds into the link destination and find out where it
# ends up.
#
# The returned filesystem path must be a format usable by Dart's URI parser,
# since the Dart command line tool treats its argument as a file URI, not a
# filename. For instance, multiple consecutive slashes should be reduced to a
# single slash, since double-slashes indicate a URI "authority", and these are
# supposed to be filenames. There is an edge case where this will return
# multiple slashes: when the input resolves to the root directory. However, if
# that were the case, we wouldn't be running this shell, so we don't do anything
# about it.
#
# The function is enclosed in a subshell to avoid changing the working directory
# of the caller.
function follow_links() (
  cd -P "$(dirname -- "$1")"
  file="$PWD/$(basename -- "$1")"
  while [[ -h "$file" ]]; do
    cd -P "$(dirname -- "$file")"
    file="$(readlink -- "$file")"
    cd -P "$(dirname -- "$file")"
    file="$PWD/$(basename -- "$file")"
  done
  echo "$file"
)

# Lookup the parent directory of the script (../), the Flutter SDK root.
PROG_NAME="$(follow_links "${BASH_SOURCE[0]}")"
BIN_DIR="$(cd "${PROG_NAME%/*}" ; pwd -P)"
SHARED_NAME="$BIN_DIR/internal/shared.sh"
FLUTTER_ROOT="$(cd "$BIN_DIR/.." ; pwd -P)"
OS="$(uname -s)"

# If we're on Windows, invoke the batch script instead to get proper locking.
if [[ $OS =~ MINGW.* || $OS =~ CYGWIN.* || $OS =~ MSYS.* ]]; then
  exec "${BIN_DIR}/flutter-dev.bat" "$@"
fi

# To define `shared::execute()` function
source "$SHARED_NAME"

# Run the Flutter tool directly without using the cached snapshot.
shared::execute "$@"