#!/usr/bin/env python3
#
# Copyright 2018 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import argparse
import glob
import multiprocessing
import os
import shutil
import subprocess
import sys

from parse_link_map import parse_link_map

sys.path.append(
    os.path.join(os.path.dirname(sys.argv[0]), '..', '..', 'run_tests',
                 'python_utils'))
import check_on_pr

# Only show diff 1KB or greater
_DIFF_THRESHOLD = 1000

_SIZE_LABELS = ('Core', 'ObjC', 'BoringSSL', 'Protobuf', 'Total')

argp = argparse.ArgumentParser(
    description='Binary size diff of gRPC Objective-C sample')

argp.add_argument('-d',
                  '--diff_base',
                  type=str,
                  help='Commit or branch to compare the current one to')

args = argp.parse_args()


def dir_size(dir):
    total = 0
    for dirpath, dirnames, filenames in os.walk(dir):
        for f in filenames:
            fp = os.path.join(dirpath, f)
            total += os.stat(fp).st_size
    return total


def get_size(where):
    build_dir = 'src/objective-c/examples/Sample/Build/Build-%s/' % where
    link_map_filename = 'Build/Intermediates.noindex/Sample.build/Release-iphoneos/Sample.build/Sample-LinkMap-normal-arm64.txt'
    # IMPORTANT: order needs to match labels in _SIZE_LABELS
    return parse_link_map(build_dir + link_map_filename)


def build(where):
    subprocess.check_call(['make', 'clean'])
    shutil.rmtree('src/objective-c/examples/Sample/Build/Build-%s' % where,
                  ignore_errors=True)
    subprocess.check_call(
        'CONFIG=opt EXAMPLE_PATH=src/objective-c/examples/Sample SCHEME=Sample ./build_one_example.sh',
        shell=True,
        cwd='src/objective-c/tests')
    os.rename('src/objective-c/examples/Sample/Build/Build',
              'src/objective-c/examples/Sample/Build/Build-%s' % where)


def _render_row(new, label, old):
    """Render row in 3-column output format."""
    try:
        formatted_new = '{:,}'.format(int(new))
    except:
        formatted_new = new
    try:
        formatted_old = '{:,}'.format(int(old))
    except:
        formatted_old = old
    return '{:>15}{:>15}{:>15}\n'.format(formatted_new, label, formatted_old)


def _diff_sign(new, old, diff_threshold=None):
    """Generate diff sign based on values"""
    diff_sign = ' '
    if diff_threshold is not None and abs(new_size[i] -
                                          old_size[i]) >= diff_threshold:
        diff_sign += '!'
    if new > old:
        diff_sign += '(>)'
    elif new < old:
        diff_sign += '(<)'
    else:
        diff_sign += '(=)'
    return diff_sign


text = 'Objective-C binary sizes\n'

build('new')
new_size = get_size('new')
old_size = None

if args.diff_base:
    old = 'old'
    where_am_i = subprocess.check_output(
        ['git', 'rev-parse', '--abbrev-ref', 'HEAD']).decode().strip()
    subprocess.check_call(['git', 'checkout', '--', '.'])
    subprocess.check_call(['git', 'checkout', args.diff_base])
    subprocess.check_call(['git', 'submodule', 'update', '--force'])
    try:
        build('old')
        old_size = get_size('old')
    finally:
        subprocess.check_call(['git', 'checkout', '--', '.'])
        subprocess.check_call(['git', 'checkout', where_am_i])
        subprocess.check_call(['git', 'submodule', 'update', '--force'])

text += '**********************STATIC******************\n'
text += _render_row('New size', '', 'Old size')
if old_size == None:
    for i in range(0, len(_SIZE_LABELS)):
        if i == len(_SIZE_LABELS) - 1:
            # skip line before rendering "Total"
            text += '\n'
        text += _render_row(new_size[i], _SIZE_LABELS[i], '')
else:
    has_diff = False
    # go through all labels but "Total"
    for i in range(0, len(_SIZE_LABELS) - 1):
        if abs(new_size[i] - old_size[i]) >= _DIFF_THRESHOLD:
            has_diff = True
        diff_sign = _diff_sign(new_size[i],
                               old_size[i],
                               diff_threshold=_DIFF_THRESHOLD)
        text += _render_row(new_size[i], _SIZE_LABELS[i] + diff_sign,
                            old_size[i])

    # render the "Total"
    i = len(_SIZE_LABELS) - 1
    diff_sign = _diff_sign(new_size[i], old_size[i])
    # skip line before rendering "Total"
    text += '\n'
    text += _render_row(new_size[i], _SIZE_LABELS[i] + diff_sign, old_size[i])
    if not has_diff:
        text += '\n No significant differences in binary sizes\n'
text += '\n'

print(text)

check_on_pr.check_on_pr('ObjC Binary Size', '```\n%s\n```' % text)