#!/bin/python3

import argparse
import os
import sys
import tempfile

from BuildEnvironment import is_apple_silicon, call_executable, BuildEnvironment
from ProjectGeneration import generate


class BazelCommandLine:
    def __init__(self, bazel_path, bazel_x86_64_path, override_bazel_version, override_xcode_version):
        self.build_environment = BuildEnvironment(
            base_path=os.getcwd(),
            bazel_path=bazel_path,
            bazel_x86_64_path=bazel_x86_64_path,
            override_bazel_version=override_bazel_version,
            override_xcode_version=override_xcode_version
        )
        self.remote_cache = None
        self.cache_dir = None
        self.additional_args = None
        self.configuration_args = None
        self.configuration_path = None

        self.common_args = [
            # https://docs.bazel.build/versions/master/command-line-reference.html
            # Ask bazel to print the actual resolved command line options.
            '--announce_rc',

            # https://github.com/bazelbuild/rules_swift
            # If enabled, Swift compilation actions will use the same global Clang module
            # cache used by Objective-C compilation actions. This is disabled by default
            # because under some circumstances Clang module cache corruption can cause the
            # Swift compiler to crash (sometimes when switching configurations or syncing a
            # repository), but disabling it also causes a noticeable build time regression
            # so it can be explicitly re-enabled by users who are not affected by those
            # crashes.
            '--features=swift.use_global_module_cache',

            # https://docs.bazel.build/versions/master/command-line-reference.html
            # Print the subcommand details in case of failure.
            '--verbose_failures',
        ]

        self.common_build_args = [
            # https://github.com/bazelbuild/rules_swift
            # If enabled and whole module optimisation is being used, the `*.swiftdoc`,
            # `*.swiftmodule` and `*-Swift.h` are generated with a separate action
            # rather than as part of the compilation.
            '--features=swift.split_derived_files_generation',

            # https://github.com/bazelbuild/rules_swift
            # If enabled the skip function bodies frontend flag is passed when using derived
            # files generation.
            '--features=swift.skip_function_bodies_for_derived_files',
            
            # Set the number of parallel processes to match the available CPU core count.
            '--jobs={}'.format(os.cpu_count()),
        ]

        self.common_debug_args = [
            # https://github.com/bazelbuild/rules_swift
            # If enabled, Swift compilation actions will use batch mode by passing
            # `-enable-batch-mode` to `swiftc`. This is a new compilation mode as of
            # Swift 4.2 that is intended to speed up non-incremental non-WMO builds by
            # invoking a smaller number of frontend processes and passing them batches of
            # source files.
            '--features=swift.enable_batch_mode',

            # https://docs.bazel.build/versions/master/command-line-reference.html
            # Set the number of parallel jobs per module to saturate the available CPU resources.
            '--swiftcopt=-j{}'.format(os.cpu_count() - 1),
        ]

        self.common_release_args = [
            # https://github.com/bazelbuild/rules_swift
            # Enable whole module optimization.
            '--features=swift.opt_uses_wmo',

            # https://github.com/bazelbuild/rules_swift
            # Use -Osize instead of -O when building swift modules.
            '--features=swift.opt_uses_osize',

            # --num-threads 0 forces swiftc to generate one object file per module; it:
            # 1. resolves issues with the linker caused by the swift-objc mixing.
            # 2. makes the resulting binaries significantly smaller (up to 9% for this project).
            '--swiftcopt=-num-threads', '--swiftcopt=0',

            # Strip unsused code.
            '--features=dead_strip',
            '--objc_enable_binary_stripping',

            # Always embed bitcode into Watch binaries. This is required by the App Store.
            '--apple_bitcode=watchos=embedded',
        ]

    def add_remote_cache(self, host):
        self.remote_cache = host

    def add_cache_dir(self, path):
        self.cache_dir = path

    def add_additional_args(self, additional_args):
        self.additional_args = additional_args

    def set_configuration_path(self, path):
        self.configuration_path = path

    def set_configuration(self, configuration):
        if configuration == 'debug_arm64':
            self.configuration_args = [
                # bazel debug build configuration
                '-c', 'dbg',

                # Build single-architecture binaries. It is almost 2 times faster is 32-bit support is not required.
                '--ios_multi_cpus=arm64',

                # Always build universal Watch binaries.
                '--watchos_cpus=armv7k,arm64_32'
            ] + self.common_debug_args
        elif configuration == 'release_arm64':
            self.configuration_args = [
                # bazel optimized build configuration
                '-c', 'opt',

                # Build single-architecture binaries. It is almost 2 times faster is 32-bit support is not required.
                '--ios_multi_cpus=arm64',

                # Always build universal Watch binaries.
                '--watchos_cpus=armv7k,arm64_32'
            ] + self.common_release_args
        elif configuration == 'release':
            self.configuration_args = [
                # bazel optimized build configuration
                '-c', 'opt',

                # Build universal binaries.
                '--ios_multi_cpus=armv7,arm64',

                # Always build universal Watch binaries.
                '--watchos_cpus=armv7k,arm64_32'
                
                # Generate DSYM files when building.
                '--apple_generate_dsym',

                # Require DSYM files as build output.
                '--output_groups=+dsyms'
            ] + self.common_release_args
        else:
            raise Exception('Unknown configuration {}'.format(configuration))

    def invoke_clean(self):
        combined_arguments = [
            self.build_environment.bazel_path,
            'clean',
            '--expunge'
        ]

        print('TelegramBuild: running {}'.format(combined_arguments))
        call_executable(combined_arguments)

    def get_project_generation_arguments(self):
        combined_arguments = []
        combined_arguments += self.common_args
        combined_arguments += self.common_debug_args

        if self.remote_cache is not None:
            combined_arguments += [
                '--remote_cache={}'.format(self.remote_cache),
                '--experimental_remote_downloader="{}"'.format(self.remote_cache)
            ]
        elif self.cache_dir is not None:
            combined_arguments += [
                '--disk_cache={path}'.format(path=self.cache_dir)
            ]

        return combined_arguments

    def invoke_build(self):
        combined_arguments = [
            self.build_environment.bazel_path,
            'build',
            'Telegram/Telegram'
        ]

        if self.configuration_path is None:
            raise Exception('configuration_path is not defined')

        combined_arguments += [
            '--override_repository=build_configuration={}'.format(self.configuration_path)
        ]

        combined_arguments += self.common_args
        combined_arguments += self.common_build_args

        if self.remote_cache is not None:
            combined_arguments += [
                '--remote_cache={}'.format(self.remote_cache),
                '--experimental_remote_downloader="{}"'.format(self.remote_cache)
            ]
        elif self.cache_dir is not None:
            combined_arguments += [
                '--disk_cache={path}'.format(path=self.cache_dir)
            ]

        combined_arguments += self.configuration_args

        print('TelegramBuild: running {}'.format(combined_arguments))
        call_executable(combined_arguments)


def clean(arguments):
    bazel_command_line = BazelCommandLine(
        bazel_path=arguments.bazel,
        bazel_x86_64_path=None,
        override_bazel_version=arguments.overrideBazelVersion,
        override_xcode_version=arguments.overrideXcodeVersion
    )

    bazel_command_line.invoke_clean()


def resolve_configuration(bazel_command_line: BazelCommandLine, arguments):
    if arguments.configurationGenerator is not None:
        if not os.path.isfile(arguments.configurationGenerator):
            print('{} is not a valid executable'.format(arguments.configurationGenerator))
            exit(1)

        temp_configuration_path = tempfile.mkdtemp()
        call_executable([
            arguments.configurationGenerator,
            temp_configuration_path
        ])

        print('TelegramBuild: using generated configuration in {}'.format(temp_configuration_path))
        bazel_command_line.set_configuration_path(temp_configuration_path)
    elif arguments.configurationPath is not None:
        absolute_configuration_path = os.path.abspath(arguments.configurationPath)
        if not os.path.isdir(absolute_configuration_path):
            print('Error: {} does not exist'.format(absolute_configuration_path))
            exit(1)
        bazel_command_line.set_configuration_path(absolute_configuration_path)
    else:
        raise Exception('Neither configurationPath nor configurationGenerator are set')


def generate_project(arguments):
    bazel_command_line = BazelCommandLine(
        bazel_path=arguments.bazel,
        bazel_x86_64_path=arguments.bazel_x86_64,
        override_bazel_version=arguments.overrideBazelVersion,
        override_xcode_version=arguments.overrideXcodeVersion
    )

    if arguments.cacheDir is not None:
        bazel_command_line.add_cache_dir(arguments.cacheDir)
    elif arguments.cacheHost is not None:
        bazel_command_line.add_remote_cache(arguments.cacheDir)

    resolve_configuration(bazel_command_line, arguments)

    disable_extensions = False
    if arguments.disableExtensions is not None:
        disable_extensions = arguments.disableExtensions

    generate(
        build_environment=bazel_command_line.build_environment,
        disable_extensions=disable_extensions,
        configuration_path=bazel_command_line.configuration_path,
        bazel_app_arguments=bazel_command_line.get_project_generation_arguments()
    )


def build(arguments):
    bazel_command_line = BazelCommandLine(
        bazel_path=arguments.bazel,
        bazel_x86_64_path=None,
        override_bazel_version=arguments.overrideBazelVersion,
        override_xcode_version=arguments.overrideXcodeVersion
    )

    if arguments.cacheDir is not None:
        bazel_command_line.add_cache_dir(arguments.cacheDir)
    elif arguments.cacheHost is not None:
        bazel_command_line.add_remote_cache(arguments.cacheDir)

    resolve_configuration(bazel_command_line, arguments)

    bazel_command_line.set_configuration(arguments.configuration)

    bazel_command_line.invoke_build()


def add_project_and_build_common_arguments(current_parser: argparse.ArgumentParser):
    group = current_parser.add_mutually_exclusive_group(required=True)
    group.add_argument(
        '--configurationPath',
        help='''
            Path to a folder containing build configuration and provisioning profiles.
            See build-system/example-configuration for an example.
            ''',
        metavar='path'
    )
    group.add_argument(
        '--configurationGenerator',
        help='''
            Path to an executable that will generate configuration data
            (project constants and provisioning profiles).
            The executable will be invoked with one parameter — path to the destination directory. 
            See build-system/generate-configuration.sh for an example.
            ''',
        metavar='path'
    )


if __name__ == '__main__':
    parser = argparse.ArgumentParser(prog='Make')

    parser.add_argument(
        '--verbose',
        action='store_true',
        default=False,
        help='Print debug info'
    )

    parser.add_argument(
        '--bazel',
        required=True,
        help='Use custom bazel binary',
        metavar='path'
    )

    parser.add_argument(
        '--overrideBazelVersion',
        action='store_true',
        help='Override bazel version with the actual version reported by the bazel binary'
    )

    parser.add_argument(
        '--overrideXcodeVersion',
        action='store_true',
        help='Override xcode version with the actual version reported by \'xcode-select -p\''
    )

    parser.add_argument(
        '--bazelArguments',
        required=False,
        help='Add additional arguments to all bazel invocations.',
        metavar='arguments'
    )

    cacheTypeGroup = parser.add_mutually_exclusive_group()
    cacheTypeGroup.add_argument(
        '--cacheHost',
        required=False,
        help='Use remote build artifact cache to speed up rebuilds (See https://github.com/buchgr/bazel-remote).',
        metavar='http://host:9092'
    )
    cacheTypeGroup.add_argument(
        '--cacheDir',
        required=False,
        help='Cache build artifacts in a local directory to speed up rebuilds.',
        metavar='path'
    )

    subparsers = parser.add_subparsers(dest='commandName', help='Commands')

    cleanParser = subparsers.add_parser(
        'clean', help='''
            Clean local bazel cache. Does not affect files cached remotely (via --cacheHost=...) or 
            locally in an external directory ('--cacheDir=...')
            '''
    )

    generateProjectParser = subparsers.add_parser('generateProject', help='Generate Xcode project')
    if is_apple_silicon():
        generateProjectParser.add_argument(
            '--bazel_x86_64',
            required=True,
            help='A standalone bazel x86_64 binary is required to generate a project on Apple Silicon.',
            metavar='path'
        )
    generateProjectParser.add_argument(
        '--buildNumber',
        required=False,
        type=int,
        default=10000,
        help='Build number.',
        metavar='number'
    )
    add_project_and_build_common_arguments(generateProjectParser)
    generateProjectParser.add_argument(
        '--disableExtensions',
        action='store_true',
        default=False,
        help='''
            The generated project will not include app extensions.
            This allows Xcode to properly index the source code.
            '''
    )

    buildParser = subparsers.add_parser('build', help='Build the app')
    buildParser.add_argument(
        '--buildNumber',
        required=True,
        type=int,
        help='Build number.',
        metavar='number'
    )
    add_project_and_build_common_arguments(buildParser)
    buildParser.add_argument(
        '--configuration',
        choices=[
            'debug_arm64',
            'release_arm64',
            'release_universal'
        ],
        required=True,
        help='Build configuration'
    )

    if len(sys.argv) < 2:
        parser.print_help()
        sys.exit(1)

    args = parser.parse_args()

    if args.verbose:
        print(args)

    if args.commandName is None:
        exit(0)

    try:
        if args.commandName == 'clean':
            clean(arguments=args)
        elif args.commandName == 'generateProject':
            generate_project(arguments=args)
        elif args.commandName == 'build':
            build(arguments=args)
        else:
            raise Exception('Unknown command')
    except KeyboardInterrupt:
        pass