#!/usr/bin/env python3

import glob
import multiprocessing
import os
import pathlib
import shutil
import subprocess
import time

import common

parser = common.get_argparse()
common.add_build_arguments(parser)
parser.add_argument(
    'extra_scons_args',
    default=[],
    metavar='extra-scons-args',
    nargs='*'
)
args = common.setup(parser)
binaries_dir = os.path.join(common.gem5_system_dir, 'binaries')
disks_dir = os.path.join(common.gem5_system_dir, 'disks')
if args.clean:
    common.rmrf(common.gem5_build_dir)
else:
    start_time = time.time()
    os.makedirs(binaries_dir, exist_ok=True)
    os.makedirs(disks_dir, exist_ok=True)
    if  not os.path.exists(os.path.join(common.gem5_src_dir, '.git')):
        subprocess.check_call([
            'git',
            '-C', common.gem5_default_src_dir,
            'worktree', 'add',
            '-b', os.path.join('wt', args.gem5_build_id),
            common.gem5_src_dir
        ])
    if args.arch == 'x86_64':
        dummy_img_path = os.path.join(disks_dir, 'linux-bigswap2.img')
        with open(dummy_img_path, 'wb') as dummy_img_file:
            zeroes = b'\x00' * (2 ** 16)
            for i in range(2 ** 10):
                dummy_img_file.write(zeroes)
        subprocess.check_call(['mkswap', dummy_img_path])
        with open(os.path.join(binaries_dir, 'x86_64-vmlinux-2.6.22.9'), 'w'):
            # This file must always be present, despite --kernel overriding that default and selecting the kernel.
            # I'm not even joking. No one has ever built x86 gem5 without the magic dist dir present.
            pass
    elif args.arch == 'arm' or args.arch == 'aarch64':
        gem5_system_src_dir = os.path.join(common.gem5_src_dir, 'system')

        # dtb
        dt_src_dir = os.path.join(gem5_system_src_dir, 'arm', 'dt')
        dt_build_dir = os.path.join(common.gem5_system_dir, 'arm', 'dt')
        subprocess.check_call(['make', '-C', dt_src_dir])
        os.makedirs(dt_build_dir, exist_ok=True)
        for dt in glob.glob(os.path.join(dt_src_dir, '*.dtb')):
            shutil.copy2(dt, dt_build_dir)

        # Bootloader 32.
        bootloader32_dir = os.path.join(gem5_system_src_dir, 'arm', 'simple_bootloader')
        # TODO use the buildroot cross compiler here, and remove the dependencies from configure.
        subprocess.check_call(['make', '-C', bootloader32_dir])
        # bootloader
        shutil.copy2(os.path.join(bootloader32_dir, 'boot_emm.arm'), binaries_dir)

        # Bootloader 64.
        bootloader64_dir = os.path.join(gem5_system_src_dir, 'arm', 'aarch64_bootloader')
        # TODO cross_compile is ignored because the make does not use CC...
        subprocess.check_call(['make', '-C', bootloader64_dir])
        shutil.copy2(os.path.join(bootloader64_dir, 'boot_emm.arm64'), binaries_dir)
    assert common.run_cmd([
            'scons',
            # TODO factor with build.
            '-j', str(multiprocessing.cpu_count()),
            '--ignore-style',
            common.gem5_executable
        ] +
        args.extra_scons_args,
        cwd=common.gem5_src_dir,
        extra_env={'PATH': '/usr/lib/ccache:' + os.environ['PATH']},
    ) == 0
    term_src_dir = os.path.join(common.gem5_src_dir, 'util/term')
    subprocess.check_call(['make', '-C', term_src_dir])
    shutil.copy2(os.path.join(term_src_dir, 'm5term'), common.gem5_m5term)
    end_time = time.time()
    common.print_time(end_time - start_time)