from __future__ import print_function
import os
import os.path
import sys
import subprocess
import platform

SUPPORTED_PYTHON_PLATFORMS = ['Windows', 'Linux', 'Darwin']

BUILD_TARGETS = [
    {
        'arch': 'arm',
        'goarch': 'arm',
        'jni_dir': 'armeabi',
        'cc': 'arm-linux-androideabi-clang',
    },
    {
        'arch': 'arm64',
        'goarch': 'arm64',
        'jni_dir': 'arm64-v8a',
        'cc': 'aarch64-linux-android-clang',
        'min_sdk': 21,
    },
    {
        'arch': 'x86',
        'goarch': '386',
        'jni_dir': 'x86',
        'cc': 'i686-linux-android-clang',
    }
]


def fail(message, *args, **kwargs):
    print((message % args).format(**kwargs))
    sys.exit(1)


def get_min_sdk(project_dir):
    with open(os.path.join(project_dir, 'app', 'build.gradle')) as file_handle:
        for line in file_handle:
            tokens = list(filter(None, line.split()))
            if len(tokens) == 2 and tokens[0] == 'minSdkVersion':
                return int(tokens[1])

    fail('Failed to find minSdkVersion')


def get_ndk_home():
    if not os.environ.get('ANDROID_NDK_HOME', ''):
        fail('ANDROID_NDK_HOME environment variable not defined')
    return os.environ['ANDROID_NDK_HOME']


if platform.system() not in SUPPORTED_PYTHON_PLATFORMS:
    fail('Unsupported python platform %s. Supported platforms: %s', platform.system(),
         ', '.join(SUPPORTED_PYTHON_PLATFORMS))

module_dir = os.path.dirname(os.path.realpath(__file__))
project_dir = os.path.realpath(os.path.join(module_dir, '..'))
# Use seperate build dir so standalone ndk isn't deleted by `gradle clean`
build_dir = os.path.join(module_dir, 'gobuild')
go_build_dir = os.path.join(build_dir, 'go-packages')
syncthing_dir = os.path.join(module_dir, 'src', 'github.com', 'syncthing', 'syncthing')
min_sdk = get_min_sdk(project_dir)

# Make sure all tags are available for git describe
# https://github.com/syncthing/syncthing-android/issues/872
subprocess.check_call([
    'git',
    '-C',
    syncthing_dir,
    'fetch',
    '--tags'
])

for target in BUILD_TARGETS:
    target_min_sdk = str(target.get('min_sdk', min_sdk))
    print('Building for', target['arch'])

    if os.environ.get('SYNCTHING_ANDROID_PREBUILT', ''):
        # The environment variable indicates the SDK and stdlib was prebuilt, set a custom paths.
        standalone_ndk_dir = '%s/standalone-ndk/android-%s-%s' % (
            get_ndk_home(), target_min_sdk, target['goarch']
        )
        pkg_argument = []
    else:
        # Build standalone NDK toolchain if it doesn't exist.
        # https://developer.android.com/ndk/guides/standalone_toolchain.html
        standalone_ndk_dir = '%s/standalone-ndk/android-%s-%s' % (
            build_dir, target_min_sdk, target['goarch']
        )
        pkg_argument = ['-pkgdir', os.path.join(go_build_dir, target['goarch'])]

    if not os.path.isdir(standalone_ndk_dir):
        print('Building standalone NDK for', target['arch'], 'API level', target_min_sdk, 'to', standalone_ndk_dir)
        subprocess.check_call([
            sys.executable,
            os.path.join(get_ndk_home(), 'build', 'tools', 'make_standalone_toolchain.py'),
            '--arch',
            target['arch'],
            '--api',
            target_min_sdk,
            '--install-dir',
            standalone_ndk_dir,
            '-v'
        ])

    print('Building syncthing')

    environ = os.environ.copy()
    environ.update({
        'GO111MODULE': 'on',
        'CGO_ENABLED': '1',
    })

    subprocess.check_call(['go', 'mod', 'download'], cwd=syncthing_dir)
    subprocess.check_call([
        'go', 'run', 'build.go', '-goos', 'android', '-goarch', target['goarch'], '-cc', os.path.join(standalone_ndk_dir, 'bin', target['cc'])
    ] + pkg_argument + ['-no-upgrade', 'build'], env=environ, cwd=syncthing_dir)

    # Copy compiled binary to jniLibs folder
    target_dir = os.path.join(project_dir, 'app', 'src', 'main', 'jniLibs', target['jni_dir'])
    if not os.path.isdir(target_dir):
        os.makedirs(target_dir)
    target_artifact = os.path.join(target_dir, 'libsyncthing.so')
    if os.path.exists(target_artifact):
        os.unlink(target_artifact)
    os.rename(os.path.join(syncthing_dir, 'syncthing'), target_artifact)

    print('Finished build for', target['arch'])

print('All builds finished')