# Copyright 2017 The Meson development team

# 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 lzma
import os
import sys
import shutil
import subprocess
import pickle
import hashlib
import tarfile, zipfile
from glob import glob
from mesonbuild.environment import detect_ninja
from mesonbuild.mesonlib import windows_proof_rmtree
from mesonbuild import mlog, build

def create_hash(fname):
    hashname = fname + '.sha256sum'
    m = hashlib.sha256()
    m.update(open(fname, 'rb').read())
    with open(hashname, 'w') as f:
        f.write('%s %s\n' % (m.hexdigest(), os.path.basename(fname)))


def create_zip(zipfilename, packaging_dir):
    prefix = os.path.dirname(packaging_dir)
    removelen = len(prefix) + 1
    with zipfile.ZipFile(zipfilename,
                         'w',
                         compression=zipfile.ZIP_DEFLATED,
                         allowZip64=True) as zf:
        zf.write(packaging_dir, packaging_dir[removelen:])
        for root, dirs, files in os.walk(packaging_dir):
            for d in dirs:
                dname = os.path.join(root, d)
                zf.write(dname, dname[removelen:])
            for f in files:
                fname = os.path.join(root, f)
                zf.write(fname, fname[removelen:])

def del_gitfiles(dirname):
    for f in glob(os.path.join(dirname, '.git*')):
        if os.path.isdir(f) and not os.path.islink(f):
            windows_proof_rmtree(f)
        else:
            os.unlink(f)

def process_submodules(dirname):
    module_file = os.path.join(dirname, '.gitmodules')
    if not os.path.exists(module_file):
        return
    subprocess.check_call(['git', 'submodule', 'update', '--init', '--recursive'], cwd=dirname)
    for line in open(module_file):
        line = line.strip()
        if '=' not in line:
            continue
        k, v = line.split('=', 1)
        k = k.strip()
        v = v.strip()
        if k != 'path':
            continue
        del_gitfiles(os.path.join(dirname, v))


def run_dist_scripts(dist_root, dist_scripts):
    assert(os.path.isabs(dist_root))
    env = os.environ.copy()
    env['MESON_DIST_ROOT'] = dist_root
    for d in dist_scripts:
        script = d['exe']
        args = d['args']
        name = ' '.join(script + args)
        print('Running custom dist script {!r}'.format(name))
        try:
            rc = subprocess.call(script + args, env=env)
            if rc != 0:
                sys.exit('Dist script errored out')
        except OSError:
            print('Failed to run dist script {!r}'.format(name))
            sys.exit(1)


def git_have_dirty_index(src_root):
    '''Check whether there are uncommitted changes in git'''
    ret = subprocess.call(['git', '-C', src_root, 'diff-index', '--quiet', 'HEAD'])
    return ret == 1

def create_dist_git(dist_name, src_root, bld_root, dist_sub, dist_scripts):
    if git_have_dirty_index(src_root):
        mlog.warning('Repository has uncommitted changes that will not be included in the dist tarball')
    distdir = os.path.join(dist_sub, dist_name)
    if os.path.exists(distdir):
        shutil.rmtree(distdir)
    os.makedirs(distdir)
    subprocess.check_call(['git', 'clone', '--shared', src_root, distdir])
    process_submodules(distdir)
    del_gitfiles(distdir)
    run_dist_scripts(distdir, dist_scripts)
    xzname = distdir + '.tar.xz'
    # Should use shutil but it got xz support only in 3.5.
    with tarfile.open(xzname, 'w:xz') as tf:
        tf.add(distdir, dist_name)
    # Create only .tar.xz for now.
    # zipname = distdir + '.zip'
    # create_zip(zipname, distdir)
    shutil.rmtree(distdir)
    return (xzname, )


def hg_have_dirty_index(src_root):
    '''Check whether there are uncommitted changes in hg'''
    out = subprocess.check_output(['hg', '-R', src_root, 'summary'])
    return b'commit: (clean)' not in out

def create_dist_hg(dist_name, src_root, bld_root, dist_sub, dist_scripts):
    if hg_have_dirty_index(src_root):
        mlog.warning('Repository has uncommitted changes that will not be included in the dist tarball')

    os.makedirs(dist_sub, exist_ok=True)
    tarname = os.path.join(dist_sub, dist_name + '.tar')
    xzname = tarname + '.xz'
    subprocess.check_call(['hg', 'archive', '-R', src_root, '-S', '-t', 'tar', tarname])
    if dist_scripts:
        mlog.warning('dist scripts are not supported in Mercurial projects')
    with lzma.open(xzname, 'wb') as xf, open(tarname, 'rb') as tf:
        shutil.copyfileobj(tf, xf)
    os.unlink(tarname)
    # Create only .tar.xz for now.
    # zipname = os.path.join(dist_sub, dist_name + '.zip')
    # subprocess.check_call(['hg', 'archive', '-R', src_root, '-S', '-t', 'zip', zipname])
    return (xzname, )


def check_dist(packagename, meson_command, privdir):
    print('Testing distribution package %s' % packagename)
    unpackdir = os.path.join(privdir, 'dist-unpack')
    builddir = os.path.join(privdir, 'dist-build')
    installdir = os.path.join(privdir, 'dist-install')
    for p in (unpackdir, builddir, installdir):
        if os.path.exists(p):
            shutil.rmtree(p)
        os.mkdir(p)
    ninja_bin = detect_ninja()
    try:
        tf = tarfile.open(packagename)
        tf.extractall(unpackdir)
        srcdir = glob(os.path.join(unpackdir, '*'))[0]
        if subprocess.call(meson_command + ['--backend=ninja', srcdir, builddir]) != 0:
            print('Running Meson on distribution package failed')
            return 1
        if subprocess.call([ninja_bin], cwd=builddir) != 0:
            print('Compiling the distribution package failed')
            return 1
        if subprocess.call([ninja_bin, 'test'], cwd=builddir) != 0:
            print('Running unit tests on the distribution package failed')
            return 1
        myenv = os.environ.copy()
        myenv['DESTDIR'] = installdir
        if subprocess.call([ninja_bin, 'install'], cwd=builddir, env=myenv) != 0:
            print('Installing the distribution package failed')
            return 1
    finally:
        shutil.rmtree(unpackdir)
        shutil.rmtree(builddir)
        shutil.rmtree(installdir)
    print('Distribution package %s tested' % packagename)
    return 0

def run(opts):
    b = build.load('.')
    # This import must be load delayed, otherwise it will get the default
    # value of None.
    from mesonbuild.mesonlib import meson_command
    src_root = b.environment.source_dir
    bld_root = b.environment.build_dir
    priv_dir = os.path.join(bld_root, 'meson-private')
    dist_sub = os.path.join(bld_root, 'meson-dist')

    dist_name = b.project_name + '-' + b.project_version

    _git = os.path.join(src_root, '.git')
    if os.path.isdir(_git) or os.path.isfile(_git):
        names = create_dist_git(dist_name, src_root, bld_root, dist_sub, b.dist_scripts)
    elif os.path.isdir(os.path.join(src_root, '.hg')):
        names = create_dist_hg(dist_name, src_root, bld_root, dist_sub, b.dist_scripts)
    else:
        print('Dist currently only works with Git or Mercurial repos')
        return 1
    if names is None:
        return 1
    error_count = 0
    for name in names:
        rc = check_dist(name, meson_command, priv_dir) # Check only one.
        if rc == 0:
            create_hash(name)
        error_count += rc
    return 1 if error_count else 0