#!/usr/bin/env python
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
##########################################################################
#
# This is a collection of helper tools to get stuff done in NSS.
#

import sys
import argparse
import fnmatch
import io
import subprocess
import os
import platform
import shutil
import tarfile
import tempfile

from hashlib import sha256

DEVNULL = open(os.devnull, 'wb')
cwd = os.path.dirname(os.path.abspath(__file__))

def run_tests(test, cycles="standard", env={}, silent=False):
    domsuf = os.getenv('DOMSUF', "localdomain")
    host = os.getenv('HOST', "localhost")
    env = env.copy()
    env.update({
        "NSS_TESTS": test,
        "NSS_CYCLES": cycles,
        "DOMSUF": domsuf,
        "HOST": host
    })
    os_env = os.environ
    os_env.update(env)
    command = cwd + "/tests/all.sh"
    stdout = stderr = DEVNULL if silent else None
    subprocess.check_call(command, env=os_env, stdout=stdout, stderr=stderr)


class cfAction(argparse.Action):
    docker_command = None
    restorecon = None

    def __call__(self, parser, args, values, option_string=None):
        self.setDockerCommand(args)

        if values:
            files = [os.path.relpath(os.path.abspath(x), start=cwd) for x in values]
        else:
            files = self.modifiedFiles()

        # First check if we can run docker.
        try:
            with open(os.devnull, "w") as f:
                subprocess.check_call(
                    self.docker_command + ["images"], stdout=f)
        except:
            self.docker_command = None

        if self.docker_command is None:
            print("warning: running clang-format directly, which isn't guaranteed to be correct")
            command = [cwd + "/automation/clang-format/run_clang_format.sh"] + files
            repr(command)
            subprocess.call(command)
            return

        files = [os.path.join('/home/worker/nss', x) for x in files]
        docker_image = 'clang-format-service:latest'
        cf_docker_folder = cwd + "/automation/clang-format"

        # Build the image if necessary.
        if self.filesChanged(cf_docker_folder):
            self.buildImage(docker_image, cf_docker_folder)

        # Check if we have the docker image.
        try:
            command = self.docker_command + [
                "image", "inspect", "clang-format-service:latest"
            ]
            with open(os.devnull, "w") as f:
                subprocess.check_call(command, stdout=f)
        except:
            print("I have to build the docker image first.")
            self.buildImage(docker_image, cf_docker_folder)

        command = self.docker_command + [
            'run', '-v', cwd + ':/home/worker/nss:Z', '--rm', '-ti', docker_image
        ]
        # The clang format script returns 1 if something's to do. We don't
        # care.
        subprocess.call(command + files)
        if self.restorecon is not None:
            subprocess.call([self.restorecon, '-R', cwd])

    def filesChanged(self, path):
        hash = sha256()
        for dirname, dirnames, files in os.walk(path):
            for file in files:
                with open(os.path.join(dirname, file), "rb") as f:
                    hash.update(f.read())
        chk_file = cwd + "/.chk"
        old_chk = ""
        new_chk = hash.hexdigest()
        if os.path.exists(chk_file):
            with open(chk_file) as f:
                old_chk = f.readline()
        if old_chk != new_chk:
            with open(chk_file, "w+") as f:
                f.write(new_chk)
            return True
        return False

    def buildImage(self, docker_image, cf_docker_folder):
        command = self.docker_command + [
            "build", "-t", docker_image, cf_docker_folder
        ]
        subprocess.check_call(command)
        return

    def setDockerCommand(self, args):
        from distutils.spawn import find_executable
        if platform.system() == "Linux":
            self.restorecon = find_executable("restorecon")
        dcmd = find_executable("docker")
        if dcmd is not None:
            self.docker_command = [dcmd]
            if not args.noroot:
                self.docker_command = ["sudo"] + self.docker_command
        else:
            self.docker_command = None

    def modifiedFiles(self):
        files = []
        if os.path.exists(os.path.join(cwd, '.hg')):
            st = subprocess.Popen(['hg', 'status', '-m', '-a'],
                                  cwd=cwd, stdout=subprocess.PIPE, universal_newlines=True)
            for line in iter(st.stdout.readline, ''):
                files += [line[2:].rstrip()]
        elif os.path.exists(os.path.join(cwd, '.git')):
            st = subprocess.Popen(['git', 'status', '--porcelain'],
                                  cwd=cwd, stdout=subprocess.PIPE)
            for line in iter(st.stdout.readline, ''):
                if line[1] == 'M' or line[1] != 'D' and \
                        (line[0] == 'M' or line[0] == 'A' or
                         line[0] == 'C' or line[0] == 'U'):
                    files += [line[3:].rstrip()]
                elif line[0] == 'R':
                    files += [line[line.index(' -> ', beg=4) + 4:]]
        else:
            print('Warning: neither mercurial nor git detected!')

        def isFormatted(x):
            return x[-2:] == '.c' or x[-3:] == '.cc' or x[-2:] == '.h'
        return [x for x in files if isFormatted(x)]


class buildAction(argparse.Action):

    def __call__(self, parser, args, values, option_string=None):
        subprocess.check_call([cwd + "/build.sh"] + values)


class testAction(argparse.Action):

    def __call__(self, parser, args, values, option_string=None):
        run_tests(values)


class covAction(argparse.Action):

    def runSslGtests(self, outdir):
        env = {
            "GTESTFILTER": "*", # Prevent parallel test runs.
            "ASAN_OPTIONS": "coverage=1:coverage_dir=" + outdir,
            "NSS_DEFAULT_DB_TYPE": "dbm"
        }

        run_tests("ssl_gtests", env=env, silent=True)

    def findSanCovFile(self, outdir):
        for file in os.listdir(outdir):
            if fnmatch.fnmatch(file, 'ssl_gtest.*.sancov'):
                return os.path.join(outdir, file)

        return None

    def __call__(self, parser, args, values, option_string=None):
        outdir = args.outdir
        print("Output directory: " + outdir)

        print("\nBuild with coverage sanitizers...\n")
        sancov_args = "edge,no-prune,trace-pc-guard,trace-cmp"
        subprocess.check_call([
            os.path.join(cwd, "build.sh"), "-c", "--clang", "--asan", "--enable-legacy-db",
            "--sancov=" + sancov_args
        ])

        print("\nRun ssl_gtests to get a coverage report...")
        self.runSslGtests(outdir)
        print("Done.")

        sancov_file = self.findSanCovFile(outdir)
        if not sancov_file:
            print("Couldn't find .sancov file.")
            sys.exit(1)

        symcov_file = os.path.join(outdir, "ssl_gtest.symcov")
        out = open(symcov_file, 'wb')
        # Don't exit immediately on error
        symbol_retcode = subprocess.call([
            "sancov",
            "-blacklist=" + os.path.join(cwd, ".sancov-blacklist"),
            "-symbolize", sancov_file,
            os.path.join(cwd, "../dist/Debug/bin/ssl_gtest")
        ], stdout=out)
        out.close()

        print("\nCopying ssl_gtests to artifacts...")
        shutil.copyfile(os.path.join(cwd, "../dist/Debug/bin/ssl_gtest"),
                        os.path.join(outdir, "ssl_gtest"))

        print("\nCoverage report: " + symcov_file)
        if symbol_retcode > 0:
            print("sancov failed to symbolize with return code {}".format(symbol_retcode))
        sys.exit(symbol_retcode)

class commandsAction(argparse.Action):
    commands = []

    def __call__(self, parser, args, values, option_string=None):
        for c in commandsAction.commands:
            print(c)

def parse_arguments():
    parser = argparse.ArgumentParser(
        description='NSS helper script. ' +
        'Make sure to separate sub-command arguments with --.')
    subparsers = parser.add_subparsers()

    parser_build = subparsers.add_parser(
        'build', help='All arguments are passed to build.sh')
    parser_build.add_argument(
        'build_args', nargs='*', help="build arguments", action=buildAction)

    parser_cf = subparsers.add_parser(
        'clang-format',
        help="""
        Run clang-format.

        By default this runs against any files that you have modified.  If
        there are no modified files, it checks everything.
        """)
    parser_cf.add_argument(
        '--noroot',
        help='On linux, suppress the use of \'sudo\' for running docker.',
        action='store_true')
    parser_cf.add_argument(
        '<file/dir>',
        nargs='*',
        help="Specify files or directories to run clang-format on",
        action=cfAction)

    parser_test = subparsers.add_parser(
        'tests', help='Run tests through tests/all.sh.')
    tests = [
        "cipher", "lowhash", "chains", "cert", "dbtests", "tools", "fips",
        "sdr", "crmf", "smime", "ssl", "ocsp", "merge", "pkits", "ec",
        "gtests", "ssl_gtests", "bogo", "interop", "policy"
    ]
    parser_test.add_argument(
        'test', choices=tests, help="Available tests", action=testAction)

    parser_cov = subparsers.add_parser(
        'coverage', help='Generate coverage report')
    cov_modules = ["ssl_gtests"]
    parser_cov.add_argument(
        '--outdir', help='Output directory for coverage report data.',
        default=tempfile.mkdtemp())
    parser_cov.add_argument(
        'module', choices=cov_modules, help="Available coverage modules",
        action=covAction)

    parser_commands = subparsers.add_parser(
        'mach-completion',
        help="list commands")
    parser_commands.add_argument(
        'mach-completion',
        nargs='*',
        action=commandsAction)

    commandsAction.commands = [c for c in subparsers.choices]
    return parser.parse_args()


def main():
    parse_arguments()


if __name__ == '__main__':
    main()