#
# Copyright (c) 2013- Facebook.  All rights reserved.
#

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

import argparse
import csv
import glob
import json
import logging
import multiprocessing
import os
import re
import shutil
import subprocess
import sys
import tempfile
import time
import xml.etree.ElementTree as ET

# Increase the limit of the CSV parser to sys.maxlimit
csv.field_size_limit(sys.maxsize)

# Infer imports
import jwlib
import utils

# list of analysis options
INFER = 'infer'
ERADICATE = 'eradicate'
CHECKERS = 'checkers'
CAPTURE = 'capture'
COMPILE = 'compile'
TRACING = 'tracing'

MODES = [COMPILE, CAPTURE, INFER, ERADICATE, CHECKERS, TRACING]

INFER_ANALYZE_BINARY = "InferAnalyze"

class AbsolutePathAction(argparse.Action):
    """Convert a path from relative to absolute in the arg parser"""
    def __call__(self, parser, namespace, values, option_string=None):
        setattr(namespace, self.dest, os.path.abspath(values))


# https://github.com/python/cpython/blob/aa8ea3a6be22c92e774df90c6a6ee697915ca8ec/Lib/argparse.py
class VersionAction(argparse._VersionAction):
    def __call__(self, parser, namespace, values, option_string=None):
        # set self.version so that argparse version action knows it
        self.version = self.get_infer_version()
        super(VersionAction, self).__call__(parser,
                                            namespace,
                                            values,
                                            option_string)

    def get_infer_version(self):
        try:
            return subprocess.check_output([
                utils.get_cmd_in_bin_dir(INFER_ANALYZE_BINARY), '-version'])
        except:
            print("Failed to run {0} binary, exiting".
                  format(INFER_ANALYZE_BINARY))
            exit(2)


base_parser = argparse.ArgumentParser(add_help=False)
base_group = base_parser.add_argument_group('global arguments')
base_group.add_argument('-o', '--out', metavar='<directory>',
                        default=utils.DEFAULT_INFER_OUT, dest='infer_out',
                        action=AbsolutePathAction,
                        help='Set the INFER results directory')
base_group.add_argument('-i', '--incremental', action='store_true',
                        help='''Do not delete the results directory across
                        Infer runs''')
base_group.add_argument('-g', '--debug', action='store_true',
                        help='Generate extra debugging information')
base_group.add_argument('-a', '--analyzer',
                        help='Select the analyzer within: {0}'.format(
                            ', '.join(MODES)),
                        default=INFER)
base_group.add_argument('-m', '--analyzer_mode', metavar='<analyzer_mode>',
                        help='''Select a special analyzer mode such as
                        graphql1 or graphql2''')
base_parser.add_argument('-v', '--version', help='Get version of the analyzer',
                         action=VersionAction)


inferJ_parser = argparse.ArgumentParser(parents=[base_parser])
inferJ_group = inferJ_parser.add_argument_group('backend arguments')
inferJ_group.add_argument('-j', '--multicore', metavar='n', type=int,
                           default=multiprocessing.cpu_count(),
                           dest='multicore', help='Set the number of cores to '
                           'be used for the analysis (default uses all cores)')
inferJ_group.add_argument('-x', '--project', metavar='<projectname>',
                           help='Project name, for recording purposes only')

inferJ_group.add_argument('-r', '--revision', metavar='<githash>',
                           help='The githash, for recording purposes only')

inferJ_group.add_argument('--buck', action='store_true', dest='buck',
                           help='To use when run with buck')

inferJ_group.add_argument('--infer_cache', metavar='<directory>',
                           help='Select a directory to contain the infer cache')

inferJ_group.add_argument('-pr', '--project_root',
                           dest='project_root',
                           default=os.getcwd(),
                           help='Location of the project root '
                                '(default is current directory)')

inferJ_group.add_argument('--objc_ml_buckets',
                           dest='objc_ml_buckets',
                           help='memory leak buckets to be checked, '
                                'separated by commas. The possible '
                                'buckets are cf (Core Foundation), '
                                'arc, narc (No arc)')

inferJ_group.add_argument('-nt', '--notest', action='store_true',
                           dest='notest',
                           help='Prints output of symbolic execution')

def detect_javac(args):
    for index, arg in enumerate(args):
        if arg == 'javac':
            return index


def get_inferJ_args(args):
    index = detect_javac(args)
    if index is None:
        cmd_args = args
    else:
        cmd_args = args[:index]
    return inferJ_parser.parse_args(cmd_args)


def get_javac_args(args):
    javac_args = args[detect_javac(args) + 1:]
    if len(javac_args) == 0:
        return None
    else:
        # replace any -g:.* flag with -g to preserve debugging symbols
        return map(lambda arg: '-g' if '-g:' in arg else arg, javac_args)


def remove_infer_out(infer_out):
    # it is safe to ignore errors here because recreating the infer_out
    # directory will fail later
    shutil.rmtree(infer_out, True)


def clean_infer_out(infer_out):

    directories = ['multicore', 'classnames', 'sources']
    extensions = ['.cfg', '.cg']

    for root, dirs, files in os.walk(infer_out):
        for d in dirs:
            if d in directories:
                path = os.path.join(root, d)
                shutil.rmtree(path)
        for f in files:
            for ext in extensions:
                if f.endswith(ext):
                    path = os.path.join(root, f)
                    os.remove(path)


def help_exit(message):
    print(message)
    inferJ_parser.print_usage()
    exit(1)


def compare_rows(row_1, row_2):
    filename_1 = row_1[utils.CSV_INDEX_FILENAME]
    filename_2 = row_2[utils.CSV_INDEX_FILENAME]
    if filename_1 < filename_2:
        return -1
    elif filename_1 > filename_2:
        return 1
    else:
        line_1 = int(row_1[utils.CSV_INDEX_LINE])
        line_2 = int(row_2[utils.CSV_INDEX_LINE])
        return line_1 - line_2


def sort_csv(csv_report, infer_out):
    collected_rows = []
    with open(csv_report, 'r') as file_in:
        reader = csv.reader(file_in)
        rows = [row for row in reader]
        if len(rows) <= 1:
            return rows
        else:
            for row in rows[1:]:
                filename = row[utils.CSV_INDEX_FILENAME]
                if os.path.isfile(filename):
                    collected_rows.append(row)
            collected_rows = sorted(
                collected_rows,
                cmp=compare_rows)
            collected_rows = [rows[0]] + collected_rows
    temporary_file = tempfile.mktemp()
    with open(temporary_file, 'w') as file_out:
        writer = csv.writer(file_out)
        writer.writerows(collected_rows)
        file_out.flush()
        shutil.move(temporary_file, csv_report)


def should_print(analyzer, row):
    error_kind = row[utils.CSV_INDEX_KIND]
    error_type = row[utils.CSV_INDEX_TYPE]
    error_bucket = ''  # can be updated later once we extract it from qualifier

    try:
        qualifier_xml = ET.fromstring(row[utils.CSV_INDEX_QUALIFIER_TAGS])
        if qualifier_xml.tag == utils.QUALIFIER_TAGS:
            bucket = qualifier_xml.find(utils.BUCKET_TAGS)
            if bucket is not None:
                error_bucket = bucket.text
    except ET.ParseError:
        pass  # this will skip any invalid xmls

    # config what to print is listed below
    error_kinds = ['ERROR', 'WARNING']

    null_style_bugs = [
        'NULL_DEREFERENCE',
        'PARAMETER_NOT_NULL_CHECKED',
        'IVAR_NOT_NULL_CHECKED',
        'PREMATURE_NIL_TERMINATION_ARGUMENT',
    ]
    null_style_buckets = ['B1', 'B2']

    other_bugs = ['RESOURCE_LEAK', 'MEMORY_LEAK', 'RETAIN_CYCLE']

    filter_by_type = True
    if analyzer in [ERADICATE, CHECKERS]:
        # report all issues for eredicate and checkers
        filter_by_type = False

    if error_kind not in error_kinds:
        return False

    if not filter_by_type:
        return True

    if not error_type:
        return False

    if error_type in null_style_bugs:
        if error_bucket and error_bucket in null_style_buckets:
            return True
        else:
            return False
    elif error_type in other_bugs:
        return True
    else:
        return False


def remove_bucket(bug_message):
    """ Remove anything from the beginning if the message that
        looks like a bucket """
    return re.sub(r'(^\[[a-zA-Z0-9]*\])', '', bug_message, 1)


def print_and_write(file_out, message):
    print(message)
    file_out.write(message + '\n')


def print_errors(csv_report, bugs_out, analyzer):
    with open(csv_report, 'r') as file_in:
        reader = csv.reader(file_in)
        reader.next()  # first line is header, skip it

        errors = filter(
            lambda row: should_print(analyzer, row),
            reader
        )
        with open(bugs_out, 'w') as file_out:
            if not errors:
                print_and_write(file_out, 'No issues found')
            for row in errors:
                filename = row[utils.CSV_INDEX_FILENAME]
                if os.path.isfile(filename):
                    kind = row[utils.CSV_INDEX_KIND]
                    line = row[utils.CSV_INDEX_LINE]
                    error_type = row[utils.CSV_INDEX_TYPE]
                    msg = remove_bucket(row[utils.CSV_INDEX_QUALIFIER])
                    print_and_write(
                        file_out,
                        '{0}:{1}: {2}: {3}\n  {4}\n'.format(
                            filename,
                            line,
                            kind.lower(),
                            error_type,
                            msg,
                        )
                    )


def run_command(cmd, debug_mode, javac_arguments, step, analyzer):
    if debug_mode:
        print('\n{0}\n'.format(' '.join(cmd)))
    try:
        return subprocess.check_call(cmd)
    except subprocess.CalledProcessError as e:
        error_msg = 'Failure during {0}, original command was\n\n{1}\n\n'
        inferJ_cmd = ['inferJ', '-g', '-a', analyzer]
        failing_cmd = inferJ_cmd + ['javac'] + javac_arguments
        logging.error(error_msg.format(
            step,
            failing_cmd
        ))
        raise e


class Infer:

    def __init__(self, args, javac_args):

        self.args = args
        if self.args.analyzer not in MODES:
            help_exit(
                'Unknown analysis mode \"{0}\"'.format(self.args.analyzer)
            )

        utils.configure_logging(self.args.debug)

        self.javac = jwlib.CompilerCall(javac_args)

        if not self.javac.args.version:
            if javac_args is None:
                help_exit('No javac command detected')

            if self.args.infer_out is None:
                help_exit('Expect INFER results directory')

            if self.args.buck:
                self.args.infer_out = os.path.join(
                    self.javac.args.classes_out,
                    utils.BUCK_INFER_OUT)
                self.args.infer_out = os.path.abspath(self.args.infer_out)

            try:
                os.mkdir(self.args.infer_out)
            except OSError as e:
                if not os.path.isdir(self.args.infer_out):
                    raise e

            self.stats = {'int': {}, 'float': {}}
            self.timing = {}

    def clean_exit(self):
        if os.path.isdir(self.args.infer_out):
            print('removing', self.args.infer_out)
            shutil.rmtree(self.args.infer_out)
        exit(os.EX_OK)

    def run_infer_frontend(self):

        infer_cmd = [utils.get_cmd_in_bin_dir('InferJava')]

        if self.args.buck:
            infer_cmd += ['-project_root', os.getcwd()]

        infer_cmd += [
            '-results_dir', self.args.infer_out,
            '-verbose_out', self.javac.verbose_out,
        ]

        if os.path.isfile(utils.MODELS_JAR):
            infer_cmd += ['-models', utils.MODELS_JAR]

        infer_cmd.append('-no-static_final')

        if self.args.debug:
            infer_cmd.append('-debug')
        if self.args.analyzer == TRACING:
            infer_cmd.append('-tracing')

        return run_command(
            infer_cmd,
            self.args.debug,
            self.javac.original_arguments,
            'frontend',
            self.args.analyzer
        )

    def compile(self):
        return self.javac.run()

    def capture(self):
        javac_status = self.compile()
        if javac_status == os.EX_OK:
            return self.run_infer_frontend()
        else:
            return javac_status

    def analyze(self):
        infer_analyze = [
            utils.get_cmd_in_bin_dir(INFER_ANALYZE_BINARY),
            '-results_dir',
            self.args.infer_out
        ]
        infer_options = []

        # remove specs if possible so that old issues are less likely
        # to be reported
        infer_options += ['-allow_specs_cleanup']

        if self.args.analyzer == ERADICATE:
            infer_options += ['-checkers', '-eradicate']
        elif self.args.analyzer == CHECKERS:
            infer_options += ['-checkers']
        else:
            if self.args.analyzer == TRACING:
                infer_options.append('-tracing')
            if os.path.isfile(utils.MODELS_JAR):
                infer_options += ['-models', utils.MODELS_JAR]

        if self.args.analyzer_mode:
            infer_options += ['-analyzer_mode', self.args.analyzer_mode]

        if self.args.infer_cache:
            infer_options += ['-infer_cache', self.args.infer_cache]

        if self.args.objc_ml_buckets:
            infer_options += ['-objc_ml_buckets', self.args.objc_ml_buckets]

        if self.args.notest:
            infer_options += ['-notest']

        if self.args.debug:
            infer_options += [
                '-developer_mode',
                '-html',
                '-dotty',
                '-print_types',
                '-trace_error',
                # '-notest',
            ]

        exit_status = os.EX_OK

        if self.args.buck:
            infer_options += ['-project_root', os.getcwd(), '-java']
            if self.javac.args.classpath is not None:
                for path in self.javac.args.classpath.split(os.pathsep):
                    if os.path.isfile(path):
                        infer_options += ['-ziplib', os.path.abspath(path)]
        elif self.args.project_root:
            infer_options += ['-project_root', self.args.project_root]

        if self.args.multicore == 1:
            analyze_cmd = infer_analyze + infer_options
            exit_status = run_command(
                analyze_cmd,
                self.args.debug,
                self.javac.original_arguments,
                'analysis',
                self.args.analyzer
            )

        else:
            if self.args.analyzer in [ERADICATE, CHECKERS]:
                infer_analyze.append('-intraprocedural')

            os.environ['INFER_OPTIONS'] = ' '.join(infer_options)

            multicore_dir = os.path.join(self.args.infer_out, 'multicore')
            pwd = os.getcwd()
            if os.path.isdir(multicore_dir):
                shutil.rmtree(multicore_dir)
            os.mkdir(multicore_dir)
            os.chdir(multicore_dir)
            os.environ['INFER_DEVELOPER'] = 'Y'
            analyze_cmd = infer_analyze + ['-makefile', 'Makefile']
            analyze_cmd += infer_options
            makefile_status = run_command(
                analyze_cmd,
                self.args.debug,
                self.javac.original_arguments,
                'create_makefile',
                self.args.analyzer
            )
            exit_status += makefile_status
            if makefile_status == os.EX_OK:
                make_cmd = ['make', '-k', '-j', str(self.args.multicore)]
                if not self.args.debug:
                    make_cmd += ['-s']
                make_status = run_command(
                    make_cmd,
                    self.args.debug,
                    self.javac.original_arguments,
                    'run_makefile',
                    self.args.analyzer
                )
                os.chdir(pwd)
                exit_status += make_status

        if self.args.buck and exit_status == os.EX_OK:
            clean_infer_out(self.args.infer_out)

        cfgs = os.path.join(self.args.infer_out, 'captured', '*', '')
        captured_total = len(glob.glob(cfgs))
        captured_plural = '' if captured_total <= 1 else 's'
        print('\n%d file%s analyzed' % (captured_total, captured_plural))

        return exit_status

    def file_stats(self, file, stats):
        if file is not None:
            stats['files'] += 1
            try:
                with open(file, 'r') as f:
                    stats['lines'] += len(list(f))
            except IOError:
                logging.warning('File {} not found'.format(file))


    def javac_stats(self):
        stats = {'files': 0, 'lines': 0}

        for arg in self.javac.original_arguments:
            file = None
            if arg.endswith('.java'):
                file = arg
                self.file_stats(file, stats)
            if arg.startswith('@'):
                with open(arg[1:], 'r') as f:
                    for line in f:
                        file = line.strip()
                        self.file_stats(file, stats)

        return stats

    def update_stats(self, csv_report):
        with open(csv_report, 'r') as file_in:
            reader = csv.reader(file_in)
            rows = [row for row in reader][1:]
            for row in rows:
                key = row[utils.CSV_INDEX_TYPE]
                previous_value = self.stats['int'].get(key, 0)
                self.stats['int'][key] = previous_value + 1

    def report_errors(self):
        """Report statistics about the computation and create a CSV file
        containing the list or errors found during the analysis"""

        csv_report = os.path.join(self.args.infer_out,
                                  utils.CSV_REPORT_FILENAME)
        bugs_out = os.path.join(self.args.infer_out,
                                utils.BUGS_FILENAME)
        procs_report = os.path.join(self.args.infer_out, 'procs.csv')

        infer_print_cmd = [utils.get_cmd_in_bin_dir('InferPrint')]
        infer_print_options = [
            '-q',
            '-results_dir', self.args.infer_out,
            '-bugs', csv_report,
            '-procs', procs_report,
            '-analyzer', self.args.analyzer
        ]
        exit_status = subprocess.check_call(
            infer_print_cmd + infer_print_options
        )
        if exit_status != os.EX_OK:
            logging.error('Error with InferPrint with the command: '
                          + infer_print_cmd)
        else:
            sort_csv(csv_report, self.args.infer_out)
            self.update_stats(csv_report)
            utils.create_json_report(self.args.infer_out)

            print('\n')
            if not self.args.buck:
                print_errors(csv_report, bugs_out, self.args.analyzer)

        return exit_status

    def save_stats(self):
        """Print timing information to infer_out/stats.json"""
        stats_path = os.path.join(self.args.infer_out, utils.STATS_FILENAME)

        self.stats['int'].update(self.javac_stats())

        self.stats['float'].update({
            'capture_time': self.timing.get('capture', 0.0),
            'analysis_time': self.timing.get('analysis', 0.0),
            'reporting_time': self.timing.get('reporting', 0.0),
        })

        # Adding the analyzer and the version of Infer
        self.stats['normal'] = {}
        self.stats['normal']['analyzer'] = self.args.analyzer
        self.stats['normal']['infer_version'] = utils.infer_version()

        with open(stats_path, 'w') as stats_file:
            json.dump(self.stats, stats_file)

    def close(self):
        if self.args.analyzer != COMPILE:
            os.remove(self.javac.verbose_out)

    def analyze_and_report(self):
        if self.args.analyzer not in [COMPILE, CAPTURE]:
            analysis_start_time = time.time()
            if self.analyze() == os.EX_OK:
                elapsed = utils.elapsed_time(analysis_start_time)
                self.timing['analysis'] = elapsed
                reporting_start_time = time.time()
                self.report_errors()
                elapsed = utils.elapsed_time(reporting_start_time)
                self.timing['reporting'] = elapsed

    def start(self):
        if self.javac.args.version:
            if self.args.buck:
                key = self.args.analyzer
                if self.args.analyzer_mode:
                    key += '_' + self.args.analyzer_mode
                print(utils.infer_key(key), file=sys.stderr)
            else:
                return self.javac.run()
        else:
            start_time = time.time()
            if self.capture() == os.EX_OK:
                self.timing['capture'] = utils.elapsed_time(start_time)
                self.analyze_and_report()
                self.close()
                elapsed = utils.elapsed_time(start_time)
                self.timing['total'] = elapsed
                self.save_stats()
                return self.stats
            else:
                return dict({})

# vim: set sw=4 ts=4 et: