# Copyright (c) 2015 - present Facebook, Inc.
# All rights reserved.
#
# This source code is licensed under the BSD style license found in the
# LICENSE file in the root directory of this source tree. An additional grant
# of patent rights can be found in the PATENTS file in the same directory.

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

import codecs
import csv
import itertools
import json
import operator
import os
import shutil
import sys
import tempfile
import xml.etree.ElementTree as ET

from . import config, source, utils


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

ISSUE_KIND_ERROR = 'ERROR'
ISSUE_KIND_WARNING = 'WARNING'
ISSUE_KIND_INFO = 'INFO'

ISSUE_TYPES = [
    'ASSERTION_FAILURE',
    'BAD_POINTER_COMPARISON',
    # 'CHECKERS_PRINTF_ARGS'
    # TODO (#8030397): revert this once all the checkers are moved to Infer
    'CONTEXT_LEAK',
    'MEMORY_LEAK',
    'RESOURCE_LEAK',
    'RETAIN_CYCLE',
    'STRONG_DELEGATE_WARNING',
    'TAINTED_VALUE_REACHING_SENSITIVE_FUNCTION',
    'IVAR_NOT_NULL_CHECKED',
    'NULL_DEREFERENCE',
    'PARAMETER_NOT_NULL_CHECKED',
    'PREMATURE_NIL_TERMINATION_ARGUMENT',
    'DIRECT_ATOMIC_PROPERTY_ACCESS',
    'CXX_REFERENCE_CAPTURED_IN_OBJC_BLOCK',
]

NULL_STYLE_ISSUE_TYPES = [
    'IVAR_NOT_NULL_CHECKED',
    'NULL_DEREFERENCE',
    'PARAMETER_NOT_NULL_CHECKED',
    'PREMATURE_NIL_TERMINATION_ARGUMENT',
]

# indices in rows of csv reports
CSV_INDEX_CLASS = 0
CSV_INDEX_KIND = 1
CSV_INDEX_TYPE = 2
CSV_INDEX_QUALIFIER = 3
CSV_INDEX_SEVERITY = 4
CSV_INDEX_LINE = 5
CSV_INDEX_PROCEDURE = 6
CSV_INDEX_PROCEDURE_ID = 7
CSV_INDEX_FILENAME = 8
CSV_INDEX_TRACE = 9
CSV_INDEX_KEY = 10
CSV_INDEX_QUALIFIER_TAGS = 11
CSV_INDEX_HASH = 12
CSV_INDEX_BUG_ID = 13
CSV_INDEX_ALWAYS_REPORT = 14
CSV_INDEX_ADVICE = 15

# field names in rows of json reports
JSON_INDEX_FILENAME = 'file'
JSON_INDEX_HASH = 'hash'
JSON_INDEX_KIND = 'kind'
JSON_INDEX_LINE = 'line'
JSON_INDEX_PROCEDURE = 'procedure'
JSON_INDEX_QUALIFIER = 'qualifier'
JSON_INDEX_QUALIFIER_TAGS = 'qualifier_tags'
JSON_INDEX_SEVERITY = 'file'
JSON_INDEX_TYPE = 'bug_type'
JSON_INDEX_TRACE = 'bug_trace'
JSON_INDEX_TRACE_LEVEL = 'level'
JSON_INDEX_TRACE_FILENAME = 'filename'
JSON_INDEX_TRACE_LINE = 'line_number'
JSON_INDEX_TRACE_DESCRIPTION = 'description'
JSON_INDEX_TRACE_NODE_TAGS = 'node_tags'
JSON_INDEX_TRACE_NODE_TAGS_TAG = 'tags'
JSON_INDEX_TRACE_NODE_TAGS_VALUE = 'value'
JSON_INDEX_INFER_SOURCE_LOC = 'infer_source_loc'
JSON_INDEX_ISL_FILE = 'file'
JSON_INDEX_ISL_LINE = 'line'
JSON_INDEX_ISL_COLUMN = 'column'

QUALIFIER_TAGS = 'qualifier_tags'
BUCKET_TAGS = 'bucket'


def clean_csv(args, csv_report):
    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[CSV_INDEX_FILENAME]
                if os.path.isfile(filename):
                    if args.no_filtering \
                       or _should_report_csv(args.analyzer, row):
                        collected_rows.append(row)
            collected_rows.sort(key=operator.itemgetter(CSV_INDEX_FILENAME,
                                                        CSV_INDEX_LINE))
            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 clean_json(args, json_report):
    rows = utils.load_json_from_path(json_report)

    def is_clean(row):
        filename = row[JSON_INDEX_FILENAME]
        return (os.path.isfile(filename) and
                (args.no_filtering or
                 _should_report_json(args.analyzer, row)))

    rows = filter(is_clean, rows)
    rows.sort(key=operator.itemgetter(JSON_INDEX_FILENAME,
                                      JSON_INDEX_LINE))
    temporary_file = tempfile.mktemp()
    utils.dump_json_to_path(rows, temporary_file)
    shutil.move(temporary_file, json_report)


def _text_of_infer_loc(loc):
    return u' (%s:%d:%d)' % (
        loc[JSON_INDEX_ISL_FILE],
        loc[JSON_INDEX_ISL_LINE],
        loc[JSON_INDEX_ISL_COLUMN],
    )

def text_of_report(report):
    filename = report[JSON_INDEX_FILENAME]
    kind = report[JSON_INDEX_KIND]
    line = report[JSON_INDEX_LINE]
    error_type = report[JSON_INDEX_TYPE]
    msg = report[JSON_INDEX_QUALIFIER]
    infer_loc = ''
    if JSON_INDEX_INFER_SOURCE_LOC in report:
        infer_loc = _text_of_infer_loc(report[JSON_INDEX_INFER_SOURCE_LOC])
    return u'%s:%d: %s: %s%s\n  %s' % (
        filename,
        line,
        kind.lower(),
        error_type,
        infer_loc,
        msg,
    )


def _text_of_report_list(reports):
    text_errors_list = []
    error_types_count = {}
    for report in reports:
        filename = report[JSON_INDEX_FILENAME]
        line = report[JSON_INDEX_LINE]
        source_context = source.build_source_context(
            filename,
            source.TERMINAL_FORMATTER,
            line,
        )
        indenter = source.Indenter() \
                         .indent_push() \
                         .add(source_context)
        source_context = unicode(indenter)
        text = '%s\n%s' % (text_of_report(report), source_context)
        text_errors_list.append(text)

        t = report[JSON_INDEX_TYPE]
        # assert failures are not very informative without knowing
        # which assertion failed
        if t == 'Assert_failure' and JSON_INDEX_INFER_SOURCE_LOC in report:
            t += _text_of_infer_loc(report[JSON_INDEX_INFER_SOURCE_LOC])
        if t not in error_types_count:
            error_types_count[t] = 1
        else:
            error_types_count[t] += 1

    n_issues = len(text_errors_list)
    if n_issues == 0:
        return 'No issues found'
    else:
        max_type_length = max(map(len, error_types_count.keys())) + 2
        sorted_error_types = error_types_count.items()
        sorted_error_types.sort(key=operator.itemgetter(1), reverse=True)
        types_text_list = map(lambda (t, count): '%s: %d' % (
            t.rjust(max_type_length),
            count,
        ), sorted_error_types)

        text_errors = '\n\n'.join(text_errors_list)

        msg = '\nFound %s\n\n%s\n\nSummary of the reports:\n\n%s' % (
            utils.get_plural('issue', n_issues),
            text_errors,
            '\n'.join(types_text_list),
        )
        return msg


def _is_user_visible(report):
    filename = report[JSON_INDEX_FILENAME]
    kind = report[JSON_INDEX_KIND]
    return (os.path.isfile(filename) and
            kind in [ISSUE_KIND_ERROR, ISSUE_KIND_WARNING])


def print_and_save_errors(json_report, bugs_out):
    errors = utils.load_json_from_path(json_report)
    errors = filter(_is_user_visible, errors)
    text = _text_of_report_list(errors)
    print(text)
    with codecs.open(bugs_out, 'w', encoding=config.LOCALE) as file_out:
        file_out.write(text)


def merge_reports_from_paths(report_paths):
    json_data = []
    for json_path in report_paths:
        json_data.extend(utils.load_json_from_path(json_path))
    return _sort_and_uniq_rows(json_data)


def _sort_and_uniq_rows(l):
    key = operator.itemgetter(JSON_INDEX_FILENAME,
                              JSON_INDEX_LINE,
                              JSON_INDEX_HASH,
                              JSON_INDEX_QUALIFIER)
    l.sort(key=key)
    groups = itertools.groupby(l, key)
    # guaranteed to be at least one element in each group
    return map(lambda (keys, dups): dups.next(), groups)


def _should_report(analyzer, error_kind, error_type, error_bucket):
    analyzers_whitelist = [
        config.ANALYZER_ERADICATE,
        config.ANALYZER_CHECKERS,
        config.ANALYZER_TRACING,
    ]
    error_kinds = [ISSUE_KIND_ERROR, ISSUE_KIND_WARNING]
    null_style_buckets = ['B1', 'B2']

    if analyzer in analyzers_whitelist:
        return True

    if error_kind not in error_kinds:
        return False

    if not error_type:
        return False

    if error_type in NULL_STYLE_ISSUE_TYPES:
        return error_bucket in null_style_buckets

    return error_type in ISSUE_TYPES


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

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

    return _should_report(analyzer, error_kind, error_type, error_bucket)


def _should_report_json(analyzer, row):
    error_kind = row[JSON_INDEX_KIND]
    error_type = row[JSON_INDEX_TYPE]
    error_bucket = ''  # can be updated later once we extract it from qualifier

    for qual_tag in row[QUALIFIER_TAGS]:
        if qual_tag['tag'] == BUCKET_TAGS:
            error_bucket = qual_tag['value']
            break

    return _should_report(analyzer, error_kind, error_type, error_bucket)


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