#!/usr/bin/env python3
#
# Copyright (c) 2019-2020, Arm Limited. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
#

import argparse
import collections
import json
import re
import shutil
import sys


# Ignore some directories, as they're imported from other projects. Their
# code style is not necessarily the same as ours, and enforcing our rules
# on their code will likely lead to many false positives. They're false in
# the sense that they may not be violations of the origin project's code
# style, when they're violations of our code style.
IGNORED_DIRS = [
    "lib/libfdt",
    "include/lib/libfdt",
    "lib/compiler-rt",
    "lib/zlib",
    "include/lib/zlib",
]

_rule_exclusions = [
    "MISRA C-2012 Rule 2.4",
    "MISRA C-2012 Rule 2.5",
    "MISRA C-2012 Rule 2.7",
    "MISRA C-2012 Rule 5.1",
    "MISRA C-2012 Rule 5.8",
    "MISRA C-2012 Rule 8.6",
    "MISRA C-2012 Rule 8.7",
    "MISRA C-2012 Rule 11.4",
    "MISRA C-2012 Rule 11.5",
    "MISRA C-2012 Rule 15.1",
    "MISRA C-2012 Rule 15.5",
    "MISRA C-2012 Rule 15.6",
    "MISRA C-2012 Rule 16.1",
    "MISRA C-2012 Rule 16.3",
    "MISRA C-2012 Rule 17.1",
    "MISRA C-2012 Rule 21.6",
    "MISRA C-2012 Directive 4.6",
    "MISRA C-2012 Directive 4.8",
    "MISRA C-2012 Directive 4.9"
]

# The following classification of rules and directives include 'MISRA C:2012
# Amendment 1'

# Directives
_dir_required = set(["1.1", "2.1", "3.1", "4.1", "4.3", "4.7", "4.10", "4.11",
    "4.12", "4.14"])

_dir_advisory = set(["4.2", "4.4", "4.5", "4.6", "4.8", "4.9", "4.13"])

# Rules
_rule_mandatory = set(["9.1", "9.2", "9.3", "12.5", "13.6", "17.3", "17.4",
    "17.6", "19.1", "21.13", "21.17", "21.18", "21.19", "21.20", "22.2", "22.5",
    "22.6"])

_rule_required = set(["1.1", "1.3", "2.1", "2.2", "3.1", "3.2", "4.1", "5.1",
    "5.2", "5.3", "5.4", "5.5", "5.6", "5.7", "5.8", "6.1", "6.2", "7.1", "7.2",
    "7.3", "7.4", "8.1", "8.2", "8.3", "8.4", "8.5", "8.6", "8.7", "8.8",
    "8.10", "8.12", "8.14", "9.2", "9.3", "9.4", "9.5", "10.1", "10.2", "10.3",
    "10.4", "10.6", "10.7", "10.8", "11.1", "11.2", "11.3", "11.6", "11.7",
    "11.8", "11.9", "12.2", "13.1", "13.2", "13.5", "14.1", "14.2", "14.3",
    "14.4", "15.2", "15.3", "15.6", "15.7", "16.1", "16.2", "16.3", "16.4",
    "16.5", "16.6", "16.7", "17.1", "17.2", "17.7", "18.1", "18.2", "18.3",
    "18.6", "18.7", "18.8", "20.3", "20.4", "20.6", "20.7", "20.8", "20.9",
    "20.11", "20.12", "20.13", "20.14", "21.1", "21.2", "21.3", "21.4", "21.5",
    "21.6", "21.7", "21.8", "21.9", "21.10", "21.11", "21.14", "21.15", "21.16",
    "22.1", "22.3", "22.4", "22.7", "22.8", "22.9", "22.10"])

_rule_advisory = set(["1.2", "2.3", "2.4", "2.5", "2.6", "2.7", "4.2", "5.9",
    "8.9", "8.11", "8.13", "10.5", "11.4", "11.5", "12.1", "12.3", "12.4",
    "13.3", "13.4", "15.1", "15.4", "15.5", "17.5", "17.8", "18.4", "18.5",
    "19.2", "20.1", "20.2", "20.5", "20.10", "21.12"])


_checker_lookup = {
        "Directive": {
            "required": _dir_required,
            "advisory": _dir_advisory
        },
        "Rule": {
            "mandatory": _rule_mandatory,
            "required": _rule_required,
            "advisory": _rule_advisory
        }
    }

_checker_re = re.compile(r"""(?P<kind>\w+) (?P<number>[\d\.]+)$""")


def _classify_checker(checker):
    match = _checker_re.search(checker)
    if match:
        kind, number = match.group("kind"), match.group("number")
        for classification, class_set in _checker_lookup[kind].items():
            if number in class_set:
                return classification

    return "unknown"


# Return a copy of the original issue description. Update file path to strip
# heading '/', and also insert CID.
def _new_issue(cid, orig_issue):
    checker = orig_issue["checker"]
    classification = _classify_checker(checker)

    return {
        "cid": cid,
        "file": orig_issue["file"].lstrip("/"),
        "line": orig_issue["mainEventLineNumber"],
        "checker": checker,
        "classification": classification,
        "description": orig_issue["mainEventDescription"]
    }

def _new_issue_v7(cid, checker, issue):
    return {
        "cid": cid,
        "file": issue["strippedFilePathname"],
        "line": issue["lineNumber"],
        "checker": checker,
        "classification": _classify_checker(checker),
        "description": issue["eventDescription"],
    }


def _cls_string(issue):
    cls = issue["classification"]

    return " (" + cls + ")" if cls != "unknown" else ""


# Given an issue, make a string formed of file name, line number, checker, and
# the CID. This could be used as a dictionary key to identify unique defects
# across the scan. Convert inegers to zero-padded strings for proper sorting.
def make_key(i):
    return (i["file"] + str(i["line"]).zfill(5) + i["checker"] +
            str(i["cid"]).zfill(5))


class Issues(object):
    """An iterator over issue events that collects a summary

    After using this object as an iterator, the totals member will contain a
    dict that maps defect types to their totals, and a "total" key with the
    total number of defects in this scan.
    """
    def __init__(self, path, show_all):
        self.path = path
        self.show_all = show_all
        self.iterated = False
        self.totals = collections.defaultdict(int)
        self.gen = None

    def filter_groups_v1(self, group):
        """Decide if we should keep an issue group from a v1-6 format dict"""
        if group["triage"]["action"] == "Ignore":
            return False
        if group["occurrences"][0]["checker"] in _rule_exclusions:
            return False
        for skip_dir in IGNORED_DIRS:
            if group["occurrences"][0]["file"].lstrip("/").startswith(skip_dir):
                return False
        # unless we're showing all groups, remove the groups that are in both
        # golden and branch
        if not self.show_all:
            return not group["presentInComparisonSnapshot"]
        return True

    def iter_issues_v1(self, report):
        # Top-level is a group of issues, all sharing a common CID
        for issue_group in filter(self.filter_groups_v1, report["issueInfo"]):
            # Pick up individual occurrence of the CID
            self.totals["total"] += 1
            for occurrence in issue_group["occurrences"]:
                self.totals[_classify_checker(occurrence["checker"])] += 1
                yield _new_issue(issue_group["cid"], occurrence)

    def filter_groups_v7(self, group):
        """Decide if we should keep an issue group from a v7 format dict"""
        if group.get("checker_name") in _rule_exclusions:
            return False
        for skip_dir in IGNORED_DIRS:
            if group["strippedMainEventFilePathname"].startswith(skip_dir):
                return False
        return True

    def iter_issues_v7(self, report):
        # TODO: filter by triage and action
        for issue_group in filter(self.filter_groups_v7, report["issues"]):
            self.totals[_classify_checker(issue_group["checkerName"])] += 1
            self.totals["total"] += 1
            for event in issue_group["events"]:
                yield _new_issue_v7(
                    issue_group.get("cid"),
                    issue_group["checkerName"],
                    event
                )

    def _gen(self):
        with open(self.path, encoding="utf-8") as fd:
            report = json.load(fd)
        if report.get("formatVersion", 0) >= 7:
            return self.iter_issues_v7(report)
        else:
            return self.iter_issues_v1(report)

    def __iter__(self):
        if self.gen is None:
            self.gen = self._gen()
        yield from self.gen

# Format issue (returned from iter_issues()) as text.
def format_issue(issue):
    return ("{file}:{line}:[{checker}{cls}]<{cid}> {description}").format_map(
            dict(issue, cls=_cls_string(issue)))


# Format issue (returned from iter_issues()) as HTML table row.
def format_issue_html(issue):
    cls = _cls_string(issue)
    cov_class = "cov-" + issue["classification"]

    return """\
<tr class="{cov_class}">
  <td class="cov-file">{file}</td>
  <td class="cov-line">{line}</td>
  <td class="cov-checker">{checker}{cls}</td>
  <td class="cov-cid">{cid}</td>
  <td class="cov-description">{description}</td>
</tr>""".format_map(dict(issue, cls=cls, cov_class=cov_class))


TOTALS_FORMAT = str.strip("""
TotalDefects:     {total}
MandatoryDefects: {mandatory}
RequiredDefects:  {required}
AdvisoryDefects:  {advisory}
""")

if __name__ == "__main__":
    parser = argparse.ArgumentParser()

    parser.add_argument("--all", default=False, dest="show_all",
            action="store_const", const=True, help="List all issues")
    parser.add_argument("--output",
            help="File to output filtered defects to in JSON")
    parser.add_argument("--totals",
            help="File to output total defects in flat text")
    parser.add_argument("json_report")

    opts = parser.parse_args()

    issue_cls = Issues(opts.json_report, opts.show_all)
    issues = []
    for issue in sorted(issue_cls, key=lambda i: make_key(i)):
        print(format_issue(issue))
        issues.append(issue)

    if opts.output:
        # Dump selected issues
        with open(opts.output, "wt") as fd:
            fd.write(json.dumps(issues))

    if opts.totals:
        with open(opts.totals, "wt") as fd:
            fd.write(TOTALS_FORMAT.format_map(issue_cls.totals))

    sys.exit(int(len(issues) > 0))