#!/usr/bin/env python3
# SPDX-License-Identifier: Apache-2.0
# Copyright (c) 2021 Intel Corporation

# A script to generate twister options based on modified files.

import argparse
import fnmatch
import glob
import json
import logging
import os
import re
import subprocess
import sys
from pathlib import Path

import yaml
from git import Repo
from west.manifest import Manifest

try:
    from yaml import CSafeLoader as SafeLoader
except ImportError:
    from yaml import SafeLoader

if "ZEPHYR_BASE" not in os.environ:
    exit("$ZEPHYR_BASE environment variable undefined.")

# These are globaly used variables. They are assigned in __main__ and are visible in further methods
# however, pylint complains that it doesn't recognized them when used (used-before-assignment).
zephyr_base = Path(os.environ['ZEPHYR_BASE'])
repository_path = zephyr_base
repo_to_scan = Repo(zephyr_base)
args = None
logging.basicConfig(format='%(levelname)s: %(message)s', level=logging.INFO)
logging.getLogger("pykwalify.core").setLevel(50)

sys.path.append(os.path.join(zephyr_base, 'scripts'))
import list_boards  # noqa: E402
from pylib.twister.twisterlib.statuses import TwisterStatus  # noqa: E402


def _get_match_fn(globs, regexes):
    # Constructs a single regex that tests for matches against the globs in
    # 'globs' and the regexes in 'regexes'. Parts are joined with '|' (OR).
    # Returns the search() method of the compiled regex.
    #
    # Returns None if there are neither globs nor regexes, which should be
    # interpreted as no match.

    if not (globs or regexes):
        return None

    regex = ""

    if globs:
        glob_regexes = []
        for glob in globs:
            # Construct a regex equivalent to the glob
            glob_regex = glob.replace(".", "\\.").replace("*", "[^/]*").replace("?", "[^/]")

            if not glob.endswith("/"):
                # Require a full match for globs that don't end in /
                glob_regex += "$"

            glob_regexes.append(glob_regex)

        # The glob regexes must anchor to the beginning of the path, since we
        # return search(). (?:) is a non-capturing group.
        regex += "^(?:{})".format("|".join(glob_regexes))

    if regexes:
        if regex:
            regex += "|"
        regex += "|".join(regexes)

    return re.compile(regex).search


class Tag:
    """
    Represents an entry for a tag in tags.yaml.

    These attributes are available:

    name:
        List of GitHub labels for the area. Empty if the area has no 'labels'
        key.

    description:
        Text from 'description' key, or None if the area has no 'description'
        key
    """

    def _contains(self, path):
        # Returns True if the area contains 'path', and False otherwise

        return (
            self._match_fn
            and self._match_fn(path)
            and not (self._exclude_match_fn and self._exclude_match_fn(path))
        )

    def __repr__(self):
        return f"<Tag {self.name}>"


class Filters:
    def __init__(
        self,
        modified_files,
        ignore_path,
        alt_tags,
        testsuite_root,
        pull_request=False,
        platforms=None,
        detailed_test_id=False,
        quarantine_list=None,
        tc_roots_th=20,
    ):
        self.modified_files = modified_files
        self.testsuite_root = testsuite_root
        self.resolved_files = []
        self.twister_options = []
        self.full_twister = False
        self.all_tests = []
        self.tag_options = []
        self.pull_request = pull_request
        self.platforms = platforms if platforms else []
        self.detailed_test_id = detailed_test_id
        self.ignore_path = ignore_path
        self.tag_cfg_file = alt_tags
        self.quarantine_list = quarantine_list
        self.tc_roots_th = tc_roots_th

    def process(self):
        self.find_modules()
        self.find_tags()
        self.find_tests()
        if not self.platforms:
            # disable for now, this is generating lots of churn when changing
            # architectures that is otherwise covered elsewhere.
            # self.find_archs()
            self.find_boards()
        else:
            for file in self.modified_files:
                if file.startswith(("boards/", "dts/")):
                    self.resolved_files.append(file)

        self.find_excludes()

    def get_plan(self, options, integration=False, use_testsuite_root=True):
        fname = "_test_plan_partial.json"
        cmd = [f"{zephyr_base}/scripts/twister", "-c"] + options + ["--save-tests", fname]
        if self.detailed_test_id:
            cmd += ["--detailed-test-id"]
        if self.testsuite_root and use_testsuite_root:
            for root in self.testsuite_root:
                cmd += ["-T", root]
        if integration:
            cmd.append("--integration")
        if self.quarantine_list:
            for q in self.quarantine_list:
                cmd += ["--quarantine-list", q]

        logging.info(" ".join(cmd))
        _ = subprocess.call(cmd)
        with open(fname, newline='') as jsonfile:
            json_data = json.load(jsonfile)
            suites = json_data.get("testsuites", [])
            self.all_tests.extend(suites)
        if os.path.exists(fname):
            os.remove(fname)

    def find_modules(self):
        if 'west.yml' in self.modified_files and args.commits is not None:
            print("Manifest file 'west.yml' changed")
            print("=========")
            old_manifest_content = repo_to_scan.git.show(f"{args.commits[:-2]}:west.yml")
            with open("west_old.yml", "w") as manifest:
                manifest.write(old_manifest_content)
            old_manifest = Manifest.from_file("west_old.yml")
            new_manifest = Manifest.from_file("west.yml")
            old_projs = set((p.name, p.revision) for p in old_manifest.projects)
            new_projs = set((p.name, p.revision) for p in new_manifest.projects)
            logging.debug(f'old_projs: {old_projs}')
            logging.debug(f'new_projs: {new_projs}')
            # Removed projects
            rprojs = set(
                filter(lambda p: p[0] not in list(p[0] for p in new_projs), old_projs - new_projs)
            )
            # Updated projects
            uprojs = set(
                filter(lambda p: p[0] in list(p[0] for p in old_projs), new_projs - old_projs)
            )
            # Added projects
            aprojs = new_projs - old_projs - uprojs

            # All projs
            projs = rprojs | uprojs | aprojs
            projs_names = [name for name, rev in projs]

            logging.info(f'rprojs: {rprojs}')
            logging.info(f'uprojs: {uprojs}')
            logging.info(f'aprojs: {aprojs}')
            logging.info(f'project: {projs_names}')

            if not projs_names:
                return
            _options = []
            for p in projs_names:
                _options.extend(["-t", p])

            if self.platforms:
                for platform in self.platforms:
                    _options.extend(["-p", platform])

            self.get_plan(_options, True)

    def find_archs(self):
        # we match both arch/<arch>/* and include/zephyr/arch/<arch> and skip common.
        archs = set()

        for f in self.modified_files:
            p = re.match(r"^arch\/([^/]+)\/", f)
            if not p:
                p = re.match(r"^include\/zephyr\/arch\/([^/]+)\/", f)
            if p and p.group(1) != 'common':
                archs.add(p.group(1))
                # Modified file is treated as resolved, since a matching scope was found
                self.resolved_files.append(f)

        _options = []
        for arch in archs:
            _options.extend(["-a", arch])

        if _options:
            logging.info('Potential architecture filters...')
            if self.platforms:
                for platform in self.platforms:
                    _options.extend(["-p", platform])

                self.get_plan(_options, True)
            else:
                self.get_plan(_options, True)

    def find_boards(self):
        changed_boards = set()
        matched_boards = {}
        resolved_files = []

        for file in self.modified_files:
            if file.endswith(".rst") or file.endswith(".png") or file.endswith(".jpg"):
                continue
            if file.startswith("boards/"):
                changed_boards.add(file)
                resolved_files.append(file)

        roots = [zephyr_base]
        if repository_path != zephyr_base:
            roots.append(repository_path)

        # Look for boards in monitored repositories
        lb_args = argparse.Namespace(
            **{
                'arch_roots': roots,
                'board_roots': roots,
                'board': None,
                'soc_roots': roots,
                'board_dir': None,
            }
        )
        known_boards = list_boards.find_v2_boards(lb_args).values()

        for changed in changed_boards:
            for board in known_boards:
                c = (zephyr_base / changed).resolve()
                if c.is_relative_to(board.dir.resolve()):
                    for file in glob.glob(os.path.join(board.dir, f"{board.name}*.yaml")):
                        with open(file, encoding='utf-8') as f:
                            b = yaml.load(f.read(), Loader=SafeLoader)
                            matched_boards[b['identifier']] = board

        logging.info(f"found boards: {','.join(matched_boards.keys())}")
        # If modified file is caught by "find_boards" workflow (change in "boards" dir AND board
        # recognized) it means a proper testing scope for this file was found and this file can
        # be removed from further consideration
        for _, board in matched_boards.items():
            relative_board_dir = str(board.dir.relative_to(zephyr_base))
            rel_resolved_files = [f for f in resolved_files if relative_board_dir in f]
            self.resolved_files.extend(rel_resolved_files)

        _options = []
        if len(matched_boards) > 20:
            msg = f"{len(matched_boards)} boards changed, this looks like a global change, "
            msg += "skipping test handling, revert to default."
            logging.warning(msg)
            self.full_twister = True
            return

        for board in matched_boards:
            _options.extend(["-p", board])

        if _options:
            logging.info('Potential board filters...')
            self.get_plan(_options)

    def find_tests(self):
        tests = set()
        for f in self.modified_files:
            if f.endswith(".rst"):
                continue
            d = os.path.dirname(f)
            scope_found = False
            while not scope_found and d:
                head, tail = os.path.split(d)
                if os.path.exists(os.path.join(d, "testcase.yaml")) or os.path.exists(
                    os.path.join(d, "sample.yaml")
                ):
                    tests.add(d)
                    # Modified file is treated as resolved, since a matching scope was found
                    self.resolved_files.append(f)
                    scope_found = True
                elif tail == "common":
                    # Look for yamls in directories collocated with common
                    testcase_yamls = glob.iglob(head + '/**/testcase.yaml', recursive=True)
                    sample_yamls = glob.iglob(head + '/**/sample.yaml', recursive=True)

                    yamls_found = [*testcase_yamls, *sample_yamls]
                    if yamls_found:
                        for yaml in yamls_found:
                            tests.add(os.path.dirname(yaml))
                        self.resolved_files.append(f)
                        scope_found = True
                    else:
                        d = os.path.dirname(d)
                else:
                    d = os.path.dirname(d)

        _options = []
        for t in tests:
            _options.extend(["-T", t])

        if len(tests) > self.tc_roots_th:
            msg = f"{len(tests)} tests changed, this looks like a global change, "
            msg += "skipping test handling, revert to default"
            logging.warning(msg)
            self.full_twister = True
            return

        if _options:
            logging.info(f'Potential test filters...({len(tests)} changed...)')
            if self.platforms:
                for platform in self.platforms:
                    _options.extend(["-p", platform])
            self.get_plan(_options, use_testsuite_root=False)

    def find_tags(self):
        with open(self.tag_cfg_file) as ymlfile:
            tags_config = yaml.safe_load(ymlfile)

        tags = {}
        for t, x in tags_config.items():
            tag = Tag()
            tag.exclude = True
            tag.name = t

            # tag._match_fn(path) tests if the path matches files and/or
            # files-regex
            tag._match_fn = _get_match_fn(x.get("files"), x.get("files-regex"))

            # Like tag._match_fn(path), but for files-exclude and
            # files-regex-exclude
            tag._exclude_match_fn = _get_match_fn(
                x.get("files-exclude"), x.get("files-regex-exclude")
            )

            tags[tag.name] = tag

        for f in self.modified_files:
            for t in tags.values():
                if t._contains(f):
                    t.exclude = False

        exclude_tags = set()
        for t in tags.values():
            if t.exclude:
                exclude_tags.add(t.name)

        for tag in exclude_tags:
            self.tag_options.extend(["-e", tag])

        if exclude_tags:
            logging.info(f'Potential tag based filters: {exclude_tags}')

    def find_excludes(self):
        with open(self.ignore_path) as twister_ignore:
            ignores = twister_ignore.read().splitlines()
            ignores = filter(lambda x: not x.startswith("#"), ignores)

        found = set()
        not_resolved = lambda x: x not in self.resolved_files  # noqa: E731
        files_not_resolved = list(filter(not_resolved, self.modified_files))

        for pattern in ignores:
            if pattern:
                found.update(fnmatch.filter(files_not_resolved, pattern))

        logging.debug(found)
        logging.debug(files_not_resolved)

        # Full twister run can be ordered by detecting great number of tests/boards changed
        # or if not all modified files were resolved (corresponding scope found)
        self.full_twister = self.full_twister or sorted(files_not_resolved) != sorted(found)

        if self.full_twister:
            _options = []
            logging.info('Need to run full or partial twister...')
            if self.platforms:
                for platform in self.platforms:
                    _options.extend(["-p", platform])

                _options.extend(self.tag_options)
                self.get_plan(_options)
            else:
                _options.extend(self.tag_options)
                self.get_plan(_options, True)
        else:
            logging.info('No twister needed or partial twister run only...')


def parse_args():
    parser = argparse.ArgumentParser(
        description="Generate twister argument files based on modified file", allow_abbrev=False
    )
    parser.add_argument('-c', '--commits', default=None, help="Commit range in the form: a..b")
    parser.add_argument(
        '-m',
        '--modified-files',
        default=None,
        help="File with information about changed/deleted/added files.",
    )
    parser.add_argument(
        '-o',
        '--output-file',
        default="testplan.json",
        help="JSON file with the test plan to be passed to twister",
    )
    parser.add_argument('-P', '--pull-request', action="store_true", help="This is a pull request")
    parser.add_argument(
        '-p',
        '--platform',
        action="append",
        help="Limit this for a platform or a list of platforms.",
    )
    parser.add_argument(
        '-t', '--tests_per_builder', default=700, type=int, help="Number of tests per builder"
    )
    parser.add_argument(
        '-n', '--default-matrix', default=10, type=int, help="Number of tests per builder"
    )
    parser.add_argument(
        '--testcase-roots-threshold',
        default=20,
        type=int,
        help="Threshold value for number of modified testcase roots, "
        "up to which an optimized scope is still applied. "
        "When exceeded, full scope will be triggered",
    )
    parser.add_argument(
        '--detailed-test-id',
        action='store_true',
        help="Include paths to tests' locations in tests' names.",
    )
    parser.add_argument(
        "--no-detailed-test-id",
        dest='detailed_test_id',
        action="store_false",
        help="Don't put paths into tests' names.",
    )
    parser.add_argument('-r', '--repo-to-scan', default=None, help="Repo to scan")
    parser.add_argument(
        '--ignore-path',
        default=os.path.join(zephyr_base, 'scripts', 'ci', 'twister_ignore.txt'),
        help="Path to a text file with patterns of files to be matched against changed files",
    )
    parser.add_argument(
        '--alt-tags',
        default=os.path.join(zephyr_base, 'scripts', 'ci', 'tags.yaml'),
        help="Path to a file describing relations between directories and tags",
    )
    parser.add_argument(
        "-T",
        "--testsuite-root",
        action="append",
        default=[],
        help="Base directory to recursively search for test cases. All "
        "testcase.yaml files under here will be processed. May be "
        "called multiple times. Defaults to the 'samples/' and "
        "'tests/' directories at the base of the Zephyr tree.",
    )
    parser.add_argument(
        "--quarantine-list",
        action="append",
        metavar="FILENAME",
        help="Load list of test scenarios under quarantine. The entries in "
        "the file need to correspond to the test scenarios names as in "
        "corresponding tests .yaml files. These scenarios "
        "will be skipped with quarantine as the reason.",
    )

    # Do not include paths in names by default.
    parser.set_defaults(detailed_test_id=False)

    return parser.parse_args()


if __name__ == "__main__":
    args = parse_args()
    files = []
    errors = 0
    if args.repo_to_scan:
        repository_path = Path(args.repo_to_scan)
        repo_to_scan = Repo(repository_path)
    if args.commits:
        commit = repo_to_scan.git.diff("--name-only", args.commits)
        files = commit.split("\n")
    elif args.modified_files:
        with open(args.modified_files) as fp:
            files = json.load(fp)

    if files:
        print("Changed files:\n=========")
        print("\n".join(files))
        print("=========")

    f = Filters(
        files,
        args.ignore_path,
        args.alt_tags,
        args.testsuite_root,
        args.pull_request,
        args.platform,
        args.detailed_test_id,
        args.quarantine_list,
        args.testcase_roots_threshold,
    )
    f.process()

    # remove dupes and filtered cases
    dup_free = []
    dup_free_set = set()
    logging.info(f'Total tests gathered: {len(f.all_tests)}')
    for ts in f.all_tests:
        if TwisterStatus(ts.get('status')) == TwisterStatus.FILTER:
            continue
        n = ts.get("name")
        a = ts.get("arch")
        p = ts.get("platform")
        t = ts.get("toolchain")
        if TwisterStatus(ts.get('status')) == TwisterStatus.ERROR:
            logging.info(f"Error found: {n} on {p} ({ts.get('reason')})")
            errors += 1
        if (n, a, p, t) not in dup_free_set:
            dup_free.append(ts)
            dup_free_set.add(
                (
                    n,
                    a,
                    p,
                    t,
                )
            )

    logging.info(f'Total tests to be run: {len(dup_free)}')
    with open(".testplan", "w") as tp:
        total_tests = len(dup_free)
        if total_tests and total_tests < args.tests_per_builder:
            nodes = 1
        else:
            nodes = round(total_tests / args.tests_per_builder)

        tp.write(f"TWISTER_TESTS={total_tests}\n")
        tp.write(f"TWISTER_NODES={nodes}\n")
        tp.write(f"TWISTER_FULL={f.full_twister}\n")
        logging.info(f'Total nodes to launch: {nodes}')

    header = [
        'test',
        'arch',
        'platform',
        'status',
        'extra_args',
        'handler',
        'handler_time',
        'used_ram',
        'used_rom',
    ]

    # write plan
    if dup_free:
        data = {}
        data['testsuites'] = dup_free
        with open(args.output_file, 'w', newline='') as json_file:
            json.dump(data, json_file, indent=4, separators=(',', ':'))

    sys.exit(errors)