# Copyright 2021 The Pigweed Authors
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.
"""Roll submodules of a git repository."""

import configparser
import io
import re

import attr
from PB.recipes.pigweed.submodule_roller import InputProperties
from recipe_engine import post_process

DEPS = [
    'fuchsia/auto_roller',
    'fuchsia/git',
    'fuchsia/status_check',
    'pigweed/checkout',
    'pigweed/roll_util',
    'recipe_engine/context',
    'recipe_engine/file',
    'recipe_engine/properties',
    'recipe_engine/step',
]

PROPERTIES = InputProperties


@attr.s
class _Submodule:
    path = attr.ib(type=str)
    name = attr.ib(type=str)
    branch = attr.ib(type=str)
    remote = attr.ib(type=str, default=None)
    dir = attr.ib(type=str, default=None)


@attr.s
class _RevisionChange:
    old = attr.ib(type=str)
    new = attr.ib(type=str)


def _update_submodule(api, checkout, path, new_revision):
    with api.context(cwd=checkout.top):
        api.git.update_submodule(
            paths=(path,), timeout=checkout.options.submodule_timeout_sec,
        )

    old_revision = api.checkout.get_revision(
        path, 'get old revision', test_data='1' * 40
    )

    with api.context(cwd=path):
        api.git('git fetch', 'fetch', 'origin', new_revision)
        api.git('git checkout', 'checkout', 'FETCH_HEAD')

    # In case new_revision is a branch name we need to retrieve the hash it
    # resolved to.
    if not re.search(r'^[0-9a-f]{40}$', new_revision):
        new_revision = api.checkout.get_revision(
            path, 'get new revision', test_data='2' * 40
        )

    return _RevisionChange(old=old_revision, new=new_revision)


def RunSteps(api, props):  # pylint: disable=invalid-name
    submodules = [
        _Submodule(path=x.path, name=x.name, branch=x.branch)
        for x in props.submodules
    ]
    cc_authors_on_rolls = props.cc_authors_on_rolls
    cc_reviewers_on_rolls = props.cc_reviewers_on_rolls
    cc_domains = props.cc_domains
    always_cc = props.always_cc

    # The checkout module will try to use trigger data to pull in a specific
    # patch. Since the triggering commit is in a different repository that
    # needs to be disabled.
    props.checkout_options.use_trigger = False
    checkout = api.checkout(props.checkout_options)

    # Confirm the given path is actually a submodule.
    gitmodules = api.file.read_text(
        'read .gitmodules', checkout.root.join('.gitmodules')
    )
    # Example .gitmodules file:
    # [submodule "third_party/pigweed"]
    #   path = third_party/pigweed
    #   url = https://pigweed.googlesource.com/pigweed/pigweed

    # configparser doesn't like leading whitespace on lines, despite what its
    # documentation says.
    gitmodules = re.sub(r'\n\s+', '\n', gitmodules)
    parser = configparser.RawConfigParser()
    parser.readfp(io.StringIO(gitmodules))

    rolls = {}

    for submodule in submodules:
        if not submodule.name:
            submodule.name = submodule.path
        submodule.dir = checkout.root.join(submodule.path)

        with api.step.nest(submodule.name) as pres:
            section = 'submodule "{}"'.format(submodule.name)
            if not parser.has_section(section):
                sections = parser.sections()
                submodules = sorted(
                    re.sub(r'^.*"(.*)"$', r'\1', x) for x in sections
                )
                raise api.step.StepFailure(
                    'no submodule "{}" (submodules: {})'.format(
                        submodule.name,
                        ', '.join('"{}"'.format(x) for x in submodules),
                    )
                )

            if not submodule.branch:
                try:
                    submodule.branch = parser.get(section, 'branch')
                except configparser.NoOptionError:
                    submodule.branch = 'main'

            submodule.remote = api.roll_util.normalize_remote(
                parser.get(section, 'url'), checkout.options.remote,
            )

            change = _update_submodule(
                api, checkout, submodule.dir, submodule.branch
            )

            direction = api.roll_util.get_roll_direction(
                submodule.dir, change.old, change.new
            )

            # If the primary roll is not necessary or is backwards we can exit
            # immediately and don't need to check deps.
            if api.roll_util.can_roll(direction):
                rolls[submodule.path] = api.roll_util.Roll(
                    project_name=str(submodule.path),
                    old_revision=change.old,
                    new_revision=change.new,
                    proj_dir=submodule.dir,
                    direction=direction,
                    nest_steps=False,
                )

            else:
                pres.step_summary_text = 'no roll required'
                api.roll_util.skip_roll_step(
                    submodule.remote, change.old, change.new
                )

    if not rolls:
        with api.step.nest('nothing to roll, exiting'):
            return

    cc = set()
    authors = api.roll_util.authors(*rolls.values())
    if cc_authors_on_rolls:
        cc.update(authors)
    if cc_reviewers_on_rolls:
        cc.update(api.roll_util.reviewers(*rolls.values()))

    def include_cc(email):
        return api.roll_util.include_cc(
            email, cc_domains, checkout.gerrit_host()
        )

    # include_cc() writes steps, so we want things sorted before calling it.
    cc = sorted(set(cc))
    cc_emails = [x.email for x in cc if include_cc(x)]

    if always_cc:
        props.auto_roller_options.cc_emails.extend(cc_emails)
    else:
        props.auto_roller_options.cc_on_failure_emails.extend(cc_emails)

    author_override = None
    with api.step.nest('authors') as pres:
        pres.step_summary_text = repr(authors)
    if len(authors) == 1 and props.forge_author:
        author_override = api.roll_util.fake_author(
            next(iter(authors))
        )._asdict()

    change = api.auto_roller.attempt_roll(
        props.auto_roller_options,
        repo_dir=checkout.root,
        commit_message=api.roll_util.message(*rolls.values()),
        author_override=author_override,
    )

    return api.auto_roller.raw_result(change)


def GenTests(api):  # pylint: disable=invalid-name
    """Create tests."""

    def _url(x):
        if x.startswith(('https://', 'sso://', '.')):
            return x
        return 'https://foo.googlesource.com/' + x

    def submodules(*subs):
        res = []
        for sub in subs:
            if isinstance(sub, str):
                res.append(dict(path=sub))
            elif isinstance(sub, dict):
                res.append(sub)
            else:
                raise ValueError(repr(sub))  # pragma: no cover
        return res

    def gitmodules(**submodules):
        branches = {}
        for k, v in submodules.items():
            if k.endswith('_branch'):
                branches[k.replace('_branch', '')] = v

        for x in branches:
            del submodules['{}_branch'.format(x)]

        text = []
        for k, v in submodules.items():
            text.append(
                '[submodule "{0}"]\n\tpath = {0}\n\turl = {1}\n'.format(
                    k, _url(v)
                )
            )
            if k in branches:
                text.append('\tbranch = {}\n'.format(branches[k]))

        return api.step_data(
            'read .gitmodules', api.file.read_text(''.join(text))
        )

    def properties(submodules, **kwargs):
        new_kwargs = api.checkout.git_properties()
        new_kwargs['submodules'] = submodules
        new_kwargs.update(kwargs)
        new_kwargs.setdefault(
            'auto_roller_options',
            {'dry_run': True, 'remote': api.checkout.pigweed_repo,},
        )
        return api.properties(**new_kwargs)

    def commit_data(name, **kwargs):
        return api.roll_util.commit_data(
            name,
            api.roll_util.commit('a' * 40, 'foo\nbar\n\nChange-Id: I1111'),
            **kwargs,
        )

    yield (
        api.status_check.test('success')
        + properties(
            submodules('a1', 'b2'),
            cc_authors_on_rolls=True,
            always_cc=True,
            forge_author=True,
        )
        + commit_data('a1', prefix='')
        + commit_data('b2', prefix='')
        + gitmodules(a1='sso://foo/a1', b2='sso://foo/b2')
        + api.roll_util.forward_roll('a1')
        + api.roll_util.forward_roll('b2')
        + api.auto_roller.dry_run_success()
    )

    yield (
        api.status_check.test('partial_noop')
        + properties(submodules('a1', 'b2'), cc_reviewers_on_rolls=True)
        + commit_data('a1', prefix='')
        + gitmodules(a1='sso://foo/a1', b2='sso://foo/b2')
        + api.roll_util.forward_roll('a1')
        + api.roll_util.noop_roll('b2')
        + api.auto_roller.dry_run_success()
    )

    yield (
        api.status_check.test('noop')
        + properties(submodules('a1', {'path': 'b2'}))
        + gitmodules(a1='a1', b2='b2', b2_branch='branch')
        + api.roll_util.noop_roll('a1')
        + api.roll_util.noop_roll('b2')
    )

    yield (
        api.status_check.test('missing', status='failure')
        + properties(submodules('a1', 'b2'), cc_authors_on_rolls=True)
        + gitmodules(a1='sso://foo/a1')
    )