# Copyright 2024 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.

from __future__ import annotations

import configparser
import dataclasses
import io
import re
from typing import TYPE_CHECKING

from PB.recipe_modules.pigweed.checkout.options import (
    Options as CheckoutOptions,
)
from recipe_engine import recipe_api

if TYPE_CHECKING:  # pragma: no cover
    from typing import Generator
    from PB.recipe_modules.pigweed.txt_roll.txt_entry import TxtEntry
    from RECIPE_MODULES.pigweed.checkout import api as checkout_api
    from RECIPE_MODULES.pigweed.roll_util import api as roll_util_api


class TxtRollApi(recipe_api.RecipeApi):

    def update(
        self,
        checkout: checkout_api.CheckoutContext,
        txt_entry: TxtEntry,
    ) -> dict[str, roll_util_api.Roll] | None:
        branch = txt_entry.branch or 'main'

        new_revision: Optional[str] = None

        # First, try to get new_revision from the trigger.
        bb_remote: Optional[str] = None
        commit = self.m.buildbucket.build.input.gitiles_commit
        if commit and commit.project:
            new_revision = commit.id
            host = commit.host
            bb_remote = f'https://{host}/{commit.project}'

        # If we still don't have a revision then it wasn't in the trigger.
        # (Perhaps this was manually triggered.) In this case we update to the
        # property-specified branch HEAD.
        if new_revision is None:
            new_revision = branch

        # If this was triggered by a gitiles poller, check that the triggering
        # repository matches project_remote.

        if bb_remote:
            if not checkout.remotes_equivalent(txt_entry.remote, bb_remote):
                raise self.m.step.StepFailure(
                    'triggering repository ({}) does not match project remote '
                    '({})'.format(bb_remote, txt_entry.remote)
                )

        project_dir = self.m.path.start_dir / 'project'

        project_checkout = self.m.checkout(
            CheckoutOptions(
                remote=txt_entry.remote,
                branch=branch,
                use_trigger=True,
            ),
            root=project_dir,
        )

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

        full_txt_path = checkout.root / txt_entry.path

        old_revision = self.m.file.read_text(
            'read old revision',
            full_txt_path,
            test_data='1' * 40,
        ).strip()

        self.m.file.write_text(
            'write new revision', full_txt_path, f'{new_revision}\n'
        )

        direction = self.m.roll_util.get_roll_direction(
            project_dir, old_revision, new_revision
        )

        # If the primary roll is not necessary or is backwards we can exit
        # immediately.
        if not self.m.roll_util.can_roll(direction):
            self.m.roll_util.skip_roll_step(
                txt_entry.remote,
                old_revision,
                new_revision,
            )
            return

        with self.m.step.nest('txt_path') as pres:
            pres.step_summary_text = repr(txt_entry.path)

        return {
            txt_entry.path: self.m.roll_util.create_roll(
                project_name=txt_entry.path,
                old_revision=old_revision,
                new_revision=new_revision,
                proj_dir=project_dir,
                direction=direction,
            ),
        }