# Copyright 2018 Pants project contributors (see CONTRIBUTORS.md).
# Licensed under the Apache License, Version 2.0 (see LICENSE).


from pants.base.build_environment import get_buildroot
from pants.engine.fs import Digest, PathGlobs, PathGlobsAndRoot
from pants.java.jar.jar_dependency_utils import ResolvedJar
from pants.task.task import TaskBase
from pants.util.dirutil import fast_relpath


class JvmResolverBase(TaskBase):
    """Common methods for both Ivy and Coursier resolves."""

    def add_directory_digests_for_jars(self, targets_and_jars):
        """For each target, get DirectoryDigests for its jars and return them zipped with the jars.

        :param targets_and_jars: List of tuples of the form (Target, [pants.java.jar.jar_dependency_utils.ResolveJar])
        :return: list[tuple[(Target, list[pants.java.jar.jar_dependency_utils.ResolveJar])]
        """

        targets_and_jars = list(targets_and_jars)

        if not targets_and_jars:
            return targets_and_jars

        jar_paths = []
        for target, jars_to_snapshot in targets_and_jars:
            for jar in jars_to_snapshot:
                jar_paths.append(fast_relpath(jar.pants_path, get_buildroot()))

        # Capture Snapshots for jars, using an optional adjacent digest. Create the digest afterward
        # if it does not exist.
        snapshots = self.context._scheduler.capture_snapshots(
            tuple(
                PathGlobsAndRoot(PathGlobs([jar]), get_buildroot(), Digest.load(jar),)
                for jar in jar_paths
            )
        )
        for snapshot, jar_path in zip(snapshots, jar_paths):
            snapshot.directory_digest.dump(jar_path)

        # We want to map back the list[Snapshot] to targets_and_jars
        # We assume that (1) jars_to_snapshot has the same number of ResolveJars as snapshots does Snapshots,
        # and that (2) capture_snapshots preserves ordering.
        digests = [snapshot.directory_digest for snapshot in snapshots]
        digest_iterator = iter(digests)

        snapshotted_targets_and_jars = []
        for target, jars_to_snapshot in targets_and_jars:
            snapshotted_jars = [
                ResolvedJar(
                    coordinate=jar.coordinate,
                    cache_path=jar.cache_path,
                    pants_path=jar.pants_path,
                    directory_digest=next(digest_iterator),
                )
                for jar in jars_to_snapshot
            ]
            snapshotted_targets_and_jars.append((target, snapshotted_jars))

        return snapshotted_targets_and_jars