# Copyright (C) 2008 The Android Open Source Project
#
# 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
#
#      http://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.

import multiprocessing
import optparse
import os
import re

from error import InvalidProjectGroupsError
from error import NoSuchProjectError
from error import RepoExitError
from event_log import EventLog
import progress


# Are we generating man-pages?
GENERATE_MANPAGES = os.environ.get("_REPO_GENERATE_MANPAGES_") == " indeed! "


# Number of projects to submit to a single worker process at a time.
# This number represents a tradeoff between the overhead of IPC and finer
# grained opportunity for parallelism. This particular value was chosen by
# iterating through powers of two until the overall performance no longer
# improved. The performance of this batch size is not a function of the
# number of cores on the system.
WORKER_BATCH_SIZE = 32


# How many jobs to run in parallel by default?  This assumes the jobs are
# largely I/O bound and do not hit the network.
DEFAULT_LOCAL_JOBS = min(os.cpu_count(), 8)


class UsageError(RepoExitError):
    """Exception thrown with invalid command usage."""


class Command:
    """Base class for any command line action in repo."""

    # Singleton for all commands to track overall repo command execution and
    # provide event summary to callers. Only used by sync subcommand currently.
    #
    # NB: This is being replaced by git trace2 events. See git_trace2_event_log.
    event_log = EventLog()

    # Whether this command is a "common" one, i.e. whether the user would
    # commonly use it or it's a more uncommon command. This is used by the help
    # command to show short-vs-full summaries.
    COMMON = False

    # Whether this command supports running in parallel. If greater than 0,
    # it is the number of parallel jobs to default to.
    PARALLEL_JOBS = None

    # Whether this command supports Multi-manifest. If False, then main.py will
    # iterate over the manifests and invoke the command once per (sub)manifest.
    # This is only checked after calling ValidateOptions, so that partially
    # migrated subcommands can set it to False.
    MULTI_MANIFEST_SUPPORT = True

    def __init__(
        self,
        repodir=None,
        client=None,
        manifest=None,
        git_event_log=None,
        outer_client=None,
        outer_manifest=None,
    ):
        self.repodir = repodir
        self.client = client
        self.outer_client = outer_client or client
        self.manifest = manifest
        self.git_event_log = git_event_log
        self.outer_manifest = outer_manifest

        # Cache for the OptionParser property.
        self._optparse = None

    def WantPager(self, _opt):
        return False

    def ReadEnvironmentOptions(self, opts):
        """Set options from environment variables."""

        env_options = self._RegisteredEnvironmentOptions()

        for env_key, opt_key in env_options.items():
            # Get the user-set option value if any
            opt_value = getattr(opts, opt_key)

            # If the value is set, it means the user has passed it as a command
            # line option, and we should use that. Otherwise we can try to set
            # it with the value from the corresponding environment variable.
            if opt_value is not None:
                continue

            env_value = os.environ.get(env_key)
            if env_value is not None:
                setattr(opts, opt_key, env_value)

        return opts

    @property
    def OptionParser(self):
        if self._optparse is None:
            try:
                me = "repo %s" % self.NAME
                usage = self.helpUsage.strip().replace("%prog", me)
            except AttributeError:
                usage = "repo %s" % self.NAME
            epilog = (
                "Run `repo help %s` to view the detailed manual." % self.NAME
            )
            self._optparse = optparse.OptionParser(usage=usage, epilog=epilog)
            self._CommonOptions(self._optparse)
            self._Options(self._optparse)
        return self._optparse

    def _CommonOptions(self, p, opt_v=True):
        """Initialize the option parser with common options.

        These will show up for *all* subcommands, so use sparingly.
        NB: Keep in sync with repo:InitParser().
        """
        g = p.add_option_group("Logging options")
        opts = ["-v"] if opt_v else []
        g.add_option(
            *opts,
            "--verbose",
            dest="output_mode",
            action="store_true",
            help="show all output",
        )
        g.add_option(
            "-q",
            "--quiet",
            dest="output_mode",
            action="store_false",
            help="only show errors",
        )

        if self.PARALLEL_JOBS is not None:
            default = "based on number of CPU cores"
            if not GENERATE_MANPAGES:
                # Only include active cpu count if we aren't generating man
                # pages.
                default = f"%default; {default}"
            p.add_option(
                "-j",
                "--jobs",
                type=int,
                default=self.PARALLEL_JOBS,
                help=f"number of jobs to run in parallel (default: {default})",
            )

        m = p.add_option_group("Multi-manifest options")
        m.add_option(
            "--outer-manifest",
            action="store_true",
            default=None,
            help="operate starting at the outermost manifest",
        )
        m.add_option(
            "--no-outer-manifest",
            dest="outer_manifest",
            action="store_false",
            help="do not operate on outer manifests",
        )
        m.add_option(
            "--this-manifest-only",
            action="store_true",
            default=None,
            help="only operate on this (sub)manifest",
        )
        m.add_option(
            "--no-this-manifest-only",
            "--all-manifests",
            dest="this_manifest_only",
            action="store_false",
            help="operate on this manifest and its submanifests",
        )

    def _Options(self, p):
        """Initialize the option parser with subcommand-specific options."""

    def _RegisteredEnvironmentOptions(self):
        """Get options that can be set from environment variables.

        Return a dictionary mapping environment variable name
        to option key name that it can override.

        Example: {'REPO_MY_OPTION': 'my_option'}

        Will allow the option with key value 'my_option' to be set
        from the value in the environment variable named 'REPO_MY_OPTION'.

        Note: This does not work properly for options that are explicitly
        set to None by the user, or options that are defined with a
        default value other than None.

        """
        return {}

    def Usage(self):
        """Display usage and terminate."""
        self.OptionParser.print_usage()
        raise UsageError()

    def CommonValidateOptions(self, opt, args):
        """Validate common options."""
        opt.quiet = opt.output_mode is False
        opt.verbose = opt.output_mode is True
        if opt.outer_manifest is None:
            # By default, treat multi-manifest instances as a single manifest
            # from the user's perspective.
            opt.outer_manifest = True

    def ValidateOptions(self, opt, args):
        """Validate the user options & arguments before executing.

        This is meant to help break the code up into logical steps. Some tips:
        * Use self.OptionParser.error to display CLI related errors.
        * Adjust opt member defaults as makes sense.
        * Adjust the args list, but do so inplace so the caller sees updates.
        * Try to avoid updating self state. Leave that to Execute.
        """

    def Execute(self, opt, args):
        """Perform the action, after option parsing is complete."""
        raise NotImplementedError

    @staticmethod
    def ExecuteInParallel(
        jobs, func, inputs, callback, output=None, ordered=False
    ):
        """Helper for managing parallel execution boiler plate.

        For subcommands that can easily split their work up.

        Args:
            jobs: How many parallel processes to use.
            func: The function to apply to each of the |inputs|. Usually a
                functools.partial for wrapping additional arguments. It will be
                run in a separate process, so it must be pickalable, so nested
                functions won't work. Methods on the subcommand Command class
                should work.
            inputs: The list of items to process. Must be a list.
            callback: The function to pass the results to for processing. It
                will be executed in the main thread and process the results of
                |func| as they become available. Thus it may be a local nested
                function. Its return value is passed back directly. It takes
                three arguments:
                - The processing pool (or None with one job).
                - The |output| argument.
                - An iterator for the results.
            output: An output manager. May be progress.Progess or
                color.Coloring.
            ordered: Whether the jobs should be processed in order.

        Returns:
            The |callback| function's results are returned.
        """
        try:
            # NB: Multiprocessing is heavy, so don't spin it up for one job.
            if len(inputs) == 1 or jobs == 1:
                return callback(None, output, (func(x) for x in inputs))
            else:
                with multiprocessing.Pool(jobs) as pool:
                    submit = pool.imap if ordered else pool.imap_unordered
                    return callback(
                        pool,
                        output,
                        submit(func, inputs, chunksize=WORKER_BATCH_SIZE),
                    )
        finally:
            if isinstance(output, progress.Progress):
                output.end()

    def _ResetPathToProjectMap(self, projects):
        self._by_path = {p.worktree: p for p in projects}

    def _UpdatePathToProjectMap(self, project):
        self._by_path[project.worktree] = project

    def _GetProjectByPath(self, manifest, path):
        project = None
        if os.path.exists(path):
            oldpath = None
            while path and path != oldpath and path != manifest.topdir:
                try:
                    project = self._by_path[path]
                    break
                except KeyError:
                    oldpath = path
                    path = os.path.dirname(path)
            if not project and path == manifest.topdir:
                try:
                    project = self._by_path[path]
                except KeyError:
                    pass
        else:
            try:
                project = self._by_path[path]
            except KeyError:
                pass
        return project

    def GetProjects(
        self,
        args,
        manifest=None,
        groups="",
        missing_ok=False,
        submodules_ok=False,
        all_manifests=False,
    ):
        """A list of projects that match the arguments.

        Args:
            args: a list of (case-insensitive) strings, projects to search for.
            manifest: an XmlManifest, the manifest to use, or None for default.
            groups: a string, the manifest groups in use.
            missing_ok: a boolean, whether to allow missing projects.
            submodules_ok: a boolean, whether to allow submodules.
            all_manifests: a boolean, if True then all manifests and
                submanifests are used. If False, then only the local
                (sub)manifest is used.

        Returns:
            A list of matching Project instances.
        """
        if all_manifests:
            if not manifest:
                manifest = self.manifest.outer_client
            all_projects_list = manifest.all_projects
        else:
            if not manifest:
                manifest = self.manifest
            all_projects_list = manifest.projects
        result = []

        if not groups:
            groups = manifest.GetGroupsStr()
        groups = [x for x in re.split(r"[,\s]+", groups) if x]

        if not args:
            derived_projects = {}
            for project in all_projects_list:
                if submodules_ok or project.sync_s:
                    derived_projects.update(
                        (p.name, p) for p in project.GetDerivedSubprojects()
                    )
            all_projects_list.extend(derived_projects.values())
            for project in all_projects_list:
                if (missing_ok or project.Exists) and project.MatchesGroups(
                    groups
                ):
                    result.append(project)
        else:
            self._ResetPathToProjectMap(all_projects_list)

            for arg in args:
                # We have to filter by manifest groups in case the requested
                # project is checked out multiple times or differently based on
                # them.
                projects = [
                    project
                    for project in manifest.GetProjectsWithName(
                        arg, all_manifests=all_manifests
                    )
                    if project.MatchesGroups(groups)
                ]

                if not projects:
                    path = os.path.abspath(arg).replace("\\", "/")
                    tree = manifest
                    if all_manifests:
                        # Look for the deepest matching submanifest.
                        for tree in reversed(list(manifest.all_manifests)):
                            if path.startswith(tree.topdir):
                                break
                    project = self._GetProjectByPath(tree, path)

                    # If it's not a derived project, update path->project
                    # mapping and search again, as arg might actually point to
                    # a derived subproject.
                    if (
                        project
                        and not project.Derived
                        and (submodules_ok or project.sync_s)
                    ):
                        search_again = False
                        for subproject in project.GetDerivedSubprojects():
                            self._UpdatePathToProjectMap(subproject)
                            search_again = True
                        if search_again:
                            project = (
                                self._GetProjectByPath(manifest, path)
                                or project
                            )

                    if project:
                        projects = [project]

                if not projects:
                    raise NoSuchProjectError(arg)

                for project in projects:
                    if not missing_ok and not project.Exists:
                        raise NoSuchProjectError(
                            "%s (%s)"
                            % (arg, project.RelPath(local=not all_manifests))
                        )
                    if not project.MatchesGroups(groups):
                        raise InvalidProjectGroupsError(arg)

                result.extend(projects)

        def _getpath(x):
            return x.relpath

        result.sort(key=_getpath)
        return result

    def FindProjects(self, args, inverse=False, all_manifests=False):
        """Find projects from command line arguments.

        Args:
            args: a list of (case-insensitive) strings, projects to search for.
            inverse: a boolean, if True, then projects not matching any |args|
                are returned.
            all_manifests: a boolean, if True then all manifests and
                submanifests are used. If False, then only the local
                (sub)manifest is used.
        """
        result = []
        patterns = [re.compile(r"%s" % a, re.IGNORECASE) for a in args]
        for project in self.GetProjects("", all_manifests=all_manifests):
            paths = [project.name, project.RelPath(local=not all_manifests)]
            for pattern in patterns:
                match = any(pattern.search(x) for x in paths)
                if not inverse and match:
                    result.append(project)
                    break
                if inverse and match:
                    break
            else:
                if inverse:
                    result.append(project)
        result.sort(
            key=lambda project: (project.manifest.path_prefix, project.relpath)
        )
        return result

    def ManifestList(self, opt):
        """Yields all of the manifests to traverse.

        Args:
            opt: The command options.
        """
        top = self.outer_manifest
        if not opt.outer_manifest or opt.this_manifest_only:
            top = self.manifest
        yield top
        if not opt.this_manifest_only:
            yield from top.all_children


class InteractiveCommand(Command):
    """Command which requires user interaction on the tty and must not run
    within a pager, even if the user asks to.
    """

    def WantPager(self, _opt):
        return False


class PagedCommand(Command):
    """Command which defaults to output in a pager, as its display tends to be
    larger than one screen full.
    """

    def WantPager(self, _opt):
        return True


class MirrorSafeCommand:
    """Command permits itself to run within a mirror, and does not require a
    working directory.
    """


class GitcClientCommand:
    """Command that requires the local client to be a GITC client."""