# 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 functools
import os
import sys

from command import Command, DEFAULT_LOCAL_JOBS
from git_config import IsImmutable
from git_command import git
import gitc_utils
from progress import Progress
from project import SyncBuffer, Project
from typing import NamedTuple
from error import RepoExitError


class ExecuteOneResult(NamedTuple):
    project: Project
    error: Exception


class StartError(RepoExitError):
    """Exit error for failed start command."""


class Start(Command):
    COMMON = True
    helpSummary = "Start a new branch for development"
    helpUsage = """
%prog <newbranchname> [--all | <project>...]
"""
    helpDescription = """
'%prog' begins a new branch of development, starting from the
revision specified in the manifest.
"""
    PARALLEL_JOBS = DEFAULT_LOCAL_JOBS

    def _Options(self, p):
        p.add_option(
            "--all",
            dest="all",
            action="store_true",
            help="begin branch in all projects",
        )
        p.add_option(
            "-r",
            "--rev",
            "--revision",
            dest="revision",
            help="point branch at this revision instead of upstream",
        )
        p.add_option(
            "--head",
            "--HEAD",
            dest="revision",
            action="store_const",
            const="HEAD",
            help="abbreviation for --rev HEAD",
        )

    def ValidateOptions(self, opt, args):
        if not args:
            self.Usage()

        nb = args[0]
        if not git.check_ref_format("heads/%s" % nb):
            self.OptionParser.error("'%s' is not a valid name" % nb)

    def _ExecuteOne(self, revision, nb, project):
        """Start one project."""
        # If the current revision is immutable, such as a SHA1, a tag or
        # a change, then we can't push back to it. Substitute with
        # dest_branch, if defined; or with manifest default revision instead.
        branch_merge = ""
        error = None
        if IsImmutable(project.revisionExpr):
            if project.dest_branch:
                branch_merge = project.dest_branch
            else:
                branch_merge = self.manifest.default.revisionExpr

        try:
            project.StartBranch(
                nb, branch_merge=branch_merge, revision=revision
            )
        except Exception as e:
            print(
                "error: unable to checkout %s: %s" % (project.name, e),
                file=sys.stderr,
            )
            error = e
        return ExecuteOneResult(project, error)

    def Execute(self, opt, args):
        nb = args[0]
        err_projects = []
        err = []
        projects = []
        if not opt.all:
            projects = args[1:]
            if len(projects) < 1:
                projects = ["."]  # start it in the local project by default

        all_projects = self.GetProjects(
            projects,
            missing_ok=bool(self.gitc_manifest),
            all_manifests=not opt.this_manifest_only,
        )

        # This must happen after we find all_projects, since GetProjects may
        # need the local directory, which will disappear once we save the GITC
        # manifest.
        if self.gitc_manifest:
            gitc_projects = self.GetProjects(
                projects, manifest=self.gitc_manifest, missing_ok=True
            )
            for project in gitc_projects:
                if project.old_revision:
                    project.already_synced = True
                else:
                    project.already_synced = False
                    project.old_revision = project.revisionExpr
                project.revisionExpr = None
            # Save the GITC manifest.
            gitc_utils.save_manifest(self.gitc_manifest)

            # Make sure we have a valid CWD.
            if not os.path.exists(os.getcwd()):
                os.chdir(self.manifest.topdir)

            pm = Progress("Syncing %s" % nb, len(all_projects), quiet=opt.quiet)
            for project in all_projects:
                gitc_project = self.gitc_manifest.paths[project.relpath]
                # Sync projects that have not been opened.
                if not gitc_project.already_synced:
                    proj_localdir = os.path.join(
                        self.gitc_manifest.gitc_client_dir, project.relpath
                    )
                    project.worktree = proj_localdir
                    if not os.path.exists(proj_localdir):
                        os.makedirs(proj_localdir)
                    project.Sync_NetworkHalf()
                    sync_buf = SyncBuffer(self.manifest.manifestProject.config)
                    project.Sync_LocalHalf(sync_buf)
                    project.revisionId = gitc_project.old_revision
                pm.update(msg="")
            pm.end()

        def _ProcessResults(_pool, pm, results):
            for result in results:
                if result.error:
                    err_projects.append(result.project)
                    err.append(result.error)
                pm.update(msg="")

        self.ExecuteInParallel(
            opt.jobs,
            functools.partial(self._ExecuteOne, opt.revision, nb),
            all_projects,
            callback=_ProcessResults,
            output=Progress(
                "Starting %s" % (nb,), len(all_projects), quiet=opt.quiet
            ),
        )

        if err_projects:
            for p in err_projects:
                print(
                    "error: %s/: cannot start %s"
                    % (p.RelPath(local=opt.this_manifest_only), nb),
                    file=sys.stderr,
                )
            msg_fmt = "cannot start %d project(s)"
            self.git_event_log.ErrorEvent(
                msg_fmt % (len(err_projects)), msg_fmt
            )
            raise StartError(aggregate_errors=err)