# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at https://mozilla.org/MPL/2.0/.

from datetime import datetime
from os import getenv
from subprocess import CalledProcessError

from django.conf import settings
from django.core.management.base import CommandError
from django.template.defaultfilters import slugify
from django.utils.functional import cached_property

from dirsync import sync

from bedrock.utils import github

from ._ftl_repo_base import FTLRepoCommand

GIT_HASH = getenv("GIT_SHA", None)


class Command(FTLRepoCommand):
    help = "Open a pull-request on the L10n Team's repo for FTL file changes"
    branch_prefix = "update-from-bedrock"
    open_branch = None
    open_pr_url = None
    github = None

    def __init__(self, stdout=None, stderr=None, no_color=False, force_color=False):
        client = github.get_client()
        if client:
            self.github = client.get_repo(settings.FLUENT_L10N_TEAM_REPO)

        super().__init__(stdout, stderr, no_color, force_color)

    def handle(self, *args, **options):
        super().handle(*args, **options)
        self.get_open_pr()
        self.update_l10n_team_files()
        self.create_branch()
        self.sync_dirs()
        changed = self.commit_changes()
        if changed:
            self.push_changes()
            self.open_pr()

    @cached_property
    def branch_name(self):
        if self.open_branch:
            return self.open_branch

        if GIT_HASH:
            branch_suffix = GIT_HASH[:8]
        else:
            branch_suffix = slugify(datetime.now().isoformat())

        return f"{self.branch_prefix}-{branch_suffix}"

    @property
    def commit_message(self):
        message = "Updates from bedrock\n\n"
        if GIT_HASH:
            message += f"From file changes in https://github.com/mozilla/bedrock/commit/{GIT_HASH}"
        else:
            message += "From file changes in https://github.com/mozilla/bedrock/commits/main"

        return message

    def sync_dirs(self):
        sync(settings.FLUENT_LOCAL_PATH, self.l10n_repo.path, "sync", content=True)

    def create_branch(self):
        if self.open_branch:
            self.stdout.write(f"Using existing branch: {self.branch_name}")
        else:
            self.l10n_repo.git("checkout", "-b", self.branch_name)
            self.stdout.write(f"Created branch: {self.branch_name}")

    def commit_changes(self):
        self.config_git()
        self.l10n_repo.git("add", ".")

        try:
            self.l10n_repo.git("commit", "-m", self.commit_message)
        except CalledProcessError:
            self.stdout.write("No changes to commit")
            return False

        self.stdout.write("Committed changes to local repo")
        return True

    def push_changes(self):
        try:
            result = self.l10n_repo.git("push", self.git_push_url, f"HEAD:{self.branch_name}")
            self.stdout.write(result)
        except CalledProcessError as cpe:
            raise CommandError(f"There was a problem pushing to {self.l10n_repo.remote_url}: {cpe}\n{cpe.output}")

        commit = self.l10n_repo.git("rev-parse", "--short", "HEAD")
        self.stdout.write(f"Pushed {commit} to {self.l10n_repo.remote_url} as {self.branch_name}")

    @property
    def git_push_url(self):
        if not settings.FLUENT_REPO_AUTH:
            raise CommandError("Git push authentication not configured")

        return self.l10n_repo.remote_url_auth(settings.FLUENT_REPO_AUTH)

    def get_open_pr(self):
        if self.github is None:
            return

        for pr in self.github.get_pulls(state="open"):
            if pr.head.ref.startswith(self.branch_prefix):
                self.open_branch = pr.head.ref
                self.open_pr_url = pr.html_url
                self.l10n_repo.branch_name = self.open_branch
                return

    def open_pr(self):
        if self.github is None:
            return

        if self.open_branch:
            self.stdout.write(f"Updated existing pull-request: {self.open_pr_url}")
            return

        title, body = self.commit_message.split("\n\n")
        pr = self.github.create_pull(
            title=title,
            body=body,
            base=self.l10n_repo.branch_name,
            head=self.branch_name,
        )
        self.stdout.write(f"Opened a pull-request: {pr.html_url}")