#!/usr/bin/env python3
import logging
import os
import subprocess
import sys

ZULIP_PATH = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
sys.path.insert(0, ZULIP_PATH)

from scripts.lib.setup_path import setup_path
from scripts.lib.zulip_tools import (
    DEPLOYMENTS_DIR,
    assert_not_running_as_root,
    get_config,
    get_config_file,
    parse_version_from,
)
from version import ZULIP_VERSION as NEW_VERSION

assert_not_running_as_root()
setup_path()
os.environ["DJANGO_SETTINGS_MODULE"] = "zproject.settings"

import django
from django.db import connection
from django.db.migrations.loader import MigrationLoader

from zerver.lib.migration_status import STALE_MIGRATIONS

django.setup()

django_pg_version = connection.cursor().connection.server_version // 10000
if os.path.exists("/etc/init.d/postgresql") and os.path.exists("/etc/zulip/zulip.conf"):
    postgresql_version = int(get_config(get_config_file(), "postgresql", "version", "0"))
    if postgresql_version == 0:
        postgresql_version = django_pg_version
        subprocess.check_call(
            [
                "crudini",
                "--set",
                "/etc/zulip/zulip.conf",
                "postgresql",
                "version",
                str(postgresql_version),
            ]
        )
    elif postgresql_version != django_pg_version:
        logging.critical(
            "PostgreSQL version mismatch: %d (running) vs %d (configured)",
            django_pg_version,
            postgresql_version,
        )
        logging.info(
            "/etc/zulip/zulip.conf claims that Zulip is running PostgreSQL\n"
            "%d, but the server is connected to a PostgreSQL running\n"
            "version %d.  Check the output from pg_lsclusters to verify\n"
            "which clusters are running, and update /etc/zulip/zulip.conf to match.\n"
            "\n"
            "In general, this results from manually upgrading PostgreSQL; you\n"
            "should follow our instructions for using our tool to do so:\n"
            "https://zulip.readthedocs.io/en/stable/production/upgrade.html#upgrading-postgresql",
            postgresql_version,
            django_pg_version,
        )
        sys.exit(1)

if django_pg_version < 13:
    logging.critical("Unsupported PostgreSQL version: %d", postgresql_version)
    logging.info(
        "Please upgrade to PostgreSQL 13 or newer first.\n"
        "See https://zulip.readthedocs.io/en/stable/production/"
        "upgrade.html#upgrading-postgresql"
    )
    sys.exit(1)

loader = MigrationLoader(connection)
missing = set(loader.applied_migrations)

missing.difference_update(STALE_MIGRATIONS)

for key, migration in loader.disk_migrations.items():
    missing.discard(key)
    missing.difference_update(migration.replaces)
if not missing:
    sys.exit(0)

print("Migrations which are currently applied, but missing in the new version:")
for app, migration_name in sorted(missing):
    print(f"  {app} - {migration_name}")

current_version = parse_version_from(os.path.join(DEPLOYMENTS_DIR, "current"))
logging.error(
    "This is not an upgrade -- the current deployment (version %s) "
    "contains %s database migrations which %s (version %s) does not.",
    current_version,
    len(missing),
    ZULIP_PATH,
    NEW_VERSION,
)
sys.exit(1)