"""初始化完整财务数据：科目 + 期间。"""

from django.core.management.base import BaseCommand
from datetime import date

from apps.core.models import Tenant
from apps.finance import services as fs
from apps.finance.models import Period


class Command(BaseCommand):
    help = "初始化完整财务：会计科目 + 当月会计期间（往前往后各 3 个月）"

    def add_arguments(self, parser):
        parser.add_argument(
            "--back", type=int, default=3, help="往前几个月"
        )
        parser.add_argument(
            "--forward", type=int, default=3, help="往后几个月"
        )

    def handle(self, *args, **options):
        back = options["back"]
        forward = options["forward"]

        for tenant in Tenant.objects.filter(is_active=True):
            # 会计科目
            n_acc = fs.init_chart_of_accounts(tenant)
            self.stdout.write(f"[{tenant.code}] 科目 +{n_acc} 条")

            # 期间：往前往后
            today = date.today()
            cur = today
            for _ in range(back):
                cur = _prev_month(cur)
            n_p = fs.ensure_periods(tenant, cur, today)
            cur = today
            for _ in range(forward):
                cur = _next_month(cur)
            n_p += fs.ensure_periods(tenant, today, cur)
            self.stdout.write(f"[{tenant.code}] 期间新增 +{n_p} 个（{today} ± {back}/{forward} 月）")

        self.stdout.write(self.style.SUCCESS("\n完整财务数据初始化完成"))


def _prev_month(d):
    if d.month == 1:
        return d.replace(year=d.year - 1, month=12, day=1)
    return d.replace(month=d.month - 1, day=1)


def _next_month(d):
    if d.month == 12:
        return d.replace(year=d.year + 1, month=1, day=1)
    return d.replace(month=d.month + 1, day=1)