"""Публикация отчётов отделом и видимость по месяцам."""
from __future__ import annotations

import re

from django.utils import timezone

from apps.reports.it_monthly.builder import (
    available_report_months,
    month_id,
    user_can_manage_it_monthly_report,
    user_can_view_all_department_reports,
    user_can_view_it_monthly_report,
)
from apps.reports.models import ReportPublication


def get_publication(
    report_type: str,
    department_id: int,
    year: int,
    month: int,
) -> ReportPublication | None:
    if not department_id:
        return None
    return ReportPublication.objects.filter(
        report_type=report_type,
        department_id=department_id,
        year=year,
        month=month,
    ).first()


def is_month_published(
    report_type: str,
    year: int,
    month: int,
    *,
    department_id: int | None = None,
) -> bool:
    qs = ReportPublication.objects.filter(
        report_type=report_type,
        year=year,
        month=month,
        status=ReportPublication.STATUS_PUBLISHED,
    )
    if department_id is not None:
        qs = qs.filter(department_id=department_id)
    return qs.exists()


def published_month_ids(
    report_type: str,
    *,
    department_id: int | None = None,
    limit: int = 24,
) -> list[str]:
    qs = ReportPublication.objects.filter(
        report_type=report_type,
        status=ReportPublication.STATUS_PUBLISHED,
    )
    if department_id is not None:
        qs = qs.filter(department_id=department_id)
    rows = qs.order_by('-year', '-month').values_list('year', 'month')[:limit]
    return [month_id(y, m) for y, m in rows]


def available_months_for_user(user, report_type: str = ReportPublication.REPORT_IT_MONTHLY) -> list[str]:
    """Месяцы в селекторе: руководитель — все из журнала; остальные — только опубликованные."""
    if user_can_manage_it_monthly_report(user):
        return available_report_months()
    if user_can_view_all_department_reports(user):
        return published_month_ids(report_type)
    dept_id = getattr(user, 'department_id', None)
    if not dept_id:
        return []
    return published_month_ids(report_type, department_id=dept_id)


def user_can_access_it_monthly_month(user, year: int, month: int) -> bool:
    if not user_can_view_it_monthly_report(user):
        return False
    if user_can_manage_it_monthly_report(user):
        return True
    if user_can_view_all_department_reports(user):
        return is_month_published(ReportPublication.REPORT_IT_MONTHLY, year, month)
    dept_id = getattr(user, 'department_id', None)
    if not dept_id:
        return False
    return is_month_published(
        ReportPublication.REPORT_IT_MONTHLY, year, month, department_id=dept_id,
    )


def publication_for_user_month(user, year: int, month: int) -> ReportPublication | None:
    """Публикация своего отдела (для кнопки руководителя / бейджа)."""
    dept_id = getattr(user, 'department_id', None)
    if not dept_id:
        return None
    return get_publication(ReportPublication.REPORT_IT_MONTHLY, dept_id, year, month)


def publish_it_monthly(user, year: int, month: int) -> ReportPublication:
    dept_id = getattr(user, 'department_id', None)
    if not dept_id:
        raise ValueError('У пользователя не указан отдел.')
    if not user_can_manage_it_monthly_report(user):
        raise PermissionError('Публиковать может только руководитель отдела.')
    now = timezone.now()
    pub, _created = ReportPublication.objects.update_or_create(
        report_type=ReportPublication.REPORT_IT_MONTHLY,
        department_id=dept_id,
        year=year,
        month=month,
        defaults={
            'status': ReportPublication.STATUS_PUBLISHED,
            'published_at': now,
            'published_by': user,
        },
    )
    return pub


def unpublish_it_monthly(user, year: int, month: int) -> None:
    dept_id = getattr(user, 'department_id', None)
    if not dept_id:
        raise ValueError('У пользователя не указан отдел.')
    if not user_can_manage_it_monthly_report(user):
        raise PermissionError('Снимать публикацию может только руководитель отдела.')
    ReportPublication.objects.filter(
        report_type=ReportPublication.REPORT_IT_MONTHLY,
        department_id=dept_id,
        year=year,
        month=month,
    ).update(
        status=ReportPublication.STATUS_DRAFT,
        published_at=None,
        published_by=None,
    )


def parse_source_month(source_month: str) -> tuple[int, int] | None:
    raw = (source_month or '').strip()
    m = re.fullmatch(r'(\d{4})-(\d{2})', raw)
    if not m:
        return None
    year, month = int(m.group(1)), int(m.group(2))
    if not (1 <= month <= 12):
        return None
    return year, month


def published_snapshot_for_month(
    *,
    department_id: int,
    year: int,
    month: int,
):
    """Опубликованный Word-снимок месяца (если есть)."""
    from apps.reports.models import ReportDocument

    mid = month_id(year, month)
    return (
        ReportDocument.objects
        .filter(
            department_id=department_id,
            kind=ReportDocument.KIND_SNAPSHOT,
            source_month=mid,
            status=ReportDocument.STATUS_PUBLISHED,
        )
        .order_by('-published_at', '-id')
        .first()
    )


def sync_month_publication_from_snapshot(user, doc) -> None:
    """Публикация Word-снимка → флаг месяца; снятие → снять месяц, если нет других снимков."""
    from apps.reports.models import ReportDocument

    if getattr(doc, 'kind', None) != ReportDocument.KIND_SNAPSHOT:
        return
    parsed = parse_source_month(getattr(doc, 'source_month', '') or '')
    if not parsed:
        return
    year, month = parsed
    dept_id = doc.department_id
    if not dept_id:
        return

    if doc.is_published:
        now = timezone.now()
        ReportPublication.objects.update_or_create(
            report_type=ReportPublication.REPORT_IT_MONTHLY,
            department_id=dept_id,
            year=year,
            month=month,
            defaults={
                'status': ReportPublication.STATUS_PUBLISHED,
                'published_at': now,
                'published_by': user,
            },
        )
        return

    still_published = ReportDocument.objects.filter(
        department_id=dept_id,
        kind=ReportDocument.KIND_SNAPSHOT,
        source_month=month_id(year, month),
        status=ReportDocument.STATUS_PUBLISHED,
    ).exclude(pk=doc.pk).exists()
    if still_published:
        return
    ReportPublication.objects.filter(
        report_type=ReportPublication.REPORT_IT_MONTHLY,
        department_id=dept_id,
        year=year,
        month=month,
    ).update(
        status=ReportPublication.STATUS_DRAFT,
        published_at=None,
        published_by=None,
    )


def unpublish_month_and_snapshots(user, year: int, month: int) -> None:
    """Снять месяц и все Word-снимки этого периода отдела."""
    from apps.reports.models import ReportDocument

    unpublish_it_monthly(user, year, month)
    dept_id = user.department_id
    ReportDocument.objects.filter(
        department_id=dept_id,
        kind=ReportDocument.KIND_SNAPSHOT,
        source_month=month_id(year, month),
        status=ReportDocument.STATUS_PUBLISHED,
    ).update(
        status=ReportDocument.STATUS_DRAFT,
        published_at=None,
        published_by=None,
    )


def report_list_rows(user) -> list[dict]:
    """Строки списка на /reports/: отчёт, отдел, период, статус публикации."""
    from apps.reports.registry import visible_reports

    dept_labels = {'it': 'IT-отдел'}
    can_manage = user_can_manage_it_monthly_report(user)
    can_all = user_can_view_all_department_reports(user)
    rows = []
    for spec in visible_reports(user):
        months = available_months_for_user(user, spec.code)
        dept_id = None if can_all else getattr(user, 'department_id', None)
        published = published_month_ids(spec.code, department_id=dept_id)
        latest_published = published[0] if published else ''
        latest_available = months[0] if months else ''
        if latest_published:
            status = 'published'
            status_label = 'Опубликован'
        elif can_manage:
            status = 'draft'
            status_label = 'Черновик'
        else:
            status = 'empty'
            status_label = 'Нет публикаций'
        rows.append({
            'code': spec.code,
            'title': spec.title,
            'description': spec.description,
            'path': spec.path,
            'department': spec.department,
            'department_label': dept_labels.get(spec.department, spec.department),
            'latest_month': latest_published or latest_available,
            'status': status,
            'status_label': status_label,
            'published_count': len(published),
        })
    return rows