from fastapi import APIRouter, Query
from typing import Optional
from sqlalchemy import func
import json
import hashlib

from bd import make_engine
from bd.tables.response import Response
from bd.tables.poll import Poll
from bd.tables.group import Group
from bd.tables.organization import Organization
from bd.tables.radar_result import RadarResult, RadarResultItem
from bd.tables.users import User
from redis_db import cache_get, cache_set

router = APIRouter(tags=["stats"], prefix="/stats")

_MONTH_NAMES = ["Янв", "Фев", "Мар", "Апр", "Май", "Июн",
                "Июл", "Авг", "Сен", "Окт", "Ноя", "Дек"]

_CACHE_TTL = 300  # 5 минут


def _cache_key(*parts) -> str:
    raw = ":".join(str(p) for p in parts)
    return hashlib.md5(raw.encode()).hexdigest()


def get_session():
    from sqlalchemy.orm import sessionmaker
    return sessionmaker(bind=make_engine(), future=True)


@router.get("/summary")
def get_summary():
    """Общая сводка: кол-во ответов, тестов, активных тестов, организаций с активностью."""
    key = _cache_key("summary")
    cached = cache_get(key)
    if cached:
        return json.loads(cached)

    Session = get_session()
    with Session() as session:
        total_responses = session.query(func.count(Response.id)).scalar() or 0
        total_polls = session.query(func.count(Poll.id)).scalar() or 0
        active_polls = session.query(func.count(Poll.id)).filter(Poll.is_active.is_(True)).scalar() or 0
        orgs_active = session.query(func.count(func.distinct(Response.organization_id))).scalar() or 0
    result = {
        "total_responses": total_responses,
        "total_polls": total_polls,
        "active_polls": active_polls,
        "orgs_active": orgs_active,
    }
    cache_set(key, json.dumps(result), _CACHE_TTL)
    return result


@router.get("/years")
def get_years():
    """Список лет, в которых есть хотя бы один ответ."""
    key = _cache_key("years")
    cached = cache_get(key)
    if cached:
        return json.loads(cached)
    Session = get_session()
    with Session() as session:
        rows = session.query(
            func.extract("year", Response.submitted_at).label("yr")
        ).distinct().order_by("yr").all()
    result = [int(r.yr) for r in rows if r.yr is not None]
    cache_set(key, json.dumps(result), _CACHE_TTL)
    return result


@router.get("/responses")
def get_responses_grouped(
    group_by: str = Query("poll", pattern="^(poll|organization|group|month)$"),
    poll_id: Optional[str] = None,
    org_id: Optional[str] = None,
    group_id: Optional[str] = None,
    year: Optional[int] = None,
):
    """
    Возвращает агрегированные данные для графиков.

    - group_by=poll         → количество ответов по каждому тесту
    - group_by=organization → количество ответов по каждой организации
    - group_by=group        → количество ответов по каждой группе
    - group_by=month        → количество ответов по месяцам (хронологически)

    Все фильтры опциональны и комбинируются.
    """
    key = _cache_key("responses", group_by, poll_id, org_id, group_id, year)
    cached = cache_get(key)
    if cached:
        return json.loads(cached)

    Session = get_session()
    result = []
    with Session() as session:

        if group_by == "poll":
            q = session.query(Poll.title, func.count(Response.id).label("cnt"))
            q = q.join(Response, Poll.id == Response.poll_id)
            if org_id:
                q = q.filter(Response.organization_id == org_id)
            if group_id:
                q = q.filter(Response.group_id == group_id)
            if year:
                q = q.filter(func.extract("year", Response.submitted_at) == year)
            if poll_id:
                q = q.filter(Response.poll_id == poll_id)
            rows = q.group_by(Poll.title).order_by(func.count(Response.id).desc()).limit(20).all()
            result = [{"label": r[0], "count": r[1]} for r in rows]

        elif group_by == "organization":
            q = session.query(Organization.name_organization, func.count(Response.id).label("cnt"))
            q = q.outerjoin(Response, Organization.id == Response.organization_id)
            if poll_id:
                q = q.filter(Response.poll_id == poll_id)
            if group_id:
                q = q.filter(Response.group_id == group_id)
            if year:
                q = q.filter(func.extract("year", Response.submitted_at) == year)
            rows = q.group_by(Organization.name_organization).order_by(
                func.count(Response.id).desc()
            ).limit(20).all()
            result = [{"label": r[0], "count": r[1] or 0} for r in rows]

        elif group_by == "group":
            q = session.query(Group.name_group, func.count(Response.id).label("cnt"))
            q = q.outerjoin(Response, Group.id == Response.group_id)
            if poll_id:
                q = q.filter(Response.poll_id == poll_id)
            if org_id:
                q = q.filter(Response.organization_id == org_id)
            if year:
                q = q.filter(func.extract("year", Response.submitted_at) == year)
            rows = q.group_by(Group.name_group).order_by(
                func.count(Response.id).desc()
            ).limit(20).all()
            result = [{"label": r[0], "count": r[1] or 0} for r in rows]

        elif group_by == "month":
            yr_col = func.extract("year", Response.submitted_at).label("yr")
            mo_col = func.extract("month", Response.submitted_at).label("mo")
            q = session.query(yr_col, mo_col, func.count(Response.id).label("cnt"))
            if poll_id:
                q = q.filter(Response.poll_id == poll_id)
            if org_id:
                q = q.filter(Response.organization_id == org_id)
            if group_id:
                q = q.filter(Response.group_id == group_id)
            if year:
                q = q.filter(func.extract("year", Response.submitted_at) == year)
            rows = q.group_by("yr", "mo").order_by("yr", "mo").all()
            result = [
                {
                    "label": f"{_MONTH_NAMES[int(r.mo) - 1]} {int(r.yr)}",
                    "count": r.cnt,
                }
                for r in rows
            ]

    cache_set(key, json.dumps(result), _CACHE_TTL)
    return result


# ---------------------------------------------------------------------------
# Эндпоинты по результатам (RadarResultItem)
# ---------------------------------------------------------------------------

@router.get("/results/avg-by-dimension")
def get_avg_by_dimension(
    poll_id: Optional[str] = None,
    org_id: Optional[str] = None,
    group_id: Optional[str] = None,
    year: Optional[int] = None,
):
    """Средний балл по каждой оси/типу."""
    key = _cache_key("avg_dim", poll_id, org_id, group_id, year)
    cached = cache_get(key)
    if cached:
        return json.loads(cached)

    Session = get_session()
    with Session() as session:
        q = (
            session.query(
                RadarResultItem.dimension_name,
                func.avg(RadarResultItem.value).label("avg"),
                func.count(RadarResultItem.id).label("cnt"),
            )
            .join(RadarResult, RadarResultItem.result_id == RadarResult.id)
            .join(Response, RadarResult.response_id == Response.id)
        )
        if poll_id:
            q = q.filter(Response.poll_id == poll_id)
        if org_id:
            q = q.filter(Response.organization_id == org_id)
        if group_id:
            q = q.filter(Response.group_id == group_id)
        if year:
            q = q.filter(func.extract("year", Response.submitted_at) == year)
        rows = q.group_by(RadarResultItem.dimension_name).order_by(func.avg(RadarResultItem.value).desc()).all()
        result = [{"label": r[0], "avg": round(float(r[1]), 2), "count": r[2]} for r in rows]

    cache_set(key, json.dumps(result), _CACHE_TTL)
    return result


@router.get("/results/leading-type")
def get_leading_type(
    poll_id: Optional[str] = None,
    org_id: Optional[str] = None,
    group_id: Optional[str] = None,
    year: Optional[int] = None,
):
    """Распределение ведущего типа: у скольких прохождений данная ось оказалась максимальной."""
    key = _cache_key("leading", poll_id, org_id, group_id, year)
    cached = cache_get(key)
    if cached:
        return json.loads(cached)

    Session = get_session()
    with Session() as session:
        max_subq = (
            session.query(
                RadarResultItem.result_id,
                func.max(RadarResultItem.value).label("max_val"),
            )
            .join(RadarResult, RadarResultItem.result_id == RadarResult.id)
            .join(Response, RadarResult.response_id == Response.id)
        )
        if poll_id:
            max_subq = max_subq.filter(Response.poll_id == poll_id)
        if org_id:
            max_subq = max_subq.filter(Response.organization_id == org_id)
        if group_id:
            max_subq = max_subq.filter(Response.group_id == group_id)
        if year:
            max_subq = max_subq.filter(func.extract("year", Response.submitted_at) == year)
        max_subq = max_subq.group_by(RadarResultItem.result_id).subquery()

        rows = (
            session.query(
                RadarResultItem.dimension_name,
                func.count(RadarResultItem.result_id).label("cnt"),
            )
            .join(max_subq, (RadarResultItem.result_id == max_subq.c.result_id) &
                            (RadarResultItem.value == max_subq.c.max_val))
            .group_by(RadarResultItem.dimension_name)
            .order_by(func.count(RadarResultItem.result_id).desc())
            .all()
        )
        result = [{"label": r[0], "count": r[1]} for r in rows]

    cache_set(key, json.dumps(result), _CACHE_TTL)
    return result


@router.get("/results/compare-groups")
def get_compare_groups(
    dimension_name: str,
    poll_id: Optional[str] = None,
    year: Optional[int] = None,
    by: str = Query("organization", pattern="^(organization|group)$"),
):
    """Средний балл по выбранной оси в разбивке по организациям или группам."""
    key = _cache_key("compare_groups", dimension_name, poll_id, year, by)
    cached = cache_get(key)
    if cached:
        return json.loads(cached)

    Session = get_session()
    with Session() as session:
        if by == "organization":
            label_col = Organization.name_organization
            q = (
                session.query(label_col, func.avg(RadarResultItem.value).label("avg"))
                .join(RadarResult, RadarResultItem.result_id == RadarResult.id)
                .join(Response, RadarResult.response_id == Response.id)
                .join(Organization, Response.organization_id == Organization.id)
                .filter(RadarResultItem.dimension_name == dimension_name)
            )
        else:
            label_col = Group.name_group
            q = (
                session.query(label_col, func.avg(RadarResultItem.value).label("avg"))
                .join(RadarResult, RadarResultItem.result_id == RadarResult.id)
                .join(Response, RadarResult.response_id == Response.id)
                .join(Group, Response.group_id == Group.id)
                .filter(RadarResultItem.dimension_name == dimension_name)
            )
        if poll_id:
            q = q.filter(Response.poll_id == poll_id)
        if year:
            q = q.filter(func.extract("year", Response.submitted_at) == year)
        rows = q.group_by(label_col).order_by(func.avg(RadarResultItem.value).desc()).limit(20).all()
        result = [{"label": r[0], "avg": round(float(r[1]), 2)} for r in rows]

    cache_set(key, json.dumps(result), _CACHE_TTL)
    return result


@router.get("/results/top-users")
def get_top_users(
    dimension_name: str,
    poll_id: Optional[str] = None,
    org_id: Optional[str] = None,
    group_id: Optional[str] = None,
    year: Optional[int] = None,
    limit: int = Query(10, ge=1, le=50),
):
    """Топ-N прохождений с наибольшим баллом по выбранной оси."""
    key = _cache_key("top_users", dimension_name, poll_id, org_id, group_id, year, limit)
    cached = cache_get(key)
    if cached:
        return json.loads(cached)

    Session = get_session()
    with Session() as session:
        q = (
            session.query(
                User.last_name,
                User.first_name,
                Poll.title,
                RadarResultItem.value,
            )
            .join(RadarResult, RadarResultItem.result_id == RadarResult.id)
            .join(Response, RadarResult.response_id == Response.id)
            .join(Poll, Response.poll_id == Poll.id)
            .outerjoin(User, Response.user_id == User.id)
            .filter(RadarResultItem.dimension_name == dimension_name)
        )
        if poll_id:
            q = q.filter(Response.poll_id == poll_id)
        if org_id:
            q = q.filter(Response.organization_id == org_id)
        if group_id:
            q = q.filter(Response.group_id == group_id)
        if year:
            q = q.filter(func.extract("year", Response.submitted_at) == year)
        rows = q.order_by(RadarResultItem.value.desc()).limit(limit).all()
        result = [
            {
                "name": f"{r[0] or '?'} {r[1] or ''}".strip(),
                "poll": r[2],
                "value": round(float(r[3]), 2),
            }
            for r in rows
        ]

    cache_set(key, json.dumps(result), _CACHE_TTL)
    return result


@router.get("/results/dimension-trend")
def get_dimension_trend(
    dimension_name: str,
    poll_id: Optional[str] = None,
    org_id: Optional[str] = None,
    group_id: Optional[str] = None,
):
    """Динамика среднего балла по оси во времени (по месяцам)."""
    key = _cache_key("dim_trend", dimension_name, poll_id, org_id, group_id)
    cached = cache_get(key)
    if cached:
        return json.loads(cached)

    Session = get_session()
    with Session() as session:
        yr_col = func.extract("year", Response.submitted_at).label("yr")
        mo_col = func.extract("month", Response.submitted_at).label("mo")
        q = (
            session.query(yr_col, mo_col, func.avg(RadarResultItem.value).label("avg"))
            .join(RadarResult, RadarResultItem.result_id == RadarResult.id)
            .join(Response, RadarResult.response_id == Response.id)
            .filter(RadarResultItem.dimension_name == dimension_name)
        )
        if poll_id:
            q = q.filter(Response.poll_id == poll_id)
        if org_id:
            q = q.filter(Response.organization_id == org_id)
        if group_id:
            q = q.filter(Response.group_id == group_id)
        rows = q.group_by("yr", "mo").order_by("yr", "mo").all()
        result = [
            {"label": f"{_MONTH_NAMES[int(r.mo) - 1]} {int(r.yr)}", "avg": round(float(r.avg), 2)}
            for r in rows
        ]

    cache_set(key, json.dumps(result), _CACHE_TTL)
    return result


@router.get("/results/dimensions")
def get_dimensions(poll_id: Optional[str] = None):
    """Список уникальных названий осей (для выпадающего списка)."""
    key = _cache_key("dimensions", poll_id)
    cached = cache_get(key)
    if cached:
        return json.loads(cached)

    Session = get_session()
    with Session() as session:
        q = session.query(RadarResultItem.dimension_name).distinct()
        if poll_id:
            q = (
                q.join(RadarResult, RadarResultItem.result_id == RadarResult.id)
                .join(Response, RadarResult.response_id == Response.id)
                .filter(Response.poll_id == poll_id)
            )
        rows = q.order_by(RadarResultItem.dimension_name).all()
        result = [r[0] for r in rows]

    cache_set(key, json.dumps(result), _CACHE_TTL)
    return result