"""Cian.ru detail page scraper — single offer enrichment.

Different from SERP (cian.py):
- URL: https://ekb.cian.ru/sale/flat/<offer_id>/ or https://www.cian.ru/sale/flat/<offer_id>/
- MFE: 'frontend-offer-card'
- State KEY: 'defaultState' (NOT 'initialState' — SERP uses initialState)
- Sister containers in same _cianConfig: bti, priceChanges, stats, agent, newObject

Parses ~88 offer fields + sister data → DetailEnrichment dataclass.
Stage 5 of CianScraper v1.
"""

from __future__ import annotations

import json
import logging
from dataclasses import dataclass, field
from typing import Any

from curl_cffi.requests import AsyncSession
from sqlalchemy import text
from sqlalchemy.orm import Session

from app.core.config import settings
from app.services.scrapers.cian_state_parser import extract_all_states, extract_state
from app.services.scrapers.repair_state_normalizer import (
    infer_repair_state_from_text,
    normalize_repair_state,
)
from app.services.scrapers.snapshot_writer import upsert_listing_snapshot

logger = logging.getLogger(__name__)


@dataclass
class DetailEnrichment:
    """Result of cian_detail.fetch_detail() — fields для UPDATE listings + sister rows."""

    # Core listing enrichment (extend existing listings row)
    cian_id: int | None = None
    windows_view_type: str | None = None  # 'yard' / 'street' / 'yardAndStreet'
    separate_wcs_count: int | None = None
    combined_wcs_count: int | None = None
    ceiling_height: float | None = None  # meters
    repair_type: str | None = None  # 'cosmetic' / 'design' / 'no' — raw Cian value
    repair_state: str | None = None  # enum: needs_repair/standard/good/excellent
    views_total: int | None = None  # Cian stats.totalViewsFormattedString → int
    views_today: int | None = None

    # BTI (вторичка only — primary buildings don't have БТИ)
    bti_data: dict[str, Any] | None = None  # raw bti.houseData snapshot

    # Price history (offer.priceChanges)
    price_changes: list[dict[str, Any]] = field(default_factory=list)

    # Agent profile (offer.agent.* expanded)
    agent_profile: dict[str, Any] | None = None

    # Newbuilding link (if offer is from a newbuilding)
    newbuilding_data: dict[str, Any] | None = None

    # Raw payload для debugging / future-extraction
    raw_offer: dict[str, Any] | None = None
    raw_sister_states: dict[str, Any] = field(default_factory=dict)


async def fetch_detail(
    offer_url: str,
    *,
    session: AsyncSession | None = None,
) -> DetailEnrichment | None:
    """Fetch detail page and extract all containers.

    Args:
        offer_url: e.g. 'https://ekb.cian.ru/sale/flat/327830237/'
        session: optional shared curl_cffi session (для batched scrapes)

    Returns: DetailEnrichment, or None если fetch / parse failed.
    """
    close_session = False
    if session is None:
        # proxies: mobile-proxy egress (#806) — без прокси datacenter-IP блокируется Cian.
        # Пусто (env не задан) → прямое подключение (dev/no-op).
        _proxy_url = settings.scraper_proxy_url
        _proxies = {"http": _proxy_url, "https": _proxy_url} if _proxy_url else None
        session = AsyncSession(
            impersonate="chrome120",
            timeout=25.0,
            proxies=_proxies,
            headers={
                "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
                "Accept-Language": "ru-RU,ru;q=0.9,en;q=0.8",
            },
        )
        close_session = True

    try:
        resp = await session.get(offer_url, allow_redirects=True)
        if resp.status_code != 200:
            logger.warning("Cian detail fetch %s → HTTP %d", offer_url, resp.status_code)
            return None
        html = resp.text

        # Primary state container — defaultState in frontend-offer-card MFE
        # NOTE: detail pages use 'defaultState', SERP uses 'initialState'
        offer_state = extract_state(html, mfe="frontend-offer-card", key="defaultState")
        if offer_state is None:
            logger.warning("Cian detail %s: defaultState extraction failed", offer_url)
            return None

        offer_data = offer_state.get("offerData", {})
        offer = offer_data.get("offer", {})

        result = DetailEnrichment(
            cian_id=offer.get("cianId") or offer.get("id"),
            windows_view_type=_extract_windows_view(offer),
            separate_wcs_count=offer.get("separateWcsCount"),
            combined_wcs_count=offer.get("combinedWcsCount"),
            ceiling_height=_parse_float(offer.get("ceilingHeight")),
            repair_type=_extract_repair_type(offer),
            repair_state=_extract_repair_state(offer),
            raw_offer=offer,
        )

        # Stats (views) — from stats key in offerData or top-level state
        stats = offer_data.get("stats") or offer_state.get("stats") or {}
        result.views_total = _parse_views(stats.get("totalViewsFormattedString"))
        result.views_today = _parse_views(stats.get("todayViewsFormattedString"))

        # Price changes — from offer.priceChanges or state-level priceChanges
        result.price_changes = _extract_price_changes(offer, offer_state)

        # Agent profile expansion
        result.agent_profile = _extract_agent_profile(offer)

        # Sister state containers: bti, newObject, plus raw stash of everything else
        all_states = extract_all_states(html)
        offer_card_states = all_states.get("frontend-offer-card", {})

        bti_state = offer_card_states.get("bti")
        if bti_state:
            result.bti_data = bti_state.get("houseData")
            result.raw_sister_states["bti"] = bti_state

        # Newbuilding link (if applicable)
        newbuilding = offer.get("newbuilding")
        if newbuilding and newbuilding.get("id"):
            result.newbuilding_data = newbuilding

        # Stash all non-defaultState sister containers for debugging / future-extraction
        for k, v in offer_card_states.items():
            if k != "defaultState":
                result.raw_sister_states[k] = v

        return result

    finally:
        if close_session:
            await session.close()


# ── Field extractors ──────────────────────────────────────────────────────────


def _extract_windows_view(offer: dict[str, Any]) -> str | None:
    return offer.get("windowsViewType")


def _extract_repair_type(offer: dict[str, Any]) -> str | None:
    # Cian: 'cosmetic' / 'design' / 'no' / 'euro' / ...
    return offer.get("repairType")


def _extract_repair_state(offer: dict[str, Any]) -> str | None:
    """Нормализованный enum из offer.repairType → needs_repair/standard/good/excellent.

    Если структурное поле repairType пустое — fallback на инференс из описания (#622).
    Структурное значение всегда в приоритете.
    """
    state = normalize_repair_state(offer.get("repairType"))
    if state is None:
        state = infer_repair_state_from_text(offer.get("description"))
    return state


def _parse_float(value: Any) -> float | None:
    if value is None:
        return None
    try:
        return float(value)
    except (ValueError, TypeError):
        return None


def _parse_views(formatted_str: str | None) -> int | None:
    """Cian's stats.totalViewsFormattedString — '1 234' → 1234."""
    if not formatted_str:
        return None
    try:
        return int(str(formatted_str).replace(" ", "").replace(",", ""))
    except (ValueError, TypeError):
        return None


def _extract_price_changes(offer: dict[str, Any], state: dict[str, Any]) -> list[dict[str, Any]]:
    """offer.priceChanges or state.priceChanges — normalize to common form."""
    raw = offer.get("priceChanges") or state.get("priceChanges") or []
    if not isinstance(raw, list):
        return []
    result = []
    for entry in raw:
        if not isinstance(entry, dict):
            continue
        result.append(
            {
                "change_time": entry.get("changeTime") or entry.get("date"),
                "price_rub": entry.get("price") or entry.get("priceRub"),
                "diff_percent": entry.get("diffPercent") or entry.get("diff_percent"),
            }
        )
    return result


def _extract_agent_profile(offer: dict[str, Any]) -> dict[str, Any] | None:
    """offer.agent or offer.agency or offer.user — extract canonical profile shape."""
    agent = offer.get("agent") or {}
    user = offer.get("user") or {}
    if not agent and not user:
        return None
    return {
        "ext_agent_id": agent.get("id") or user.get("cianUserId"),
        "company_name": agent.get("companyName") or user.get("companyName"),
        "is_pro": agent.get("isPro") or user.get("isPro"),
        "skills": agent.get("skills") or [],
        "account_type": agent.get("accountType") or user.get("accountType"),
    }


# ── Save helpers ──────────────────────────────────────────────────────────────


def save_detail_enrichment(db: Session, listing_id: int, enrichment: DetailEnrichment) -> None:
    """Persist DetailEnrichment to DB:

    - UPDATE listings SET windows_view_type, ceiling_height, ... WHERE id = listing_id
    - INSERT INTO offer_price_history rows (if price_changes non-empty)
    - INSERT INTO agents (if agent_profile) and link via agent_id_fk
    - bti_data не сохраняется здесь — это задача Stage 6 (houses), где есть house_id

    Idempotency: re-running безопасно (UPSERT / ON CONFLICT DO NOTHING semantics).
    """
    # Extend listings row with detail-enriched fields
    db.execute(
        text("""
            UPDATE listings SET
                windows_view_type  = COALESCE(:wvt, windows_view_type),
                separate_wcs_count = COALESCE(:swc, separate_wcs_count),
                combined_wcs_count = COALESCE(:cwc, combined_wcs_count),
                ceiling_height     = COALESCE(:ch,  ceiling_height),
                repair_type        = COALESCE(:rt,  repair_type),
                repair_state       = COALESCE(:rs,  repair_state),
                views_total        = COALESCE(:vt,  views_total),
                views_today        = COALESCE(:vd,  views_today)
            WHERE id = CAST(:lid AS bigint)
        """),
        {
            "lid": listing_id,
            "wvt": enrichment.windows_view_type,
            "swc": enrichment.separate_wcs_count,
            "cwc": enrichment.combined_wcs_count,
            "ch": enrichment.ceiling_height,
            "rt": enrichment.repair_type,
            "rs": enrichment.repair_state,
            "vt": enrichment.views_total,
            "vd": enrichment.views_today,
        },
    )

    # Snapshot: point-in-time observation в listings_snapshots.
    # Берём price_rub / price_per_m2 из listings строки (только что обновлённой).
    # Используем COALESCE — на случай если listings.price_rub NULL (не должно быть, но safe).
    _snap_row = db.execute(
        text("""
            SELECT price_rub, price_per_m2
            FROM listings
            WHERE id = CAST(:lid AS bigint)
        """),
        {"lid": listing_id},
    ).fetchone()
    _snap_written = False
    if _snap_row is not None and _snap_row.price_rub is not None:
        try:
            with db.begin_nested():
                upsert_listing_snapshot(
                    db,
                    listing_id=listing_id,
                    price_rub=int(_snap_row.price_rub),
                    price_per_m2=int(_snap_row.price_per_m2) if _snap_row.price_per_m2 else None,
                    run_id=None,
                    status="active",
                )
            _snap_written = True
        except Exception as exc:
            logger.warning(
                "save_detail_enrichment: snapshot write failed listing_id=%s: %s",
                listing_id,
                exc,
            )

    # Price changes — INSERT new rows, de-dup by listing_id + change_time
    for change in enrichment.price_changes:
        if not change.get("change_time") or not change.get("price_rub"):
            continue
        db.execute(
            text("""
                INSERT INTO offer_price_history
                    (listing_id, change_time, price_rub, diff_percent, source)
                VALUES (
                    CAST(:lid AS bigint),
                    CAST(:ct AS timestamptz),
                    CAST(:price AS numeric),
                    CAST(:diff AS numeric),
                    'cian'
                )
                ON CONFLICT ON CONSTRAINT offer_price_history_listing_change_uq DO NOTHING
            """),
            {
                "lid": listing_id,
                "ct": change["change_time"],
                "price": change["price_rub"],
                "diff": change.get("diff_percent"),
            },
        )

    # Agent profile UPSERT — store agent row and link to listing
    if enrichment.agent_profile and enrichment.agent_profile.get("ext_agent_id"):
        ap = enrichment.agent_profile
        row = db.execute(
            text("""
                INSERT INTO agents
                    (ext_source, ext_agent_id, company_name, is_pro, skills, account_type)
                VALUES (
                    'cian',
                    :eai,
                    :cn,
                    :ip,
                    CAST(:sk AS jsonb),
                    :at
                )
                ON CONFLICT (ext_source, ext_agent_id) DO UPDATE SET
                    company_name = COALESCE(EXCLUDED.company_name, agents.company_name),
                    is_pro       = COALESCE(EXCLUDED.is_pro,       agents.is_pro),
                    skills       = COALESCE(EXCLUDED.skills,       agents.skills),
                    account_type = COALESCE(EXCLUDED.account_type, agents.account_type)
                RETURNING id
            """),
            {
                "eai": str(ap["ext_agent_id"]),
                "cn": ap.get("company_name"),
                "ip": ap.get("is_pro"),
                "sk": json.dumps(ap.get("skills") or []),
                "at": ap.get("account_type"),
            },
        )
        agent_db_id = row.scalar_one_or_none()
        if agent_db_id is not None:
            db.execute(
                text("""
                    UPDATE listings
                    SET agent_id_fk = CAST(:aid AS bigint)
                    WHERE id = CAST(:lid AS bigint)
                      AND agent_id_fk IS NULL
                """),
                {"aid": agent_db_id, "lid": listing_id},
            )

    db.commit()
    logger.info(
        "Cian detail enrichment saved for listing_id=%s "
        "(price_changes=%d, agent=%s, snapshot=%s)",
        listing_id,
        len(enrichment.price_changes),
        bool(enrichment.agent_profile),
        _snap_written,
    )