import logging
import random
import threading
import time
from dataclasses import dataclass, field

import polars as pl

from constants import ARCGIS_PATH, CHANNELS, DATA_DIR, DELAY_BETWEEN_OUTCODES, SCRAPE_HOMECOUK, SCRAPE_OPENRENT, SCRAPE_RIGHTMOVE, SEED
from homecouk import CookiesExpiredError
from homecouk import load_cookies as load_homecouk_cookies
from homecouk import make_client as make_homecouk_client
from homecouk import search_outcode as homecouk_search_outcode
from http_client import make_client
from metrics import (
    cookie_refreshes_total,
    cross_source_dedup_total,
    homecouk_enabled,
    openrent_enabled,
    scrape_elapsed_seconds,
    scrape_errors_total,
    scrape_outcodes_done,
    scrape_outcodes_total,
    scrape_properties_total,
    scrape_state,
)
from openrent import WafChallengeError
from openrent import load_cookies as load_openrent_cookies
from openrent import make_client as make_openrent_client
from openrent import search_outcode as openrent_search_outcode
from rightmove import resolve_outcode_id, search_outcode
from spatial import PostcodeSpatialIndex
from storage import write_parquet

log = logging.getLogger("rightmove")


@dataclass
class ScrapeStatus:
    state: str = "idle"  # idle | running | done | error
    channel: str = ""
    outcode: str = ""
    outcodes_done: int = 0
    outcodes_total: int = 0
    properties_buy: int = 0
    properties_rent: int = 0
    # Per-source counts for current channel
    rm_properties: int = 0
    hk_properties: int = 0
    or_properties: int = 0
    errors: list[str] = field(default_factory=list)
    started_at: float = 0.0
    finished_at: float = 0.0


status = ScrapeStatus()
status_lock = threading.Lock()


def _sync_gauges() -> None:
    """Push current ScrapeStatus values into Prometheus gauges. Must hold status_lock."""
    for state in ("idle", "running", "done", "error"):
        scrape_state.labels(state=state).set(1 if status.state == state else 0)
    scrape_outcodes_done.set(status.outcodes_done)
    scrape_outcodes_total.set(status.outcodes_total)
    # Total properties (both sources combined)
    scrape_properties_total.labels(channel="buy", source="total").set(status.properties_buy)
    scrape_properties_total.labels(channel="rent", source="total").set(status.properties_rent)
    # Per-source breakdown for current channel
    ch = "buy" if status.channel == "BUY" else "rent"
    scrape_properties_total.labels(channel=ch, source="rightmove").set(status.rm_properties)
    scrape_properties_total.labels(channel=ch, source="homecouk").set(status.hk_properties)
    scrape_properties_total.labels(channel=ch, source="openrent").set(status.or_properties)
    if status.started_at:
        end = status.finished_at if status.finished_at else time.time()
        scrape_elapsed_seconds.set(end - status.started_at)
    else:
        scrape_elapsed_seconds.set(0)


def load_outcodes() -> list[str]:
    """Load England-only outcodes from arcgis parquet."""
    log.info("Loading outcodes from %s", ARCGIS_PATH)
    df = pl.read_parquet(ARCGIS_PATH, columns=["pcd", "ctry", "lat", "long"])
    england = df.filter(pl.col("ctry") == "E92000001")
    log.info("England postcodes: %d", len(england))

    outcodes = (
        england.select(pl.col("pcd").str.extract(r"^([A-Z]{1,2}\d[A-Z0-9]?)", 1).alias("outcode"))
        .drop_nulls()
        .get_column("outcode")
        .unique()
        .sort()
        .to_list()
    )
    log.info("Unique England outcodes: %d", len(outcodes))
    return outcodes


def build_postcode_index() -> PostcodeSpatialIndex:
    """Build spatial index from arcgis England postcodes."""
    log.info("Building postcode spatial index from %s", ARCGIS_PATH)
    df = pl.read_parquet(ARCGIS_PATH, columns=["pcd", "ctry", "lat", "long"])
    england = df.filter(pl.col("ctry") == "E92000001").drop_nulls(subset=["lat", "long"])
    return PostcodeSpatialIndex(
        england.get_column("lat").to_list(),
        england.get_column("long").to_list(),
        england.get_column("pcd").to_list(),
    )


def build_postcode_coords() -> dict[str, tuple[float, float]]:
    """Build postcode → (lat, lng) lookup from arcgis England postcodes.
    Used by OpenRent scraper to resolve coordinates from postcodes."""
    log.info("Building postcode coords lookup from %s", ARCGIS_PATH)
    df = pl.read_parquet(ARCGIS_PATH, columns=["pcd", "ctry", "lat", "long"])
    england = df.filter(pl.col("ctry") == "E92000001").drop_nulls(subset=["lat", "long"])
    coords: dict[str, tuple[float, float]] = {}
    for pcd, lat, lng in zip(
        england.get_column("pcd").to_list(),
        england.get_column("lat").to_list(),
        england.get_column("long").to_list(),
    ):
        coords[pcd] = (lat, lng)
    log.info("Postcode coords lookup: %d postcodes", len(coords))
    return coords


def _dedup_key(p: dict) -> tuple:
    """Composite key for cross-source deduplication: (postcode, bedrooms, price).
    Two listings on different portals for the same physical property will share
    these attributes even though their IDs differ."""
    return (p.get("Postcode", ""), p.get("Bedrooms", 0), p.get("price", 0))


def run_scrape(
    outcodes: list[str],
    pc_index: PostcodeSpatialIndex,
    pc_coords: dict[str, tuple[float, float]] | None = None,
) -> None:
    """Main scrape loop — runs in background thread.
    Scrapes Rightmove, home.co.uk, and OpenRent, merging into one dataset."""
    global status
    with status_lock:
        status.state = "running"
        status.started_at = time.time()
        status.errors = []
        status.properties_buy = 0
        status.properties_rent = 0
        _sync_gauges()

    # Shuffle for geographic diversity
    shuffled = list(outcodes)
    random.seed(SEED)
    random.shuffle(shuffled)

    if not SCRAPE_RIGHTMOVE and not SCRAPE_HOMECOUK and not SCRAPE_OPENRENT:
        log.warning("All scrapers disabled — nothing to do")
        with status_lock:
            status.state = "done"
            status.finished_at = time.time()
            _sync_gauges()
        return

    client = make_client() if SCRAPE_RIGHTMOVE else None
    if not SCRAPE_RIGHTMOVE:
        log.info("Rightmove scraping DISABLED (SCRAPE_RIGHTMOVE=false)")

    # home.co.uk: must be enabled via SCRAPE_HOMECOUK + cookies available
    hk_client = None
    hk_failed = False
    if not SCRAPE_HOMECOUK:
        log.info("home.co.uk scraping DISABLED (SCRAPE_HOMECOUK=false)")
        homecouk_enabled.set(0)
    else:
        hk_result = load_homecouk_cookies()
        hk_client = make_homecouk_client(*hk_result) if hk_result else None
        if hk_client:
            log.info("home.co.uk scraping ENABLED")
            homecouk_enabled.set(1)
        else:
            log.info("home.co.uk scraping DISABLED (need FlareSolverr or HOMECOUK_CF_CLEARANCE + HOMECOUK_SESSION)")
            homecouk_enabled.set(0)

    # OpenRent: must be enabled via SCRAPE_OPENRENT + cookies available
    or_client = None
    or_failed = False
    if not SCRAPE_OPENRENT:
        log.info("OpenRent scraping DISABLED (SCRAPE_OPENRENT=false)")
        openrent_enabled.set(0)
    else:
        or_result = load_openrent_cookies()
        or_client = make_openrent_client(*or_result) if or_result else None
        if or_client:
            log.info("OpenRent scraping ENABLED")
            openrent_enabled.set(1)
        else:
            log.info("OpenRent scraping DISABLED (need FlareSolverr or OPENRENT_WAF_TOKEN)")
            openrent_enabled.set(0)

    # Build postcode coords if OpenRent is active and caller didn't provide them
    if or_client and pc_coords is None:
        pc_coords = build_postcode_coords()

    try:
        for channel_cfg in CHANNELS:
            channel_name = channel_cfg["channel"]
            file_suffix = "buy" if channel_name == "BUY" else "rent"
            all_properties: dict[str, dict] = {}  # dedup by id
            seen_dedup_keys: set[tuple] = set()  # cross-source dedup by (postcode, beds, price)
            rm_count = 0  # Rightmove properties this channel
            hk_count = 0  # home.co.uk properties this channel
            hk_dedup_count = 0  # home.co.uk skipped as cross-source duplicates
            or_count = 0  # OpenRent properties this channel
            or_dedup_count = 0  # OpenRent skipped as cross-source duplicates

            with status_lock:
                status.channel = channel_name
                status.outcodes_done = 0
                status.outcodes_total = len(shuffled)
                status.rm_properties = 0
                status.hk_properties = 0
                status.or_properties = 0

            log.info("=== Starting %s channel (%d outcodes) ===", channel_name, len(shuffled))

            for i, outcode in enumerate(shuffled):
                with status_lock:
                    status.outcode = outcode
                    status.outcodes_done = i

                log.debug("Outcode %s (%d/%d) — %d properties so far",
                          outcode, i + 1, len(shuffled), len(all_properties))

                made_requests = False

                # --- Rightmove ---
                if SCRAPE_RIGHTMOVE:
                    made_requests = True
                    try:
                        outcode_id = resolve_outcode_id(client, outcode)
                        if not outcode_id:
                            log.debug("No Rightmove ID for outcode %s, skipping", outcode)
                        else:
                            props = search_outcode(client, outcode_id, outcode, channel_cfg, pc_index)
                            for p in props:
                                pid = p["id"]
                                if pid not in all_properties:
                                    all_properties[pid] = p
                                    seen_dedup_keys.add(_dedup_key(p))
                                    rm_count += 1
                    except Exception as e:
                        msg = f"Error scraping Rightmove {outcode}/{channel_name}: {e}"
                        log.error(msg)
                        scrape_errors_total.labels(source="rightmove").inc()
                        with status_lock:
                            status.errors.append(msg)

                # --- home.co.uk ---
                if hk_client and not hk_failed:
                    made_requests = True
                    try:
                        hk_props = homecouk_search_outcode(
                            hk_client, outcode, channel_name, pc_index,
                        )
                        for p in hk_props:
                            pid = p["id"]
                            key = _dedup_key(p)
                            if pid in all_properties or key in seen_dedup_keys:
                                hk_dedup_count += 1
                                cross_source_dedup_total.labels(
                                    channel="buy" if channel_name == "BUY" else "rent",
                                ).inc()
                                continue
                            all_properties[pid] = p
                            seen_dedup_keys.add(key)
                            hk_count += 1
                        if hk_props:
                            log.info("home.co.uk %s: +%d properties", outcode, len(hk_props))
                    except CookiesExpiredError:
                        log.warning("home.co.uk cookies expired — attempting refresh via FlareSolverr")
                        hk_client.close()
                        hk_result = load_homecouk_cookies()
                        if hk_result:
                            hk_client = make_homecouk_client(*hk_result)
                            log.info("home.co.uk cookies refreshed, continuing")
                            cookie_refreshes_total.labels(result="success").inc()
                        else:
                            log.warning("Cookie refresh failed, disabling home.co.uk for rest of scrape")
                            hk_client = None
                            hk_failed = True
                            homecouk_enabled.set(0)
                            cookie_refreshes_total.labels(result="failure").inc()
                            with status_lock:
                                status.errors.append("home.co.uk cookies expired and refresh failed")
                    except Exception as e:
                        msg = f"Error scraping home.co.uk {outcode}/{channel_name}: {e}"
                        log.error(msg)
                        scrape_errors_total.labels(source="homecouk").inc()
                        with status_lock:
                            status.errors.append(msg)

                # --- OpenRent (RENT channel only) ---
                if or_client and not or_failed and channel_name == "RENT":
                    made_requests = True
                    try:
                        or_props = openrent_search_outcode(
                            or_client, outcode, pc_index, pc_coords,
                        )
                        for p in or_props:
                            pid = p["id"]
                            key = _dedup_key(p)
                            if pid in all_properties or key in seen_dedup_keys:
                                or_dedup_count += 1
                                cross_source_dedup_total.labels(channel="rent").inc()
                                continue
                            all_properties[pid] = p
                            seen_dedup_keys.add(key)
                            or_count += 1
                        if or_props:
                            log.info("OpenRent %s: +%d properties", outcode, len(or_props))
                    except WafChallengeError:
                        log.warning("OpenRent WAF cookies expired — attempting refresh via FlareSolverr")
                        or_client.close()
                        or_result = load_openrent_cookies()
                        if or_result:
                            or_client = make_openrent_client(*or_result)
                            log.info("OpenRent cookies refreshed, continuing")
                            cookie_refreshes_total.labels(result="success").inc()
                        else:
                            log.warning("Cookie refresh failed, disabling OpenRent for rest of scrape")
                            or_client = None
                            or_failed = True
                            openrent_enabled.set(0)
                            cookie_refreshes_total.labels(result="failure").inc()
                            with status_lock:
                                status.errors.append("OpenRent WAF cookies expired and refresh failed")
                    except Exception as e:
                        msg = f"Error scraping OpenRent {outcode}/{channel_name}: {e}"
                        log.error(msg)
                        scrape_errors_total.labels(source="openrent").inc()
                        with status_lock:
                            status.errors.append(msg)

                with status_lock:
                    if channel_name == "BUY":
                        status.properties_buy = len(all_properties)
                    else:
                        status.properties_rent = len(all_properties)
                    status.rm_properties = rm_count
                    status.hk_properties = hk_count
                    status.or_properties = or_count
                    _sync_gauges()

                log.info("Outcode %s: total %d (rm: %d, hk: %d, or: %d)",
                         outcode, len(all_properties), rm_count, hk_count, or_count)

                if made_requests and i < len(shuffled) - 1:
                    time.sleep(DELAY_BETWEEN_OUTCODES)

            # Write parquet
            deduped = list(all_properties.values())
            output_path = DATA_DIR / f"online_listings_{file_suffix}.parquet"
            write_parquet(deduped, output_path, channel=file_suffix)

            with status_lock:
                if channel_name == "BUY":
                    status.properties_buy = len(deduped)
                else:
                    status.properties_rent = len(deduped)
                status.outcodes_done = len(shuffled)
                _sync_gauges()

            log.info(
                "=== %s channel complete: %d unique (rm: %d, hk: %d, or: %d, cross-dedup: %d) ===",
                channel_name, len(deduped), rm_count, hk_count, or_count,
                hk_dedup_count + or_dedup_count,
            )

        with status_lock:
            status.state = "done"
            status.finished_at = time.time()
            _sync_gauges()
            elapsed = status.finished_at - status.started_at
            log.info("Scrape complete in %.0fs — buy: %d, rent: %d",
                     elapsed, status.properties_buy, status.properties_rent)

    except Exception as e:
        log.exception("Fatal scrape error")
        with status_lock:
            status.state = "error"
            status.errors.append(f"Fatal: {e}")
            status.finished_at = time.time()
            _sync_gauges()
    finally:
        if client:
            client.close()
        if hk_client:
            hk_client.close()
        if or_client:
            or_client.close()