"""Historical CRCON ingestion bootstrap and incremental refresh."""

from __future__ import annotations

import argparse
import json
import time
from concurrent.futures import ThreadPoolExecutor
from dataclasses import dataclass
from typing import Iterable
from urllib.error import HTTPError, URLError
from urllib.parse import urlencode
from urllib.request import Request, urlopen

from .config import (
    get_historical_crcon_detail_workers,
    get_historical_crcon_page_size,
    get_historical_crcon_request_timeout_seconds,
)
from .historical_storage import (
    finalize_ingestion_run,
    get_refresh_cutoff_for_server,
    initialize_historical_storage,
    list_historical_coverage_report,
    list_historical_servers,
    start_ingestion_run,
    upsert_historical_match,
)


PUBLIC_INFO_ENDPOINT = "/api/get_public_info"
MATCH_LIST_ENDPOINT = "/api/get_scoreboard_maps"
MATCH_DETAIL_ENDPOINT = "/api/get_map_scoreboard"
DEFAULT_DETAIL_FETCH_RETRIES = 3


@dataclass(slots=True)
class IngestionStats:
    """Mutable counters for one ingestion execution."""

    pages_processed: int = 0
    matches_seen: int = 0
    matches_inserted: int = 0
    matches_updated: int = 0
    player_rows_inserted: int = 0
    player_rows_updated: int = 0

    def apply(self, delta: dict[str, int]) -> None:
        self.matches_inserted += delta.get("matches_inserted", 0)
        self.matches_updated += delta.get("matches_updated", 0)
        self.player_rows_inserted += delta.get("player_rows_inserted", 0)
        self.player_rows_updated += delta.get("player_rows_updated", 0)


def run_bootstrap(
    *,
    server_slug: str | None = None,
    max_pages: int | None = None,
    page_size: int | None = None,
    start_page: int = 1,
    detail_workers: int | None = None,
) -> dict[str, object]:
    """Run a first full historical import against one or all configured servers."""
    return _run_ingestion(
        mode="bootstrap",
        server_slug=server_slug,
        max_pages=max_pages,
        page_size=page_size,
        start_page=start_page,
        detail_workers=detail_workers,
        incremental=False,
    )


def run_incremental_refresh(
    *,
    server_slug: str | None = None,
    max_pages: int | None = None,
    page_size: int | None = None,
    start_page: int = 1,
    detail_workers: int | None = None,
) -> dict[str, object]:
    """Refresh recent historical pages without replaying the whole archive."""
    return _run_ingestion(
        mode="incremental",
        server_slug=server_slug,
        max_pages=max_pages,
        page_size=page_size,
        start_page=start_page,
        detail_workers=detail_workers,
        incremental=True,
    )


def _run_ingestion(
    *,
    mode: str,
    server_slug: str | None,
    max_pages: int | None,
    page_size: int | None,
    start_page: int,
    detail_workers: int | None,
    incremental: bool,
) -> dict[str, object]:
    initialize_historical_storage()
    stats = IngestionStats()
    selected_servers = _select_servers(server_slug)
    processed_servers: list[dict[str, object]] = []
    runs: list[int] = []

    try:
        for server in selected_servers:
            run_id = start_ingestion_run(mode=mode, target_server_slug=str(server["slug"]))
            runs.append(run_id)
            cutoff = (
                get_refresh_cutoff_for_server(str(server["slug"]))
                if incremental
                else None
            )
            server_stats = _ingest_server(
                server=server,
                stats=stats,
                max_pages=max_pages,
                page_size=page_size,
                start_page=start_page,
                detail_workers=detail_workers,
                cutoff=cutoff,
            )
            processed_servers.append(server_stats)
            finalize_ingestion_run(
                run_id,
                status="success",
                pages_processed=server_stats["pages_processed"],
                matches_seen=server_stats["matches_seen"],
                matches_inserted=server_stats["matches_inserted"],
                matches_updated=server_stats["matches_updated"],
                player_rows_inserted=server_stats["player_rows_inserted"],
                player_rows_updated=server_stats["player_rows_updated"],
                notes=f"public_name={server_stats['public_name']}",
            )
    except Exception as exc:
        for run_id in runs:
            finalize_ingestion_run(
                run_id,
                status="failed",
                pages_processed=stats.pages_processed,
                matches_seen=stats.matches_seen,
                matches_inserted=stats.matches_inserted,
                matches_updated=stats.matches_updated,
                player_rows_inserted=stats.player_rows_inserted,
                player_rows_updated=stats.player_rows_updated,
                notes=str(exc),
            )
        raise

    return {
        "status": "ok",
        "mode": mode,
        "page_size": page_size or get_historical_crcon_page_size(),
        "start_page": start_page,
        "detail_workers": detail_workers or get_historical_crcon_detail_workers(),
        "servers": processed_servers,
        "coverage": list_historical_coverage_report(server_slug=server_slug),
        "totals": {
            "pages_processed": stats.pages_processed,
            "matches_seen": stats.matches_seen,
            "matches_inserted": stats.matches_inserted,
            "matches_updated": stats.matches_updated,
            "player_rows_inserted": stats.player_rows_inserted,
            "player_rows_updated": stats.player_rows_updated,
        },
    }


def _ingest_server(
    *,
    server: dict[str, object],
    stats: IngestionStats,
    max_pages: int | None,
    page_size: int | None,
    start_page: int,
    detail_workers: int | None,
    cutoff: str | None,
) -> dict[str, object]:
    resolved_page_size = page_size or get_historical_crcon_page_size()
    resolved_detail_workers = detail_workers or get_historical_crcon_detail_workers()
    page_limit = max_pages or 1000000
    start_page = max(1, start_page)
    local_stats = IngestionStats()
    public_info = _fetch_public_info(str(server["scoreboard_base_url"]))
    discovered_total_matches: int | None = None
    last_page_processed: int | None = None

    for page_number in range(start_page, start_page + page_limit):
        payload = _fetch_match_page(
            str(server["scoreboard_base_url"]),
            page=page_number,
            limit=resolved_page_size,
        )
        if discovered_total_matches is None:
            discovered_total_matches = _coerce_int(payload.get("total"))
        page_matches = _coerce_match_list(payload.get("maps"))
        if not page_matches:
            break

        local_stats.pages_processed += 1
        stats.pages_processed += 1
        last_page_processed = page_number
        stop_after_page = False
        match_ids_to_fetch: list[str] = []

        for match_summary in page_matches:
            local_stats.matches_seen += 1
            stats.matches_seen += 1

            reference_timestamp = _pick_match_timestamp(match_summary)
            if cutoff and reference_timestamp and reference_timestamp < cutoff:
                stop_after_page = True
                continue

            match_id = _stringify(match_summary.get("id"))
            if match_id:
                match_ids_to_fetch.append(match_id)

        for detail_payload in _fetch_match_details(
            str(server["scoreboard_base_url"]),
            match_ids_to_fetch,
            max_workers=resolved_detail_workers,
        ):
            delta = upsert_historical_match(
                server_slug=str(server["slug"]),
                match_payload=detail_payload,
            )
            local_stats.apply(delta)
            stats.apply(delta)

        if stop_after_page:
            break

    return {
        "server_slug": server["slug"],
        "public_name": _extract_public_name(public_info),
        "server_number": public_info.get("server_number") or server.get("server_number"),
        "pages_processed": local_stats.pages_processed,
        "matches_seen": local_stats.matches_seen,
        "discovered_total_matches": discovered_total_matches,
        "matches_inserted": local_stats.matches_inserted,
        "matches_updated": local_stats.matches_updated,
        "player_rows_inserted": local_stats.player_rows_inserted,
        "player_rows_updated": local_stats.player_rows_updated,
        "start_page": start_page,
        "last_page_processed": last_page_processed,
        "cutoff": cutoff,
    }


def _select_servers(server_slug: str | None) -> list[dict[str, object]]:
    servers = list_historical_servers()
    if server_slug is None:
        return servers

    normalized = server_slug.strip()
    selected = [server for server in servers if server["slug"] == normalized]
    if not selected:
        raise ValueError(f"Unknown historical server slug: {server_slug}")
    return selected


def _fetch_public_info(base_url: str) -> dict[str, object]:
    return _fetch_dict_payload(base_url, PUBLIC_INFO_ENDPOINT)


def _fetch_match_page(base_url: str, *, page: int, limit: int) -> dict[str, object]:
    return _fetch_dict_payload(
        base_url,
        MATCH_LIST_ENDPOINT,
        {"page": page, "limit": limit},
        context=f"page={page}",
    )


def _fetch_match_detail(base_url: str, *, match_id: str) -> dict[str, object]:
    return _fetch_dict_payload(
        base_url,
        MATCH_DETAIL_ENDPOINT,
        {"map_id": match_id},
        context=f"match={match_id}",
    )


def _fetch_match_details(
    base_url: str,
    match_ids: list[str],
    *,
    max_workers: int,
) -> list[dict[str, object]]:
    if not match_ids:
        return []
    if max_workers <= 1:
        return [
            _fetch_match_detail(base_url, match_id=match_id)
            for match_id in match_ids
        ]

    with ThreadPoolExecutor(max_workers=max_workers) as executor:
        futures = [
            executor.submit(_fetch_match_detail, base_url, match_id=match_id)
            for match_id in match_ids
        ]
        return [future.result() for future in futures]


def _fetch_json(
    base_url: str,
    endpoint: str,
    query: dict[str, object] | None = None,
) -> object:
    url = f"{base_url}{endpoint}"
    if query:
        url = f"{url}?{urlencode(query)}"

    request = Request(
        url,
        headers={
            "Accept": "application/json",
            "User-Agent": "HLL-Vietnam-Historical-Ingestion/0.1",
        },
    )
    try:
        with urlopen(
            request,
            timeout=get_historical_crcon_request_timeout_seconds(),
        ) as response:
            return json.loads(response.read().decode("utf-8"))
    except HTTPError as exc:
        raise RuntimeError(f"Historical CRCON request failed: {url} ({exc.code})") from exc
    except URLError as exc:
        raise RuntimeError(f"Historical CRCON request failed: {url} ({exc.reason})") from exc


def _fetch_dict_payload(
    base_url: str,
    endpoint: str,
    query: dict[str, object] | None = None,
    *,
    context: str = "",
    retries: int = DEFAULT_DETAIL_FETCH_RETRIES,
) -> dict[str, object]:
    last_error: Exception | None = None
    for attempt in range(1, retries + 1):
        try:
            payload = _unwrap_result(_fetch_json(base_url, endpoint, query))
        except Exception as exc:  # pragma: no cover - network path
            last_error = exc
        else:
            if isinstance(payload, dict):
                return payload
            last_error = ValueError(
                f"Unexpected payload type for {base_url}{endpoint} {context}".strip()
            )

        if attempt < retries:
            time.sleep(0.5 * attempt)

    assert last_error is not None
    raise last_error


def _coerce_match_list(payload: object) -> list[dict[str, object]]:
    if not isinstance(payload, list):
        return []
    return [item for item in payload if isinstance(item, dict)]


def _unwrap_result(payload: object) -> object:
    if not isinstance(payload, dict):
        return payload
    if "result" not in payload:
        return payload
    return payload.get("result")


def _pick_match_timestamp(match_payload: dict[str, object]) -> str | None:
    for key in ("end", "start", "creation_time"):
        value = match_payload.get(key)
        if isinstance(value, str) and value.strip():
            return value.strip()
    return None


def _extract_public_name(public_info: dict[str, object]) -> str | None:
    name_value = public_info.get("name")
    if isinstance(name_value, str):
        return name_value
    if isinstance(name_value, dict):
        raw_name = name_value.get("name")
        return raw_name.strip() if isinstance(raw_name, str) and raw_name.strip() else None
    return None


def _stringify(value: object) -> str | None:
    if value is None:
        return None
    text = str(value).strip()
    return text or None


def _coerce_int(value: object) -> int | None:
    if value in (None, ""):
        return None
    try:
        return int(value)
    except (TypeError, ValueError):
        return None


def build_arg_parser() -> argparse.ArgumentParser:
    """Create the CLI parser for manual historical ingestion runs."""
    parser = argparse.ArgumentParser(
        description="Historical CRCON ingestion for HLL Vietnam.",
    )
    parser.add_argument(
        "mode",
        choices=("bootstrap", "refresh"),
        help="bootstrap imports the archive, refresh only recent pages",
    )
    parser.add_argument(
        "--server",
        dest="server_slug",
        help="optional historical server slug",
    )
    parser.add_argument(
        "--max-pages",
        type=int,
        help="optional page cap for local validation",
    )
    parser.add_argument(
        "--page-size",
        type=int,
        help="override CRCON page size",
    )
    parser.add_argument(
        "--start-page",
        type=int,
        default=1,
        help="resume bootstrap or refresh from a specific page number",
    )
    parser.add_argument(
        "--detail-workers",
        type=int,
        help="parallel worker count for per-match detail requests",
    )
    return parser


def main(argv: Iterable[str] | None = None) -> int:
    """Run the historical ingestion CLI."""
    parser = build_arg_parser()
    args = parser.parse_args(list(argv) if argv is not None else None)

    if args.mode == "bootstrap":
        result = run_bootstrap(
            server_slug=args.server_slug,
            max_pages=args.max_pages,
            page_size=args.page_size,
            start_page=args.start_page,
            detail_workers=args.detail_workers,
        )
    else:
        result = run_incremental_refresh(
            server_slug=args.server_slug,
            max_pages=args.max_pages,
            page_size=args.page_size,
            start_page=args.start_page,
            detail_workers=args.detail_workers,
        )

    print(json.dumps(result, indent=2))
    return 0


if __name__ == "__main__":
    raise SystemExit(main())