from __future__ import annotations

import argparse
import csv
import json
import sys
from datetime import UTC, datetime
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from okx_codex_trader.okx_client import OkxClient


SYMBOLS = ("BTC-USDT-SWAP", "ETH-USDT-SWAP")
DIRECT_BARS = ("15m", "5m", "3m")
DERIVED_BARS = ("1H", "4H")
BASE_BAR = "15m"
BAR_MS = {
    "3m": 180_000,
    "5m": 300_000,
    "15m": 900_000,
    "1H": 3_600_000,
    "4H": 14_400_000,
}


def iso_text(ts: int | None) -> str | None:
    if ts is None:
        return None
    return datetime.fromtimestamp(ts / 1000, UTC).isoformat().replace("+00:00", "Z")


def scan_csv(path: Path, interval_ms: int) -> dict[str, object]:
    rows = 0
    first_ts: int | None = None
    last_ts: int | None = None
    duplicate_timestamps = 0
    non_increasing_steps = 0
    unexpected_intervals = 0
    seen: set[int] = set()

    if not path.exists():
        return {
            "rows": 0,
            "first_ts": None,
            "first_time": None,
            "last_ts": None,
            "last_time": None,
            "duplicate_timestamps": 0,
            "non_increasing_steps": 0,
            "unexpected_intervals": 0,
        }

    with path.open("r", encoding="utf-8", newline="") as handle:
        for row in csv.DictReader(handle):
            ts = int(row["ts"])
            rows += 1
            if first_ts is None:
                first_ts = ts
            if ts in seen:
                duplicate_timestamps += 1
            seen.add(ts)
            if last_ts is not None:
                diff = ts - last_ts
                if diff <= 0:
                    non_increasing_steps += 1
                if diff != interval_ms:
                    unexpected_intervals += 1
            last_ts = ts

    return {
        "rows": rows,
        "first_ts": first_ts,
        "first_time": iso_text(first_ts),
        "last_ts": last_ts,
        "last_time": iso_text(last_ts),
        "duplicate_timestamps": duplicate_timestamps,
        "non_increasing_steps": non_increasing_steps,
        "unexpected_intervals": unexpected_intervals,
    }


def remote_last_ts(client: OkxClient, symbol: str, bar: str) -> int | None:
    candles = client.get_recent_candles(symbol, bar, 2)
    return candles[-1].ts if candles else None


def last_complete_derived_ts(base_last_ts: int | None, derived_interval_ms: int) -> int | None:
    if base_last_ts is None:
        return None
    label = (base_last_ts // derived_interval_ms) * derived_interval_ms
    required_last_base_ts = label + derived_interval_ms - BAR_MS[BASE_BAR]
    if base_last_ts >= required_last_base_ts:
        return label
    previous = label - derived_interval_ms
    return previous if previous >= 0 else None


def build_report(cache_dir: Path, client: OkxClient) -> dict[str, object]:
    direct_rows = []
    base_by_symbol: dict[str, dict[str, object]] = {}

    for symbol in SYMBOLS:
        for bar in DIRECT_BARS:
            local = scan_csv(cache_dir / symbol / f"{bar}.csv", BAR_MS[bar])
            remote_ts = remote_last_ts(client, symbol, bar)
            local_ts = local["last_ts"]
            lag_ms = None if local_ts is None or remote_ts is None else max(0, remote_ts - int(local_ts))
            row = {
                "symbol": symbol,
                "bar": bar,
                **local,
                "remote_last_ts": remote_ts,
                "remote_last_time": iso_text(remote_ts),
                "lag_ms": lag_ms,
                "lag_bars": None if lag_ms is None else lag_ms // BAR_MS[bar],
                "needs_update": bool(lag_ms and lag_ms > 0),
            }
            direct_rows.append(row)
            if bar == BASE_BAR:
                base_by_symbol[symbol] = row

    derived_rows = []
    for symbol in SYMBOLS:
        base = base_by_symbol[symbol]
        for bar in DERIVED_BARS:
            interval = BAR_MS[bar]
            local_ts = last_complete_derived_ts(base["last_ts"], interval)  # type: ignore[arg-type]
            remote_ts = last_complete_derived_ts(base["remote_last_ts"], interval)  # type: ignore[arg-type]
            lag_ms = None if local_ts is None or remote_ts is None else max(0, remote_ts - local_ts)
            derived_rows.append(
                {
                    "symbol": symbol,
                    "bar": bar,
                    "derived_from": BASE_BAR,
                    "local_last_complete_ts": local_ts,
                    "local_last_complete_time": iso_text(local_ts),
                    "remote_last_complete_ts": remote_ts,
                    "remote_last_complete_time": iso_text(remote_ts),
                    "lag_ms": lag_ms,
                    "lag_bars": None if lag_ms is None else lag_ms // interval,
                    "needs_update": bool(lag_ms and lag_ms > 0),
                }
            )

    direct_update_bars = sorted({str(row["bar"]) for row in direct_rows if row["needs_update"]})
    derived_update_bars = sorted({str(row["bar"]) for row in derived_rows if row["needs_update"]})
    return {
        "created_at": datetime.now(UTC).isoformat(timespec="seconds").replace("+00:00", "Z"),
        "cache_dir": str(cache_dir),
        "direct_bars": direct_rows,
        "derived_bars": derived_rows,
        "conclusion": {
            "direct_bars_needing_update": direct_update_bars,
            "derived_bars_needing_update": derived_update_bars,
            "can_continue_1h_4h_closed_bar_exploration": not derived_update_bars,
            "update_before_3m_5m_exploration": any(bar in direct_update_bars for bar in ("3m", "5m")),
            "update_before_latest_15m_signal_work": "15m" in direct_update_bars,
        },
    }


def main() -> int:
    parser = argparse.ArgumentParser(description="Diagnose local candle freshness for ETH exploration.")
    parser.add_argument("--cache-dir", type=Path, default=Path("data/okx-candles"))
    parser.add_argument("--output-file", type=Path, default=Path("reports/eth-exploration/data-freshness-diagnostic.json"))
    args = parser.parse_args()

    report = build_report(args.cache_dir, OkxClient())
    args.output_file.parent.mkdir(parents=True, exist_ok=True)
    args.output_file.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")
    print(json.dumps(report, indent=2, sort_keys=True))
    return 0


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