"""Stockage des biais de marché.

- Redis : état COURANT (lu par la stratégie en live/dry-run). TTL court.
- Historique CSV horodaté par paire : trace durable pour backtester l'IA
  (la stratégie en mode backtest lit le biais valide à chaque bougie).
"""
from __future__ import annotations

import csv
import json
import os
from datetime import datetime, timezone
from pathlib import Path
from typing import Optional

import redis

from models import MarketBias

_KEY_PREFIX = "bias:"
_DEFAULT_TTL = 3 * 3600  # 3 h : un biais expire s'il n'est pas rafraîchi
_HISTORY_HEADER = ["timestamp", "direction", "confidence", "key_support", "key_resistance"]


def _client() -> redis.Redis:
    url = os.environ.get("REDIS_URL", "redis://localhost:6379/0")
    return redis.Redis.from_url(url, decode_responses=True)


def _key(pair: str) -> str:
    return f"{_KEY_PREFIX}{pair}"


def write_bias(bias: MarketBias, ttl: int = _DEFAULT_TTL, r: Optional[redis.Redis] = None) -> None:
    r = r or _client()
    r.set(_key(bias.pair), bias.model_dump_json(), ex=ttl)


def read_bias(pair: str, r: Optional[redis.Redis] = None) -> Optional[MarketBias]:
    r = r or _client()
    raw = r.get(_key(pair))
    if not raw:
        return None
    try:
        return MarketBias.model_validate_json(raw)
    except Exception:  # noqa: BLE001 — donnée corrompue : on l'ignore
        return None


def _history_path(history_dir: str, pair: str) -> Path:
    return Path(history_dir) / f"{pair.replace('/', '_')}.csv"


def append_history(
    bias: MarketBias, history_dir: str, ts: Optional[datetime] = None
) -> None:
    """Ajoute une ligne horodatée à l'historique CSV de la paire (créé si absent)."""
    ts = ts or datetime.now(timezone.utc)
    path = _history_path(history_dir, bias.pair)
    path.parent.mkdir(parents=True, exist_ok=True)
    write_header = not path.exists()
    with path.open("a", newline="", encoding="utf-8") as f:
        writer = csv.writer(f)
        if write_header:
            writer.writerow(_HISTORY_HEADER)
        writer.writerow(
            [
                ts.isoformat(),
                bias.direction,
                bias.confidence,
                bias.key_support if bias.key_support is not None else "",
                bias.key_resistance if bias.key_resistance is not None else "",
            ]
        )


def read_all(r: Optional[redis.Redis] = None) -> dict[str, MarketBias]:
    r = r or _client()
    out: dict[str, MarketBias] = {}
    for key in r.scan_iter(f"{_KEY_PREFIX}*"):
        raw = r.get(key)
        if not raw:
            continue
        try:
            bias = MarketBias.model_validate_json(raw)
            out[bias.pair] = bias
        except Exception:  # noqa: BLE001
            continue
    return out