"""Incremental history updater — appends new daily data to history.json from cache."""

import json
import logging
import os
from datetime import datetime, timezone

log = logging.getLogger(__name__)

DATA_DIR = os.path.join(os.path.dirname(os.path.dirname(os.path.abspath(__file__))), "data")
HISTORY_PATH = os.path.join(DATA_DIR, "history.json")
CACHE_PATH = os.path.join(DATA_DIR, "cache.json")


def update_history():
    """Append today's values from cache to history.json. Only adds NEW dates."""
    if not os.path.exists(HISTORY_PATH):
        log.warning("No history.json found — run full collection first")
        return False

    if not os.path.exists(CACHE_PATH):
        log.warning("No cache.json found — run a scrape first")
        return False

    with open(HISTORY_PATH) as f:
        history = json.load(f)
    with open(CACHE_PATH) as f:
        cache = json.load(f)

    today = datetime.now(timezone.utc).strftime("%Y-%m-%d")
    updated = False

    # Map of cache keys to history keys and how to extract the value
    mappings = {
        "puell_multiple": {"history_key": "puell_multiple", "value_key": "value"},
        "mvrv_zscore": {"history_key": "mvrv_zscore", "value_key": "value"},
        "reserve_risk": {"history_key": "reserve_risk", "value_key": "value"},
        "rhodl_ratio": {"history_key": "rhodl_ratio", "value_key": "value"},
        "nupl": {"history_key": "nupl", "value_key": "value"},
        "200w_sma": {"history_key": "200w_sma", "value_key": "value"},
        "lth_realized_price": {"history_key": "lth_realized_price", "value_key": "value"},
        "lth_supply": {"history_key": "lth_supply", "value_key": "value"},
    }

    for cache_key, mapping in mappings.items():
        hkey = mapping["history_key"]
        if hkey not in history:
            continue

        h = history[hkey]
        dates = h.get("dates", [])
        values = h.get("values", [])

        # Skip if today already in history
        if dates and dates[-1] >= today:
            continue

        # Get value from cache
        cached = cache.get(cache_key, {})
        val = cached.get(mapping["value_key"])
        if val is not None:
            dates.append(today)
            values.append(val)
            h["dates"] = dates
            h["values"] = values
            updated = True
            log.info("Appended %s: %s = %s", hkey, today, val)

    # Also update btc_price from cache
    price_data = cache.get("price", {})
    btc_price = price_data.get("price")
    if btc_price and "btc_price" in history:
        h = history["btc_price"]
        if h["dates"][-1] < today:
            h["dates"].append(today)
            h["values"].append(btc_price)
            updated = True

    # BTC price for SMA chart
    if btc_price and "btc_price_sma" in history:
        h = history["btc_price_sma"]
        if h["dates"][-1] < today:
            h["dates"].append(today)
            h["values"].append(btc_price)
            updated = True

    # BTC price for LTH chart
    if btc_price and "btc_price_lth" in history:
        h = history["btc_price_lth"]
        if h["dates"][-1] < today:
            h["dates"].append(today)
            h["values"].append(btc_price)
            updated = True

    # Fear & Greed
    fg = cache.get("fear_greed", {})
    fg_val = fg.get("value")
    if fg_val is not None and "fear_greed" in history:
        h = history["fear_greed"]
        if h["dates"][-1] < today:
            h["dates"].append(today)
            h["values"].append(int(fg_val))
            updated = True

    if updated:
        with open(HISTORY_PATH, "w") as f:
            json.dump(history, f)
        log.info("History updated with %s data", today)
    else:
        log.info("History already up to date (last date >= %s)", today)

    return updated