#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from __future__ import annotations

import json
import sys
import urllib.parse
import urllib.request


def fetch_closes(symbol: str, range_: str = "6mo", interval: str = "1d") -> list[float]:
    base = f"https://query1.finance.yahoo.com/v8/finance/chart/{symbol}"
    params = {"range": range_, "interval": interval}
    url = f"{base}?{urllib.parse.urlencode(params)}"

    req = urllib.request.Request(url, headers={"User-Agent": "Mozilla/5.0"})
    with urllib.request.urlopen(req, timeout=30) as resp:
        data = json.loads(resp.read().decode("utf-8", errors="replace"))

    result = data.get("chart", {}).get("result", [])
    if not result:
        return []

    quote = result[0].get("indicators", {}).get("quote", [])
    if not quote:
        return []

    closes = quote[0].get("close", [])
    return [float(x) for x in closes if x is not None]


def ema(values: list[float], period: int) -> list[float]:
    if not values:
        return []
    k = 2 / (period + 1)
    out = [values[0]]
    for v in values[1:]:
        out.append(v * k + out[-1] * (1 - k))
    return out


def macd(closes: list[float]) -> tuple[list[float], list[float], list[float]]:
    ema12 = ema(closes, 12)
    ema26 = ema(closes, 26)
    dif = [a - b for a, b in zip(ema12, ema26)]
    dea = ema(dif, 9)
    hist = [d - s for d, s in zip(dif, dea)]
    return dif, dea, hist


def main() -> None:
    symbol = sys.argv[1] if len(sys.argv) > 1 else "00922.TW"
    closes = fetch_closes(symbol)

    if len(closes) < 35:
        print(f"{symbol} 資料不足，無法判斷 MACD（至少 35 筆，當前 {len(closes)}）")
        return

    dif, dea, hist = macd(closes)

    d0, d1 = dif[-1], dif[-2]
    s0, s1 = dea[-1], dea[-2]
    h0, h1 = hist[-1], hist[-2]

    golden_cross = d1 <= s1 and d0 > s0
    death_cross = d1 >= s1 and d0 < s0
    low_zone = d0 < 0 and s0 < 0

    if golden_cross and low_zone:
        signal = "✅ 低位金叉：偏多訊號"
    elif golden_cross:
        signal = "✅ 金叉：短線轉強"
    elif death_cross:
        signal = "⚠️ 死叉：短線轉弱"
    elif h0 > h1 and h0 > 0:
        signal = "📈 多頭延續（柱體擴大）"
    elif h0 < h1 and h0 < 0:
        signal = "📉 空頭延續（柱體擴大）"
    else:
        signal = "👀 MACD 震盪中，先觀察"

    print(f"{symbol} MACD 摘要")
    print(f"- DIF：{d0:.4f}")
    print(f"- DEA：{s0:.4f}")
    print(f"- HIST：{h0:.4f}")
    print(f"- 訊號：{signal}")


if __name__ == "__main__":
    main()