nas08-scripts/Stocks/WebService/app.py

import os
import time
import sqlite3
import threading
from datetime import datetime, timedelta

import requests
from flask import Flask, request, jsonify

app = Flask(__name__)

# ---- Config ----
FINNHUB_API_KEY = os.environ.get("FINNHUB_API_KEY", "")
SHARED_SECRET = os.environ.get("PROXY_SECRET", "")
DB_PATH = os.environ.get("DB_PATH", "/data/cache.db")
FINNHUB_MAX_PER_MIN = 40  # stay safely under Finnhub's 60/min cap

_db_lock = threading.Lock()

def get_db():
    conn = sqlite3.connect(DB_PATH)
    conn.execute("""
        CREATE TABLE IF NOT EXISTS historical_cache (
            ticker TEXT NOT NULL,
            requested_date TEXT NOT NULL,
            resolved_date TEXT NOT NULL,
            price REAL NOT NULL,
            PRIMARY KEY (ticker, requested_date)
        )
    """)
    return conn

_current_cache = {}
_current_cache_lock = threading.Lock()
CURRENT_TTL_SECONDS = 60

_finnhub_calls = []
_finnhub_lock = threading.Lock()

def finnhub_throttle():
    with _finnhub_lock:
        now = time.time()
        while _finnhub_calls and _finnhub_calls[0] < now - 60:
            _finnhub_calls.pop(0)
        if len(_finnhub_calls) >= FINNHUB_MAX_PER_MIN:
            sleep_for = 60 - (now - _finnhub_calls[0]) + 0.1
            time.sleep(max(sleep_for, 0))
        _finnhub_calls.append(time.time())


def check_auth():
    key = request.args.get("key", "")
    return bool(SHARED_SECRET) and key == SHARED_SECRET


@app.route("/current")
def current_price():
    if not check_auth():
        return jsonify({"error": "unauthorized"}), 401

    ticker = request.args.get("ticker", "").upper().strip()
    if not ticker:
        return jsonify({"error": "missing ticker"}), 400

    now = time.time()
    with _current_cache_lock:
        cached = _current_cache.get(ticker)
        if cached and (now - cached[1]) < CURRENT_TTL_SECONDS:
            return jsonify({"ticker": ticker, "price": cached[0], "quote_time": cached[2], "cached": True})

    finnhub_throttle()
    r = requests.get(
        "https://finnhub.io/api/v1/quote",
        params={"symbol": ticker, "token": FINNHUB_API_KEY},
        timeout=10,
    )
    data = r.json()

    if not data or data.get("c") in (None, 0):
        return jsonify({"ticker": ticker, "error": "no data"}), 502

    price = data["c"]
    quote_time = None
    if data.get("t"):
        quote_time = datetime.utcfromtimestamp(data["t"]).isoformat() + "Z"

    with _current_cache_lock:
        _current_cache[ticker] = (price, now, quote_time)

    return jsonify({"ticker": ticker, "price": price, "quote_time": quote_time, "cached": False})


@app.route("/historical")
def historical_price():
    if not check_auth():
        return jsonify({"error": "unauthorized"}), 401

    ticker = request.args.get("ticker", "").upper().strip()
    date_str = request.args.get("date", "").strip()
    if not ticker or not date_str:
        return jsonify({"error": "missing ticker or date"}), 400

    try:
        target_date = datetime.strptime(date_str, "%Y-%m-%d")
    except ValueError:
        return jsonify({"error": "date must be YYYY-MM-DD"}), 400

    with _db_lock:
        conn = get_db()
        row = conn.execute(
            "SELECT resolved_date, price FROM historical_cache WHERE ticker=? AND requested_date=?",
            (ticker, date_str),
        ).fetchone()
        conn.close()

    if row:
        return jsonify({"ticker": ticker, "requested_date": date_str, "resolved_date": row[0], "price": row[1], "cached": True})

    period2 = int((target_date + timedelta(days=1)).timestamp())
    period1 = int((target_date - timedelta(days=10)).timestamp())

    url = f"https://query1.finance.yahoo.com/v8/finance/chart/{ticker}"
    headers = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36"}
    r = requests.get(url, params={"period1": period1, "period2": period2, "interval": "1d"}, headers=headers, timeout=10)

    if r.status_code != 200:
        return jsonify({"ticker": ticker, "error": f"yahoo http {r.status_code}"}), 502

    data = r.json()
    try:
        result = data["chart"]["result"][0]
        timestamps = result["timestamp"]
        closes = result["indicators"]["quote"][0]["close"]
    except (KeyError, IndexError, TypeError):
        return jsonify({"ticker": ticker, "error": "no historical data"}), 502

    best = None
    for ts, close in zip(timestamps, closes):
        if close is None:
            continue
        day = datetime.utcfromtimestamp(ts)
        if day.date() <= target_date.date():
            if best is None or day > best[0]:
                best = (day, close)

    if best is None:
        return jsonify({"ticker": ticker, "error": "no trading day found in window"}), 502

    resolved_date = best[0].strftime("%Y-%m-%d")
    price = round(best[1], 4)

    with _db_lock:
        conn = get_db()
        conn.execute(
            "INSERT OR REPLACE INTO historical_cache (ticker, requested_date, resolved_date, price) VALUES (?, ?, ?, ?)",
            (ticker, date_str, resolved_date, price),
        )
        conn.commit()
        conn.close()

    return jsonify({"ticker": ticker, "requested_date": date_str, "resolved_date": resolved_date, "price": price, "cached": False})


@app.route("/health")
def health():
    return jsonify({"status": "ok"})


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5005)