1#!/usr/bin/env python3
2"""Generate TradingView-style candlestick chart.
3 
4Usage: Copy to scripts/, customize the Config section, run with:
5    python3 scripts/my_chart.py
6"""
7import os
8import sys
9import requests
10import pandas as pd
11import mplfinance as mpf
12import time
13 
14# ============================================================
15# Proxy Auto-Configuration (for deployed environments)
16# ============================================================
17if not os.getenv("HTTP_PROXY") and os.getenv("PROXY_HOST"):
18    host = os.getenv("PROXY_HOST")
19    port = os.getenv("PROXY_PORT", "8080")
20    # Handle IPv6 addresses
21    if ":" in host and not host.startswith("["):
22        host = f"[{host}]"
23    proxy_url = f"http://{host}:{port}"
24    os.environ["HTTP_PROXY"] = proxy_url
25    os.environ["HTTPS_PROXY"] = proxy_url
26 
27# ============================================================
28# Config — customize these for each chart
29# ============================================================
30COIN_ID = "bitcoin"
31DAYS = 30
32INTERVAL = None  # None for auto-select, or "daily"/"hourly"
33OUTPUT_FILE = "output/btc_30d_chart.png"
34 
35# ============================================================
36# Smart Interval Selection
37# ============================================================
38def select_interval(days):
39    """Auto-select optimal interval based on time range."""
40    if days <= 31:
41        return "hourly"  # Max granularity for short term
42    else:
43        return "daily"   # Efficient for longer periods
44 
45if INTERVAL is None:
46    INTERVAL = select_interval(DAYS)
47 
48# ============================================================
49# Fetch OHLC from CoinGecko with Error Handling
50# ============================================================
51API_KEY = os.getenv("COINGECKO_API_KEY")
52if not API_KEY:
53    print("ERROR: COINGECKO_API_KEY not set", file=sys.stderr)
54    sys.exit(1)
55 
56now = int(time.time())
57from_ts = now - (DAYS * 86400)
58 
59url = f"https://pro-api.coingecko.com/api/v3/coins/{COIN_ID}/ohlc/range"
60params = {"vs_currency": "usd", "from": from_ts, "to": now, "interval": INTERVAL}
61headers = {"x-cg-pro-api-key": API_KEY}
62 
63# Retry logic with exponential backoff
64raw = None
65for attempt in range(3):
66    try:
67        resp = requests.get(url, params=params, headers=headers, timeout=15)
68        resp.raise_for_status()
69        raw = resp.json()
70 
71        # Validate response
72        if not isinstance(raw, list) or len(raw) == 0:
73            raise ValueError("Empty or invalid data received from API")
74 
75        # Validate data format
76        if not all(isinstance(item, list) and len(item) == 5 for item in raw):
77            raise ValueError("Invalid OHLC data format")
78 
79        break  # Success
80    except Exception as e:
81        if attempt == 2:  # Last attempt
82            print(f"ERROR: Failed to fetch data after 3 attempts: {e}", file=sys.stderr)
83            sys.exit(1)
84        time.sleep(2 ** attempt)  # Exponential backoff: 1s, 2s
85 
86# ============================================================
87# Build DataFrame
88# ============================================================
89df = pd.DataFrame(raw, columns=["Timestamp", "Open", "High", "Low", "Close"])
90df["Date"] = pd.to_datetime(df["Timestamp"], unit="ms")
91df.set_index("Date", inplace=True)
92df.drop(columns=["Timestamp"], inplace=True)
93 
94# ============================================================
95# TradingView Style
96# ============================================================
97mc = mpf.make_marketcolors(
98    up='#26a69a', down='#ef5350',
99    edge='inherit', wick='inherit', volume='inherit', ohlc='inherit',
100)
101style = mpf.make_mpf_style(
102    marketcolors=mc,
103    facecolor='#131722', edgecolor='#131722', figcolor='#131722',
104    gridcolor='#1e222d', gridstyle='--', y_on_right=True,
105    rc={'axes.labelcolor': '#d1d4dc', 'xtick.color': '#d1d4dc',
106        'ytick.color': '#d1d4dc', 'font.size': 10},
107)
108 
109# ============================================================
110# Plot
111# ============================================================
112os.makedirs("output", exist_ok=True)
113 
114mpf.plot(
115    df, type='candle', style=style, volume=False,
116    title=f'\n{COIN_ID.upper()} — {DAYS}D Candlestick',
117    figsize=(14, 8),
118    savefig=dict(fname=OUTPUT_FILE, dpi=150, bbox_inches='tight',
119                 facecolor='#131722', edgecolor='#131722'),
120)
121 
122print(f"Chart saved: {OUTPUT_FILE}")
123