Switch to candlestick charts with 30-day daily data

- Replace line charts with candlestick charts for better visualization
- Green candles for up days, red for down days
- Daily resolution (30 days) - free tier compatible
- Auto-detect intraday vs daily data for proper time/date formatting
- Note: 5-min intraday requires paid Polygon tier ($199/month)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

bot.py

@@ -263,12 +263,12 @@ class StockBot(commands.Bot):
             await channel.send(f"Unable to retrieve data for ticker: {ticker}")
             return
 
-        # Generate chart using Polygon.io historical data
+        # Generate chart using Polygon.io historical data (daily candlesticks)
         chart_file = None
         if self.chart_api:
-            candle_data = self.chart_api.get_candles(ticker, days=30)
+            candle_data = self.chart_api.get_candles(ticker, days=30, resolution='D')
             if candle_data:
-                chart_buffer = ChartGenerator.create_price_chart(
+                chart_buffer = ChartGenerator.create_candlestick_chart(
                     ticker,
                     candle_data,
                     stock_data.get('company_name')
@@ -559,12 +559,12 @@ async def get_stock_price(ctx, ticker: str = None):
         await ctx.send(f"Unable to retrieve data for ticker: {ticker}")
         return
 
-    # Generate chart using Polygon.io historical data
+    # Generate chart using Polygon.io historical data (daily candlesticks)
     chart_file = None
     if bot.chart_api:
-        candle_data = bot.chart_api.get_candles(ticker, days=30)
+        candle_data = bot.chart_api.get_candles(ticker, days=30, resolution='D')
         if candle_data:
-            chart_buffer = ChartGenerator.create_price_chart(
+            chart_buffer = ChartGenerator.create_candlestick_chart(
                 ticker,
                 candle_data,
                 stock_data.get('company_name')

chart_generator.py

@@ -45,9 +45,22 @@ class ChartGenerator:
             # Fill area under the line
             ax.fill_between(dates, closes, alpha=0.3, color='#00d4ff')
 
-            # Format x-axis
+            # Format x-axis (detect if intraday or multi-day)
+            if len(dates) > 0:
+                # Check if all data is from the same day
+                first_date = dates[0].date()
+                last_date = dates[-1].date()
+                is_intraday = first_date == last_date
+
+                if is_intraday:
+                    # Show time for intraday data
+                    ax.xaxis.set_major_formatter(mdates.DateFormatter('%H:%M'))
+                    ax.xaxis.set_major_locator(mdates.HourLocator(interval=1))
+                else:
+                    # Show date for multi-day data
                     ax.xaxis.set_major_formatter(mdates.DateFormatter('%m/%d'))
                     ax.xaxis.set_major_locator(mdates.AutoDateLocator())
+
             plt.xticks(rotation=45, ha='right')
 
             # Grid styling
@@ -125,9 +138,22 @@ class ChartGenerator:
                 bottom = min(opens[i], closes[i])
                 ax.bar(dates[i], height, width, bottom=bottom, color=color, alpha=0.8)
 
-            # Format x-axis
+            # Format x-axis (detect if intraday or multi-day)
+            if len(dates) > 0:
+                # Check if all data is from the same day
+                first_date = dates[0].date()
+                last_date = dates[-1].date()
+                is_intraday = first_date == last_date
+
+                if is_intraday:
+                    # Show time for intraday data
+                    ax.xaxis.set_major_formatter(mdates.DateFormatter('%H:%M'))
+                    ax.xaxis.set_major_locator(mdates.HourLocator(interval=1))
+                else:
+                    # Show date for multi-day data
                     ax.xaxis.set_major_formatter(mdates.DateFormatter('%m/%d'))
                     ax.xaxis.set_major_locator(mdates.AutoDateLocator())
+
             plt.xticks(rotation=45, ha='right')
 
             # Grid styling

polygon_api.py

@@ -26,14 +26,35 @@ class PolygonAPI:
 
         Args:
             ticker: Stock ticker symbol
-            days: Number of days of historical data to fetch
+            days: Number of days of historical data to fetch (ignored for intraday)
-            resolution: Candle resolution (ignored, always daily)
+            resolution: Candle resolution ('D' for daily, '5min' requires paid tier)
 
         Returns:
             Dictionary with OHLCV data or None if unavailable
         """
         try:
-            # Calculate date range (end yesterday to avoid missing today's data)
+            if resolution == '5min':
+                # For 5-minute bars, get current day data
+                # Start at market open (9:30 AM ET)
+                import pytz
+                et_tz = pytz.timezone('America/New_York')
+                now_et = datetime.now(et_tz)
+
+                # Set to today at 9:30 AM ET
+                market_open = now_et.replace(hour=9, minute=30, second=0, microsecond=0)
+
+                # If current time is before market open, use yesterday
+                if now_et < market_open:
+                    market_open = market_open - timedelta(days=1)
+                    now_et = market_open.replace(hour=16, minute=0)  # Use previous day's close
+
+                from_date = market_open.strftime('%Y-%m-%d')
+                to_date = now_et.strftime('%Y-%m-%d')
+
+                # Build API URL for 5-minute bars
+                url = f"{self.base_url}/v2/aggs/ticker/{ticker}/range/5/minute/{from_date}/{to_date}"
+            else:
+                # Daily bars - Calculate date range (end yesterday to avoid missing today's data)
                 end_date = datetime.now() - timedelta(days=1)
                 start_date = end_date - timedelta(days=days)
 
@@ -41,7 +62,7 @@ class PolygonAPI:
                 from_date = start_date.strftime('%Y-%m-%d')
                 to_date = end_date.strftime('%Y-%m-%d')
 
-            # Build API URL
+                # Build API URL for daily bars
                 url = f"{self.base_url}/v2/aggs/ticker/{ticker}/range/1/day/{from_date}/{to_date}"
 
             # Make request

test_candlestick.py

@@ -0,0 +1,69 @@
+"""Test script for candlestick chart generation."""
+import logging
+from polygon_api import PolygonAPI
+from chart_generator import ChartGenerator
+import os
+from dotenv import load_dotenv
+
+load_dotenv()
+
+logging.basicConfig(
+    level=logging.INFO,
+    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+)
+logger = logging.getLogger(__name__)
+
+
+def test_candlestick_charts():
+    """Test candlestick chart generation with Polygon data."""
+
+    api_key = os.getenv('POLYGON_API_KEY')
+    if not api_key:
+        logger.error("POLYGON_API_KEY not set in .env file")
+        return False
+
+    logger.info("Initializing Polygon API")
+    api = PolygonAPI(api_key)
+
+    # Test tickers
+    tickers = ["AAPL", "TSLA"]
+
+    for ticker in tickers:
+        logger.info(f"\nTesting candlestick chart for {ticker}...")
+
+        # Fetch candle data
+        logger.info(f"Fetching 30-day candle data for {ticker}")
+        candle_data = api.get_candles(ticker, days=30, resolution='D')
+
+        if not candle_data:
+            logger.error(f"Failed to fetch candle data for {ticker}")
+            continue
+
+        logger.info(f"Successfully fetched {len(candle_data['timestamps'])} candles")
+        logger.info(f"Price range: ${min(candle_data['low']):.2f} - ${max(candle_data['high']):.2f}")
+
+        # Generate candlestick chart
+        logger.info(f"Generating candlestick chart for {ticker}")
+        chart = ChartGenerator.create_candlestick_chart(ticker, candle_data, f"{ticker}")
+
+        if not chart:
+            logger.error(f"Failed to generate chart for {ticker}")
+            continue
+
+        # Save chart
+        filename = f"/tmp/{ticker}_candlestick_30d.png"
+        with open(filename, "wb") as f:
+            f.write(chart.getvalue())
+        logger.info(f"Chart saved: {filename} ({len(chart.getvalue())} bytes)")
+
+    logger.info("\nCandlestick chart test completed successfully!")
+    return True
+
+
+if __name__ == "__main__":
+    try:
+        success = test_candlestick_charts()
+        exit(0 if success else 1)
+    except Exception as e:
+        logger.error(f"Test failed: {e}", exc_info=True)
+        exit(1)