From 3f13475485c017b9d858c6d448c2caf729d25d09 Mon Sep 17 00:00:00 2001 From: MarkLo Date: Sun, 14 Dec 2025 03:11:47 +0800 Subject: [PATCH] feat: add Heikin Ashi candlestick and volume charts to PDF reports - Add matplotlib for chart generation - Implement _calculate_heikin_ashi() for HA OHLC calculation - Implement _generate_price_chart() to create candlestick + volume charts - Charts are generated as PNG images and embedded in PDF - Fallback to text summary if chart generation fails - First page now shows visual charts like the web interface --- backend/app/services/pdf_generator.py | 252 +++++++++++++++++++++++--- backend/requirements.txt | 1 + 2 files changed, 227 insertions(+), 26 deletions(-) diff --git a/backend/app/services/pdf_generator.py b/backend/app/services/pdf_generator.py index 6300ad92..9974b417 100644 --- a/backend/app/services/pdf_generator.py +++ b/backend/app/services/pdf_generator.py @@ -2,21 +2,30 @@ """ PDF Generation Service for Analyst Reports Converts markdown reports to PDF format with Chinese character support +Includes Heikin Ashi candlestick charts and volume bar charts """ import io import re -from typing import Optional +from typing import Optional, List, Dict from datetime import datetime from reportlab.lib.pagesizes import A4 from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle from reportlab.lib.units import cm from reportlab.lib.enums import TA_LEFT, TA_CENTER -from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, PageBreak +from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, PageBreak, Image from reportlab.pdfbase import pdfmetrics from reportlab.pdfbase.ttfonts import TTFont from reportlab.lib.colors import HexColor import markdown +# Matplotlib for chart generation +import matplotlib +matplotlib.use('Agg') # Use non-interactive backend for server +import matplotlib.pyplot as plt +import matplotlib.dates as mdates +from matplotlib.patches import Rectangle +import numpy as np + class PDFGenerator: """Generate PDF reports from markdown content""" @@ -162,6 +171,178 @@ class PDFGenerator: # Set primary font self.primary_font = self.custom_font if self.custom_font else self.chinese_font + def _calculate_heikin_ashi(self, price_data: List[Dict]) -> List[Dict]: + """ + Calculate Heikin Ashi values from regular OHLC data + + Args: + price_data: List of dicts with Open, High, Low, Close + + Returns: + List of dicts with HA_Open, HA_High, HA_Low, HA_Close + """ + if not price_data: + return [] + + ha_data = [] + + for i, candle in enumerate(price_data): + open_price = candle.get('Open', 0) + high_price = candle.get('High', 0) + low_price = candle.get('Low', 0) + close_price = candle.get('Adj Close', candle.get('Close', 0)) + + # Current HA Close = (Open + High + Low + Close) / 4 + ha_close = (open_price + high_price + low_price + close_price) / 4 + + if i == 0: + # First candle: HA Open = (Open + Close) / 2 + ha_open = (open_price + close_price) / 2 + else: + # HA Open = (Previous HA Open + Previous HA Close) / 2 + prev_ha = ha_data[i - 1] + ha_open = (prev_ha['HA_Open'] + prev_ha['HA_Close']) / 2 + + # HA High = Max(High, HA Open, HA Close) + ha_high = max(high_price, ha_open, ha_close) + + # HA Low = Min(Low, HA Open, HA Close) + ha_low = min(low_price, ha_open, ha_close) + + ha_data.append({ + 'Date': candle.get('Date', ''), + 'HA_Open': ha_open, + 'HA_High': ha_high, + 'HA_Low': ha_low, + 'HA_Close': ha_close, + 'Volume': candle.get('Volume', 0), + }) + + return ha_data + + def _generate_price_chart(self, price_data: List[Dict], ticker: str) -> bytes: + """ + Generate Heikin Ashi candlestick chart and volume bar chart as PNG image + + Args: + price_data: List of price data dicts + ticker: Stock ticker symbol + + Returns: + PNG image as bytes + """ + if not price_data or len(price_data) < 2: + return None + + # Calculate Heikin Ashi data + ha_data = self._calculate_heikin_ashi(price_data) + + # Prepare data for plotting + dates = [] + ha_opens = [] + ha_highs = [] + ha_lows = [] + ha_closes = [] + volumes = [] + + for i, d in enumerate(ha_data): + dates.append(i) # Use index for x-axis + ha_opens.append(d['HA_Open']) + ha_highs.append(d['HA_High']) + ha_lows.append(d['HA_Low']) + ha_closes.append(d['HA_Close']) + volumes.append(d['Volume']) + + # Create figure with two subplots + fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(10, 6), + gridspec_kw={'height_ratios': [3, 1]}, + sharex=True) + fig.patch.set_facecolor('white') + + # Set Chinese font for matplotlib + plt.rcParams['font.sans-serif'] = ['Arial Unicode MS', 'SimHei', 'STSong', 'sans-serif'] + plt.rcParams['axes.unicode_minus'] = False + + # Plot Heikin Ashi candlesticks + width = 0.8 + for i in range(len(dates)): + # Determine color: green if close > open (bullish), red otherwise + if ha_closes[i] >= ha_opens[i]: + color = '#22c55e' # Green for bullish + body_color = '#22c55e' + else: + color = '#ef4444' # Red for bearish + body_color = '#ef4444' + + # Draw the wick (high-low line) + ax1.plot([dates[i], dates[i]], [ha_lows[i], ha_highs[i]], + color=color, linewidth=1) + + # Draw the body (open-close rectangle) + body_bottom = min(ha_opens[i], ha_closes[i]) + body_height = abs(ha_closes[i] - ha_opens[i]) + rect = Rectangle((dates[i] - width/2, body_bottom), width, body_height, + facecolor=body_color, edgecolor=color, linewidth=0.5) + ax1.add_patch(rect) + + # Style price chart + ax1.set_ylabel('Price ($)', fontsize=10) + ax1.set_title(f'{ticker} Heikin Ashi Chart', fontsize=12, fontweight='bold') + ax1.grid(True, alpha=0.3) + ax1.set_facecolor('#fafafa') + + # Plot volume bars + volume_colors = ['#22c55e' if ha_closes[i] >= ha_opens[i] else '#ef4444' + for i in range(len(dates))] + ax2.bar(dates, volumes, width=width, color=volume_colors, alpha=0.7) + + # Style volume chart + ax2.set_ylabel('Volume', fontsize=10) + ax2.set_xlabel('Trading Days', fontsize=10) + ax2.grid(True, alpha=0.3) + ax2.set_facecolor('#fafafa') + + # Format volume y-axis + ax2.yaxis.set_major_formatter(plt.FuncFormatter( + lambda x, p: f'{x/1e6:.1f}M' if x >= 1e6 else f'{x/1e3:.0f}K' if x >= 1e3 else f'{x:.0f}' + )) + + # Add date labels at intervals + if len(ha_data) > 0: + # Show first, middle, and last date labels + label_indices = [0, len(ha_data)//2, len(ha_data)-1] + labels = [] + positions = [] + for idx in label_indices: + if idx < len(ha_data): + date_str = ha_data[idx].get('Date', '') + if date_str: + # Format date to show only month/day + try: + if len(date_str) >= 10: + labels.append(date_str[5:10]) # MM-DD + else: + labels.append(date_str) + except: + labels.append(date_str) + positions.append(idx) + + if positions and labels: + ax2.set_xticks(positions) + ax2.set_xticklabels(labels) + + # Tight layout + plt.tight_layout() + + # Save to bytes buffer + buf = io.BytesIO() + plt.savefig(buf, format='png', dpi=150, bbox_inches='tight', + facecolor='white', edgecolor='none') + plt.close(fig) + buf.seek(0) + + return buf.getvalue() + def generate_analyst_report_pdf( self, analyst_name: str, @@ -329,32 +510,51 @@ class PDFGenerator: elements.append(Paragraph("結束價格", stat_label_style)) elements.append(Paragraph(f"${end_price:.2f}", stat_value_style)) - # Add latest price data summary if available - if price_data and len(price_data) > 0: - elements.append(Spacer(1, 0.5*cm)) - elements.append(Paragraph("最近交易數據", heading_style)) - elements.append(Spacer(1, 0.2*cm)) - - # Show last 5 trading days - recent_data = price_data[-5:] if len(price_data) >= 5 else price_data - for day in reversed(recent_data): - date = day.get('Date', 'N/A') - close = day.get('Close', 0) - adj_close = day.get('Adj Close', close) - volume = day.get('Volume', 0) + # Add Heikin Ashi Chart and Volume Chart + if price_data and len(price_data) >= 5: + try: + # Generate chart image + chart_bytes = self._generate_price_chart(price_data, ticker) - # Format volume - if volume >= 1000000000: - vol_str = f"{volume/1000000000:.2f}B" - elif volume >= 1000000: - vol_str = f"{volume/1000000:.2f}M" - elif volume >= 1000: - vol_str = f"{volume/1000:.2f}K" - else: - vol_str = str(volume) + if chart_bytes: + elements.append(Spacer(1, 0.5*cm)) + elements.append(Paragraph("價格走勢與交易量", heading_style)) + elements.append(Spacer(1, 0.3*cm)) + + # Create image from bytes + chart_buffer = io.BytesIO(chart_bytes) + + # Add chart image to PDF (width fits A4 page with margins) + chart_img = Image(chart_buffer, width=17*cm, height=10.2*cm) + elements.append(chart_img) + + except Exception as e: + # If chart generation fails, fall back to text summary + print(f"Chart generation failed: {e}") + elements.append(Spacer(1, 0.5*cm)) + elements.append(Paragraph("最近交易數據", heading_style)) + elements.append(Spacer(1, 0.2*cm)) - day_text = f"{date}：收盤 ${adj_close:.2f}，成交量 {vol_str}" - elements.append(Paragraph(day_text, stat_style)) + # Show last 5 trading days as text fallback + recent_data = price_data[-5:] if len(price_data) >= 5 else price_data + for day in reversed(recent_data): + date = day.get('Date', 'N/A') + close = day.get('Close', 0) + adj_close = day.get('Adj Close', close) + volume = day.get('Volume', 0) + + # Format volume + if volume >= 1000000000: + vol_str = f"{volume/1000000000:.2f}B" + elif volume >= 1000000: + vol_str = f"{volume/1000000:.2f}M" + elif volume >= 1000: + vol_str = f"{volume/1000:.2f}K" + else: + vol_str = str(volume) + + day_text = f"{date}：收盤 ${adj_close:.2f}，成交量 {vol_str}" + elements.append(Paragraph(day_text, stat_style)) # Page break before analyst content elements.append(PageBreak()) diff --git a/backend/requirements.txt b/backend/requirements.txt index c835855b..7b55db97 100644 --- a/backend/requirements.txt +++ b/backend/requirements.txt @@ -52,6 +52,7 @@ tenacity>=8.2.0 # PDF and document generation reportlab>=4.0.0 markdown>=3.5.0 +matplotlib>=3.8.0 # Toon format for token optimization git+https://github.com/toon-format/toon-python.git