src/pdf_generator.py

"""
PDF Report Generator for Farmer.Chat
Exports query results as downloadable PDF
"""

from reportlab.lib.pagesizes import letter, A4
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import inch
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, PageBreak
from reportlab.lib import colors
from reportlab.lib.enums import TA_CENTER, TA_LEFT
from datetime import datetime
import json
import os
from typing import Dict, Any


def generate_pdf_report(
    query: str,
    advice: str,
    data: Dict[str, Any],
    location: Dict[str, Any]
) -> str:
    """
    Generate PDF report from query results
    
    Args:
        query: Farmer's question
        advice: Generated advice
        data: Compiled data from MCP servers
        location: Location information
    
    Returns:
        str: Path to generated PDF file
    """
    # Create output directory
    output_dir = "./pdf_reports"
    os.makedirs(output_dir, exist_ok=True)
    
    # Generate filename
    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
    filename = f"farmer_chat_report_{timestamp}.pdf"
    filepath = os.path.join(output_dir, filename)
    
    # Create PDF
    doc = SimpleDocTemplate(filepath, pagesize=letter)
    story = []
    styles = getSampleStyleSheet()
    
    # Custom styles
    title_style = ParagraphStyle(
        'CustomTitle',
        parent=styles['Heading1'],
        fontSize=24,
        textColor=colors.HexColor('#2E7D32'),
        spaceAfter=30,
        alignment=TA_CENTER
    )
    
    heading_style = ParagraphStyle(
        'CustomHeading',
        parent=styles['Heading2'],
        fontSize=16,
        textColor=colors.HexColor('#1B5E20'),
        spaceAfter=12,
        spaceBefore=20
    )
    
    # Title
    story.append(Paragraph("🌾 Farmer.Chat Report", title_style))
    story.append(Spacer(1, 0.2*inch))
    
    # Metadata section
    metadata_data = [
        ["Report Generated:", datetime.now().strftime("%B %d, %Y at %I:%M %p")],
        ["Location:", f"{location['name']}"],
        ["Coordinates:", f"{location['lat']}°N, {location['lon']}°E"],
        ["Data Sources:", f"{len(data.get('successful_servers', []))} MCP Servers"]
    ]
    
    metadata_table = Table(metadata_data, colWidths=[2*inch, 4*inch])
    metadata_table.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (0, -1), colors.HexColor('#E8F5E9')),
        ('TEXTCOLOR', (0, 0), (-1, -1), colors.black),
        ('ALIGN', (0, 0), (-1, -1), 'LEFT'),
        ('FONTNAME', (0, 0), (0, -1), 'Helvetica-Bold'),
        ('FONTNAME', (1, 0), (1, -1), 'Helvetica'),
        ('FONTSIZE', (0, 0), (-1, -1), 10),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 8),
        ('GRID', (0, 0), (-1, -1), 1, colors.grey)
    ]))
    
    story.append(metadata_table)
    story.append(Spacer(1, 0.3*inch))
    
    # Query section
    story.append(Paragraph("Your Query", heading_style))
    story.append(Paragraph(query, styles['Normal']))
    story.append(Spacer(1, 0.2*inch))
    
    # Advice section
    story.append(Paragraph("Recommendations", heading_style))
    
    # Split advice into paragraphs
    advice_paragraphs = advice.split('\n\n')
    for para in advice_paragraphs:
        if para.strip():
            story.append(Paragraph(para.strip(), styles['Normal']))
            story.append(Spacer(1, 0.1*inch))
    
    story.append(Spacer(1, 0.2*inch))
    
    # Data section
    story.append(Paragraph("Data Sources", heading_style))
    
    compiled_data = data.get('data', {})
    
    for server_name, server_data in compiled_data.items():
        # Server heading
        server_title = server_name.replace('_', ' ').title()
        story.append(Paragraph(f"<b>{server_title}</b>", styles['Normal']))
        story.append(Spacer(1, 0.05*inch))
        
        # Server data table
        server_items = []
        if isinstance(server_data, dict):
            for key, value in server_data.items():
                if isinstance(value, (str, int, float)):
                    display_key = key.replace('_', ' ').title()
                    server_items.append([display_key, str(value)])
        
        if server_items:
            data_table = Table(server_items, colWidths=[2.5*inch, 3.5*inch])
            data_table.setStyle(TableStyle([
                ('BACKGROUND', (0, 0), (0, -1), colors.HexColor('#F1F8E9')),
                ('TEXTCOLOR', (0, 0), (-1, -1), colors.black),
                ('ALIGN', (0, 0), (-1, -1), 'LEFT'),
                ('FONTNAME', (0, 0), (0, -1), 'Helvetica'),
                ('FONTNAME', (1, 0), (1, -1), 'Helvetica'),
                ('FONTSIZE', (0, 0), (-1, -1), 9),
                ('BOTTOMPADDING', (0, 0), (-1, -1), 6),
                ('GRID', (0, 0), (-1, -1), 0.5, colors.grey)
            ]))
            story.append(data_table)
            story.append(Spacer(1, 0.15*inch))
    
    # Footer
    story.append(Spacer(1, 0.3*inch))
    footer_style = ParagraphStyle(
        'Footer',
        parent=styles['Normal'],
        fontSize=9,
        textColor=colors.grey,
        alignment=TA_CENTER
    )
    story.append(Paragraph("Generated by Farmer.Chat - Agricultural Intelligence System", footer_style))
    story.append(Paragraph("Powered by Multi-stage MCP Pipeline", footer_style))
    
    # Build PDF
    doc.build(story)
    
    return filepath