nas-tools/dashboard/backend/services/pdf_service.py

"""
PDF Invoice Generation Service
"""

import io
from datetime import datetime
from typing import Any

from reportlab.lib import colors
from reportlab.lib.pagesizes import letter
from reportlab.lib.styles import ParagraphStyle, getSampleStyleSheet
from reportlab.lib.units import inch
from reportlab.platypus import Paragraph, SimpleDocTemplate, Spacer, Table, TableStyle


def generate_invoice_pdf(
    invoice_number: str,
    client: dict[str, Any],
    time_entries: list[dict[str, Any]],
    hourly_rate: float = 100.0,
    company_name: str = "Your Company",
    company_address: str = "",
    company_email: str = "",
    company_phone: str = "",
) -> bytes:
    """
    Generate PDF invoice from time entries

    Returns: PDF bytes
    """
    buffer = io.BytesIO()
    doc = SimpleDocTemplate(buffer, pagesize=letter)
    elements = []
    styles = getSampleStyleSheet()

    # Custom styles
    title_style = ParagraphStyle(
        "CustomTitle",
        parent=styles["Heading1"],
        fontSize=24,
        textColor=colors.HexColor("#1F2937"),
        spaceAfter=30,
    )

    header_style = ParagraphStyle(
        "Header",
        parent=styles["Normal"],
        fontSize=10,
        textColor=colors.HexColor("#6B7280"),
    )

    # Company Header
    elements.append(Paragraph(company_name, title_style))
    if company_address:
        elements.append(Paragraph(company_address, header_style))
    if company_email:
        elements.append(Paragraph(f"Email: {company_email}", header_style))
    if company_phone:
        elements.append(Paragraph(f"Phone: {company_phone}", header_style))

    elements.append(Spacer(1, 0.3 * inch))

    # Invoice Title
    invoice_title = ParagraphStyle(
        "InvoiceTitle",
        parent=styles["Heading2"],
        fontSize=18,
        textColor=colors.HexColor("#4F46E5"),
    )
    elements.append(Paragraph("INVOICE", invoice_title))
    elements.append(Spacer(1, 0.2 * inch))

    # Invoice Details
    invoice_date = datetime.now().strftime("%B %d, %Y")
    invoice_data = [
        ["Invoice Number:", invoice_number],
        ["Invoice Date:", invoice_date],
        ["Client:", client.get("name", "N/A")],
    ]

    if client.get("company"):
        invoice_data.append(["Company:", client["company"]])
    if client.get("email"):
        invoice_data.append(["Email:", client["email"]])

    invoice_table = Table(invoice_data, colWidths=[2 * inch, 4 * inch])
    invoice_table.setStyle(
        TableStyle(
            [
                ("FONTNAME", (0, 0), (0, -1), "Helvetica-Bold"),
                ("FONTNAME", (1, 0), (1, -1), "Helvetica"),
                ("FONTSIZE", (0, 0), (-1, -1), 10),
                ("TEXTCOLOR", (0, 0), (0, -1), colors.HexColor("#374151")),
                ("TEXTCOLOR", (1, 0), (1, -1), colors.HexColor("#1F2937")),
                ("VALIGN", (0, 0), (-1, -1), "TOP"),
                ("BOTTOMPADDING", (0, 0), (-1, -1), 8),
            ]
        )
    )
    elements.append(invoice_table)
    elements.append(Spacer(1, 0.4 * inch))

    # Time Entries Table
    table_data = [["Date", "Description", "Hours", "Rate", "Amount"]]

    total_hours = 0
    total_amount = 0

    for entry in time_entries:
        hours = entry["duration_minutes"] / 60
        rate = entry.get("hourly_rate", hourly_rate)
        amount = hours * rate

        total_hours += hours
        total_amount += amount

        date_str = entry["started_at"].strftime("%Y-%m-%d") if entry.get("started_at") else "N/A"
        desc = entry.get("description", "Work performed")

        table_data.append(
            [date_str, desc[:50] + "..." if len(desc) > 50 else desc, f"{hours:.2f}", f"${rate:.2f}", f"${amount:.2f}"]
        )

    # Add totals row
    table_data.append(["", "Total", f"{total_hours:.2f}", "", f"${total_amount:.2f}"])

    # Create table
    time_table = Table(table_data, colWidths=[1.2 * inch, 2.8 * inch, 0.8 * inch, 0.8 * inch, 1 * inch])
    time_table.setStyle(
        TableStyle(
            [
                # Header row
                ("BACKGROUND", (0, 0), (-1, 0), colors.HexColor("#4F46E5")),
                ("TEXTCOLOR", (0, 0), (-1, 0), colors.whitesmoke),
                ("FONTNAME", (0, 0), (-1, 0), "Helvetica-Bold"),
                ("FONTSIZE", (0, 0), (-1, 0), 11),
                ("BOTTOMPADDING", (0, 0), (-1, 0), 12),
                # Data rows
                ("FONTNAME", (0, 1), (-1, -2), "Helvetica"),
                ("FONTSIZE", (0, 1), (-1, -2), 9),
                ("ROWBACKGROUNDS", (0, 1), (-1, -2), [colors.white, colors.HexColor("#F9FAFB")]),
                ("GRID", (0, 0), (-1, -2), 0.5, colors.HexColor("#E5E7EB")),
                # Total row
                ("BACKGROUND", (0, -1), (-1, -1), colors.HexColor("#F3F4F6")),
                ("FONTNAME", (0, -1), (-1, -1), "Helvetica-Bold"),
                ("FONTSIZE", (0, -1), (-1, -1), 11),
                ("TOPPADDING", (0, -1), (-1, -1), 12),
                ("BOTTOMPADDING", (0, -1), (-1, -1), 12),
                # Alignment
                ("ALIGN", (2, 0), (-1, -1), "RIGHT"),
                ("VALIGN", (0, 0), (-1, -1), "MIDDLE"),
            ]
        )
    )

    elements.append(time_table)
    elements.append(Spacer(1, 0.5 * inch))

    # Payment Terms
    terms_style = ParagraphStyle(
        "Terms",
        parent=styles["Normal"],
        fontSize=9,
        textColor=colors.HexColor("#6B7280"),
    )
    elements.append(Paragraph("<b>Payment Terms:</b> Due within 30 days", terms_style))
    elements.append(Spacer(1, 0.1 * inch))
    elements.append(Paragraph("Thank you for your business!", terms_style))

    # Build PDF
    doc.build(elements)

    pdf_bytes = buffer.getvalue()
    buffer.close()

    return pdf_bytes


def generate_invoice_from_project(
    project_id: int, client: dict[str, Any], time_entries: list[dict[str, Any]], invoice_number: str = None
) -> bytes:
    """Generate invoice for a project"""
    if not invoice_number:
        invoice_number = f"INV-{datetime.now().strftime('%Y%m%d')}-{project_id}"

    return generate_invoice_pdf(
        invoice_number=invoice_number,
        client=client,
        time_entries=time_entries,
        company_name="Your OPC",
        company_address="123 Business St, City, State 12345",
        company_email="billing@youropc.com",
        company_phone="+1 (555) 123-4567",
    )