app.py

import gradio as gr
from datetime import datetime
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import letter
import os
from openai import OpenAI
from dotenv import load_dotenv
import json
import base64
from sendgrid import SendGridAPIClient
from sendgrid.helpers.mail import Mail, Attachment, FileContent, FileName, FileType, Disposition
from babel.numbers import format_currency
from reportlab.lib.styles import getSampleStyleSheet
from reportlab.platypus import Paragraph

load_dotenv(override=True)
client = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))

import gradio as gr
from datetime import datetime
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import letter
import os
from openai import OpenAI
from dotenv import load_dotenv
import json
import base64
from sendgrid import SendGridAPIClient
from sendgrid.helpers.mail import Mail, Attachment, FileContent, FileName, FileType, Disposition
from babel.numbers import format_currency
from reportlab.lib.styles import getSampleStyleSheet
from reportlab.platypus import Paragraph

load_dotenv(override=True)
client = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))

def format_inr(amount):
    """Format amount as Indian Rupees (INR) using 'Rs.' instead of symbol"""
    formatted = format_currency(amount, 'INR', locale='en_IN')
    # Replace the ₹ symbol with 'Rs.' to avoid font issues
    return formatted.replace('₹', 'Rs.')

def parse_natural_language(prompt_text):
    """Use OpenAI to parse plain text into structured product data with per-item GST"""
    system_prompt = (
        "You are a helpful assistant. Extract the customer name, address (if any), gstin (if any), "
        "and a list of products with description, code (optional), quantity, price per unit, "
        "and GST percentage for each product from the following text. "
        "Respond ONLY with a JSON object like this: "
        "{"
        "\"customer_name\": \"...\", "
        "\"gstin\": \"...\", "
        "\"address\": \"...\", "
        "\"products\": [{\"description\": \"...\", \"code\": \"...\", \"qty\": ..., \"rate\": ..., \"gst_percentage\": ...}] "
        "}"
    )

    messages = [
        {"role": "system", "content": system_prompt},
        {"role": "user", "content": prompt_text}
    ]

    response = client.chat.completions.create(
        model="gpt-3.5-turbo",  # Changed from non-existent "gpt-4o-mini"
        messages=messages
    )

    text = response.choices[0].message.content
    print("LLM returned:", text)

    try:
        parsed = json.loads(text)
    except json.JSONDecodeError:
        raise ValueError(f"Could not decode response: {text}")

    return parsed


def generate_proforma_invoice_from_prompt(prompt_text):
    parsed = parse_natural_language(prompt_text)

    customer_name = parsed.get("customer_name", "Unknown")
    address = parsed.get("address", "Not provided")
    gstin = parsed.get("gstin", "")
    products = parsed.get("products", [])

    today = datetime.today().strftime("%Y%m%d")
    safe_customer_name = customer_name.replace(" ", "_")
    filename = f"Proforma_Invoice_{safe_customer_name}_{today}.pdf"

    grand_total = 0
    product_rows = []

    for row in products:
        try:
            description = str(row["description"])
            code = str(row.get("code", ""))
            qty = float(row["qty"])
            rate = float(row["rate"])
            gst_pct = float(row.get("gst_percentage", 0))

            row_subtotal = qty * rate
            row_gst = (row_subtotal * gst_pct) / 100
            row_total_with_gst = row_subtotal + row_gst

            grand_total += row_total_with_gst

            product_rows.append({
                'description': description,
                'code': code,
                'qty': qty,
                'rate': rate,
                'subtotal': row_subtotal,
                'gst_pct': gst_pct,
                'gst_value': row_gst,
                'total_with_gst': row_total_with_gst
            })

        except (KeyError, ValueError) as e:
            print(f"Error processing product row {row}: {e}")
            continue

    c = canvas.Canvas(filename, pagesize=letter)
    width, height = letter

    # Logo
    logo_path = "Truevybeslogo.png"
    if os.path.exists(logo_path):
        LOGO_WIDTH = 120
        LOGO_HEIGHT = 40
        x_pos = width - 50 - LOGO_WIDTH
        y_pos = height - 50 - LOGO_HEIGHT
        c.drawImage(
            logo_path,
            x_pos,
            y_pos,
            width=LOGO_WIDTH,
            height=LOGO_HEIGHT,
            preserveAspectRatio=True
        )

    c.setFont("Helvetica-Bold", 16)
    c.drawString(50, height - 70, "PROFORMA INVOICE")

    c.setFont("Helvetica", 10)
    c.drawString(50, height - 100, "Consignor:")
    c.drawString(120, height - 100, "True Vybes")
    c.drawString(50, height - 115, "D-1/902, Nilkanth Greens Maple CHS,")
    c.drawString(50, height - 130, "GB Road, Manpada,")
    c.drawString(50, height - 145, "Thane - 400607")
    c.drawString(50, height - 160, "GSTIN: 27BV0PS7767J2ZF")

    c.drawString(50, height - 190, "Consignee:")
    c.drawString(120, height - 190, customer_name)

    address_lines = address.split('\n')
    for i, line in enumerate(address_lines):
        c.drawString(120, height - 205 - (i * 15), line)

    c.drawString(120, height - 205 - (len(address_lines) * 15), f"GSTIN: {gstin}")
    c.drawString(400, height - 190, f"Date: {datetime.today().strftime('%d-%b-%Y')}")

    # Table header
    table_top = height - 250 - (len(address_lines) * 15)
    c.line(50, table_top, width - 50, table_top)
    c.setFont("Helvetica-Bold", 9)
    c.drawString(50, table_top - 15, "Description")
    c.drawString(170, table_top - 15, "Code")
    c.drawString(240, table_top - 15, "Qty")
    c.drawString(280, table_top - 15, "Rate/Unit")
    c.drawString(360, table_top - 15, "GST %")
    c.drawString(410, table_top - 15, "GST Value")
    c.drawString(480, table_top - 15, "Total w/ GST")
    c.line(50, table_top - 20, width - 50, table_top - 20)

    # Product rows
    c.setFont("Helvetica", 9)
    row_y = table_top - 35

    # Create a style for the description text
    styles = getSampleStyleSheet()
    style = styles["Normal"]
    style.fontName = "Helvetica"
    style.fontSize = 9
    style.leading = 10
    style.splitLongWords = True
    style.alignment = 0  # Left align

    for product in product_rows:
        # Create a Paragraph for the description to enable word wrapping
        desc_para = Paragraph(product['description'], style)
        desc_width = 110  # Width of description column
        desc_height = 20  # Initial height
        
        # Draw the wrapped description
        desc_para.wrapOn(c, desc_width, 800)
        desc_para.drawOn(c, 50, row_y - desc_para.height + 5)
        
        # Calculate the height needed for this row
        row_height = max(desc_para.height, 20)
        
        # Draw other columns
        c.drawString(170, row_y, product['code'])
        c.drawString(240, row_y, str(product['qty']))
        c.drawString(280, row_y, format_inr(product['rate']))
        c.drawString(360, row_y, f"{product['gst_pct']}%")
        c.drawString(410, row_y, format_inr(product['gst_value']))
        c.drawString(480, row_y, format_inr(product['total_with_gst']))
        
        # Move to next row position based on the height needed
        row_y -= row_height + 5

    # Final grand total
    c.line(350, row_y - 10, width - 50, row_y - 10)
    c.setFont("Helvetica-Bold", 10)
    c.drawString(400, row_y - 25, "GRAND TOTAL")
    c.drawString(480, row_y - 25, format_inr(grand_total))

    # Bank & Terms
    bank_y = row_y - 60
    c.setFont("Helvetica", 10)
    c.drawString(50, bank_y, "Bank Details For True Vybes")
    c.drawString(50, bank_y - 15, "A/C Name: True Vybes")
    c.drawString(50, bank_y - 30, "A/C No.: 9747864920")
    c.drawString(50, bank_y - 45, "A/C Type: Current")
    c.drawString(50, bank_y - 60, "IFSC Code: KKBK0000656")

    terms_y = bank_y - 90
    c.drawString(50, terms_y, "Other terms and conditions:")
    c.drawString(50, terms_y - 15, "GST: Extra at actuals")
    c.drawString(50, terms_y - 30, "Payment terms: 50% advance and 50% before dispatch")
    c.drawString(50, terms_y - 45, "Lead Time: 1 to 2 days from the date of confirmed order and receipt of payment")
    c.drawString(50, terms_y - 60, "Validity: The validity of this price is 10 days from today")
    c.drawString(50, terms_y - 75, "Freight: Extra on To-Pay basis")

    c.line(width - 150, terms_y - 90, width - 50, terms_y - 90)
    c.drawString(width - 140, terms_y - 105, "Authorised Signatory")

    c.save()

    send_invoice_email(filename)

    return filename

def send_invoice_email(pdf_filename):
    SENDGRID_API_KEY = os.getenv("SENDGRID_API_KEY")
    if not SENDGRID_API_KEY:
        raise RuntimeError("SENDGRID_API_KEY is not set in your environment")

    message = Mail(
        from_email="truevybescg@gmail.com",
        to_emails="truevybescg@gmail.com",
        subject="New Proforma Invoice",
        html_content="<p>Dear True Vybes Team,<br><br>Please find attached the new Proforma Invoice.<br><br>Regards,<br>Automated System</p>"
    )

    with open(pdf_filename, "rb") as f:
        data = f.read()
        encoded = base64.b64encode(data).decode()

    attachment = Attachment()
    attachment.file_content = FileContent(encoded)
    attachment.file_type = FileType("application/pdf")
    attachment.file_name = FileName(os.path.basename(pdf_filename))
    attachment.disposition = Disposition("attachment")
    message.attachment = attachment

    try:
        sg = SendGridAPIClient(SENDGRID_API_KEY)
        response = sg.send(message)
        print(f"Email sent. Status code: {response.status_code}")
    except Exception as e:
        print(f"Error sending email: {e}")

# Gradio Interface
with gr.Blocks() as demo:
    gr.Markdown("# 📄 True Vybes NLP Proforma Invoice Generator")

    user_prompt = gr.Textbox(
        label="Proforma Invoice Request",
        placeholder="E.g. Create PI for Customer, GST-18902801280128, Addresss -Andheri Mumbai, 300 candles at 20 each with 5% GST, 500 umbrella at 200 each with GST 18%",
        lines=4
    )

    generate_btn = gr.Button("Generate Invoice")
    output_file = gr.File(label="Download Invoice")

    generate_btn.click(
        fn=generate_proforma_invoice_from_prompt,
        inputs=user_prompt,
        outputs=output_file
    )

if __name__ == "__main__":
    demo.launch(share=True)