import gradio as gr
import pandas as pd
from fpdf import FPDF
from datetime import datetime
import tempfile  # Use for temporary file handling
import os

# Initialize an empty DataFrame to store all records of invoices (acting as our ledger)
ledger = pd.DataFrame(columns=["Head", "Company Name", "SP/Station", "Invoice No", "Date", "Amount"])

# Function to add a new invoice under a specific head
def add_invoice(head, company_name, sp_station, invoice_no, date, amount):
    global ledger
    try:
        # Add the new record to the ledger
        new_row = {
            "Head": head,
            "Company Name": company_name,
            "SP/Station": sp_station,
            "Invoice No": invoice_no,
            "Date": date,
            "Amount": float(amount)
        }
        ledger = pd.concat([ledger, pd.DataFrame([new_row])], ignore_index=True)

        # Filter the ledger for the selected head
        filtered_ledger = ledger[ledger["Head"] == head]

        # Calculate the total for the selected head
        total_amount = filtered_ledger["Amount"].sum()
        return filtered_ledger, f"Total for {head}: {total_amount}"

    except Exception as e:
        print(f"Error during adding invoice: {e}")
        return pd.DataFrame(), "Error during adding invoice"

# Function to search and display all previous records by head
def search_by_head(head):
    global ledger
    try:
        # Filter the ledger for the selected head
        filtered_ledger = ledger[ledger["Head"] == head]

        # Calculate the total for the selected head
        total_amount = filtered_ledger["Amount"].sum()

        return filtered_ledger, f"Total for {head}: {total_amount}"

    except Exception as e:
        print(f"Error during search by head: {e}")
        return pd.DataFrame(), "Error during search by head"

# Function to generate a PDF report for a specific head
def generate_ledger_pdf(head):
    global ledger
    try:
        # Use a temporary directory to save the file
        with tempfile.NamedTemporaryFile(delete=False, suffix=".pdf") as tmp_file:
            pdf_file_path = tmp_file.name  # Get the temporary file path

            # Create a PDF
            pdf = FPDF()
            pdf.add_page()
            pdf.set_font("Arial", 'B', 16)
            pdf.cell(200, 10, txt=f"Ledger Report for {head}", ln=True, align="C")
            pdf.set_font("Arial", size=12)
            current_date = datetime.now().strftime("%d/%m/%Y")
            pdf.cell(200, 10, txt=f"Report Date: {current_date}", ln=True, align="C")
            pdf.ln(10)

            # Table headers
            pdf.cell(40, 10, txt="Company Name", border=1, align="C")
            pdf.cell(40, 10, txt="SP/Station", border=1, align="C")
            pdf.cell(30, 10, txt="Invoice No", border=1, align="C")
            pdf.cell(30, 10, txt="Date", border=1, align="C")
            pdf.cell(50, 10, txt="Amount", border=1, ln=True, align="C")

            # Filter records by head
            filtered_ledger = ledger[ledger["Head"] == head]

            for _, row in filtered_ledger.iterrows():
                pdf.cell(40, 10, txt=str(row['Company Name']), border=1, align="C")
                pdf.cell(40, 10, txt=str(row['SP/Station']), border=1, align="C")
                pdf.cell(30, 10, txt=str(row['Invoice No']), border=1, align="C")
                pdf.cell(30, 10, txt=str(row['Date']), border=1, align="C")
                pdf.cell(50, 10, txt=str(row['Amount']), border=1, ln=True, align="C")

            # Total amount for the head
            total_amount = filtered_ledger["Amount"].sum()
            pdf.cell(140, 10, txt="Total Amount", border=1, align="R")
            pdf.cell(50, 10, txt=str(total_amount), border=1, ln=True, align="C")

            # Save PDF file
            pdf.output(pdf_file_path)

            # Return the file path for download
            return pdf_file_path

    except Exception as e:
        print(f"Error during PDF generation: {e}")
        return None

# Gradio interface
with gr.Blocks() as app:
    # Section for adding new invoices with Head and Company Name fields
    with gr.Row():
        head = gr.Textbox(label="Head")
        company_name = gr.Textbox(label="Company Name")
        sp_station = gr.Textbox(label="SP/Station")
        invoice_no = gr.Textbox(label="Invoice No")
        date = gr.Textbox(label="Date")
        amount = gr.Number(label="Amount")
        add_button = gr.Button("Add Invoice")
    
    # Section for searching and displaying ledger by head
    with gr.Row():
        search_head = gr.Textbox(label="Search by Head")
        search_button = gr.Button("Search Ledger")
        ledger_records = gr.DataFrame(label="Ledger Records")
        total_display = gr.Textbox(label="Total Amount", interactive=False)
    
    # Section for generating and displaying PDF link
    with gr.Row():
        generate_pdf_button = gr.Button("Generate PDF")
        pdf_output = gr.File(label="Download PDF")

    # Define button functionalities
    add_button.click(add_invoice, [head, company_name, sp_station, invoice_no, date, amount], [ledger_records, total_display])
    
    def search_ledger(head):
        filtered_ledger, total = search_by_head(head)
        return filtered_ledger, total

    search_button.click(search_ledger, [search_head], [ledger_records, total_display])

    def generate_pdf(head):
        pdf_path = generate_ledger_pdf(head)
        if pdf_path:
            return pdf_path
        else:
            return None

    generate_pdf_button.click(generate_pdf, [search_head], [pdf_output])

# Launch the app
app.launch(share=True)