app.py

import gradio as gr
import pandas as pd

# Create the tax rule DataFrame
data = {
    "Salary Range (Million Toman)": ["0 - 12", "12 - 16.5", "16.5 - 27", "27 - 40", "Above 40"],
    "Tax Rate (%)": [0, 10, 15, 20, 30],
    "Description": [
        "Exempt from tax", 
        "10% tax for this range", 
        "15% tax for this range", 
        "20% tax for this range", 
        "30% tax for this range"
    ]
}

df = pd.DataFrame(data)

def calculate_tax(salary):
    insurance = salary * 0.07  # 7% insurance deduction
    tax = 0
    
    if salary <= 12:
        tax = 0
    elif salary <= 16.5:
        tax = (salary - 12) * 0.10
    elif salary <= 27:
        tax = (16.5 - 12) * 0.10 + (salary - 16.5) * 0.15
    elif salary <= 4.0:
        tax = (16.5 - 12) * 0.10 + (27 - 16.5) * 0.15 + (salary - 27) * 0.20
    else:
        tax = (16.5 - 12) * 0.10 + (27 - 16.5) * 0.15 + (40 - 27) * 0.20 + (salary - 40) * 0.30
    
    net_income = salary - tax - insurance
    cost_percent = ((tax + insurance) / salary) * 100  # percentage of total cost
    return f"Tax: {tax:.3f} Million Toman", f"Insurance: {insurance:.3f} Million Toman", f"Net Salary: {net_income:.3f} Million Toman", f"Cost Percentage: {cost_percent:.2f}%"

def reverse_calculate(actual_income):
    low = 0.0  # minimum salary boundary
    high = actual_income / 0.93 * 1.5  # estimate upper bound
    gross_salary = 0

    # Using binary search to find the correct gross salary
    while high - low > 0.0001:
        mid = (low + high) / 2
        net_income_from_mid = float(calculate_tax(mid)[2].split()[2])
        if net_income_from_mid < actual_income:
            low = mid
        else:
            high = mid
    
    gross_salary = (low + high) / 2
    tax, insurance, _, _ = calculate_tax(gross_salary)
    cost_percent = ((gross_salary - actual_income) / gross_salary) * 100
    return f"Tax: {tax}", f"Insurance: {insurance}", f"Gross Salary: {gross_salary:.3f} Million Toman", f"Cost Percentage: {cost_percent:.2f}%"

# Gradio app interface
with gr.Blocks() as interface:
    gr.Markdown("### Iran Salary Tax Calculator (1403) - Million Toman")

    with gr.Row():
        with gr.Column():
            salary_input = gr.Number(label="Enter Gross Salary (Million Toman)", precision=3)
            tax_output = gr.Textbox(label="Tax")
            insurance_output = gr.Textbox(label="Insurance")
            net_income_output = gr.Textbox(label="Net Salary")
            cost_percent_output = gr.Textbox(label="Cost Percentage")
            salary_input.change(fn=calculate_tax, inputs=salary_input, outputs=[tax_output, insurance_output, net_income_output, cost_percent_output])
        
        with gr.Column():
            actual_income_input = gr.Number(label="Enter Net Salary (Million Toman)", precision=3)
            reverse_tax_output = gr.Textbox(label="Tax")
            reverse_insurance_output = gr.Textbox(label="Insurance")
            gross_salary_output = gr.Textbox(label="Gross Salary")
            reverse_cost_percent_output = gr.Textbox(label="Cost Percentage")
            actual_income_input.change(fn=reverse_calculate, inputs=actual_income_input, outputs=[reverse_tax_output, reverse_insurance_output, gross_salary_output, reverse_cost_percent_output])
    gr.Markdown("### Tax Calculation Rules")
    gr.DataFrame(df)
    
interface.launch()