//static methods for calculations--------------------------------------------------------------------
static TaxOutput CalculateTax()
{
TaxOutput taxOutput = new TaxOutput();
double grossSalaryForCalculation = 0;
//deduct childcare vouchers before starting tax calculation
grossSalaryForCalculation = grossSalaryInput - childcareVoucherAmount;
taxOutput.PersonalAllowance = CalculatePersonalAllowance(grossSalaryForCalculation);
taxOutput.TaxBasicRate = CalculateBasicRateTax(grossSalaryForCalculation);
taxOutput.TaxHigherRate = CalculateHigherRateTax(grossSalaryForCalculation, taxOutput.PersonalAllowance);
taxOutput.TaxAdditionalRate = CalculateAdditionalRateTax(grossSalaryForCalculation);
taxOutput.NationalInsurance = CalculateNationalInsurance(grossSalaryForCalculation);
taxOutput.TotalDeductions = taxOutput.TaxBasicRate + taxOutput.TaxHigherRate + taxOutput.TaxAdditionalRate + taxOutput.NationalInsurance + childcareVoucherAmount + pensionAnnualAmount + studentLoanAnnualDeduction;
taxOutput.NetSalary = grossSalaryInput - taxOutput.TotalDeductions;
taxOutput.ChildcareVoucherAmount = childcareVoucherAmount;
taxOutput.PensionAnnualAmount = pensionAnnualAmount;
taxOutput.GrossSalaryInput = grossSalaryInput;
taxOutput.StudentLoanAnnualDeduction = studentLoanAnnualDeduction;
//add contributions
//if deductions exceed income
if (taxOutput.NetSalary < 0)
{
taxOutput.NetSalary = 0;
taxOutput.TotalDeductions = grossSalaryInput;
pensionAnnualAmount = grossSalaryInput - taxOutput.TaxBasicRate - taxOutput.TaxHigherRate - taxOutput.TaxAdditionalRate - taxOutput.NationalInsurance - childcareVoucherAmount - studentLoanAnnualDeduction;
}
return(taxOutput);
}
void DrawTaxGraph(TaxOutput taxOutput)
{
ClientScript.RegisterStartupScript(this.GetType(), "anything", "drawTax('" + taxOutput.NetSalary + "','"
+ taxOutput.TaxBasicRate + "','"
+ taxOutput.TaxHigherRate + "','"
+ taxOutput.TaxAdditionalRate + "','"
+ taxOutput.NationalInsurance + "','"
+ pensionAnnualAmount + "','"
+ childcareVoucherAmount + "');", true);
}
void DrawContributionsGraph(TaxOutput taxOutput)
{
ClientScript.RegisterStartupScript(this.GetType(), "anything", "drawContributions('" + taxOutput.PensionsContribution + "','"
+ taxOutput.HealthContribution + "','"
+ taxOutput.EducationContribution + "','"
+ taxOutput.DefenceContribution + "','"
+ taxOutput.WelfareContribution + "','"
+ taxOutput.ProtectionContribution + "','"
+ taxOutput.TransportContribution + "','"
+ taxOutput.GeneralContribution + "','"
+ taxOutput.OtherContribution + "','"
+ taxOutput.InterestContribution + "');", true);
}
protected void btnCalculateTax_Click(object sender, EventArgs e)
{
//TaxOutput taxOutput = new TaxOutput();
validInput = Double.TryParse(tbGrossSalary.Text, out grossSalaryInput);
if (validInput)
{
TaxOutput taxOutput = CalculateTax();
//output displayed with currency symbols and thousands separator
lblChildcareVoucherAmount.Text = childcareVoucherAmount.ToString("C");
lblStudentLoanAmount.Text = studentLoanAnnualDeduction.ToString("C");
lblpensionAnnualAmount.Text = pensionAnnualAmount.ToString("C");
lblPersonalAllowance.Text = taxOutput.PersonalAllowance.ToString("C");
lblBasicRateTax.Text = taxOutput.TaxBasicRate.ToString("C");
lblHigherRateTax.Text = taxOutput.TaxHigherRate.ToString("C");
lblAdditionalRateTax.Text = taxOutput.TaxAdditionalRate.ToString("C");
lblNationalInsurancePaid.Text = taxOutput.NationalInsurance.ToString("C");
lblTotalDeductions.Text = taxOutput.TotalDeductions.ToString("C");
lblNetSalary.Text = taxOutput.NetSalary.ToString("C");
//if user says they are paying more pension than they get in salary
if ((taxOutput.NetSalary == 0) && (pensionAnnualAmount > 0))
{
lblPensionError.Text = "Aren't your pension contributions a bit too high?";
}
double totalTaxAndNiPaid = taxOutput.TaxBasicRate + taxOutput.TaxHigherRate
+ taxOutput.TaxAdditionalRate + taxOutput.NationalInsurance;
taxOutput.PensionsContribution = totalTaxAndNiPaid * pensionsSpending;
taxOutput.HealthContribution = totalTaxAndNiPaid * healthSpending;
taxOutput.EducationContribution = totalTaxAndNiPaid * educationSpending;
taxOutput.DefenceContribution = totalTaxAndNiPaid * defenceSpending;
taxOutput.WelfareContribution = totalTaxAndNiPaid * welfareSpending;
taxOutput.ProtectionContribution = totalTaxAndNiPaid * protectionSpending;
taxOutput.TransportContribution = totalTaxAndNiPaid * transportSpending;
taxOutput.GeneralContribution = totalTaxAndNiPaid * generalSpending;
taxOutput.OtherContribution = totalTaxAndNiPaid * otherSpending;
taxOutput.InterestContribution = totalTaxAndNiPaid * interestSpending;
//DrawCharts(taxOutput);
//DrawTaxGraph(taxOutput);
//DrawContributionsGraph(taxOutput);
DrawBothCharts(taxOutput);
}
}
void DrawCharts(TaxOutput taxOutput)
{
hldataSource.Visible = true;
double totalTaxAndNiPaid = taxOutput.TaxBasicRate + taxOutput.TaxHigherRate
+ taxOutput.TaxAdditionalRate + taxOutput.NationalInsurance;
double pensionsContribution = totalTaxAndNiPaid * pensionsSpending;
double healthContribution = totalTaxAndNiPaid * healthSpending;
double educationContribution = totalTaxAndNiPaid * educationSpending;
double defenceContribution = totalTaxAndNiPaid * defenceSpending;
double welfareContribution = totalTaxAndNiPaid * welfareSpending;
double protectionContribution = totalTaxAndNiPaid * protectionSpending;
double transportContribution = totalTaxAndNiPaid * transportSpending;
double generalContribution = totalTaxAndNiPaid * generalSpending;
double otherContribution = totalTaxAndNiPaid * otherSpending;
double interestContribution = totalTaxAndNiPaid * interestSpending;
ClientScript.RegisterStartupScript(GetType(), "draw", "drawContributions('" + taxOutput.PersonalAllowance + "','"
+ taxOutput.TaxBasicRate + "','"
+ taxOutput.TaxHigherRate + "','"
+ taxOutput.TaxAdditionalRate + "','"
+ taxOutput.NationalInsurance + "','"
+ taxOutput.NetSalary + "','"
+ childcareVoucherAmount + "','"
+ studentLoanAnnualDeduction + "','"
+ pensionAnnualAmount + "','"
+ grossSalaryInput + "','"
+ pensionsContribution + "','"
+ healthContribution + "','"
+ educationContribution + "','"
+ defenceContribution + "','"
+ welfareContribution + "','"
+ protectionContribution + "','"
+ transportContribution + "','"
+ generalContribution + "','"
+ otherContribution + "','"
+ interestContribution + "','"
+ totalTaxAndNiPaid + "');", true);
}
void DrawBothCharts(TaxOutput taxOutput)
{
hldataSource.Visible = true;
ClientScript.RegisterStartupScript(this.GetType(), "anything", "draw('" + taxOutput.NetSalary + "','"
+ taxOutput.TaxBasicRate + "','"
+ taxOutput.TaxHigherRate + "','"
+ taxOutput.TaxAdditionalRate + "','"
+ taxOutput.NationalInsurance + "','"
+ taxOutput.PensionAnnualAmount + "','"
+ taxOutput.ChildcareVoucherAmount + "','"
+ taxOutput.StudentLoanAnnualDeduction + "','"
+ taxOutput.PensionsContribution + "','"
+ taxOutput.HealthContribution + "','"
+ taxOutput.EducationContribution + "','"
+ taxOutput.DefenceContribution + "','"
+ taxOutput.WelfareContribution + "','"
+ taxOutput.ProtectionContribution + "','"
+ taxOutput.TransportContribution + "','"
+ taxOutput.GeneralContribution + "','"
+ taxOutput.OtherContribution + "','"
+ taxOutput.InterestContribution
+ "');", true);
}
