#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#define rate_pension 5
#define health 1
int main()
{
        int choice, child;
        double income, gift, total,taxIncome, tax, remainder,temp1, temp2,temp3;
        char contr, insur,run;
        system("cls");
        while (9)
            {
                system("cls");
                printf(" Choose one of the following options: \n");
                printf(" 1. Tax calculator \n");
                printf(" 0. Exit \n");
                printf(" Your selection <0 -> 1>: ");
                scanf("%d",&choice);
                if ((choice!=0) && (choice!=1))
                   {
                      printf("*** Typing error. Please try again ***");
                      getch();
                   }
                else if (choice==0)
                    break;
                else if (choice==1)
                    {
                        head:system("cls");
                        printf("           Income tax Calculator \n");
                        printf("==================================================== \n");
                        printf("Enter personal information: \n");
                        so1:printf("Income for the current month <in thousand VND>: ");
                            scanf("%lf", &income);
                            if (income<0)
                            {
                            printf("\nInvalid input, try again.\n");
                            goto so1;
                            }
                        so2:printf("\n Pension contributions (%d%%) (y/n)? ",rate_pension,health);
                            fflush(stdin);
                            scanf("%c",&contr);
                            if ((contr!='y') && (contr!='Y') && (contr!='n')&& (contr!='N'))
                            {
                            printf("\nInvalid input, try again.\n");
                            goto so2;
                            }
                        so3:printf("\n Health insurance (%d%%) (y/n)? ",health,rate_pension);
                            fflush(stdin);
                            scanf("%c",&insur);
                            if ((insur!='y') && (insur!='Y') && (insur!='n')&& (insur!='N'))
                            {
                            printf("\nInvalid input, try again.\n");
                            goto so3;
                            }
                        so4:printf("\n Number of Dependants < 18 years old: ");
                            scanf("%d",&child);
                            if (child<0)
                            {
                            printf("\nInvalid input, try again.\n");
                            goto so4;
                            }
                        so5:printf("\n Gift of charity: ");
                            scanf("%lf",&gift);
                            if (gift<0&&gift>=income)
                            {
                            printf("\nInvalid input, try again.\n");
                            goto so5;
                            }
                        if ((contr=='y') || (contr=='Y'))
                            temp1=income*rate_pension/100;
                        else  temp1=0;
                        if ((insur=='y') || (insur=='Y'))
                            temp2=health*income/100;
                        else temp2=0;
                        temp3=child*1600;
                        total=4000 + temp1 + temp2 + temp3+gift;
                        remainder= income - total;
                        tax=0;

                        if (remainder<=5000) tax=tax + (remainder)*0.05;
                        if (remainder>5000) tax=tax + 0.05*5000;
                        if ((remainder>5000) && (remainder<=10000))
                           tax=tax + 0.10*(remainder-5000);
                        if ((remainder>5000) && (remainder>10000))
                           tax=tax + 0.10*(10000-5000);
                        if ((remainder>10000) && (remainder<=18000))
                           tax=tax + 0.15*(remainder - 10000);
                        if ((remainder>10000) && (remainder>18000))
                           tax=tax + 0.15*(18000-10000);
                        if ((remainder>18000) && (remainder<=32000))
                           tax=tax + 0.2*(remainder-18000);
                        if ((remainder>18000) && (remainder>32000))
                           tax=tax + 0.20*(32000-18000);
                        if ((remainder>32000) && (remainder<=52000))
                           tax=tax + (remainder-32000)*0.25;
                        if ((remainder>32000) && (remainder>52000))
                           tax=tax + 0.25*(52000-32000);
                        if ((remainder>52000) && (remainder<=80000))
                           tax=tax + (remainder-52000)*0.3;
                        if (remainder>80000) tax=tax + 0.35*(remainder-80000);
                        if ((remainder>52000) && (remainder>80000))
                           tax=tax + 0.3*(80000-52000);

                        printf("\nGross Income                      %5.1lf \n", income);
                        printf("Deduction: \n");
                        printf("   Personal allowance              4000.0 \n");
                        printf("   Pension contributions           %.1lf \n",temp1);
                        printf("   Health insurance                %.1lf \n",temp2);
                        printf("   Dependants                      %.1f \n",temp3);
                        printf("   Charity                         %.1lf \n",gift);
                        printf("   -----------------------------------------\n");
                        printf("   Total                           %.1lf \n",total);
                        printf("Taxable Income                     %.1lf \n",remainder);
                        printf("Income tax                         %.1lf \n",tax);
                        printf("Net Income                         %.1lf \n",income-tax);
                        so6:printf("\nAnother run (y/n)");
		                fflush(stdin);
                        scanf("%c",&run);
                        if ((run!='y') && (run!='Y') && (run!='n')&& (run!='N'))
                        {
                        printf("\nInvalid input, try again.\n");
                        goto so6;
                        }
						else if ((run=='y') || (run=='Y'))
						goto head;
						else if ((run=='n') || (run=='N'))
						break;
					    }
            }
        return(0);
}
/*
Assignment 1  - Income tax
Class ID               : CS1401
Student ID             : HE141012
Student Name           : Hà Long Duy
Due Date               : 18/03/2019
I declare that this assignment is my own work in accordance with FPT Policy.
*/