library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;

entity shoupiao is
port
( clk :in std_logic;
  cancel:in std_logic;
  reset : in std_logic;
  ok :in std_logic;
destination:in integer range 1 to 12;
  initial : in integer range 1 to 12;
  number : in integer range 1 to 3;
  coin05 :in std_logic;
  coin1 :in std_logic;
  paper1: in std_logic;
   paper2:in std_logic;
   paper5:in std_logic;
  paper10:in std_logic;
  comeout: out std_logic;
  charge: out integer range 1 to 20
);
end shoupiao;

architecture behave of shoupiao is
   type state is (s0,s1,s2,s3);
   signal s : state;
   
    
   begin

      
  process(clk,reset)
    variable money: integer:=0;
    variable cost : integer:=0;
    variable trip : integer:=0;
   begin  
      if reset='1' then
            s<=s0;
     else
       if clk'event and clk='1' then
       case s is 
       when s0=>
        if  ok='1' then
              s<=s1;
          else
               s<=s0;
      end if;
       when s1=>
        if destination /= initial then
             if destination > initial then
                trip:=(destination-initial);
             elsif destination<initial then
                trip:=(initial-destination);
               end if; 
              s<=s2;
          else
              s<=s1;
        end if;
        when s2=>
          if cancel='1' then
             s<=s1;
          end if;      
        if number=1 then
           if trip<=6 then
           cost:=4;
          else cost:=8;
          end if;
            s<=s3;
        elsif number=2 then
           if trip<=6 then
           cost:=8;
           else cost:=16;
           end if;
             s<=s3;
        elsif number=3 then
           if trip<=6 then
           cost:=12;
            else cost:=24;
               end if;
             s<=s3;
         else s<=s2;
         end if;
        when s3=>
           if cancel='1' then
            s<=s1;
          end if;
             if money=cost then
            comeout<='1';
           elsif money>=cost then
             comeout<='1';
             charge<=money-cost;
           elsif coin05='1' then
             money:=money+1;
           elsif coin1='1' then
              money:=money+2;
            elsif paper1='1' then
              money:=money+2;
            elsif paper2='1' then
              money:=money+4;
            elsif paper5='1' then
              money:=money+10;
            elsif paper10='1' then
              money:=money+20;
            else s<=s3;
             end if;
                   end case;
                      end if;
    end if;
                         end process;
                           end behave;