`include "seven_seg.sv"

module seven_seg_tb();
    logic [3:0] in_num;
    logic [0:0] in_rbi_inv;
    logic [7:0] out_segments;
    logic [7:0] true_segments[17];

    seven_seg dut(in_num, in_rbi_inv, out_segments);

    integer N;
    integer i;
    integer error_count;
    initial begin

        // Initialise truth table
        true_segments[0 ] = ~(8'b10111111);
        true_segments[1 ] = ~(8'b10000110);
        true_segments[2 ] = ~(8'b11011011);
        true_segments[3 ] = ~(8'b11001111);
        true_segments[4 ] = ~(8'b11100110);
        true_segments[5 ] = ~(8'b11101101);
        true_segments[6 ] = ~(8'b11111101);
        true_segments[7 ] = ~(8'b10000111);
        true_segments[8 ] = ~(8'b11111111);
        true_segments[9 ] = ~(8'b11100111);
        true_segments[10] = ~(8'b11110111);
        true_segments[11] = ~(8'b11111100);
        true_segments[12] = ~(8'b10111001);
        true_segments[13] = ~(8'b11011110);
        true_segments[14] = ~(8'b11111001);
        true_segments[15] = ~(8'b11110001);
        true_segments[16] = ~(8'b00000000); // Special case for RBI
        
        $display("Beginning seven-segment tests");

        in_num = 4'd0;
        in_rbi_inv = 1'b0;
        error_count = 0;
        #1;
        if (out_segments !== true_segments[16]) begin
            $display("\t\x1b[38;5;9mNumber 0b%b failed to decode to 0b%b, producing 0b%b\x1b[m", in_num, true_segments[16], out_segments);
            error_count = error_count + 1;
        end
        for (N=1; N < 15; ++N) begin
            in_num = in_num + 1;
            #1;
            if (out_segments !== true_segments[N]) begin
                $display("\t\x1b[38;5;9mNumber 0b%b failed to decode to 0b%b, producing 0b%b\x1b[m", in_num, true_segments[N], out_segments);
                error_count = error_count + 1;
            end
        end

        in_num = 4'd0;
        in_rbi_inv = 1'b1;
        for (N=0; N < 15; ++N) begin
            #1;
            if (out_segments !== true_segments[N]) begin
                $display("\t\x1b[38;5;9mNumber 0b%b failed to decode to 0b%b, producing 0b%b\x1b[m", in_num, true_segments[N], out_segments);
                error_count = error_count + 1;
            end
            in_num = in_num + 1;
        end

        if (error_count == 0) $display("\x1b[38;5;10mAll seven-segment tests passing\x1b[m");
        else $display("\x1b[38;5;9m%0d seven-segment test(s) failing\x1b[m", error_count);
    end
endmodule