`timescale 1ns/1ps
module Parameterized_Ping_Pong_Counter (
    input clk,
    input rst_n,
    input enable,
    input flip,
    input [3:0] max,
    input [3:0] min,
    output reg direction,
    output reg [3:0] out
);

reg [3:0] pre_out;

always @(posedge clk or negedge rst_n) begin
    pre_out = out;
    if (!rst_n) begin
        out <= min;
        direction <= 1'b1;
    end
    else begin
        if (enable && (pre_out <= max && pre_out >= min) && max > min) begin
            if (flip) begin
                direction = !direction;
            end
            if (pre_out == max) begin
                direction = 1'b0;
            end
            else if (pre_out == min) begin
                direction = 1'b1;
            end
            if (direction == 1'b1) begin
                out <= pre_out + 1'b1;
            end
            else begin
                out <= pre_out - 1'b1;
            end
        end
    end
end

endmodule

// Output signals can be reg or wire
// add your design here
/*
reg [3:0] next_out;
reg [3:0] pre_out;
reg just_reset = 1'b0;

always @(*) begin
    if (enable) begin
        if (max == min) begin
            next_out = out;
        end
        if (max - min == 1) begin
            if (out == max) begin
                next_out = out - 1;
                direction = 1'b1;
            end
            else begin
                next_out = out + 1;
                direction = 1'b0;
            end
        end
        else begin
            if (out == max) begin
                next_out = out - 1;
            end
            else if (out == min) begin
                next_out = out + 1;
            end
            else if (pre_out == max || pre_out == min) begin
                if (just_reset) begin
                    if (direction) begin
                        next_out = out + 1;
                    end
                    else begin
                        next_out = out - 1;
                    end
                    just_reset = 0;
                end
                else begin
                    direction = !direction;
                    if (direction) begin
                        next_out = out + 1;
                    end
                    else begin
                        next_out = out - 1;
                    end
                end
            end
            else begin
                if (direction) begin
                    next_out = out + 1;
                end
                else begin
                    next_out = out - 1;
                end
            end
        end
    end
end

always @(posedge clk or negedge rst_n) begin
    if (~rst_n) begin
        out <= min;
        direction <= 1'b1;
        just_reset = 1'b1;
    end else begin
        if (enable) begin
            if (flip) begin
                if (direction) begin
                    direction <= 1'b0;
                end
                else begin
                    direction <= 1'b1;
                end
            end
            out <= next_out;
            pre_out <= out;
        end
    end
end

always @(negedge clk) begin
    next_out_value <= next_out;
    out_value = out;
end
*/

/*
        if (direction) begin
            if (out < max) begin
                next_out = out + 1'b1;
            end
            if (out == max) begin
                direction = 1'b0;
            end
        end
        else begin
            if (out > min) begin
                next_out = out - 1'b1;
            end
            if (out == min) begin
                direction = 1'b1;
            end
        end
*/

/*
            if (direction == 1'b1) begin
                if (count == 1'b0) begin
                    if (out == max) begin
                        next_out = out - 1'b1;
                        count = 1'b1;
                    end
                    else begin
                        next_out = out + 1'b1;
                    end
                end
                else begin
                    next_out = out - 1'b1;
                    direction = 1'b0;
                    count = 1'b0;
                end
            end
            else begin
                if (count == 1'b0) begin
                    if (out == min) begin
                        next_out = out + 1'b1;
                        count = 1'b1;
                    end
                    else begin
                        next_out = out - 1'b1;
                    end
                end
                else begin
                    next_out = out + 1'b1;
                    direction = 1'b1;
                    count= 1'b0;
                end
            end
*/