using System;
using System.IO;

namespace DMGHeader {
    internal static class Program {
        internal static void DumpHeader(DmgHeader header) {
            Console.Write("Entry Point: ");
            if(header.EntryPoint.Jump == JumpType.None) {
                Console.WriteLine("No jump found.");
            } else {
                var jumpType = header.EntryPoint.Jump == JumpType.Absolute ? "Absolute" : "Relative";
                Console.WriteLine($"{jumpType} jump to ROM position 0x{header.EntryPoint.JumpAddress:X4}");
            }

            Console.WriteLine($"Logo Check: {(header.ValidLogo ? "PASSED" : "FAILED")}");
            Console.WriteLine($"Title/Manufacturer Code: {header.Title}");

            Console.Write("CGB Mode: ");
            switch(header.CgbMode) {
                case CgbMode.Disabled:
                    Console.WriteLine("Disabled");
                    break;
                case CgbMode.PaletteOnly:
                    Console.WriteLine("Palette Only");
                    break;
                case CgbMode.Enhanced:
                    Console.WriteLine("Enhanced");
                    break;
                case CgbMode.Required:
                    Console.WriteLine("Required");
                    break;
                default:
                    Console.WriteLine("Unknown");
                    break;
            }

            Console.WriteLine($"SGB: {(header.SgbSupport ? "Supported" : "Not Supported")}");
            Console.WriteLine($"Cartridge Type: {header.CartridgeType}");
            Console.WriteLine($"ROM Size: {header.RomSize}");
            Console.WriteLine($"Cartridge RAM Size: {header.ExternalRamSize}");

            Console.Write("Destination Code: ");
            switch(header.DestinationCode) {
                case DestinationCode.Japanese:
                    Console.WriteLine("Japanese");
                    break;
                case DestinationCode.NonJapanese:
                    Console.WriteLine("Non-Japanese");
                    break;
                case DestinationCode.Unknown:
                    Console.WriteLine("Unknown/Invalid Code");
                    break;
                default:
                    Console.WriteLine("-- INVALID ENUM VALUE -- ");
                    break;
            }

            Console.WriteLine($"Mask ROM Version: 0x{header.MaskRomVersion:X2}");
            Console.WriteLine($"Header Checksum: 0x{header.HeaderChecksum:X2}");
            Console.WriteLine($"Header Checksum Status: {(header.ValidHeaderChecksum ? "VALID" : "NOT VALID")}");
            Console.WriteLine($"Cartridge Checksum: 0x{header.CartridgeChecksum:X4}");
            Console.WriteLine();

        }

        private static int Main(string[] args) {
            if(args.Length == 0) {
                Console.WriteLine("usage: DMGHeader [filename]");
                return 0;
            }

            var filename = args[0];

            if(!File.Exists(filename)) {
                Console.WriteLine("File not found!");
                return 1;
            }

            var header = new DmgHeader(filename);
            DumpHeader(header);

            return 0;
        }
    }
}