go-fds/blocks.go

package fds

import (
	"fmt"
)

type BlockType byte

const (
	BtInfo       BlockType = 0x01
	BtFileAmount BlockType = 0x02
	BtFileHeader BlockType = 0x03
	BtFileData   BlockType = 0x04
)

func (bt BlockType) String() string {
	switch bt {
	case BtInfo:
		return "BlockInfo"
	case BtFileAmount:
		return "BlockAmount"
	case BtFileHeader:
		return "BlockFileHeader"
	case BtFileData:
		return "BlockFileData"
	}

	return "Unknown block"
}

type DiskBlock interface {
	Type() BlockType
	String() string
}

// Block 1
type BlockInfo struct {
	// always 0x01
	BlockCode byte

	// literal ASCII: "*NINTENDO-HVC*"
	DiskVerification [14]byte
	Licensee uint8

	// 3 byte ASCII code
	GameName [3]byte

	// 0x20: " " normal disk
	// 0x45: "E" Event
	// 0x4A: "J" Unknown
	// 0x52: "R" Reduction in price via advert (lmao what?)
	GameType uint8

	GameVersion uint8
	SideNumber uint8
	DiskNumber uint8

	// 0x01 for FMC blue-disk
	// 0x00 otherwise
	DiskType uint8

	Unknown_18 uint8 // unknown; 0x00 in all known games

	BootReadFileCode uint8

	Unknown_1A [5]byte // unknown; 0xFF x5

	// BCD YMD, but 1-indexed from Japanese calendar era (fuck you, lmao).
	ManufacturingDate [3]byte

	CountryCode uint8 // 0x49 = japan
	Unknown_23 uint8 // region code?
	Unknown_24 uint8 // location/site?
	Unknown_25 [2]byte // raw: 0x00 0x22
	Unknown_27 [5]byte // game info representation?

	// BCD YMD (same as above).  Disk Writer kiosk write date?
	RewrittenDate [3]byte

	Unknown_2F uint8
	Unknown_30 uint8 // raw: 0x80

	DiskWriterSerial uint16

	Unknown_33 uint8 // raw: 0x07

	// BCD format. 0x00 == original
	RewriteCount byte

	// 0x00 = SideA; 0x01 = SideB
	ActualDiskSide uint8

	// 0x00 yellow
	// 0xFF blue
	// 0xFE prototype/internal (white or pink)
	DiskTypeOther uint8

	DiskVersion uint8

	// CRC-16/KERMIT. apparently this will work: github.com/sigurn/crc16
	CRC uint16 // omitted from FDS files (fucking whyyyyyyy)
}

func (b *BlockInfo) Type() BlockType {
	return BtInfo
}

func (b *BlockInfo) String() string {
	return fmt.Sprintf("FdsBlockInfo Licensee:%02X GameName:%q GameType:%c",
		b.Licensee,
		b.GameName,
		b.GameType,
	)
}

const Template_FdsBlockInfo string = `Licensee: {{.Licensee}}
  {{.LicEn}}
  {{.LicJp}}
Name: {{.GameName}} Version: {{.GameVersion}} Type: {{.GameType}}`

func (b *BlockInfo) Info() string {
	return "yup"
}

//func (b *BlockInfo) Info() string {
//	return fmt.Sprintf("Licensee:%02X\n %s\n %s\nGameName: %s",
//		b.Licensee,
//		LicenseeEnName(b.Licensee),
//		LicenseeJpName(b.Licensee),
//	)
//}

type BlockFileAmount struct {
	BlockCode byte // raw: 0x02
	FileAmount uint8
	CRC uint16 // omitted from FDS files (fucking whyyyyyyy)
}

func (b *BlockFileAmount) Type() BlockType {
	return BtFileAmount
}

func (b *BlockFileAmount) String() string {
	return fmt.Sprintf("BlockFileAmount FileAmount:%d", b.FileAmount)
}

type BlockFileHeader struct {
	BlockCode byte // raw: 0x03

	FileNumber uint8
	FileId uint8
	FileName [8]byte
	FileAddress uint16 // destination when loading
	FileSize uint16

	// 0x00: Program (PRAM)
	// 0x01: Character (CRAM)
	// 0x02: Nametable (VRAM)
	FileType uint8

	CRC uint16 // omitted from FDS files (fucking whyyyyyyy)
}

func (b *BlockFileHeader) Type() BlockType {
	return BtFileHeader
}

func (b *BlockFileHeader) String() string {
	return fmt.Sprintf("BlockFileHeader FileNumber:%d FileId:%d FileName:%q FileAddress:$%04X FileSize:%d FileType:%d",
		b.FileNumber,
		b.FileId,
		string(b.FileName[:]),
		b.FileAddress,
		b.FileSize,
		b.FileType,
	)
}

type BlockFileData struct {
	BlockCode byte // raw: 0x04

	// Disk data (FdsFileHeader.FileSize length)
	Data []byte

	CRC uint16 // omitted from FDS files (fucking whyyyyyyy)
}

func (b *BlockFileData) Type() BlockType {
	return BtFileData
}

func (b *BlockFileData) String() string {
	return "BlockFileData"
}