Poke_Transporter_GB/include/link_handler.h

// Loosely based on code created by StevenChaulk
// Source: https://github.com/stevenchaulk/arduino-poke-gen2

#ifndef LINK_HANDLER_H_
#define LINK_HANDLER_H_

#include <tonc.h>
#include "libraries/gba-link-connection/LinkSPI.hpp"
#include "pokemon_party.h"

#define DATA_PER_PACKET 8
#define PACKET_DATA_START 2
#define PACKET_DATA_AT(i) (PACKET_DATA_START + (i * 2))
#define PACKET_FLAG_AT(i) (PACKET_DATA_START + (i * 2) + 1)
#define PACKET_CHECKSUM (PACKET_DATA_START + (2 * DATA_PER_PACKET))
#define PACKET_LOCATION_UPPER (PACKET_CHECKSUM + 1)
#define PACKET_LOCATION_LOWER (PACKET_CHECKSUM + 2)

// 0xFD, 0x00, data bytes per packet, flag bytes per packet, the checksum, and two location bytes
#define PACKET_SIZE (1 + 1 + (2 * DATA_PER_PACKET) + 1 + 2) // Originally 13

#define TIMEOUT 2
#define TIMEOUT_ONE_LENGTH 1000000 // Maybe keep a 10:1 ratio between ONE and TWO?
#define TIMEOUT_TWO_LENGTH 100000

#define SPI_TEXT_OUT_ARRAY_ELEMENT_SIZE 64

enum GameBoyROM
{
    RED_JP_v0,
    RED_JP_v1,
    RED_EN,
    RED_FR,
    RED_IT,
    RED_DE,
    RED_SP,
    GREEN_JP_v0,
    GREEN_JP_v1,
    BLUE_JP,
    BLUE_EN,
    BLUE_FR,
    BLUE_IT,
    BLUE_DE,
    BLUE_SP,
    YELLOW_JP_v0,
    YELLOW_JP_v1,
    YELLOW_JP_v2,
    YELLOW_JP_v3,
    YELLOW_EN,
    YELLOW_FR,
    YELLOW_IT,
    YELLOW_DE,
    YELLOW_SP,
    GOLD_JP_v0,
    GOLD_JP_v1,
    GOLD_EN,
    GOLD_FR,
    GOLD_IT,
    GOLD_DE,
    GOLD_SP,
    GOLD_KOR,
    SILVER_JP_v0,
    SILVER_JP_v1,
    SILVER_EN,
    SILVER_FR,
    SILVER_IT,
    SILVER_DE,
    SILVER_SP,
    SILVER_KOR,
    CRYSTAL_JP,
    CRYSTAL_EN,
    CRYSTAL_FR,
    CRYSTAL_IT,
    CRYSTAL_DE,
    CRYSTAL_SP,

    NO_GB_ROM,
    GB_ROM_ERROR,
};

// This table has the 3 checksums, followed by the enum value
const u16 GameBoyROMChecksumTable[][4]{
    {0x32, 0xA2, 0xC1, RED_JP_v0},
    {0x31, 0xB8, 0x66, RED_JP_v1},
    {0x20, 0x91, 0xE6, RED_EN},
    {0x18, 0x7A, 0xFC, RED_FR},
    {0x18, 0x89, 0xD2, RED_IT},
    {0x18, 0x5C, 0xDC, RED_DE},
    {0x18, 0x38, 0x4A, RED_SP},
    {0x9C, 0xDD, 0xD5, GREEN_JP_v0},
    {0x9B, 0xF5, 0x47, GREEN_JP_v1},
    {0xE5, 0xDC, 0x36, BLUE_JP},
    {0xD3, 0x9D, 0x0A, BLUE_EN},
    {0xCB, 0x56, 0xA4, BLUE_FR},
    {0xCB, 0x5E, 0x9C, BLUE_IT},
    {0xCB, 0x2E, 0xBC, BLUE_DE},
    {0xCB, 0x14, 0xD7, BLUE_SP},
    {0x20, 0x9C, 0x29, YELLOW_JP_v0},
    {0x1F, 0x88, 0x58, YELLOW_JP_v1},
    {0x1E, 0xED, 0xD9, YELLOW_JP_v2},
    {0x1D, 0xD9, 0x84, YELLOW_JP_v3},
    {0x97, 0x04, 0x7C, YELLOW_EN},
    {0x61, 0x66, 0xFB, YELLOW_FR},
    {0x5C, 0x4E, 0x8F, YELLOW_IT},
    {0x5F, 0xB7, 0xC1, YELLOW_DE},
    {0x52, 0x56, 0x37, YELLOW_SP},
    {0x48, 0x8A, 0x70, GOLD_JP_v0},
    {0x47, 0x84, 0x60, GOLD_JP_v1},
    {0x4B, 0x68, 0x2D, GOLD_EN},
    {0x4A, 0x6F, 0xC6, GOLD_FR},
    {0x47, 0xCE, 0x0C, GOLD_IT},
    {0x4C, 0xDC, 0x97, GOLD_DE},
    {0x3D, 0x93, 0x53, GOLD_SP},
    {0x08, 0x77, 0x8A, GOLD_KOR},
    {0x27, 0x76, 0x91, SILVER_JP_v0},
    {0x26, 0x1D, 0x34, SILVER_JP_v1},
    {0x2A, 0x0D, 0xAE, SILVER_EN},
    {0x29, 0xFB, 0x8C, SILVER_FR},
    {0x26, 0x73, 0x50, SILVER_IT},
    {0x2B, 0xCD, 0x6E, SILVER_DE},
    {0x1C, 0x06, 0x4B, SILVER_SP},
    {0xE7, 0x98, 0x5B, SILVER_KOR},
    {0x22, 0x9A, 0x40, CRYSTAL_JP},
    {0x26, 0x18, 0xD2, CRYSTAL_EN},
    {0x26, 0xF2, 0xE2, CRYSTAL_FR},
    {0x23, 0xDB, 0xBA, CRYSTAL_IT},
    {0x28, 0x49, 0x82, CRYSTAL_DE},
    {0x19, 0x42, 0xF4, CRYSTAL_SP},
};

enum CompositeState
{
    NO_COMPOSITE_STATE,
    INITIAL_CONNECTION
};

enum SubstateState
{
    NO_SUBSTATE,

    // INITIAL_CONNECTION
    CLOCK,
    SAVE_SUCCESS,
    MENU_OPEN,
    MENU_SUCCESS,
    WAIT_FOR_TRADE,
    TRADE_PREAMBLE,
    TRADE,
    MAIL,
    WAIT_FOR_PAYLOAD,
    GET_CHECKSUM,
    END,
};

enum LinkConnectionError
{
    NO_ERROR,
};

class LinkConnection
{
public:
    LinkConnection *globalPtr;

    CompositeState compState = NO_COMPOSITE_STATE;
    SubstateState subState = NO_SUBSTATE;

    CompositeState prevCompState = NO_COMPOSITE_STATE;
    SubstateState prevSubState = NO_SUBSTATE;

    LinkConnectionError lastError = NO_ERROR;

    uint8_t inData;
    uint8_t outData;

    int compStateCounter = 0; // the counter for the total number of bytes sent compstate
    int subStateCounter = 0;  // The counter for the total number of bytes sent in this substate

    int gen = 0;       // The generation we are trading with
    GameBoyROM currROM = NO_GB_ROM; // The GameBoy ROM we're communicating with

    int FF_count = 0;   // The number of 0xFF bytes that have been in a row
    int zero_count = 0; // The number of 0x00 bytes that have been in a row

    int mosi_delay = 4;      // inital delay, speeds up once sending
    int received_offset = 0; // The offset contained in the last packet
    int next_offset = 0;     // The offset we are sending in the next packet
    int packet_index = 0;    // The index of the current packet

    bool failed_packet = false;    // Flags if a packet failed
    bool init_packet = true;       // Flags if a packet is the inital one
    bool end_of_data = false;      // Flags if we are at the end of the data
    bool test_packet_fail = false; // ???

    byte data_packet[PACKET_SIZE];
    byte curr_payload[0x2A0];
    int curr_payload_size = 0;
    byte dataOutBuffer[0xFF];
    int dataOutBufferCurrIndex = 0;

    bool paused = false; // Used for pausing and sending one byte at a time

    void setup(const u16 *debug_charset);
    void startConnection(CompositeState startState);
    bool earlyExit();
    void exchangeBytes();
    void printData();
    void writeData();
    void handleStateLogic();

private:
    void load_universal_payload();
    void LoadCurrGameFromChecksum();
    void logicState_initConnection();

    // Used for debug features
#define LINE_WIDTH 24
#define NUM_LINES 8
    char stuff[NUM_LINES][LINE_WIDTH];
    char line[LINE_WIDTH] = "OUT";
    int link_cable_array_index = 0;
    int link_cable_memory_section_index = 0;
    const u16 *debug_charset;
};

extern LinkConnection globalLinkCable;
void linkCableIRQ();

#endif /* LINK_HANDLER_H_ */