#pragma once

#include <stdint.h>

typedef enum {
    R0 = 0,
    R1 = 1,
    R2 = 2,
    R3 = 3,
    Rbp = 4,
    Rsp = 5,
    Rip = 6,
    Rfl = 7,
    Rcs = 8,
} Reg;

typedef enum {
    Fl_Zero,
    Fl_Eq,
    Fl_Be,
    Fl_Lt,
    Fl_Err,
    Fl_Int,
    Fl_Vcd,
} Flag;

typedef enum {
    Op_Nop,
    Op_Hlt,
    Op_Jmp,
    Op_Jnz,
    Op_Test,
    Op_Cmp,
    Op_Mov8,
    Op_Mov16,
    Op_In,
    Op_Out,
    Op_Lit,
    Op_Int,
    Op_IRet,
    Op_Or,
    Op_Xor,
    Op_And,
    Op_Shl,
    Op_RShl,
    Op_Shr,
    Op_RShr,
    Op_Add,
    Op_Sub,
    Op_RSub,
    Op_Mul,
    Op_IMul,
    Op_Div,
    Op_IDiv,
    Op_RDiv,
    Op_RIDiv,
    Op_Mod,
    Op_RMod,
} Op;

typedef struct Drive Drive;
typedef void (*DriveReadFn)(Drive* drive, uint8_t* block, uint16_t i);
typedef void (*DriveWriteFn)(Drive* drive, const uint8_t* block, uint16_t i);

struct Drive {
    void* self;
    uint16_t block_size;
    uint16_t block_amount;
    DriveReadFn read;
    DriveWriteFn write;
};

typedef enum {
    InterruptType_None,
    InterruptType_Shutdown,
    InterruptType_KeyEvent,
} InterruptType;

typedef struct {
    InterruptType type;
    union {
        uint16_t keycode;
    };
} Interrupt;

#define VCD_BUFFER_OFFSET 0x0c00
#define VCD_BUFFER_SIZE 480
#define VCD_SCREEN_WIDTH 40
#define VCD_SCREEN_HEIGHT 12

typedef struct IODevice IODevice;
typedef void (*IODeviceSetCharFn)(
    IODevice* device, uint16_t offset, uint8_t value);
typedef void (*IODeviceWaitForInterruptFn)(IODevice* device);
typedef Interrupt (*IODeviceMaybeNextInterruptFn)(IODevice* device);

struct IODevice {
    void* self;
    IODeviceSetCharFn set_char;
    IODeviceWaitForInterruptFn wait_for_interrupt;
    IODeviceMaybeNextInterruptFn maybe_next_interrupt;
};

void vm_start(Drive* boot_drive, IODevice* io_device);

const char* op_str(Op op);