#ifndef LCOLONQ_6502_H
#define LCOLONQ_6502_H

#include <lcq/6502/types.h>

typedef enum {
    L6502_FLAG_CARRY = 1 << 1,
    L6502_FLAG_ZERO = 1 << 2,
    L6502_FLAG_INTERRUPT_DISABLE = 1 << 3,
    L6502_FLAG_DECIMAL = 1 << 4,
    L6502_FLAG_BREAK_COMMAND = 1 << 5,
    L6502_FLAG_OVERFLOW = 1 << 6,
    L6502_FLAG_NEGATIVE = 1 << 7,
} l6502_flag;

typedef enum {
    L6502_REG_SP = 0,
    L6502_REG_A,
    L6502_REG_X,
    L6502_REG_Y,
    L6502_REG_FLAGS,
    L6502_REG__MARKER,
} l6502_reg;

typedef u8 (*l6502_mem_read_handler)(void *data, u16 addr);
typedef void (*l6502_mem_write_handler)(void *data, u16 addr, u8 val);
typedef struct {
    l6502_mem_read_handler rh;
    l6502_mem_write_handler wh;
    void *data;
} l6502_mem;
void l6502_mem_basic_new(l6502_mem *m);

typedef struct {
    u16 pc;
    u8 regs[L6502_REG__MARKER];
    l6502_mem mem;
} l6502_emu;

static inline u8 l6502_flag_get(l6502_emu *e, l6502_flag f) { return (e->regs[L6502_REG_FLAGS] & (u8) f) != 0; }
static inline void l6502_flag_set(l6502_emu *e, l6502_flag f, u8 v) {
    if (v) e->regs[L6502_REG_FLAGS] |= (u8) f;
    else e->regs[L6502_REG_FLAGS] &= ~((u8) f);
}
static inline u8 l6502_read(l6502_emu *e, u16 addr) { return e->mem.rh(e->mem.data, addr); }
static inline void l6502_write(l6502_emu *e, u16 addr, u8 val) { e->mem.wh(e->mem.data, addr, val); }
static inline u16 l6502_read_addr(l6502_emu *e, u16 addr) {
    u8 alo = l6502_read(e, addr);
    u8 ahi = l6502_read(e, addr + 1);
    return ahi << 8 | alo;
}
static inline u8 l6502_pop(l6502_emu *e) { return l6502_read(e, 0x0100 + (u16) ++e->regs[L6502_REG_SP]); }
static inline void l6502_push(l6502_emu *e, u8 val) { l6502_write(e, 0x0100 + (u16) e->regs[L6502_REG_SP]--, val); }
static inline u16 l6502_pop_addr(l6502_emu *e) {
    u8 ahi = l6502_pop(e);
    u8 alo = l6502_pop(e);
    return ahi << 8 | alo;
}
static inline void l6502_push_addr(l6502_emu *e, u16 addr) {
    l6502_push(e, (u8) (addr & 0xff));
    l6502_push(e, (u8) (addr >> 8));
}

void l6502_emulate(l6502_emu *e);

#endif