#ifndef DCPU16_H_3XXIQQG2
#define DCPU16_H_3XXIQQG2

/* the target system's concept of a word */
typedef unsigned short DCPU16_WORD;

/* how much ram the system has */
#define DCPU16_RAM 0x10000

/* these are used for accounting/watchpointing/&c */
typedef unsigned int dcpu16_acct_event_;
#define DCPU16_ACCT_EV_READ     (1<<1)
#define DCPU16_ACCT_EV_WRITE    (1<<2)
#define DCPU16_ACCT_EV_NOP      (1<<3)

struct dcpu16_acct_cb {
    void (*fn)(dcpu16_acct_event_ e, DCPU16_WORD addr);
    dcpu16_acct_event_ mask;
};

/* a self-contained dcpu16 core */
struct dcpu16 {
    unsigned long long cycle;           /* number of cycles this core has executed */
    DCPU16_WORD reg[8];                 /* system registers, a b c x y z i j */
    DCPU16_WORD pc;                     /* program counter */
    DCPU16_WORD sp;                     /* stack pointer */
    DCPU16_WORD o;                      /* overflow */
    unsigned int skip_ : 1;             /* skip execution of next instruction */
    DCPU16_WORD ram[DCPU16_RAM];        /* memory */
    DCPU16_WORD reg_work_[2];           /* (private) work registers for holding literal values while decoding instructions */
    struct dcpu16_acct_cb *cb_table_;   /* list of callbacks to invoke under certain conditions */
    size_t cb_table_entries_;           /* callback list maintenance */
    size_t cb_table_allocated_;         /* callback list maintenance */
};

/* instantiate a new core */
struct dcpu16 *dcpu16_new(void);

/* reset a core to initial state */
void dcpu16_reset(struct dcpu16 *);

/* print the current state of a core */
void dcpu16_state_print(struct dcpu16 *);

/* print the contents of ram from second to third argument */
void dcpu16_dump_ram(struct dcpu16 *, DCPU16_WORD, DCPU16_WORD);

/* print the instruction at the specified address, returns number of words consumed in decoding */
DCPU16_WORD dcpu16_disassemble_print(struct dcpu16 *, DCPU16_WORD);

/* register a callback for an accounting event */
int dcpu16_acct_add(struct dcpu16 *, dcpu16_acct_event_ mask, void (*fn)(dcpu16_acct_event_, DCPU16_WORD));

/* execute the next instruction */
void dcpu16_step(struct dcpu16 *);

/* release a core */
void dcpu16_delete(struct dcpu16 **);

/* register callbacks to handle warning and debug messages, default is writing to stderr, may be set to null */
void dcpu16_warn_cb_set(void (*)(char *, ...));
void dcpu16_trace_cb_set(void (*)(char *, ...));

#endif /* DCPU16_H_3XXIQQG2 */