/* xslate.h */
#include "xshelper.h"

#if defined(__GNUC__) && !defined(TX_NO_DTC)
/* enable DTC optimization */
#define TX_DIRECT_THREADED_CODE
#endif

#define TX_RAW_CLASS   "Text::Xslate::Type::Raw"
#define TX_PAIR_CLASS  "Text::Xslate::Type::Pair"
#define TX_MACRO_CLASS "Text::Xslate::Type::Macro"

/* arbitrary initial buffer size */
#define TX_HINT_SIZE 200

/* max calling depth (execution/macrocall) */
#define TX_MAX_DEPTH 100

#define TXC(name) static void CAT2(TXCODE_, name)(pTHX_ tx_state_t* const txst PERL_UNUSED_DECL)
/* TXC_xxx macros provide the information of arguments, interpreted by tool/opcode.pl */
#define TXC_w_sv(n)   TXC(n) /* has TX_op_arg_sv as a SV */
#define TXC_w_key(n)  TXC(n) /* has TX_op_arg_sv as a keyword */
#define TXC_w_sviv(n) TXC(n) /* has TX_op_arg_sv able to SvIVX */
#define TXC_w_int(n)  TXC(n) /* has TX_op_arg_iv */
#define TXC_w_var(n)  TXC(n) /* has TX_op_arg_iv as a local variable index */
#define TXC_goto(n)   TXC(n) /* has TX_op_arg_pc for goto */

#define TXARGf_SV   ((U8)(0x01))
#define TXARGf_INT  ((U8)(0x02))
#define TXARGf_KEY  ((U8)(0x04))
#define TXARGf_VAR  ((U8)(0x08))
#define TXARGf_PC   ((U8)(0x10))

#define TXCODE_W_SV   (TXARGf_SV)
#define TXCODE_W_SVIV (TXARGf_SV | TXARGf_INT)
#define TXCODE_W_KEY  (TXARGf_SV | TXARGf_KEY)
#define TXCODE_W_INT  (TXARGf_INT)
#define TXCODE_W_VAR  (TXARGf_INT | TXARGf_VAR)
#define TXCODE_GOTO   (TXARGf_PC)

/* TX_st and TX_op are valid only in opcodes */
#define TX_st (txst)

#define TX_pop()   (*(PL_stack_sp--))

#define TX_frame_at(st, ix) ((AV*)AvARRAY((st)->frames)[ix])
#define TX_current_framex(st) TX_frame_at((st), (st)->current_frame)
#define TX_current_frame()    TX_current_framex(TX_st)

#define TX_CATCH_ERROR() UNLIKELY(!!sv_true(ERRSV))

/* template object, stored in $self->{template}{$file} */
enum tx_tobj_ix {
    TXo_MTIME,

    TXo_CACHEPATH,
    TXo_FULLPATH, /* TXo_FULLPATH must be the last one */
    /* dependencies here */
    TXo_least_size
};

/* vm execution frame object */
enum tx_frame_ix {
    TXframe_NAME,
    TXframe_OUTPUT,
    TXframe_RETADDR,

    TXframe_START_LVAR, /* TXframe_START_LVAR must be the last one */
    /* local variables here */
    TXframe_least_size = TXframe_START_LVAR
};

/* macro object */
enum tx_macro_ix {
    TXm_NAME,
    TXm_ADDR,
    TXm_NARGS,
    TXm_OUTER,

    TXm_size,
};

/* for-loop variables */
enum tx_for_ix {
    TXfor_ITEM,
    TXfor_ITER,
    TXfor_ARRAY,
};

struct tx_state_s;
struct tx_code_s;
struct tx_info_s;

typedef struct tx_state_s  tx_state_t;
typedef struct tx_code_s   tx_code_t;
typedef struct tx_info_s   tx_info_t;

#define TX_op            (TX_st->pc)
#define TX_PC2POS(st, p) ((UV)((p) - (st)->code))
#define TX_POS2PC(st, u) ((st)->code + (u))

typedef tx_code_t* tx_pc_t;

#define TX_RETURN_NEXT() STMT_START { TX_st->pc++;     return; } STMT_END
#define TX_RETURN_PC(x)  STMT_START { TX_st->pc = (x); return; } STMT_END

#ifdef TX_DIRECT_THREADED_CODE

typedef const void* tx_exec_t;
#define TX_RUNOPS(st) tx_runops(aTHX_ st)

#else /* TX_DIRECT_THREADED_CODE */

typedef void (*tx_exec_t)(pTHX_ tx_state_t* const);
#define TX_RUNOPS(st) STMT_START {                      \
        while((st)->pc->exec_code != TXCODE_end) {      \
            CALL_FPTR((st)->pc->exec_code)(aTHX_ (st)); \
        }                                               \
    } STMT_END

#endif /* TX_DIRECT_THREADED_CODE */

/* virtual machine state */
struct tx_state_s {
    tx_pc_t pc;      /* the program counter */

    tx_code_t* code; /* compiled code */
    U32        code_len;

    SV* output;

    /* registers */

    SV* sa;
    SV* sb;
    SV* targ;

    /* variables */

    HV* vars;    /* template variables */

    /* stack frame */
    AV* frames;        /* see enum txframeo_ix */
    I32 current_frame; /* current frame index */
    SV** pad;          /* AvARRAY(frame[current_frame]) + 3 */

    HV* symbol; /* symbol table (e.g. name => \&body | [macro object]) */

    U32 hint_size; /* suggested template size (bytes) */

    AV* tmpl;    /* template objects. see enum txtmplo_ix */
    SV* engine;  /* Text::Xslate instance */
    tx_info_t* info;  /* index -> an oinfo object */
};

/* opcode structure */
struct tx_code_s {
    tx_exec_t exec_code;

    union {
        SV*     sv;
        IV      iv;
        tx_pc_t pc;
    } u_arg;
};

/* opcode information */
struct tx_info_s {
    U16 optype;
    U16 line;
    SV* file;
};

#define TX_VERBOSE_DEFAULT 1

void
tx_warn(pTHX_ tx_state_t* const, const char* const fmt, ...)
    __attribute__format__(__printf__, pTHX_2, pTHX_3);

void
tx_error(pTHX_ tx_state_t* const, const char* const fmt, ...)
    __attribute__format__(__printf__, pTHX_2, pTHX_3);

const char*
tx_neat(pTHX_ SV* const sv);

SV*
tx_call_sv(pTHX_ tx_state_t* const st, SV* const sv, I32 const flags, const char* const name);

SV*
tx_proccall(pTHX_ tx_state_t* const st, SV* const proc, const char* const name);

SV*
tx_mark_raw(pTHX_ SV* const str);

SV*
tx_unmark_raw(pTHX_ SV* const str);

int
tx_sv_is_array_ref(pTHX_ SV* const sv);

int
tx_sv_is_hash_ref(pTHX_ SV* const sv);

int
tx_sv_is_code_ref(pTHX_ SV* const sv);

/* builtin method stuff */

SV*
tx_methodcall(pTHX_ tx_state_t* const st, SV* const method);

SV*
tx_merge_hash(pTHX_ tx_state_t* const st, SV* base, SV* value);

void
tx_register_builtin_methods(pTHX_ HV* const hv);