#ifndef AMALGAM_SSA_H
#define AMALGAM_SSA_H

#include "../std/buffer.h"
#include "../std/hash_map.h"
#include "../std/defs.h"
#include "../defs.h"

#include <setjmp.h>

#define SSA_ERR_EXTERN_FUNC_SIG_MISMATCH -20

/* Important: The number of fields in this enum can't exceed 255 */
typedef enum {
    SSA_ASSIGN_INTER,
    SSA_ASSIGN_STRING,
    SSA_ASSIGN_REG,
    SSA_ADD,
    SSA_SUB,
    SSA_IMUL,
    SSA_MUL,
    SSA_IDIV,
    SSA_DIV,
    SSA_EQUALS,
    SSA_AND,
    SSA_FUNC_START,
    SSA_FUNC_END,
    SSA_PUSH,
    SSA_PUSH_RET,
    SSA_CALL_START,
    SSA_CALL,
    SSA_CALL_EXTERN,
    SSA_JUMP_ZERO,
    SSA_JUMP,
    SSA_RET,
    SSA_LABEL
} SsaInstruction;

typedef enum {
    SSA_NUMBER_TYPE_INTEGER,
    SSA_NUMBER_TYPE_FLOAT
} SsaNumberType;

typedef struct {
    union {
        i64 integer;
        f64 floating;
    } value;
    SsaNumberType type;
} SsaNumber;

typedef struct {
    FunctionSignature *func_sig;
    BufferView name;
} SsaExternFunc;

typedef struct {
    FunctionSignature *func_sig;
    BufferView name;
} SsaExportFunc;

typedef struct {
    FunctionSignature *func_sig;
} SsaFunc;

typedef i16 JumpOffset;
typedef i16 SsaRegister;
typedef u16 SsaIntermediateIndex;
typedef u16 SsaStringIndex;
typedef u16 SsaExternFuncIndex;
typedef u16 SsaExportFuncIndex;
typedef u16 SsaFuncIndex;
typedef u16 SsaLabelIndex;

typedef struct {
    Buffer/*instruction data*/ instructions;
    HashMapType(SsaNumber, SsaIntermediateIndex) intermediates_map;
    Buffer/*SsaNumber*/ intermediates;
    HashMapType(BufferView, SsaStringIndex) strings_map;
    Buffer/*BufferView*/ strings;
    HashMapType(BufferView, SsaExternFuncIndex) extern_funcs_map;
    Buffer/*SsaExternFunc*/ extern_funcs;
    Buffer/*SsaExportFunc*/ export_funcs;
    Buffer/*SsaFunc*/ funcs;

    SsaIntermediateIndex intermediate_counter;
    SsaStringIndex string_counter;
    SsaExternFuncIndex extern_func_counter;
    SsaExportFuncIndex export_func_counter;
    SsaFuncIndex func_counter;
    SsaRegister reg_counter;
    SsaRegister param_counter;
    SsaLabelIndex label_counter;
    Parser *parser; /* Borrowed */
} Ssa;

typedef struct {
    SsaRegister lhs;
    u16 rhs;
} SsaInsForm1;

typedef struct {
    SsaRegister result;
    SsaRegister lhs;
    SsaRegister rhs;
} SsaInsForm2;

typedef struct {
    u8 flags;
    u16 num_local_vars_regs;
} SsaInsFuncStart;

typedef struct {
    FunctionDecl *func_decl;
    u8 import_index;
} SsaInsFuncCall;

typedef struct {
    LhsExpr *func_decl_lhs;
    int import_index;
} SsaInsFuncCallExtern;

typedef struct {
    u8 num_args;
} SsaInsCallStart;

typedef struct {
    SsaRegister condition_reg;
    SsaLabelIndex target_label;
} SsaInsJumpZero;

typedef struct {
    SsaLabelIndex target_label;
} SsaInsJump;

/* None of these functions are thread-safe */
SsaNumber create_ssa_integer(i64 value);
SsaNumber create_ssa_float(f64 value);

SsaNumber ssa_get_intermediate(Ssa *self, SsaIntermediateIndex index);
BufferView ssa_get_string(Ssa *self, SsaStringIndex index);

CHECK_RESULT int ssa_init(Ssa *self, Parser *parser);

typedef struct {
    jmp_buf env;
    Ssa *ssa;
    amal_compiler *compiler;
    /* 0 if the current scope belongs to the file, otherwise ParserFileScopeReference's import_index (the import file that contains the scope) */
    u8 import_index;
} SsaCompilerContext;

/* longjump to context->env on failure */
void scope_generate_ssa(Scope *self, SsaCompilerContext *context);

#endif