#ifndef AMALGAM_IR_H
#define AMALGAM_IR_H

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

#include <setjmp.h>

#define IR_ERR_EXTERN_FUNC_SIG_MISMATCH -20

/* Important: The number of fields in this enum can't exceed 255 */
typedef enum {
    IR_ASSIGN_INTER,
    IR_ASSIGN_STRING,
    IR_ASSIGN_REG,
    IR_ASSIGN_FUNC,
    IR_ADD,
    IR_SUB,
    IR_IMUL,
    IR_MUL,
    IR_IDIV,
    IR_DIV,
    IR_EQUALS,
    IR_NOT_EQUAL,
    IR_AND,
    IR_ILT,
    IR_ILE,
    IR_IGT,
    IR_IGE,
    IR_LT,
    IR_LE,
    IR_GT,
    IR_GE,
    IR_FUNC_START,
    IR_FUNC_END,
    IR_PUSH,
    IR_PUSH_RET,
    IR_CALL_START,
    IR_CALL,
    IR_CALL_EXTERN,
    IR_CALLR,
    IR_JUMP_ZERO,
    IR_JUMP,
    IR_RET,
    IR_LABEL
} IrInstruction;

typedef enum {
    IR_NUMBER_TYPE_INTEGER,
    IR_NUMBER_TYPE_FLOAT
} IrNumberType;

typedef struct {
    union {
        i64 integer;
        f64 floating;
    } value;
    IrNumberType type;
} IrNumber;

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

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

typedef struct {
    FunctionSignature *func_sig;
} IrFunc;

typedef i16 JumpOffset;
typedef i16 IrRegister;
typedef u16 IrIntermediateIndex;
typedef u16 IrStringIndex;
typedef u16 IrExternFuncIndex;
typedef u16 IrExportFuncIndex;
typedef u16 IrFuncIndex;
typedef u16 IrLabelIndex;

typedef struct {
    Buffer/*instruction data*/ instructions;
    HashMapType(IrNumber, IrIntermediateIndex) intermediates_map;
    Buffer/*IrNumber*/ intermediates;
    HashMapType(BufferView, IrStringIndex) strings_map;
    Buffer/*BufferView*/ strings;
    HashMapType(BufferView, IrExternFuncIndex) extern_funcs_map;
    Buffer/*IrExternFunc*/ extern_funcs;
    Buffer/*IrExportFunc*/ export_funcs;
    Buffer/*IrFunc*/ funcs;

    IrIntermediateIndex intermediate_counter;
    IrStringIndex string_counter;
    IrExternFuncIndex extern_func_counter;
    IrExportFuncIndex export_func_counter;
    IrFuncIndex func_counter;
    IrRegister reg_counter;
    IrRegister param_counter;
    IrLabelIndex label_counter;
    Parser *parser; /* Borrowed */
} Ir;

typedef struct {
    IrRegister lhs;
    u16 rhs;
} IrInsForm1;

typedef struct {
    IrRegister result;
    IrRegister lhs;
    IrRegister rhs;
} IrInsForm2;

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

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

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

typedef struct {
    u8 num_args;
} IrInsCallStart;

typedef struct {
    IrRegister condition_reg;
    IrLabelIndex target_label;
} IrInsJumpZero;

typedef struct {
    IrLabelIndex target_label;
} IrInsJump;

/* None of these functions are thread-safe */
IrNumber create_ir_integer(i64 value);
IrNumber create_ir_float(f64 value);

IrNumber ir_get_intermediate(Ir *self, IrIntermediateIndex index);
BufferView ir_get_string(Ir *self, IrStringIndex index);

CHECK_RESULT int ir_init(Ir *self, Parser *parser);

typedef struct {
    jmp_buf env;
    Ir *ir;
    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;
} IrCompilerContext;

/* longjump to context->env on failure */
void scope_generate_ir(Scope *self, IrCompilerContext *context);
/* longjump to context->env on failure */
void scope_generate_function_ids(Scope *self, IrCompilerContext *context);
/* longjump to context->env on failure */
void scope_generate_functions_ir(Scope *self, IrCompilerContext *context);

#endif