#ifndef AMALGAM_BYTECODE_H
#define AMALGAM_BYTECODE_H

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

#include <setjmp.h>

/*doc(Opcode)
    Variable length opcodes. Sizes range from 1 to 4 bytes.
    # Instruction formats
    Instructions can be in 7 different formats:
    1. 1 byte: Opcode(u8)
    2. 2 bytes: Opcode(u8) + register(u8)
    3. 3 bytes: Opcode(u8) + register(u8) + register(u8)
    4. 3 bytes:\
    4.1 Opcode(u8) + intermediate(u16)\
    4.2 Opcode(u8) + data(u16)\
    4.3 Opcode(u8) + offset(i16)\
    4.4 Opcode(u8) + num_reg(u16)\
    4.5 Opcode(u8) + register(u8) + num_args(u8)
    5. 4 bytes: Opcode(u8) + register(u8) + register(u8) + register(u8)
    6. 4 bytes:\
    6.1 Opcode(u8) + register(u8) + offset(i16)\
    6.2 Opcode(u8) + register(u8) + intermediate(u16)\
    6.3 Opcode(u8) + register(u8) + data(u16)
    7. 4 bytes: Opcode(u8) + index(u16) + num_args(u8)
*/
typedef enum {
    AMAL_OP_NOP,         /* No operation (do nothing). This can be used for patching code */
    AMAL_OP_SETZ,        /* setz reg             - Set register value to 0 */
    AMAL_OP_MOV,         /* mov dst, src         - Move src register to dst register */
    AMAL_OP_MOVI,        /* movi dst, src        - Move src intermediate to dst register */
    AMAL_OP_MOVD,        /* movd dst, src        - Move src data to dst register */
    AMAL_OP_ADD,         /* add dst, reg1, reg2  - Add reg1 and reg2 and put the result in dst */
    AMAL_OP_SUB,         /* sub dst, reg1, reg2  - Substract reg2 from reg1 and put the result in dst */
    AMAL_OP_IMUL,        /* imul dst, reg1, reg2 - Signed multiplication */
    AMAL_OP_MUL,         /* mul dst, reg1, reg2  - Unsigned multiplication */
    AMAL_OP_IDIV,        /* idiv dst, reg1, reg2 - Signed division */
    AMAL_OP_DIV,         /* div dst, reg1, reg2  - Unsigned division */
    AMAL_OP_PUSH,        /* push reg             - Push register onto stack */
    AMAL_OP_PUSHI,       /* pushi int            - Push intermediate onto stack */
    AMAL_OP_PUSHD,       /* pushd data           - Push data onto stack */
    AMAL_OP_CALL,        /* call fi, num_args    - Call a function using function index (fi) and num_args arguments. fi is u16 and num_args is u8 */
    AMAL_OP_CALLR,       /* callr reg, num_args  - Call a function using a register. Used for function pointers. num_args is u8 */
    AMAL_OP_CMP,         /* cmp dst, reg1, reg2  - Set dst to 1 if reg1 equals reg2, otherwise set it to 0 */
    AMAL_OP_JZ,          /* jz reg, offset       - Jump to offset if reg is zero. offset is i16 */
    AMAL_OP_JMP,         /* jmp offset           - Unconditional jump to offset. offset is i16 */
    AMAL_OP_RET,         /* ret                  - Return from the function */
    AMAL_OP_FUNC_START,  /* func_start num_reg   - Start of a function which has num_reg registers allocated. num_reg is a u16 */
    AMAL_OP_FUNC_END     /* func_end             - End of a function. Implementation should do a ret here */
} AmalOpcode;

typedef u8 AmalOpcodeType;

typedef struct {
    Buffer/*<headers + instruction data>*/ data;
} Bytecode;

typedef struct {
    jmp_buf env;
    Bytecode bytecode;
    Parser *parser; /* borrowed */
} BytecodeCompilerContext;

CHECK_RESULT int bytecode_init(Bytecode *self, ArenaAllocator *allocator);

/* longjump to self->env on failure */
void generate_bytecode_from_ssa(BytecodeCompilerContext *self);

#endif