#ifndef BYTEIO_H
#define BYTEIO_H

struct byte_writer {
    struct arena *arena;  /* If arena is set, then the writer cannot overflow and will instead allocate more memory as it grows */
    struct string buff;
    b32 overflowed;
    u8 *at;
};

struct byte_reader {
    struct string buff;
    b32 overflowed;
    u8 *at;
};

/* ========================== *
 * Writer
 * ========================== */

struct byte_writer bw_from_buffer(struct string buff);
struct byte_writer bw_from_arena(struct arena *arena);
struct byte_writer bw_branch(struct byte_writer *bw, u64 size);

void bw_seek(struct byte_writer *bw, u64 amount);
void bw_seek_to(struct byte_writer *bw, u64 pos);

void br_write_bytes(struct byte_writer *bw, struct string bytes);
void bw_write_u8(struct byte_writer *bw, u8 v);
void bw_write_u16(struct byte_writer *bw, u16 v);
void bw_write_u32(struct byte_writer *bw, u32 v);
void bw_write_u64(struct byte_writer *bw, u64 v);
void bw_write_i8(struct byte_writer *bw, i8 v);
void bw_write_i16(struct byte_writer *bw, i16 v);
void bw_write_i32(struct byte_writer *bw, i32 v);
void bw_write_i64(struct byte_writer *bw, i64 v);
void bw_write_var_uint(struct byte_writer *bw, u64 v);
void bw_write_var_sint(struct byte_writer *bw, i64 v);
void bw_write_f32(struct byte_writer *bw, f32 v);
void bw_write_f64(struct byte_writer *bw, f64 v);
void bw_write_v2(struct byte_writer *bw, struct v2 v);
void bw_write_string(struct byte_writer *bw, struct string str);

/* Returns a string containing written bytes only */
INLINE struct string bw_get_written(struct byte_writer *bw)
{
    struct string buff = ZI;
    buff.text = bw->buff.text;
    buff.len = bw->at - bw->buff.text;
    return buff;
}

INLINE u64 bw_pos(struct byte_writer *bw)
{
    return bw->at - bw->buff.text;
}

/* ========================== *
 * Reader
 * ========================== */

 /* Will fill struct with zeroes on overflow */
#define br_read_to_struct(br_ptr, var_ptr) (br_read_to_buffer(br_ptr, STRING(sizeof(*var_ptr), (u8 *)var_ptr)))

struct byte_reader br_from_buffer(struct string buff);

void *br_seek(struct byte_reader *br, u64 amount);
void *br_seek_to(struct byte_reader *br, u64 pos);

void br_read_to_buffer(struct byte_reader *br, struct string s);
u8 br_read_u8(struct byte_reader *br);
u16 br_read_u16(struct byte_reader *br);
u32 br_read_u32(struct byte_reader *br);
u64 br_read_u64(struct byte_reader *br);
i8 br_read_i8(struct byte_reader *br);
i16 br_read_i16(struct byte_reader *br);
i32 br_read_i32(struct byte_reader *br);
i64 br_read_i64(struct byte_reader *br);
u64 br_read_var_uint(struct byte_reader *br);
i64 br_read_var_sint(struct byte_reader *br);
f32 br_read_f32(struct byte_reader *br);
f64 br_read_f64(struct byte_reader *br);
struct v2 br_read_v2(struct byte_reader *br);
struct string br_read_string(struct arena *arena, struct byte_reader *br);

INLINE u64 br_bytes_left(const struct byte_reader *br)
{
    return br->overflowed ? 0 : br->buff.len - (br->at - br->buff.text);
}

INLINE u64 br_pos(struct byte_reader *br)
{
    return br->at - br->buff.text;
}

#endif