#ifndef DRIVE_H
#define DRIVE_H

#include <stdbool.h>
#include <stdint.h>

#define DRIVE_LOOKAHEAD 16

extern const uint8_t SECTORS_PER_TRACK[40];
extern const uint8_t BITRATE_PER_TRACK[40];
extern const uint8_t GCR_CONV[16];

typedef struct drive_s {
	bool spinning;
	uint8_t timer;
	uint8_t *image;

	uint8_t track;
	uint8_t halftrack;
	uint32_t image_ptr;
	uint8_t sector;
	uint8_t byte;

	uint16_t gcr_word;
	uint8_t gcr_bits;
	uint8_t bit_counter;

	uint8_t gap_remain;
	uint8_t sync_remain;
	uint8_t header_remain;
	uint16_t data_remain;
	uint8_t data_checksum;

	uint8_t current_idx;
	uint8_t lookahead_idx;
	uint16_t unlatched[DRIVE_LOOKAHEAD];
	uint16_t latched[DRIVE_LOOKAHEAD];
	bool sync[DRIVE_LOOKAHEAD];
	bool byte_ready[DRIVE_LOOKAHEAD];
} drive_t;

void drive_init(drive_t *drive);
void drive_step_up(drive_t *drive);
void drive_step_down(drive_t *drive);
bool drive_cycle(drive_t *drive, uint8_t cycles, bool advance);

#endif