#ifndef LZW_H_
#define LZW_H_

#include <stddef.h>
#include <stdint.h>
#include <stdio.h>

struct lzw_dict_entry {
    uint16_t prefix; /* Code containing the first length-1 bytes in this code */
    uint16_t length; /* Length of this code */
    uint16_t usecount; /* How many codes have this code as a prefix */
    uint16_t lru_prev; /* Previous entry in the lru list */
    uint16_t lru_next; /* Next entry in the lru list */
    uint8_t last; /* Last byte in this code */
    uint8_t first; /* First byte in this code */
};

struct lzw_ctx {
    struct lzw_dict_entry dict[4096]; /* Dictionary entries */
    uint8_t output_buffer[4096]; /* Temporary buffer used to collect the byte string corresponding to a code */
    int eos; /* Flag indicating that the end of stream code was encountered */
    int input_buffer; /* Temporary buffer used in the extraction of 12bit codes from the compressed stream */
    uint16_t lru_head; /* Index of the first entry in the lru list */
    uint16_t lru_tail; /* Index of the last entry in the lru list */
    uint16_t last_emitted_code; /* Code emitted in the previous round */
    uint16_t output_buffer_start;
    uint16_t output_buffer_used;
    uint16_t input_code;
    uint16_t input_code_bits;
    size_t compressed_bytes_processed;
    size_t uncompressed_bytes_processed;
    size_t codes_processed;
};

void lzw_init(struct lzw_ctx* c);
int lzw_decompress(struct lzw_ctx* c, uint8_t* src, size_t src_count, size_t* src_consumed, uint8_t* dst, size_t dst_count, size_t* dst_consumed);

#endif