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#include "shim_deflate.h"
#include "igzip_lib.h"
#include "crc.h"

#include <stdio.h>
#include <stdlib.h>

int
deflateInit2_(z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy)
{
        if (!strm) {
                fprintf(stderr, "Error: z_streamp is NULL\n");
                return -1;
        }

#ifdef DEBUG
        fprintf(stderr,
                "\nInitializing deflate with level: %d, method: %d, windowBits: %d, memLevel: %d, "
                "strategy: %d\n",
                level, method, windowBits, memLevel, strategy);
#endif

        struct isal_zstream *isal_strm =
                (struct isal_zstream *) malloc(sizeof(struct isal_zstream));
        if (!isal_strm) {
                fprintf(stderr, "Error: Memory allocation for isal_zstream failed\n");
                return -1;
        }

        /* Setup ISA-L compression context */
        isal_deflate_init(isal_strm);

        isal_strm->end_of_stream = 0;
        isal_strm->flush = NO_FLUSH;
        strm->total_out = 0;
        strm->total_in = 0;

        // Map Zlib levels to ISA-L levels
        if (level >= 1 && level <= 2) {
                isal_strm->level = 1;
                isal_strm->level_buf = malloc(ISAL_DEF_LVL1_DEFAULT);
                isal_strm->level_buf_size = ISAL_DEF_LVL1_DEFAULT;
        } else if ((level >= 3 && level <= 6) || level == -1) {
                isal_strm->level = 2;
                isal_strm->level_buf = malloc(ISAL_DEF_LVL2_DEFAULT);
                isal_strm->level_buf_size = ISAL_DEF_LVL2_DEFAULT;
        } else if (level >= 7 && level <= 9) {
                isal_strm->level = 3;
                isal_strm->level_buf = malloc(ISAL_DEF_LVL3_DEFAULT);
                isal_strm->level_buf_size = ISAL_DEF_LVL3_DEFAULT;
        } else {
                fprintf(stderr, "Error: Invalid compression level\n");
                return -1;
        }

        if (!isal_strm->level_buf) {
                free(isal_strm);
                fprintf(stderr, "Error: Memory allocation for level_buf failed\n");
                return -1;
        }
        deflate_state *s = (deflate_state *) malloc(sizeof(deflate_state));
        if (!s) {
                free(isal_strm->level_buf);
                free(isal_strm);
                fprintf(stderr, "Error: Memory allocation for deflate_state failed\n");
                return -1;
        }

        s->level = level;
        s->w_bits = windowBits;
        s->strm = strm;

        // Set stream->gzip_flag and hist_bits
        // Ensure hist_bits are non-negative
        if (windowBits < 0) {
                // Raw deflate mode - no headers/trailers
                isal_strm->gzip_flag = IGZIP_DEFLATE;
                isal_strm->hist_bits = -windowBits;
        } else {
                // Standard zlib format
                isal_strm->gzip_flag = IGZIP_ZLIB;
                isal_strm->hist_bits = windowBits;
        }

        s->isal_strm = isal_strm;
        strm->state = (struct internal_state *) s;

        return Z_OK;
}

int
deflateInit_(z_streamp strm, int level)
{
        if (!strm) {
                fprintf(stderr, "Error: z_streamp is NULL\n");
                return -1;
        }

        return deflateInit2_(strm, level, 0, 15, 8, 0); // hardcoded windowBits
}

int
deflate(z_streamp strm, int flush)
{
        int ret;

        if (!strm) {
                fprintf(stderr, "Error: z_streamp is NULL\n");
                return -1;
        }

        deflate_state *s = (deflate_state *) strm->state;
        if (!s) {
                fprintf(stderr, "Error: deflate_state is NULL\n");
                return -1;
        }

        struct isal_zstream *isal_strm = s->isal_strm;
        if (!isal_strm) {
                fprintf(stderr, "Error: deflate isal_strm is NULL\n");
                return -1;
        }

        // set stream->avail_in, next_in, avail_out, next_out (from zstream)​
        isal_strm->next_out = strm->next_out;
        isal_strm->avail_out = strm->avail_out;
        isal_strm->next_in = strm->next_in;
        isal_strm->avail_in = strm->avail_in;
        isal_strm->total_out = strm->total_out;
        isal_strm->total_in = strm->total_in;

        // stream->flush mapping
        switch (flush) {
        case Z_NO_FLUSH:
                isal_strm->flush = NO_FLUSH;
                break;
        case Z_SYNC_FLUSH:
        case Z_PARTIAL_FLUSH:
        case Z_BLOCK:
                isal_strm->flush = SYNC_FLUSH;
                break;
        case Z_FULL_FLUSH:
                isal_strm->flush = FULL_FLUSH;
                break;
        case Z_FINISH:
                isal_strm->flush = FULL_FLUSH;
                isal_strm->end_of_stream = 1;
                break;
        default:
                fprintf(stderr, "Error: Invalid flush value\n");
                return -1;
        }

#ifdef DEBUG
        fprintf(stderr, "Gzip flag: %d, Window bits: %d, Flush: %d, Level: %d\n",
                isal_strm->gzip_flag, isal_strm->hist_bits, isal_strm->flush, isal_strm->level);
        fprintf(stderr, "Before isal_deflate: avail_in=%u, next_in=%p, avail_out=%u, next_out=%p\n",
                isal_strm->avail_in, isal_strm->next_in, isal_strm->avail_out, isal_strm->next_out);
        fprintf(stderr, "Total out: %u, Total in %lu\n", isal_strm->total_out, strm->total_in);
#endif

        int comp = isal_deflate(isal_strm);

        strm->avail_out = isal_strm->avail_out;
        strm->avail_in = isal_strm->avail_in;
        strm->next_in = isal_strm->next_in;
        strm->next_out = isal_strm->next_out;
        strm->total_out = isal_strm->total_out;
        strm->total_in = isal_strm->total_in;

#ifdef DEBUG
        fprintf(stderr, "After isal_deflate: avail_in=%u, next_in=%p, avail_out=%u, next_out=%p\n",
                strm->avail_in, strm->next_in, strm->avail_out, strm->next_out);
        fprintf(stderr, "Total out: %lu, Total in: %lu\n", strm->total_out, strm->total_in);
#endif

        if (comp == COMP_OK) {
                if (isal_strm->end_of_stream && isal_strm->avail_out > 0) {
                        ret = Z_STREAM_END; // Compression is done
                } else {
                        ret = Z_OK;
                }
        } else {
                ret = Z_ERRNO; // Compression error
        }

#ifdef DEBUG
        if (ret == Z_OK) {
                fprintf(stderr, "Deflate finished successfully Z_OK\n");
        } else if (ret == Z_STREAM_END) {
                fprintf(stderr, "Deflate finished successfully Z_STREAM_END\n");
        } else {
                fprintf(stderr, "Deflate finished with error code: %d\n", ret);
                switch (comp) {
                case INVALID_FLUSH:
                        fprintf(stderr, "Error: Invalid flush\n");
                        break;
                case INVALID_PARAM:
                        fprintf(stderr, "Error: Invalid parameter\n");
                        break;
                case STATELESS_OVERFLOW:
                        fprintf(stderr, "Error: Stateless overflow\n");
                        break;
                case ISAL_INVALID_OPERATION:
                        fprintf(stderr, "Error: Invalid operation\n");
                        break;
                case ISAL_INVALID_STATE:
                        fprintf(stderr, "Error: Invalid state\n");
                        break;
                case ISAL_INVALID_LEVEL:
                        fprintf(stderr, "Error: Invalid level\n");
                        break;
                case ISAL_INVALID_LEVEL_BUF:
                        fprintf(stderr, "Error: Invalid level buffer\n");
                        break;
                }
        }
#endif

        return ret;
}

int
deflateEnd(z_streamp strm)
{
        if (!strm) {
                fprintf(stderr, "Error: z_streamp is NULL\n");
                return -1;
        }

        // Free allocated memory for level_buf and isal_strm
        if (strm->state) {
                const deflate_state *s = (deflate_state *) strm->state;
                if (s && s->isal_strm) {
                        if (s->isal_strm->level_buf) {
                                free(s->isal_strm->level_buf);
                        }
                        free(s->isal_strm);
                }
                free(strm->state);
                strm->state = NULL;
        }

#ifdef DEBUG
        fprintf(stderr, "Deflate end\n");
#endif
        return Z_OK;
}

int
deflateSetHeader(z_streamp strm, void *head)
{
        (void) head; // Suppress unused parameter warning
        return Z_OK;
}

int
deflateSetDictionary(z_streamp strm, unsigned char *dict_data, unsigned int dict_len)
{
        if (!strm || !strm->state || !dict_data || dict_len == 0)
                return Z_STREAM_ERROR;

        deflate_state *s = (deflate_state *) strm->state;

        if (!s || !s->isal_strm)
                return Z_STREAM_ERROR;

        return isal_deflate_set_dict(s->isal_strm, dict_data, dict_len);
}

int
compress2(uint8_t *dest, unsigned long *dest_len, const uint8_t *source, unsigned long source_len,
          int level)
{
        z_stream strm;
        int err;
        const unsigned int max = (unsigned int) -1;
        unsigned long left = *dest_len;
        if (dest == NULL || dest_len == NULL || source == NULL) {
                return Z_STREAM_ERROR;
        }
        *dest_len = 0;

        strm.zalloc = NULL;
        strm.zfree = NULL;
        strm.opaque = NULL;

        err = deflateInit_(&strm, level);
        if (err != Z_OK)
                return err;

        strm.next_out = dest;
        strm.avail_out = 0;
        strm.next_in = (uint8_t *) source;
        strm.avail_in = 0;

        do {
                if (strm.avail_out == 0) {
                        strm.avail_out = left > (unsigned long) max ? max : (unsigned int) left;
                        left -= strm.avail_out;
                }
                if (strm.avail_in == 0) {
                        strm.avail_in =
                                source_len > (unsigned long) max ? max : (unsigned int) source_len;
                        source_len -= strm.avail_in;
                }
                err = deflate(&strm, source_len ? Z_NO_FLUSH : Z_FINISH);
        } while (err == Z_OK);

        *dest_len = strm.total_out;
        deflateEnd(&strm);

        return err == Z_STREAM_END ? Z_OK : err;
}

int
compress(uint8_t *dest, unsigned long *dest_len, const uint8_t *source, unsigned long source_len)
{
        return compress2(dest, dest_len, source, source_len, Z_DEFAULT_COMPRESSION);
}

unsigned long
crc32(unsigned long crc, const unsigned char *buf, unsigned int len)
{
        return crc32_gzip_refl(crc, buf, len);
}

unsigned long
adler32(unsigned long adler, const unsigned char *buf, unsigned int len)
{
        return isal_adler32(adler, buf, len);
}