#include "lzw.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int decompress_file(char* filename)
{
    char* outfilename;
    FILE *fp, *outfp;
    int i;
    unsigned int ifnlen, ofnlen;
    struct lzw_ctx* ctx;
    uint8_t bufin[4096], bufout[4096];
    uint8_t *pin, *pout;
    size_t to_decompress, space;
    int res;

    ctx = (struct lzw_ctx*)malloc(sizeof(struct lzw_ctx));
    if (ctx == NULL)
        return 0;
    lzw_init(ctx);

    fp = fopen(filename, "rb");
    if (fp == NULL) {
        perror("fopen()");
        return -1;
    }

    /* NOLINTBEGIN(clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling) */
    ifnlen = strlen(filename);
    ofnlen = ifnlen + 5;
    outfilename = (char*)malloc(ofnlen);
    strncpy(outfilename, filename, ofnlen);
    for (i = ifnlen - 1; i > 0 && outfilename[i] != '/'; i--)
        if (outfilename[i] == '.') {
            outfilename[i] = '\0';
            break;
        }
    if (strcmp(filename, outfilename) == 0)
        strncat(outfilename, ".out", ofnlen);
    /* NOLINTEND(clang-analyzer-security.insecureAPI.DeprecatedOrUnsafeBufferHandling) */

    printf("Writing to %s\n", outfilename);
    outfp = fopen(outfilename, "wb");
    if (outfp == NULL) {
        perror("fopen()");
        free(outfilename);
        return -1;
    }

    to_decompress = 0;
    space = sizeof(bufout);
    pout = bufout;
    while (ctx->eos == 0) {
        if (to_decompress == 0) {
            to_decompress = fread(bufin, 1, sizeof(bufin), fp);
            pin = bufin;
        }
        if (space == 0) {
            fwrite(bufout, 1, sizeof(bufout), outfp);
            space = sizeof(bufout);
            pout = bufout;
        }
        res = lzw_decompress(ctx, pin, &to_decompress, pout, &space);
        pin = bufin + sizeof(bufin) - to_decompress;
        pout = bufout + sizeof(bufout) - space;
    }
    if (space < sizeof(bufout))
        fwrite(bufout, 1, sizeof(bufout) - space, outfp);

    free(outfilename);
    fclose(outfp);
    fclose(fp);

    return 0;
}

int main(int argc, char* argv[])
{
    int i;

    for (i = 1; i < argc; i++) {
        printf("Decompressing %s\n", argv[i]);
        decompress_file(argv[i]);
    }

    return EXIT_SUCCESS;
}