#ifdef _MSC_VER
#  define _CRT_SECURE_NO_WARNINGS
#endif

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <limits.h>

#ifndef PATH_MAX
#  define PATH_MAX MAX_PATH
#endif

#define SEARCH_PATHS_MAX 64
#define FILE_PATHS_MAX 1024

static int fline(char **line, size_t *n, FILE *fp) {
    int chr;
    char *pos;
    if (!line || !n || !fp)
        return -1;
    if (!*line)
        if (!(*line = (char *)malloc((*n=64))))
            return -1;
    chr = *n;
    pos = *line;
    for (;;) {
        int c = fgetc(fp);
        if (chr < 2) {
            *n += (*n > 16) ? *n : 64;
            chr = *n + *line - pos;
            if (!(*line = (char *)realloc(*line,*n)))
                return -1;
            pos = *n - chr + *line;
        }
        if (ferror(fp))
            return -1;
        if (c == EOF) {
            if (pos == *line)
                return -1;
            else
                break;
        }
        *pos++ = c;
        chr--;
        if (c == '\n')
            break;
    }
    *pos = '\0';
    return pos - *line;
}

static FILE *open_file(const char *name, const char *mode, const char (*searches)[PATH_MAX], int count) {
    int i;
    for (i = 0; i < count; i++) {
        char buffer[FILENAME_MAX + PATH_MAX];
        FILE *fp;
#ifndef _MSC_VER
        snprintf(buffer, sizeof(buffer), "%s/%s", searches[i], name);
#else
        _snprintf(buffer, sizeof(buffer), "%s/%s", searches[i], name);
#endif
        if ((fp = fopen(buffer, mode)))
            return fp;
    }
    return !count ? fopen(name, mode) : NULL;
}

static int strcicmp(const char *s1, const char *s2) {
    const unsigned char *us1 = (const unsigned char *)s1,
                        *us2 = (const unsigned char *)s2;
    while (tolower(*us1) == tolower(*us2)) {
        if (*us1++ == '\0')
            return 0;
        us2++;
    }
    return tolower(*us1) - tolower(*us2);
}

/* styles */
enum { kCamel, kSnake };
/* identifiers */
enum { kData, kEnd, kSize };

static const char *styled(int style, int ident) {
    switch (style) {
    case kCamel:
        switch (ident) {
        case kData: return "Data";
        case kEnd: return "End";
        case kSize: return "Size";
        }
        break;
    case kSnake:
        switch (ident) {
        case kData: return "_data";
        case kEnd: return "_end";
        case kSize: return "_size";
        }
        break;
    }
}

int main(int argc, char **argv) {
    int ret, i, paths, files = 0, style = kCamel;
    char outfile[FILENAME_MAX] = "data.c";
    char search_paths[SEARCH_PATHS_MAX][PATH_MAX];
    char prefix[FILENAME_MAX] = "g";
    char file_paths[FILE_PATHS_MAX][PATH_MAX];
    FILE *out = NULL;

    argc--;
    argv++;

    #define s(IDENT) styled(style, IDENT)

    if (argc == 0) {
usage:
        fprintf(stderr, "%s [-help] [-Ipath...] | <files> | [-o output] | [-p prefix]\n", argv[-1]);
        fprintf(stderr, "   -o         - output file [default is \"data.c\"]\n");
        fprintf(stderr, "   -p         - specify a prefix for symbol names (default is \"g\")\n");
        fprintf(stderr, "   -S<style>  - specify a style for symbol generation (default is \"camelcase\")\n");
        fprintf(stderr, "   -I<path>   - specify an include path for the tool to use\n");
        fprintf(stderr, "   -help      - this\n");
        fprintf(stderr, "example:\n");
        fprintf(stderr, "   %s icon.png music.mp3 -o file.c\n", argv[-1]);
        fprintf(stderr, "styles (for -S):\n");
        fprintf(stderr, "   camelcase\n");
        fprintf(stderr, "   snakecase\n");
        return 1;
    }

    for (i = 0, paths = 0; i < argc; i++) {
        if (!strcmp(argv[i], "-o")) {
            if (i + 1 < argc) {
                strcpy(outfile, argv[i + 1]);
                memmove(argv+i+1, argv+i+2, (argc-i-2) * sizeof *argv);
                argc--;
                continue;
            }
        } else if (!strcmp(argv[i], "-p")) {
            /* supports "-p" with no prefix as well as
             * "-p -" which is another way of saying "no prefix"
             * and "-p <prefix>" for an actual prefix.
             */
            if (argv[i+1][0] == '-') {
                prefix[0] = '\0';
                /* is it just a -? */
                if (i + 1 < argc && !strcmp(argv[i+1], "-")) {
                    memmove(argv+i+1, argv+i+2, (argc-i-2) * sizeof *argv);
                    argc--;
                }
                continue;
            }
            strcpy(prefix, argv[i + 1]);
            memmove(argv+i+1, argv+i+2, (argc-i-2) * sizeof *argv);
            argc--;
            continue;
        } else if (!strncmp(argv[i], "-I", 2)) {
            char *name = argv[i] + 2; /* skip "-I"; */
            if (paths >= SEARCH_PATHS_MAX) {
                fprintf(stderr, "maximum search paths exceeded\n");
                return 1;
            }
            strcpy(search_paths[paths++], name);
            continue;
        } else if (!strncmp(argv[i], "-S", 2)) {
            char *name = argv[i] + 2; /* skip "-S"; */
            if (!strcicmp(name, "camel") || !strcicmp(name, "camelcase"))
                style = kCamel;
            else if (!strcicmp(name, "snake") || !strcicmp(name, "snakecase"))
                style = kSnake;
            else
                goto usage;
            continue;
        } else if (!strcmp(argv[i], "-help")) {
            goto usage;
        } else {
            if (files >= sizeof file_paths / sizeof *file_paths) {
                fprintf(stderr, "maximum file paths exceeded\n");
                return 1;
            }
            strcpy(file_paths[files++], argv[i]);
        }
    }

    if (!(out = fopen(outfile, "w"))) {
        fprintf(stderr, "failed to open `%s' for output\n", outfile);
        return 1;
    }

    fprintf(out, "/* File automatically generated by incbin */\n");
    /* Be sure to define the prefix if we're not using the default */
    if (strcmp(prefix, "g"))
        fprintf(out, "#define INCBIN_PREFIX %s\n", prefix);
    if (style != 0)
        fprintf(out, "#define INCBIN_STYLE INCBIN_STYLE_SNAKE\n");
    fprintf(out, "#include \"incbin.h\"\n\n");
    fprintf(out, "#ifdef __cplusplus\n");
    fprintf(out, "extern \"C\" {\n");
    fprintf(out, "#endif\n\n");

    for (i = 0; i < files; i++) {
        FILE *fp = open_file(file_paths[i], "r", search_paths, paths);
        char *line = NULL;
        size_t size = 0;
        if (!fp) {
            fprintf(stderr, "failed to open `%s' for reading\n", file_paths[i]);
            fclose(out);
            return 1;
        }
        while (fline(&line, &size, fp) != -1) {
            char *inc, *beg, *sep, *end, *name, *file;
            FILE *f;
            if (!(inc = strstr(line, "INCBIN"))) continue;
            if (!(beg = strchr(inc, '(')))       continue;
            if (!(sep = strchr(beg, ',')))       continue;
            if (!(end = strchr(sep, ')')))       continue;
            name = beg + 1;
            file = sep + 1;
            while (isspace(*name)) name++;
            while (isspace(*file)) file++;
            sep--;
            while (isspace(*sep)) sep--;
            *++sep = '\0';
            end--;
            while (isspace(*end)) end--;
            *++end = '\0';
            fprintf(out, "/* INCBIN(%s, %s); */\n", name, file);
            fprintf(out, "INCBIN_CONST INCBIN_ALIGN unsigned char %s%s%s[] = {\n    ", prefix, name, s(kData));
            *--end = '\0';
            file++;
            if (!(f = open_file(file, "rb", search_paths, paths))) {
                fprintf(stderr, "failed to include data `%s'\n", file);
                goto end;
            } else {
                long size, i;
                unsigned char *data, count;
                fseek(f, 0, SEEK_END);
                size = ftell(f);
                fseek(f, 0, SEEK_SET);
                if (!(data = (unsigned char *)malloc(size))) {
                    fprintf(stderr, "out of memory\n");
                    fclose(f);
                    ret = 1;
                    goto end;
                }
                if (fread(data, size, 1, f) != 1) {
                    fprintf(stderr, "failed reading include data `%s'\n", file);
                    free(data);
                    fclose(f);
                    ret = 1;
                    goto end;
                }
                for (i = 0; i < size; i++) {
                    if (count == 12) {
                        fprintf(out, "\n    ");
                        count = 0;
                    }
                    fprintf(out, i != size - 1 ? "0x%02X, " : "0x%02X", data[i]);
                    count++;
                }
                free(data);
                fclose(f);
            }
            fprintf(out, "\n};\n");
            fprintf(out, "INCBIN_CONST INCBIN_ALIGN unsigned char *const %s%s%s = g%s%s + sizeof(g%s%s);\n", prefix, name, s(kEnd), name, s(kData), name, s(kData));
            fprintf(out, "INCBIN_CONST unsigned int %s%s%s = sizeof(g%s%s);\n", prefix, name, s(kSize), name, s(kData));
        }
end:
        free(line);
        fclose(fp);
        printf("included `%s'\n", file_paths[i]);
    }

    if (ret == 0) {
        fprintf(out, "\n#ifdef __cplusplus\n");
        fprintf(out, "}\n");
        fprintf(out, "#endif\n");
        fclose(out);
        printf("generated `%s'\n", outfile);
        return 0;
    }

    fclose(out);
    remove(outfile);
    return 1;
}