/* vi: set sw=4 ts=4: */
/*
 * Applet table generator.
 * Runs on host and produces include/applet_tables.h
 *
 * Copyright (C) 2007 Denys Vlasenko <vda.linux@googlemail.com>
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <ctype.h>

#undef ARRAY_SIZE
#define ARRAY_SIZE(x) ((unsigned)(sizeof(x) / sizeof((x)[0])))

#include "../include/autoconf.h"
#include "../include/applet_metadata.h"

struct bb_applet {
        const char *name;
        const char *main;
        enum bb_install_loc_t install_loc;
        enum bb_suid_t need_suid;
        /* true if instead of fork(); exec("applet"); waitpid();
         * one can do fork(); exit(applet_main(argc,argv)); waitpid(); */
        unsigned char noexec;
        /* Even nicer */
        /* true if instead of fork(); exec("applet"); waitpid();
         * one can simply call applet_main(argc,argv); */
        unsigned char nofork;
};

/* Define struct bb_applet applets[] */
#include "../include/applets.h"

enum { NUM_APPLETS = ARRAY_SIZE(applets) };

static int offset[NUM_APPLETS];

static int cmp_name(const void *a, const void *b)
{
        const struct bb_applet *aa = a;
        const struct bb_applet *bb = b;
        return strcmp(aa->name, bb->name);
}

static int str_isalnum_(const char *s)
{
        while (*s) {
                if (!isalnum(*s) && *s != '_')
                        return 0;
                s++;
        }
        return 1;
}

int main(int argc, char **argv)
{
        int i;
        int ofs;
//      unsigned MAX_APPLET_NAME_LEN = 1;

        qsort(applets, NUM_APPLETS, sizeof(applets[0]), cmp_name);

        ofs = 0;
        for (i = 0; i < NUM_APPLETS; i++) {
                offset[i] = ofs;
                ofs += strlen(applets[i].name) + 1;
        }
        /* We reuse 4 high-order bits of offset array for other purposes,
         * so if they are indeed needed, refuse to proceed */
        if (ofs > 0xfff)
                return 1;
        if (!argv[1])
                return 1;

        i = open(argv[1], O_WRONLY | O_TRUNC | O_CREAT, 0666);
        if (i < 0)
                return 1;
        dup2(i, 1);

        /* Keep in sync with include/busybox.h! */

        printf("/* This is a generated file, don't edit */\n\n");

        printf("#define NUM_APPLETS %u\n", NUM_APPLETS);
        if (NUM_APPLETS == 1) {
                printf("#define SINGLE_APPLET_STR \"%s\"\n", applets[0].name);
                printf("#define SINGLE_APPLET_MAIN %s_main\n", applets[0].main);
        }
        printf("\n");

        //printf("#ifndef SKIP_definitions\n");
        printf("const char applet_names[] ALIGN1 = \"\"\n");
        for (i = 0; i < NUM_APPLETS; i++) {
                printf("\"%s\" \"\\0\"\n", applets[i].name);
//              if (MAX_APPLET_NAME_LEN < strlen(applets[i].name))
//                      MAX_APPLET_NAME_LEN = strlen(applets[i].name);
        }
        printf(";\n\n");

        for (i = 0; i < NUM_APPLETS; i++) {
                if (str_isalnum_(applets[i].name))
                        printf("#define APPLET_NO_%s %d\n", applets[i].name, i);
        }
        printf("\n");

        printf("#ifndef SKIP_applet_main\n");
        printf("int (*const applet_main[])(int argc, char **argv) = {\n");
        for (i = 0; i < NUM_APPLETS; i++) {
                printf("%s_main,\n", applets[i].main);
        }
        printf("};\n");
        printf("#endif\n\n");

        printf("const uint16_t applet_nameofs[] ALIGN2 = {\n");
        for (i = 0; i < NUM_APPLETS; i++) {
                printf("0x%04x,\n",
                        offset[i]
#if ENABLE_FEATURE_PREFER_APPLETS
                        + (applets[i].nofork << 12)
                        + (applets[i].noexec << 13)
#endif
#if ENABLE_FEATURE_SUID
                        + (applets[i].need_suid << 14) /* 2 bits */
#endif
                );
        }
        printf("};\n\n");

#if ENABLE_FEATURE_INSTALLER
        printf("const uint8_t applet_install_loc[] ALIGN1 = {\n");
        i = 0;
        while (i < NUM_APPLETS) {
                int v = applets[i].install_loc; /* 3 bits */
                if (++i < NUM_APPLETS)
                        v |= applets[i].install_loc << 4; /* 3 bits */
                printf("0x%02x,\n", v);
                i++;
        }
        printf("};\n");
#endif
        //printf("#endif /* SKIP_definitions */\n");
//      printf("\n");
//      printf("#define MAX_APPLET_NAME_LEN %u\n", MAX_APPLET_NAME_LEN);

        if (argv[2]) {
                char line_old[80];
                char line_new[80];
                FILE *fp;

                line_old[0] = 0;
                fp = fopen(argv[2], "r");
                if (fp) {
                        fgets(line_old, sizeof(line_old), fp);
                        fclose(fp);
                }
                sprintf(line_new, "#define NUM_APPLETS %u\n", NUM_APPLETS);
                if (strcmp(line_old, line_new) != 0) {
                        fp = fopen(argv[2], "w");
                        if (!fp)
                                return 1;
                        fputs(line_new, fp);
                }
        }

        return 0;
}