/* Copyright (c) 2007-2008, UNINETT AS */
/* See LICENSE for licensing information. */

#define _GNU_SOURCE
#include "gconfig.h"
#include "debug.h"
#include "util.h"
#include <ctype.h>
#include <errno.h>
#include <glob.h>
#include <libgen.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* returns NULL on error, where to continue parsing if token and ok. E.g. "" will return token with empty string */
char *strtokenquote(char *s, char **token, char *del, char *quote, char *comment) {
    char *t = s, *q, *r;

    if (!t || !token || !del)
        return NULL;
    while (*t && strchr(del, *t))
        t++;
    if (!*t || (comment && strchr(comment, *t))) {
        *token = NULL;
        return t + 1; /* needs to be non-NULL, but value doesn't matter */
    }
    if (quote && (q = strchr(quote, *t))) {
        t++;
        r = t;
        while (*t && *t != *q)
            t++;
        if (!*t || (t[1] && !strchr(del, t[1])))
            return NULL;
        *t = '\0';
        *token = r;
        return t + 1;
    }
    *token = t;
    t++;
    while (*t && !strchr(del, *t))
        t++;
    *t = '\0';
    return t + 1;
}

int pushgconfdata(struct gconffile **cf, const char *data) {
    int i;
    struct gconffile *newcf;

    if (!*cf) {
        newcf = malloc(sizeof(struct gconffile) * 2);
        if (!newcf)
            return 0;
        memset(newcf, 0, sizeof(struct gconffile) * 2);
    } else {
        for (i = 0; (*cf)[i].data || (*cf)[i].path;)
            i++;
        newcf = realloc(*cf, sizeof(struct gconffile) * (i + 2));
        if (!newcf)
            return 0;
        memmove(newcf + 1, newcf, sizeof(struct gconffile) * (i + 1));
        memset(newcf, 0, sizeof(struct gconffile));
    }
    newcf[0].data = data;
    *cf = newcf;
    return 1;
}

FILE *pushgconffile(struct gconffile **cf, FILE *file, const char *description) {
    int i;
    struct gconffile *newcf;
    char *desc;

    if (!file) {
        debug(DBG_INFO, "could not read config from %s", description);
        return NULL;
    }
    debug(DBG_DBG, "reading config from %s", description);

    desc = stringcopy(description, 0);
    if (!desc)
        goto errmalloc;

    if (!*cf) {
        newcf = malloc(sizeof(struct gconffile) * 2);
        if (!newcf)
            goto errmalloc;
        memset(newcf, 0, sizeof(struct gconffile) * 2);
    } else {
        for (i = 0; (*cf)[i].data || (*cf)[i].path;)
            i++;
        newcf = realloc(*cf, sizeof(struct gconffile) * (i + 2));
        if (!newcf)
            goto errmalloc;
        memmove(newcf + 1, newcf, sizeof(struct gconffile) * (i + 1));
        memset(newcf, 0, sizeof(struct gconffile));
    }
    newcf[0].file = file;
    newcf[0].path = desc;
    *cf = newcf;
    return file;

errmalloc:
    free(desc);
    fclose(file);
    debug(DBG_ERR, "malloc failed");
    return NULL;
}

FILE *pushgconfpath(struct gconffile **cf, const char *path) {
    FILE *f;

    f = fopen(path, "r");
    return pushgconffile(cf, f, path);
}

int pushgconfpaths(struct gconffile **cf, const char *cfgpath) {
    int i, result, n = 0;
    glob_t globbuf;
    char *path, *curfile = NULL, *dir;

    /* if cfgpath is relative, make it relative to current config */
    if (*cfgpath == '/')
        path = (char *)cfgpath;
    else {
        /* dirname may modify its argument */
        curfile = stringcopy((*cf)->path, 0);
        if (!curfile) {
            debug(DBG_ERR, "malloc failed");
            goto exit;
        }
        dir = dirname(curfile);

        if (asprintf(&path, "%s/%s", dir, cfgpath) < 0) {
            path = NULL;
            goto exit;
        }
    }
    memset(&globbuf, 0, sizeof(glob_t));
    if ((result = glob(path, 0, NULL, &globbuf))) {
        if (result != GLOB_NOMATCH) {
            debug(DBG_WARN, "could not glob %s", path);
            n = -1;
            goto exit;
        }
    }

    for (i = globbuf.gl_pathc - 1; i >= 0; i--) {
        if (!pushgconfpath(cf, globbuf.gl_pathv[i])) {
            n = -1;
            break;
        }
        n++;
    }
    globfree(&globbuf);

exit:
    if (curfile) {
        free(curfile);
        free(path);
    }
    return n;
}

int popgconf(struct gconffile **cf) {
    int i;

    if (!*cf)
        return 0;
    for (i = 0; (*cf)[i].data || (*cf)[i].path;)
        i++;
    if (i && (*cf)[0].file) {
        fclose((*cf)[0].file);
        if ((*cf)[0].path) {
            debug(DBG_DBG, "closing config file %s", (*cf)[0].path);
            free((*cf)[0].path);
        }
    }
    if (i < 2) {
        free(*cf);
        *cf = NULL;
        return 0;
    }
    memmove(*cf, *cf + 1, sizeof(struct gconffile) * i);
    return 1;
}

void freegconfmstr(char **mstr) {
    int i;

    if (mstr) {
        for (i = 0; mstr[i]; i++)
            free(mstr[i]);
        free(mstr);
    }
}

void freegconf(struct gconffile **cf) {
    int i;

    if (!*cf)
        return;

    for (i = 0; (*cf)[i].data || (*cf)[i].path; i++) {
        if ((*cf)[i].file) {
            fclose((*cf)[i].file);
            if ((*cf)[i].path) {
                debug(DBG_DBG, "closing config file %s", (*cf)[i].path);
                free((*cf)[i].path);
            }
        }
    }
    free(*cf);
    *cf = NULL;
}

struct gconffile *openconfigfile(const char *file) {
    struct gconffile *cf = NULL;

    if (!pushgconfpath(&cf, file)) {
        debug(DBG_ERR, "could not read config file %s\n%s", file, strerror(errno));
        return NULL;
    }
    debug(DBG_DBG, "reading config file %s", file);
    return cf;
}

/* Parses config with following syntax:
 * One of these:
 * option-name value
 * option-name = value
 * Or:
 * option-name value {
 *     option-name [=] value
 *     ...
 * }
 */

int getlinefromcf(struct gconffile *cf, char *line, const size_t size) {
    size_t i, pos;

    if (!cf)
        return 0;

    if (cf->file)
        return fgets(line, size, cf->file) ? 1 : 0;
    else if (cf->data) {
        pos = cf->datapos;
        if (!cf->data[pos])
            return 0;
        for (i = pos; cf->data[i] && cf->data[i] != '\n';)
            i++;
        if (cf->data[i] == '\n')
            i++;
        if (i - pos > size - 1)
            i = size - 1 + pos;
        memcpy(line, cf->data + pos, i - pos);
        line[i - pos] = '\0';
        cf->datapos = i;
        return 1;
    }
    return 0;
}

int getconfigline(struct gconffile **cf, char *block, char **opt, char **val, int *conftype) {
    char line[2048];
    char *tokens[3], *s;
    int tcount;

    *opt = NULL;
    *val = NULL;
    *conftype = 0;

    if (!cf || !*cf || (!(*cf)->file && !(*cf)->data))
        return 1;

    for (;;) {
        if (!getlinefromcf(*cf, line, 2048)) {
            if (popgconf(cf))
                continue;
            return 1;
        }
        s = line;
        for (tcount = 0; tcount < 3; tcount++) {
            s = strtokenquote(s, &tokens[tcount], " \t\r\n", "\"'", tcount ? NULL : "#");
            if (!s) {
                debug(DBG_ERR, "Syntax error in line starting with: %s", line);
                return 0;
            }
            if (!tokens[tcount])
                break;
        }
        if (!tcount || **tokens == '#')
            continue;

        if (**tokens == '}') {
            if (block)
                return 1;
            debug(DBG_ERR, "configuration error, found } with no matching {");
            return 0;
        }
        break;
    }

    switch (tcount) {
    case 2:
        *opt = stringcopy(tokens[0], 0);
        if (!*opt)
            goto errmalloc;
        *val = stringcopy(tokens[1], 0);
        if (!*val)
            goto errmalloc;
        *conftype = CONF_STR;
        break;
    case 3:
        if (tokens[1][0] == '=' && tokens[1][1] == '\0') {
            *opt = stringcopy(tokens[0], 0);
            if (!*opt)
                goto errmalloc;
            *val = stringcopy(tokens[2], 0);
            if (!*val)
                goto errmalloc;
            *conftype = CONF_STR;
            break;
        }
        if (tokens[2][0] == '{' && tokens[2][1] == '\0') {
            *opt = stringcopy(tokens[0], 0);
            if (!*opt)
                goto errmalloc;
            *val = stringcopy(tokens[1], 0);
            if (!*val)
                goto errmalloc;
            *conftype = CONF_CBK;
            break;
        }
        /* fall through */
    default:
        if (block)
            debug(DBG_ERR, "configuration error in block %s, line starting with %s", block, tokens[0]);
        else
            debug(DBG_ERR, "configuration error, syntax error in line starting with %s", tokens[0]);
        return 0;
    }

    if (**val)
        return 1;

    debug(DBG_ERR, "configuration error, option %s needs a non-empty value", *opt);
    goto errexit;

errmalloc:
    debug(DBG_ERR, "malloc failed");
errexit:
    free(*opt);
    *opt = NULL;
    free(*val);
    *val = NULL;
    return 0;
}

static uint8_t hexdigit2int(char d) {
    if (d >= '0' && d <= '9')
        return d - '0';
    if (d >= 'a' && d <= 'f')
        return 10 + d - 'a';
    if (d >= 'A' && d <= 'F')
        return 10 + d - 'A';
    return 0;
}

static int ishexbyte(char *str, uint8_t accept_null) {
    if (str[0] && str[1])
        return (isxdigit((int)str[0]) && isxdigit((int)str[1]) &&
                (accept_null || !(str[0] == '0' && str[1] == '0')));
    return 0;
}

static char hextochar(char *hex) {
    return 16 * hexdigit2int(hex[0]) + hexdigit2int(hex[1]);
}

int unhex(char *str, uint8_t process_null) {
    char *t = str, *s = str;
    while (*t) {
        if (t[0] == '%' && ishexbyte(t + 1, process_null)) {
            *s++ = hextochar(t + 1);
            t += 3;
        } else if (t[0] == '%' && t[1] == '%') {
            t += 2;
            while (ishexbyte(t, process_null)) {
                *s++ = hextochar(t);
                t += 2;
            }
        } else
            *s++ = *t++;
    }
    *s = '\0';
    return (s - str);
}

typedef int (*t_fptr)(struct gconffile **, void *, char *, char *, char *);

/* returns 1 if ok, 0 on error */
/* caller must free returned values also on error */
int getgenericconfig(struct gconffile **cf, char *block, ...) {
    va_list ap;
    char *opt = NULL, *val, *word, *optval, **str = NULL, ***mstr = NULL, **newmstr, *endptr;
    uint8_t *bln = NULL;
    long int *lint = NULL;
    int type = 0, conftype = 0, n;
    t_fptr cbk = NULL;
    void *cbkarg = NULL;

    for (;;) {
        free(opt);
        if (!getconfigline(cf, block, &opt, &val, &conftype))
            return 0;
        if (!opt)
            return 1;

        if (conftype == CONF_STR && !strcasecmp(opt, "include")) {
            if ((n = pushgconfpaths(cf, val)) < 0) {
                debug(DBG_ERR, "failed to include config file %s", val);
                goto errexit;
            }
            debug(DBG_DBG, "getgenericconfig: include %s, %d file(s)", val, n);
            free(val);
            continue;
        }

        va_start(ap, block);
        while ((word = va_arg(ap, char *))) {
            type = va_arg(ap, int);
            switch (type) {
            case CONF_STR: /*intentional fall-thru, these are identical*/
            case CONF_STR_NOESC:
                str = va_arg(ap, char **);
                if (!str)
                    goto errparam;
                break;
            case CONF_MSTR: /*intentional fall-thru, these are identical*/
            case CONF_MSTR_NOESC:
                mstr = va_arg(ap, char ***);
                if (!mstr)
                    goto errparam;
                break;
            case CONF_BLN:
                bln = va_arg(ap, uint8_t *);
                if (!bln)
                    goto errparam;
                break;
            case CONF_LINT:
                lint = va_arg(ap, long int *);
                if (!lint)
                    goto errparam;
                break;
            case CONF_CBK:
                cbk = va_arg(ap, t_fptr);
                if (!cbk)
                    goto errparam;
                cbkarg = va_arg(ap, void *);
                break;
            default:
                goto errparam;
            }
            if (!strcasecmp(opt, word))
                break;
        }
        va_end(ap);

        if (!word) {
            if (block)
                debug(DBG_ERR, "configuration error in block %s, unknown option %s", block, opt);
            debug(DBG_ERR, "configuration error, unknown option %s", opt);
            goto errexit;
        }

        if (((type == CONF_STR || type == CONF_STR_NOESC || type == CONF_MSTR || type == CONF_MSTR_NOESC ||
              type == CONF_BLN || type == CONF_LINT) &&
             conftype != CONF_STR) ||
            (type == CONF_CBK && conftype != CONF_CBK)) {
            if (block)
                debug(DBG_ERR, "configuration error in block %s, wrong syntax for option %s", block, opt);
            debug(DBG_ERR, "configuration error, wrong syntax for option %s", opt);
            goto errexit;
        }

        switch (type) {
        case CONF_STR: /*intentional fall-thru, these are almost identical*/
        case CONF_STR_NOESC:
            if (*str) {
                debug(DBG_ERR, "configuration error, option %s already set to %s", opt, *str);
                goto errexit;
            }
            if (type == CONF_STR)
                unhex(val, 0);
            *str = val;
            break;
        case CONF_MSTR: /*intentional fall-thru, these are almost identical*/
        case CONF_MSTR_NOESC:
            if (*mstr)
                for (n = 0; (*mstr)[n];)
                    n++;
            else
                n = 0;
            newmstr = realloc(*mstr, sizeof(char *) * (n + 2));
            if (!newmstr) {
                debug(DBG_ERR, "malloc failed");
                goto errexit;
            }
            if (type == CONF_MSTR)
                unhex(val, 0);
            newmstr[n] = val;
            newmstr[n + 1] = NULL;
            *mstr = newmstr;
            break;
        case CONF_BLN:
            if (!strcasecmp(val, "on"))
                *bln = 1;
            else if (!strcasecmp(val, "off"))
                *bln = 0;
            else {
                if (block)
                    debug(DBG_ERR, "configuration error in block %s, value for option %s must be on or off, not %s", block, opt, val);
                else
                    debug(DBG_ERR, "configuration error, value for option %s must be on or off, not %s", opt, val);
                goto errexit;
            }
            break;
        case CONF_LINT:
            endptr = NULL;
            *lint = strtol(val, &endptr, 0);
            if (*lint == LONG_MIN || *lint == LONG_MAX || !endptr || endptr == val || *endptr != '\0') {
                if (block)
                    debug(DBG_ERR, "configuration error in block %s, value for option %s must be an integer, not %s", block, opt, val);
                else
                    debug(DBG_ERR, "configuration error, value for option %s must be an integer, not %s", opt, val);
                goto errexit;
            }
            break;
        case CONF_CBK:
            if (asprintf(&optval, "%s %s", opt, val) < 0) {
                debug(DBG_ERR, "malloc failed");
                goto errexit;
            }
            if (!cbk(cf, cbkarg, optval, opt, val)) {
                free(optval);
                goto errexit;
            }
            free(val);
            free(optval);
            continue;
        default:
            goto errparam;
        }
        if (block)
            debug(DBG_DBG, "getgenericconfig: block %s: %s = %s", block, opt, val);
        else
            debug(DBG_DBG, "getgenericconfig: %s = %s", opt, val);
        if (type == CONF_BLN || type == CONF_LINT)
            free(val);
    }

errparam:
    debug(DBG_ERR, "getgenericconfig: internal parameter error");
errexit:
    va_end(ap);
    free(opt);
    free(val);
    return 0;
}

/* Local Variables: */
/* c-file-style: "stroustrup" */
/* End: */
