/** BEGIN COPYRIGHT BLOCK
 * Copyright (C) 2001 Sun Microsystems, Inc. Used by permission.
 * Copyright (C) 2009 Red Hat, Inc.
 * All rights reserved.
 *
 * License: GPL (version 3 or any later version).
 * See LICENSE for details.
 * END COPYRIGHT BLOCK **/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

/* guide.c - Guide and Enhanced Guide syntax routines */

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include "syntax.h"

static int guide_filter_ava(Slapi_PBlock *pb, struct berval *bvfilter, Slapi_Value **bvals, int ftype, Slapi_Value **retVal);
static int guide_filter_sub(Slapi_PBlock *pb, char *initial, char **any, char * final, Slapi_Value **bvals);
static int guide_values2keys(Slapi_PBlock *pb, Slapi_Value **val, Slapi_Value ***ivals, int ftype);
static int guide_assertion2keys_ava(Slapi_PBlock *pb, Slapi_Value *val, Slapi_Value ***ivals, int ftype);
static int guide_assertion2keys_sub(Slapi_PBlock *pb, char *initial, char **any, char * final, Slapi_Value ***ivals);
static int guide_compare(struct berval *v1, struct berval *v2);
static int enhancedguide_validate(struct berval *val);
static int guide_validate(struct berval *val);
static int criteria_validate(const char *start, const char *end);
static int andterm_validate(const char *start, const char *end, const char **last);
static int term_validate(const char *start, const char *end, const char **last);
static void guide_normalize(
    Slapi_PBlock *pb,
    char *s,
    int trim_spaces,
    char **alt);

/* the first name is the official one from RFC 4517 */
static char *guide_names[] = {"Guide", "guide", GUIDE_SYNTAX_OID, 0};

static char *enhancedguide_names[] = {"Enhanced Guide", "enhancedguide",
                                      ENHANCEDGUIDE_SYNTAX_OID, 0};

static Slapi_PluginDesc guide_pdesc = {"guide-syntax", VENDOR, DS_PACKAGE_VERSION,
                                       "Guide attribute syntax plugin"};

static Slapi_PluginDesc enhancedguide_pdesc = {"enhancedguide-syntax",
                                               VENDOR, DS_PACKAGE_VERSION,
                                               "Enhanced Guide attribute syntax plugin"};

int
guide_init(Slapi_PBlock *pb)
{
    int rc, flags;

    slapi_log_err(SLAPI_LOG_PLUGIN, SYNTAX_PLUGIN_SUBSYSTEM, "=> guide_init\n");

    rc = slapi_pblock_set(pb, SLAPI_PLUGIN_VERSION,
                          (void *)SLAPI_PLUGIN_VERSION_01);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_DESCRIPTION,
                           (void *)&guide_pdesc);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_FILTER_AVA,
                           (void *)guide_filter_ava);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_FILTER_SUB,
                           (void *)guide_filter_sub);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_VALUES2KEYS,
                           (void *)guide_values2keys);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_ASSERTION2KEYS_AVA,
                           (void *)guide_assertion2keys_ava);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_ASSERTION2KEYS_SUB,
                           (void *)guide_assertion2keys_sub);
    flags = SLAPI_PLUGIN_SYNTAX_FLAG_ORDERING;
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_FLAGS,
                           (void *)&flags);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_NAMES,
                           (void *)guide_names);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_OID,
                           (void *)GUIDE_SYNTAX_OID);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_COMPARE,
                           (void *)guide_compare);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_VALIDATE,
                           (void *)guide_validate);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_NORMALIZE,
                           (void *)guide_normalize);

    slapi_log_err(SLAPI_LOG_PLUGIN, SYNTAX_PLUGIN_SUBSYSTEM, "<= guide_init %d\n", rc);
    return (rc);
}

int
enhancedguide_init(Slapi_PBlock *pb)
{
    int rc, flags;

    slapi_log_err(SLAPI_LOG_PLUGIN, SYNTAX_PLUGIN_SUBSYSTEM, "=> guide_init\n");

    rc = slapi_pblock_set(pb, SLAPI_PLUGIN_VERSION,
                          (void *)SLAPI_PLUGIN_VERSION_01);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_DESCRIPTION,
                           (void *)&enhancedguide_pdesc);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_FILTER_AVA,
                           (void *)guide_filter_ava);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_FILTER_SUB,
                           (void *)guide_filter_sub);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_VALUES2KEYS,
                           (void *)guide_values2keys);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_ASSERTION2KEYS_AVA,
                           (void *)guide_assertion2keys_ava);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_ASSERTION2KEYS_SUB,
                           (void *)guide_assertion2keys_sub);
    flags = SLAPI_PLUGIN_SYNTAX_FLAG_ORDERING;
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_FLAGS,
                           (void *)&flags);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_NAMES,
                           (void *)enhancedguide_names);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_OID,
                           (void *)ENHANCEDGUIDE_SYNTAX_OID);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_COMPARE,
                           (void *)guide_compare);
    rc |= slapi_pblock_set(pb, SLAPI_PLUGIN_SYNTAX_VALIDATE,
                           (void *)enhancedguide_validate);

    slapi_log_err(SLAPI_LOG_PLUGIN, SYNTAX_PLUGIN_SUBSYSTEM, "<= guide_init %d\n", rc);
    return (rc);
}

static int
guide_filter_ava(
    Slapi_PBlock *pb,
    struct berval *bvfilter,
    Slapi_Value **bvals,
    int ftype,
    Slapi_Value **retVal)
{
    int filter_normalized = 0;
    int syntax = SYNTAX_CIS;
    if (pb) {
        slapi_pblock_get(pb, SLAPI_PLUGIN_SYNTAX_FILTER_NORMALIZED,
                         &filter_normalized);
        if (filter_normalized) {
            syntax |= SYNTAX_NORM_FILT;
        }
    }
    return (string_filter_ava(bvfilter, bvals, syntax,
                              ftype, retVal));
}


static int
guide_filter_sub(
    Slapi_PBlock *pb,
    char *initial,
    char **any,
    char * final,
    Slapi_Value **bvals)
{
    return (string_filter_sub(pb, initial, any, final, bvals, SYNTAX_CIS));
}

static int
guide_values2keys(
    Slapi_PBlock *pb,
    Slapi_Value **vals,
    Slapi_Value ***ivals,
    int ftype)
{
    return (string_values2keys(pb, vals, ivals, SYNTAX_CIS,
                               ftype));
}

static int
guide_assertion2keys_ava(
    Slapi_PBlock *pb,
    Slapi_Value *val,
    Slapi_Value ***ivals,
    int ftype)
{
    return (string_assertion2keys_ava(pb, val, ivals,
                                      SYNTAX_CIS, ftype));
}

static int
guide_assertion2keys_sub(
    Slapi_PBlock *pb,
    char *initial,
    char **any,
    char * final,
    Slapi_Value ***ivals)
{
    return (string_assertion2keys_sub(pb, initial, any, final, ivals,
                                      SYNTAX_CIS));
}

static int
guide_compare(
    struct berval *v1,
    struct berval *v2)
{
    return value_cmp(v1, v2, SYNTAX_CIS, 3 /* Normalise both values */);
}

static int
enhancedguide_validate(
    struct berval *val)
{
    int rc = 0; /* assume the value is valid */
    const char *start = NULL;
    const char *end = NULL;
    const char *p = NULL;
    const char *sharp = NULL;

    /* Per RFC4517:
     *
     * EnhancedGuide = object-class SHARP WSP criteria WSP
     *                    SHARP WSP subset
     * subset        = "baseobject" / "oneLevel" / "wholeSubtree"
     */

    /* Don't allow a 0 length string */
    if ((val == NULL) || (val->bv_len == 0)) {
        rc = 1;
        goto exit;
    }

    start = &(val->bv_val[0]);
    end = &(val->bv_val[val->bv_len - 1]);

    /* Find the first SHARP. */
    for (p = start; p <= end; p++) {
        if (IS_SHARP(*p)) {
            sharp = p;
            break;
        }
    }

    /* Fail if we didn't find a SHARP, or if SHARP
     * is at the start or end of the value. */
    if ((sharp == NULL) || (sharp == start) || (sharp == end)) {
        rc = 1;
        goto exit;
    }

    /* Reset p and end to validate the object-class. */
    p = start;
    end = sharp - 1;

    /* Skip any leading spaces. */
    while ((p < sharp) && IS_SPACE(*p)) {
        p++;
    }

    /* Skip any trailing spaces. */
    while ((end > p) && IS_SPACE(*end)) {
        end--;
    }

    /* See if we only found spaces before the SHARP. */
    if (end < p) {
        rc = 1;
        goto exit;
    }

    /* Validate p to end as object-class.  This is the same
     * as an oid, which is either a keystring or a numericoid. */
    if (IS_LEADKEYCHAR(*p)) {
        rc = keystring_validate(p, end);
        /* check if the value matches the numericoid form */
    } else if (isdigit(*p)) {
        rc = numericoid_validate(p, end);
    } else {
        rc = 1;
    }

    /* We're done if the object-class failed to validate. */
    if (rc != 0) {
        goto exit;
    }

    /* Reset start and end to validate the criteria. */
    start = sharp + 1;
    end = &(val->bv_val[val->bv_len - 1]);

    /* Find the next SHARP. */
    for (p = start; p <= end; p++) {
        if (IS_SHARP(*p)) {
            sharp = p;
            break;
        }
    }

    /* Fail if we didn't find a SHARP, or if SHARP
     * is at the start or end of the value. */
    if ((sharp == NULL) || (sharp == start) || (sharp == end)) {
        rc = 1;
        goto exit;
    }

    /* Reset p and end to validate the criteria. */
    p = start;
    end = sharp - 1;

    /* Skip any leading spaces. */
    while ((p < sharp) && IS_SPACE(*p)) {
        p++;
    }

    /* Skip any trailing spaces. */
    while ((end > p) && IS_SPACE(*end)) {
        end--;
    }

    /* See if we only found spaces before the SHARP. */
    if (end < p) {
        rc = 1;
        goto exit;
    }

    /* Validate p to end as criteria. */
    if ((rc = criteria_validate(p, end)) != 0) {
        goto exit;
    }

    /* Reset start and end to validate the subset.  We're
     * guaranteed to have a character after sharp. */
    p = start = sharp + 1;
    end = &(val->bv_val[val->bv_len - 1]);

    /* Skip any leading spaces. */
    while ((p < end) && IS_SPACE(*p)) {
        p++;
    }

    /* Validate the subset. */
    switch (end - p + 1) {
    case 8:
        if (strncmp(p, "oneLevel", 8) != 0) {
            rc = 1;
        }
        break;
    case 10:
        if (strncmp(p, "baseobject", 10) != 0) {
            rc = 1;
        }
        break;
    case 12:
        if (strncmp(p, "wholeSubtree", 12) != 0) {
            rc = 1;
        }
        break;
    default:
        rc = 1;
    }

exit:
    return rc;
}

static int
guide_validate(
    struct berval *val)
{
    int rc = 0; /* assume the value is valid */
    const char *start = NULL;
    const char *end = NULL;
    const char *p = NULL;
    const char *sharp = NULL;

    /* Per RFC4517:
     *
     * Guide        = [ object-class SHARP ] criteria
     * object-class = WSP oid WSP
     * criteria     = and-term *( BAR and-term )
     * and-term     = term *( AMPERSAND term )
     * term         = EXCLAIM term /
     *                attributetype DOLLAR match-type /
     *                LPAREN criteria RPAREN /
     *                true /
     *                false
     * match-type   = "EQ" / "SUBSTR" / "GE" / "LE" / "APPROX"
     * true         = "?true"
     * false        = "?false"
     */

    /* Don't allow a 0 length string */
    if ((val == NULL) || (val->bv_len == 0)) {
        rc = 1;
        goto exit;
    }

    start = &(val->bv_val[0]);
    end = &(val->bv_val[val->bv_len - 1]);

    /* Look for a SHARP.  If we have one, the value should
     * begin with the optional object-class. */
    for (p = start; p <= end; p++) {
        if (IS_SHARP(*p)) {
            sharp = p;
            break;
        }
    }

    if (sharp) {
        /* "criteria" must exist, so the SHARP
         * can't be at the end of the value. */
        if (sharp == end) {
            rc = 1;
            goto exit;
        }

        /* An optional object-class should be present.  Reset
         * p to the beginning of the value and end to just
         * before the SHARP to validate the object-class.
         * We'll reset end later. */
        p = start;
        end = sharp - 1;

        /* This can happen if the value begins with SHARP. */
        if (end < start) {
            rc = 1;
            goto exit;
        }

        /* Skip any leading spaces. */
        while ((p < sharp) && IS_SPACE(*p)) {
            p++;
        }

        /* Skip any trailing spaces. */
        while ((end > p) && IS_SPACE(*end)) {
            end--;
        }

        /* See if we only found spaces before the SHARP. */
        if (end < p) {
            rc = 1;
            goto exit;
        }

        /* Validate p to end as object-class.  This is the same
         * as an oid, which is either a keystring or a numericoid. */
        if (IS_LEADKEYCHAR(*p)) {
            rc = keystring_validate(p, end);
            /* check if the value matches the numericoid form */
        } else if (isdigit(*p)) {
            rc = numericoid_validate(p, end);
        } else {
            rc = 1;
        }

        /* If the object-class failed to validate, we're done. */
        if (rc != 0) {
            goto exit;
        }

        /* Reset p and end to point to the criteria. */
        p = sharp + 1;
        end = &(val->bv_val[val->bv_len - 1]);
    } else {
        /* Reset p. */
        p = start;
    }

    /* Validate the criteria. */
    rc = criteria_validate(p, end);

exit:
    return rc;
}

/* criteria_validate()
 *
 * Helper to validate criteria element.
 */
static int
criteria_validate(const char *start, const char *end)
{
    const char *p = start;
    const char *last = NULL;
    int rc = 0;

    /* Validate the criteria, which is just made up of a number
     * of and-term elements.  Validate one and-term at a time. */
    while (p <= end) {
        if ((rc = andterm_validate(p, end, &last)) != 0) {
            goto exit;
        }
        p = last + 1;

        /* p should be pointing at a BAR, or one past
         * the end of the entire value.  If we have
         * not reached the end, ensure that the next
         * character is a BAR and that there is at
         * least another character after the BAR. */
        if ((p <= end) && ((p == end) || (*p != '|'))) {
            rc = 1;
            goto exit;
        }

        /* Advance the pointer past the BAR so
         * it points at the beginning of the
         * next and-term (if there is one). */
        p++;
    }

exit:
    return rc;
}

/*
 * andterm_validate()
 *
 * This function will validate a single and-term.  If the and-term
 * is valid, 0 will be returned, otherwise non-zero will be returned.
 * A pointer to the last character of the and-term will be set in the
 * "last" parameter in the valid case.
 */
static int
andterm_validate(const char *start, const char *end, const char **last)
{
    const char *p = start;
    int rc = 0;

    if ((start == NULL) || (end == NULL)) {
        rc = 1;
        goto exit;
    }

    while (p <= end) {
        if ((rc = term_validate(p, end, last)) != 0) {
            goto exit;
        }
        p = *last + 1;

        /* p should be pointing at an ampersand, a bar, or
         * one past the end of the entire value.  If we have
         * not reached the end, ensure that the next
         * character is an ampersand or a bar and that
         * there is at least another character afterwards. */
        if ((p <= end) && ((p == end) || ((*p != '&') && (*p != '|')))) {
            rc = 1;
            goto exit;
        }

        /* If p is a bar, we're done. */
        if (*p == '|') {
            break;
        }

        /* Advance the pointer past the ampersand
         * or bar so it points at the beginning of
         * the next term or and-term (if there is
         * one). */
        p++;
    }

exit:
    return rc;
}

static int
term_validate(const char *start, const char *end, const char **last)
{
    int rc = 0;
    const char *p = start;

    /* Per RFC 4517:
     *
     * term         = EXCLAIM term /
     *                attributetype DOLLAR match-type /
     *                LPAREN criteria RPAREN /
     *                true /
     *                false
     * match-type   = "EQ" / "SUBSTR" / "GE" / "LE" / "APPROX"
     * true         = "?true"
     * false        = "?false"
     */

    /* See if the term is prefixed by an EXCLAIM. */
    if (*p == '!') {
        p++;
        /* Ensure the value doesn't end with an EXCLAIM. */
        if (p > end) {
            rc = 1;
            goto exit;
        }
    }

    /* Check for valid terms. */
    switch (*p) {
    case '?': {
        /* true or false */
        int length = 0;

        p++;
        length = end - p + 1;

        if ((length >= 5) && (strncmp(p, "false", 5) == 0)) {
            /* Found false.  We're done. */
            *last = p + 4;
            goto exit;
        }

        if ((length >= 4) && (strncmp(p, "true", 4) == 0)) {
            /* Found true.  We're done. */
            *last = p + 3;
            goto exit;
        }

        /* We didn't find true or false.  Fail. */
        rc = 1;
        goto exit;
    }
    case '(': {
        /* LPAREN criteria RPAREN */
        const char *lparen = p;

        while ((p <= end) && !IS_RPAREN(*p)) {
            p++;
        }

        if (p > end) {
            /* We didn't find a RPAREN.  Fail. */
            rc = 1;
            goto exit;
        } else {
            /* p is pointing at the RPAREN.  Validate
                     * everything between the parens as criteria. */
            rc = criteria_validate(lparen + 1, p - 1);
            *last = p;
        }
        break;
    }
    default: {
        /* attributetype DOLLAR match-type */
        const char *attrtype = p;

        while ((p <= end) && !IS_DOLLAR(*p)) {
            p++;
        }

        if (p > end) {
            /* We didn't find a DOLLAR.  Fail. */
            rc = 1;
            goto exit;
        } else {
            /* p is pointing at the DOLLAR.  Validate
                     * the attributetype before the DOLLAR. */
            if (IS_LEADKEYCHAR(*attrtype)) {
                rc = keystring_validate(attrtype, p - 1);
                /* check if the value matches the numericoid form */
            } else if (isdigit(*attrtype)) {
                rc = numericoid_validate(attrtype, p - 1);
            } else {
                rc = 1;
            }

            /* If the attributetype was invalid, we're done. */
            if (rc != 0) {
                goto exit;
            }

            /* Validate that a valid match-type
                     * is after the DOLLAR. */
            if (p == end) {
                rc = 1;
                goto exit;
            } else {
                int length = 0;

                p++;
                length = end - p + 1;

                if (length >= 6) {
                    /* APPROX, SUBSTR */
                    if ((strncmp(p, "APPROX", 6) == 0) ||
                        (strncmp(p, "SUBSTR", 6) == 0)) {
                        /* We found a valid match-type.
                                 * We're done. */
                        *last = p + 5;
                        goto exit;
                    }
                }

                if (length >= 2) {
                    /* EQ, GE, LE */
                    if ((strncmp(p, "EQ", 2) == 0) ||
                        (strncmp(p, "GE", 2) == 0) ||
                        (strncmp(p, "LE", 2) == 0)) {
                        /* We found a valid match-type.
                                 * We're done. */
                        *last = p + 1;
                        goto exit;
                    }
                }

                /* We failed to find a valid match-type. */
                rc = 1;
                goto exit;
            }
        }
    }
    }

exit:
    return rc;
}

static void
guide_normalize(
    Slapi_PBlock *pb __attribute__((unused)),
    char *s,
    int trim_spaces,
    char **alt)
{
    value_normalize_ext(s, SYNTAX_CIS, trim_spaces, alt);
    return;
}