/*======================================================================
 FILE: icalclassify.c
 CREATOR: ebusboom 23 aug 2000

 (C) COPYRIGHT 2000, Eric Busboom <eric@civicknowledge.com>

 This library is free software; you can redistribute it and/or modify
 it under the terms of either:

    The LGPL as published by the Free Software Foundation, version
    2.1, available at: https://www.gnu.org/licenses/lgpl-2.1.html

 Or:

    The Mozilla Public License Version 2.0. You may obtain a copy of
    the License at https://www.mozilla.org/MPL/
======================================================================*/

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

#include "icalclassify.h"
#include "icalmemory.h"

#include <ctype.h>
#include <stdlib.h>

struct icalclassify_parts
{
    icalcomponent *c;
    icalcomponent_kind inner_kind;
    icalproperty_method method;
    char *organizer;
    icalparameter_partstat reply_partstat;
    char *reply_attendee;
    char *uid;
    int sequence;
    struct icaltimetype dtstamp;
    struct icaltimetype recurrence_id;
};

char *icalclassify_lowercase(const char *str)
{
    char *p = 0;
    char *xnew;

    if (str == 0) {
        return 0;
    }

    xnew = icalmemory_strdup(str);
    for (p = xnew; *p != 0; p++) {
        *p = tolower((int)*p);
    }

    return xnew;
}

/** Returns a set of components that intersect in time with comp. For
component X and Y to intersect:
    X.DTSTART < Y.DTEND && X.DTEND > Y.DTSTART
*/

icalcomponent *icalclassify_find_overlaps(icalset *set, icalcomponent *comp)
{
    icalcomponent *return_set;
    icalcomponent *c;
    struct icaltime_span span, compspan;

    icalerror_clear_errno();
    compspan = icalcomponent_get_span(comp);

    if (icalerrno != ICAL_NO_ERROR) {
        return 0;
    }

    return_set = icalcomponent_new(ICAL_XROOT_COMPONENT);

    for (c = icalset_get_first_component(set); c != 0; c = icalset_get_next_component(set)) {

        icalerror_clear_errno();

        span = icalcomponent_get_span(c);

        if (icalerrno != ICAL_NO_ERROR) {
            continue;
        }

        if (compspan.start < span.end && compspan.end > span.start) {

            icalcomponent *clone = icalcomponent_new_clone(c);

            icalcomponent_add_component(return_set, clone);
        }
    }

    if (icalcomponent_count_components(return_set, ICAL_ANY_COMPONENT) != 0) {
        return return_set;
    } else {
        icalcomponent_free(return_set);
        return 0;
    }
}

icalproperty *icalclassify_find_attendee(icalcomponent *c, const char *attendee)
{
    icalproperty *p;
    icalcomponent *inner;
    char *lattendee;
    char *upn;

    if (attendee == 0) {
        return 0;
    }

    lattendee = icalclassify_lowercase(attendee);
    upn = strchr(lattendee, ':');

    if (upn == 0) {
        upn = lattendee;
    } else {
        upn++;  /* skip the ";" */
    }

    inner = icalcomponent_get_first_real_component(c);

    for (p = icalcomponent_get_first_property(inner, ICAL_ATTENDEE_PROPERTY);
         p != 0;
         p = icalcomponent_get_next_property(inner, ICAL_ATTENDEE_PROPERTY)) {
        char *this_upn;
        char *this_attendee = icalclassify_lowercase(icalproperty_get_attendee(p));

        if (!this_attendee)
            continue;

        this_upn = strchr(this_attendee, ':');

        if (this_upn == 0) {
            free(this_attendee);
            continue;
        } else {
            this_upn++;
        }

        if (strcmp(this_upn, upn) == 0) {
            free(lattendee);
            free(this_attendee);
            return p;
        }

        free(this_attendee);
    }
    free(lattendee);

    return 0;
}

void icalssutil_free_parts(struct icalclassify_parts *parts)
{
    if (parts == 0) {
        return;
    }

    if (parts->organizer != 0) {
        free(parts->organizer);
    }

    if (parts->uid != 0) {
        free(parts->uid);
    }

    if (parts->reply_attendee) {
        free(parts->reply_attendee);
    }
}

void icalssutil_get_parts(icalcomponent *c, struct icalclassify_parts *parts)
{
    icalproperty *p;
    icalcomponent *inner;

    memset(parts, 0, sizeof(struct icalclassify_parts));

    parts->method = ICAL_METHOD_NONE;
    parts->sequence = 0;
    parts->reply_partstat = ICAL_PARTSTAT_NONE;

    if (c == 0) {
        return;
    }

    parts->c = c;

    p = icalcomponent_get_first_property(c, ICAL_METHOD_PROPERTY);
    if (p != 0) {
        parts->method = icalproperty_get_method(p);
    }

    inner = icalcomponent_get_first_real_component(c);

    parts->inner_kind = icalcomponent_isa(inner);

    p = icalcomponent_get_first_property(inner, ICAL_ORGANIZER_PROPERTY);
    if (p != 0) {
        const char *p_organizer = icalproperty_get_organizer(p);

        if (p_organizer != 0) {
            parts->organizer = strdup(p_organizer);
        }
    }

    p = icalcomponent_get_first_property(inner, ICAL_SEQUENCE_PROPERTY);
    if (p != 0) {
        parts->sequence = icalproperty_get_sequence(p);
    }

    p = icalcomponent_get_first_property(inner, ICAL_UID_PROPERTY);
    if (p != 0) {
        const char *p_uid = icalproperty_get_uid(p);

        if (p_uid != 0) {
            parts->uid = strdup(p_uid);
        }
    }

    p = icalcomponent_get_first_property(inner, ICAL_RECURRENCEID_PROPERTY);
    if (p != 0) {
        parts->recurrence_id = icalproperty_get_recurrenceid(p);
    }

    p = icalcomponent_get_first_property(inner, ICAL_DTSTAMP_PROPERTY);
    if (p != 0) {
        parts->dtstamp = icalproperty_get_dtstamp(p);
    }

    if (parts->method == ICAL_METHOD_REPLY) {
        icalparameter *param;

        p = icalcomponent_get_first_property(inner, ICAL_ATTENDEE_PROPERTY);

        if (p != 0) {
            const char *attendee = 0;

            param = icalproperty_get_first_parameter(p, ICAL_PARTSTAT_PARAMETER);

            if (param != 0) {
                parts->reply_partstat = icalparameter_get_partstat(param);
            }
            attendee = icalproperty_get_attendee(p);
            if (attendee)
                parts->reply_attendee = strdup(attendee);
        }
    }
}

int icalssutil_is_rescheduled(icalcomponent *a, icalcomponent *b)
{
    icalproperty *p1, *p2;
    icalcomponent *i1, *i2;
    char *temp1, *temp2;
    int i;

    icalproperty_kind kind_array[] = {
        ICAL_DTSTART_PROPERTY,
        ICAL_DTEND_PROPERTY,
        ICAL_DURATION_PROPERTY,
        ICAL_DUE_PROPERTY,
        ICAL_RRULE_PROPERTY,
        ICAL_RDATE_PROPERTY,
        ICAL_EXRULE_PROPERTY,
        ICAL_EXDATE_PROPERTY,
        ICAL_NO_PROPERTY
    };

    i1 = icalcomponent_get_first_real_component(a);
    i2 = icalcomponent_get_first_real_component(b);

    for (i = 0; kind_array[i] != ICAL_NO_PROPERTY; i++) {
        int cmp;

        p1 = icalcomponent_get_first_property(i1, kind_array[i]);
        p2 = icalcomponent_get_first_property(i2, kind_array[i]);

        if ((p1 != 0) ^ (p2 != 0)) {
            /* Return true if the property exists in one component and not
               the other */
            return 1;
        } else if (!p1 && !p2)
            continue;

        temp1 = icalproperty_as_ical_string_r(p1);
        temp2 = icalproperty_as_ical_string_r(p2);
        cmp = strcmp(temp1, temp2);
        free(temp1);
        free(temp2);

        if (p1 && cmp != 0) {
            return 1;
        }
    }

    return 0;
}

#define icalclassify_pre \
int rtrn = 0;

#define icalclassify_post \
return rtrn;

int icalclassify_publish_new(struct icalclassify_parts *comp,
                             struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre;
    _unused(user);

    if (comp->method == ICAL_METHOD_PUBLISH &&
        match == 0 && comp->inner_kind != ICAL_VFREEBUSY_COMPONENT) {
        rtrn = 1;
    }

    icalclassify_post;
}

int icalclassify_publish_update(struct icalclassify_parts *comp,
                                struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre;
    _unused(user);

    if (comp->method == ICAL_METHOD_PUBLISH &&
        match != 0 && comp->inner_kind != ICAL_VFREEBUSY_COMPONENT) {
        rtrn = 1;
    }

    icalclassify_post;
}

int icalclassify_publish_freebusy(struct icalclassify_parts *comp,
                                  struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre;

    _unused(match);
    _unused(user);
    if (comp->method == ICAL_METHOD_PUBLISH && comp->inner_kind == ICAL_VFREEBUSY_COMPONENT) {
        rtrn = 1;
    }

    icalclassify_post;
}

int icalclassify_request_new(struct icalclassify_parts *comp,
                             struct icalclassify_parts *match, const char *user)
{
    /* Method is  REQUEST, and there is no match */

    icalclassify_pre _unused(user);

    if (match->c == 0 && comp->method == ICAL_METHOD_REQUEST) {
        rtrn = 1;
    }

icalclassify_post}

int icalclassify_request_update(struct icalclassify_parts *comp,
                                struct icalclassify_parts *match, const char *user)
{
    /* REQUEST method, Higher SEQUENCE than match, and all
       time-related properties are unchanged */

    icalclassify_pre _unused(user);

    if (match != 0 &&
        comp->sequence >= match->sequence && !icalssutil_is_rescheduled(comp->c, match->c)) {
        rtrn = 1;
    }

icalclassify_post}

int icalclassify_request_reschedule(struct icalclassify_parts *comp,
                                    struct icalclassify_parts *match, const char *user)
{
    /* REQUEST method, Higher SEQUENCE than match, and one or more
       time-related properties are changed */
    icalclassify_pre _unused(user);

    if (match->c != 0 &&
        comp->sequence > match->sequence && icalssutil_is_rescheduled(comp->c, match->c)) {
        rtrn = 1;
    }

icalclassify_post}

int icalclassify_request_delegate(struct icalclassify_parts *comp,
                                  struct icalclassify_parts *match, const char *user)
{
    icalproperty *attendee;
    icalparameter *param;

    icalclassify_pre;
    _unused(match);

    attendee = icalclassify_find_attendee(comp->c, user);

    if (attendee == 0) {
        return 0;
    }

    param = icalproperty_get_first_parameter(attendee, ICAL_DELEGATEDFROM_PARAMETER);

    if (param != 0) {
        rtrn = 1;
    }

icalclassify_post}

int icalclassify_request_new_organizer(struct icalclassify_parts *comp,
                                       struct icalclassify_parts *match, const char *user)
{
    /*   Organizer has changed between match and component */
    icalclassify_pre _unused(comp);
    _unused(match);
    _unused(user);

    icalerror_set_errno(ICAL_UNIMPLEMENTED_ERROR);
icalclassify_post}

int icalclassify_request_status(struct icalclassify_parts *comp,
                                struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(comp);
    _unused(match);
    _unused(user);

    icalerror_set_errno(ICAL_UNIMPLEMENTED_ERROR);
icalclassify_post}

int icalclassify_request_forward(struct icalclassify_parts *comp,
                                 struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(comp);
    _unused(match);
    _unused(user);

    icalerror_set_errno(ICAL_UNIMPLEMENTED_ERROR);
icalclassify_post}

int icalclassify_request_freebusy(struct icalclassify_parts *comp,
                                  struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(comp);
    _unused(match);
    _unused(user);

    icalerror_set_errno(ICAL_UNIMPLEMENTED_ERROR);
icalclassify_post}

int icalclassify_reply_accept(struct icalclassify_parts *comp,
                              struct icalclassify_parts *match, const char *user)
{
    icalproperty *attendee;

    icalclassify_pre;
    _unused(user);

    attendee = icalclassify_find_attendee(match->c, comp->reply_attendee);

    if (attendee != 0 && comp->reply_partstat == ICAL_PARTSTAT_ACCEPTED) {
        rtrn = 1;
    }

icalclassify_post}

int icalclassify_reply_decline(struct icalclassify_parts *comp,
                               struct icalclassify_parts *match, const char *user)
{
    icalproperty *attendee;

    icalclassify_pre;
    _unused(user);

    attendee = icalclassify_find_attendee(match->c, comp->reply_attendee);

    if (attendee != 0 && comp->reply_partstat == ICAL_PARTSTAT_DECLINED) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_reply_delegate(struct icalclassify_parts *comp,
                                struct icalclassify_parts *match, const char *user)
{
    icalproperty *attendee;

    icalclassify_pre;
    _unused(user);

    attendee = icalclassify_find_attendee(match->c, comp->reply_attendee);

    if (attendee != 0 && comp->reply_partstat == ICAL_PARTSTAT_DELEGATED) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_reply_crasher_accept(struct icalclassify_parts *comp,
                                      struct icalclassify_parts *match, const char *user)
{
    icalproperty *attendee;

    icalclassify_pre;
    _unused(user);

    attendee = icalclassify_find_attendee(match->c, comp->reply_attendee);

    if (attendee == 0 && comp->reply_partstat == ICAL_PARTSTAT_ACCEPTED) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_reply_crasher_decline(struct icalclassify_parts *comp,
                                       struct icalclassify_parts *match, const char *user)
{
    icalproperty *attendee;

    icalclassify_pre;
    _unused(user);

    attendee = icalclassify_find_attendee(match->c, comp->reply_attendee);

    if (attendee == 0 && comp->reply_partstat == ICAL_PARTSTAT_DECLINED) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_add_instance(struct icalclassify_parts *comp,
                              struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(match);
    _unused(user);

    if (comp->method == ICAL_METHOD_ADD) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_cancel_event(struct icalclassify_parts *comp,
                              struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(match);
    _unused(user);
    if (comp->method == ICAL_METHOD_CANCEL) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_cancel_instance(struct icalclassify_parts *comp,
                                 struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(match);
    _unused(user);
    if (comp->method == ICAL_METHOD_CANCEL) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_cancel_all(struct icalclassify_parts *comp,
                            struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(match);
    _unused(user);
    if (comp->method == ICAL_METHOD_CANCEL) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_refesh(struct icalclassify_parts *comp,
                        struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(match);
    _unused(user);
    if (comp->method == ICAL_METHOD_REFRESH) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_counter(struct icalclassify_parts *comp,
                         struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(match);
    _unused(user);
    if (comp->method == ICAL_METHOD_COUNTER) {
        rtrn = 1;
    }
icalclassify_post}

int icalclassify_delinecounter(struct icalclassify_parts *comp,
                               struct icalclassify_parts *match, const char *user)
{
    icalclassify_pre _unused(match);
    _unused(user);

    if (comp->method == ICAL_METHOD_DECLINECOUNTER) {
        rtrn = 1;
    }

icalclassify_post}

static const struct icalclassify_map
{
    icalproperty_method method;
    int (*fn) (struct icalclassify_parts *comp, struct icalclassify_parts *match,
               const char *user);
    icalproperty_xlicclass class;
} icalclassify_map[] = {
  {ICAL_METHOD_PUBLISH, icalclassify_publish_new, ICAL_XLICCLASS_PUBLISHNEW},
  {ICAL_METHOD_PUBLISH, icalclassify_publish_update, ICAL_XLICCLASS_PUBLISHUPDATE},
  {ICAL_METHOD_PUBLISH, icalclassify_publish_freebusy, ICAL_XLICCLASS_PUBLISHFREEBUSY},
  {ICAL_METHOD_REQUEST, icalclassify_request_delegate, ICAL_XLICCLASS_REQUESTDELEGATE},
  {ICAL_METHOD_REQUEST, icalclassify_request_new, ICAL_XLICCLASS_REQUESTNEW},
  {ICAL_METHOD_REQUEST, icalclassify_request_update, ICAL_XLICCLASS_REQUESTUPDATE},
  {ICAL_METHOD_REQUEST, icalclassify_request_reschedule, ICAL_XLICCLASS_REQUESTRESCHEDULE},
  {ICAL_METHOD_REQUEST, icalclassify_request_new_organizer, ICAL_XLICCLASS_REQUESTNEWORGANIZER},
  {ICAL_METHOD_REQUEST, icalclassify_request_forward, ICAL_XLICCLASS_REQUESTFORWARD},
  {ICAL_METHOD_REQUEST, icalclassify_request_status, ICAL_XLICCLASS_REQUESTSTATUS},
  {ICAL_METHOD_REQUEST, icalclassify_request_freebusy, ICAL_XLICCLASS_REQUESTFREEBUSY},
  {ICAL_METHOD_REPLY, icalclassify_reply_accept, ICAL_XLICCLASS_REPLYACCEPT},
  {ICAL_METHOD_REPLY, icalclassify_reply_decline, ICAL_XLICCLASS_REPLYDECLINE},
  {ICAL_METHOD_REPLY, icalclassify_reply_delegate, ICAL_XLICCLASS_REPLYDELEGATE},
  {ICAL_METHOD_REPLY, icalclassify_reply_crasher_accept, ICAL_XLICCLASS_REPLYCRASHERACCEPT},
  {ICAL_METHOD_REPLY, icalclassify_reply_crasher_decline, ICAL_XLICCLASS_REPLYCRASHERDECLINE},
  {ICAL_METHOD_ADD, icalclassify_add_instance, ICAL_XLICCLASS_ADDINSTANCE},
  {ICAL_METHOD_CANCEL, icalclassify_cancel_event, ICAL_XLICCLASS_CANCELEVENT},
  {ICAL_METHOD_CANCEL, icalclassify_cancel_instance, ICAL_XLICCLASS_CANCELINSTANCE},
  {ICAL_METHOD_CANCEL, icalclassify_cancel_all, ICAL_XLICCLASS_CANCELALL},
  {ICAL_METHOD_REFRESH, icalclassify_refesh, ICAL_XLICCLASS_REFRESH},
  {ICAL_METHOD_COUNTER, icalclassify_counter, ICAL_XLICCLASS_COUNTER},
  {ICAL_METHOD_DECLINECOUNTER, icalclassify_delinecounter, ICAL_XLICCLASS_DECLINECOUNTER},
  {ICAL_METHOD_NONE, NULL, ICAL_XLICCLASS_NONE}
};

icalproperty_xlicclass icalclassify(icalcomponent *c, icalcomponent *match, const char *user)
{
    icalcomponent *inner;
    icalproperty *p;
    icalproperty_method method;
    icalproperty_xlicclass class = ICAL_XLICCLASS_UNKNOWN;

    int i;

    struct icalclassify_parts comp_parts;
    struct icalclassify_parts match_parts;

    inner = icalcomponent_get_first_real_component(c);

    if (inner == 0) {
        return ICAL_XLICCLASS_NONE;
    }

    icalssutil_get_parts(c, &comp_parts);
    icalssutil_get_parts(match, &match_parts);

    /* Determine if the incoming component is obsoleted by the match */
    if (match != 0 && (comp_parts.method == ICAL_METHOD_REQUEST)) {
        assert(!((icaltime_is_utc(comp_parts.dtstamp) == 1) ^
                 (icaltime_is_utc(match_parts.dtstamp) == 1)));

        if (comp_parts.sequence < match_parts.sequence &&
            icaltime_compare(comp_parts.dtstamp, match_parts.dtstamp) > 0) {
            /* comp has a smaller sequence and a later DTSTAMP */
            class = ICAL_XLICCLASS_MISSEQUENCED;
            goto CLEANUP;
        }

        if ((comp_parts.sequence < match_parts.sequence) ||
            (comp_parts.sequence == match_parts.sequence &&
             icaltime_compare(comp_parts.dtstamp, match_parts.dtstamp) <= 0)) {
            class = ICAL_XLICCLASS_OBSOLETE;
            goto CLEANUP;
        }
    }

    p = icalcomponent_get_first_property(c, ICAL_METHOD_PROPERTY);
    if (p == 0) {
        class = ICAL_XLICCLASS_UNKNOWN;
        goto CLEANUP;
    }
    method = icalproperty_get_method(p);

    for (i = 0; icalclassify_map[i].method != ICAL_METHOD_NONE; i++) {
        if (icalclassify_map[i].method == method) {
            if ((*(icalclassify_map[i].fn)) (&comp_parts, &match_parts, user) == 1) {
                class = icalclassify_map[i].class;
                break;
            }
        }
    }

  CLEANUP:
    icalssutil_free_parts(&comp_parts);
    icalssutil_free_parts(&match_parts);

    return class;
}