/* Copyright (c) 1993 by Sanjay Ghemawat */
#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include "WeekDay.h"

#include "basic.h"
#include "arrays.h"
#include "cal_tcl.h"
#include "calfile.h"
#include "calendar.h"
#include "ical.h"
#include "item_tcl.h"
#include "dispatch.h"

/*
 * Item* -> Item_Tcl* map.
 */
static Tcl_HashTable itemMap;
static int itemMapInited = 0;

static int check_permission(Tcl_Interp* tcl, Item_Tcl* item);
// effects	If "item" can be modified legally, then mark
//		containing calendar as modified and return true.
//		Else store an error message in "tcl->result"
//		and return false.

static void trigger_item(Tcl_Interp* tcl, Item_Tcl* item,
			 char const* = "change");
// effects	If "item" belongs to a calendar, generate a trigger message
//		for it.  The generate trigger is of type "change" by default,
//		but that can be overridden by providing a different value for
//		the optional last argument.

Item_Tcl::Item_Tcl(Tcl_Interp* tcl, Item* i, CalFile* c)
    : Object(tcl, "Item")
{
    item = i;
    cal = c;

    if (! itemMapInited) {
	itemMapInited = 1;
	Tcl_InitHashTable(&itemMap, TCL_ONE_WORD_KEYS);
    }
    int newentry;
    Tcl_HashEntry* entry = Tcl_CreateHashEntry(&itemMap,(char*)item,&newentry);
    assert(newentry);
    Tcl_SetHashValue(entry, (ClientData)this);
}

Item_Tcl::~Item_Tcl() {
    Tcl_HashEntry* entry = Tcl_FindHashEntry(&itemMap, (char*)item);
    assert((entry != 0) && (Tcl_GetHashValue(entry) == ((ClientData) this)));
    Tcl_DeleteHashEntry(entry);
}

Item_Tcl* Item_Tcl::find(Item* item) {
    Tcl_HashEntry* entry = Tcl_FindHashEntry(&itemMap, (char*)item);
    return ((entry == 0) ? 0 : ((Item_Tcl*) Tcl_GetHashValue(entry)));
}

/*
 * Forward declaration of handler procedures.
 */
static int item_length	(ClientData, Tcl_Interp*, int, char*[]);
static int item_startt	(ClientData, Tcl_Interp*, int, char*[]);
static int item_clone	(ClientData, Tcl_Interp*, int, char*[]);
static int item_is	(ClientData, Tcl_Interp*, int, char*[]);
static int item_delete	(ClientData, Tcl_Interp*, int, char*[]);
static int item_cal	(ClientData, Tcl_Interp*, int, char*[]);
static int item_text	(ClientData, Tcl_Interp*, int, char*[]);
static int item_early	(ClientData, Tcl_Interp*, int, char*[]);
static int item_owner	(ClientData, Tcl_Interp*, int, char*[]);
static int item_owned	(ClientData, Tcl_Interp*, int, char*[]);
static int item_own	(ClientData, Tcl_Interp*, int, char*[]);
static int item_hilite	(ClientData, Tcl_Interp*, int, char*[]);
static int item_todo	(ClientData, Tcl_Interp*, int, char*[]);
static int item_is_done	(ClientData, Tcl_Interp*, int, char*[]);
static int item_done	(ClientData, Tcl_Interp*, int, char*[]);
static int item_alarms	(ClientData, Tcl_Interp*, int, char*[]);
static int item_option	(ClientData, Tcl_Interp*, int, char*[]);
static int item_doption	(ClientData, Tcl_Interp*, int, char*[]);
static int item_empty	(ClientData, Tcl_Interp*, int, char*[]);
static int item_repeat	(ClientData, Tcl_Interp*, int, char*[]);
static int item_first	(ClientData, Tcl_Interp*, int, char*[]);
static int item_type	(ClientData, Tcl_Interp*, int, char*[]);
static int item_desc	(ClientData, Tcl_Interp*, int, char*[]);
static int item_cont	(ClientData, Tcl_Interp*, int, char*[]);
static int item_next	(ClientData, Tcl_Interp*, int, char*[]);
static int item_range	(ClientData, Tcl_Interp*, int, char*[]);
static int item_date	(ClientData, Tcl_Interp*, int, char*[]);
static int item_start	(ClientData, Tcl_Interp*, int, char*[]);
static int item_finish	(ClientData, Tcl_Interp*, int, char*[]);
static int item_ondel	(ClientData, Tcl_Interp*, int, char*[]);
static int item_dayr	(ClientData, Tcl_Interp*, int, char*[]);
static int item_wdays	(ClientData, Tcl_Interp*, int, char*[]);

static int item_monthr		(ClientData, Tcl_Interp*, int, char*[]);
static int item_mday		(ClientData, Tcl_Interp*, int, char*[]);
static int item_mlday		(ClientData, Tcl_Interp*, int, char*[]);
static int item_mworkday	(ClientData, Tcl_Interp*, int, char*[]);
static int item_mlworkday	(ClientData, Tcl_Interp*, int, char*[]);
static int item_mweekday	(ClientData, Tcl_Interp*, int, char*[]);
static int item_mlweekday	(ClientData, Tcl_Interp*, int, char*[]);

static Dispatch_Entry item_dispatch[] = {
    { "delete",			0, 0, item_delete	},
    { "clone",			0, 0, item_clone	},

    { "length",			0, 1, item_length	},
    { "starttime",		0, 1, item_startt	},
    { "alarms",			0, 1, item_alarms	},
    { "option",			1, 2, item_option	},
    { "delete_option",		1, 1, item_doption	},

    { "is",			1, 1, item_is		},
    { "calendar",		0, 0, item_cal		},
    { "text",			0, 1, item_text		},
    { "earlywarning",		0, 1, item_early	},
    { "owner",			0, 1, item_owner	},
    { "owned",			0, 0, item_owned	},
    { "own",			0, 0, item_own		},
    { "hilite",			0, 1, item_hilite	},
    { "todo",			0, 1, item_todo		},
    { "is_done",		0, 0, item_is_done	},
    { "done",			1, 1, item_done		},

    { "contains",		1, 1, item_cont		},
    { "empty",			0, 0, item_empty	},
    { "repeats",		0, 0, item_repeat	},
    { "first",			0, 0, item_first	},
    { "next",			1, 1, item_next		},
    { "range",			2, 2, item_range	},
    { "type",			0, 0, item_type		},
    { "describe_repeat",	0, 0, item_desc		},

    { "date",			1, 1, item_date		},
    { "dayrepeat",		2, 2, item_dayr		},

    { "monthrepeat",		2, 2, item_monthr	},
    { "month_day",		1, 3, item_mday		},
    { "month_last_day",		1, 3, item_mlday	},
    { "month_work_day",		1, 3, item_mworkday	},
    { "month_last_work_day",	1, 3, item_mlworkday	},
    { "month_week_day",		2, 4, item_mweekday	},
    { "month_last_week_day",	2, 4, item_mlweekday	},

    { "weekdays",		0, -1, item_wdays	},
    { "start",			1, 1, item_start	},
    { "finish",			1, 1, item_finish	},
    { "deleteon",		1, 1, item_ondel	},

    { 0,			0, 0, 0			}
};

int Item_Tcl::method(int argc, char* argv[]) {
    return Dispatch(item_dispatch, (ClientData)this, tcl(), argc, argv);
}

/*
 * Handler procedures.
 */

static int item_length(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    Appointment* appt = item->value()->AsAppointment();
    if (appt != 0) {
	if (argc == 0) {
	    char buffer[100];
	    sprintf(buffer, "%d", appt->GetLength());
	    Tcl_SetResult(tcl, buffer, TCL_VOLATILE);
	    return TCL_OK;
	}

	int length;
	if ((Tcl_GetInt(tcl, argv[0], &length) != TCL_OK) ||
	    (length < 1) ||
	    (length > 24*60)) {
	    TCL_Error(tcl, "invalid appointment length");
	}
	if (! check_permission(tcl, item)) return TCL_ERROR;

	appt->SetLength(length);
	trigger_item(tcl, item);

	TCL_Return(tcl, "");
    }

    TCL_Error(tcl, "unknown command");
}

static int item_startt(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    Appointment* appt = item->value()->AsAppointment();
    if (appt == 0) {
	TCL_Error(tcl, "unknown command");
    }

    if (argc == 0) {
	char buffer[100];
	sprintf(buffer, "%d", appt->GetStart());
	Tcl_SetResult(tcl, buffer, TCL_VOLATILE);
	return TCL_OK;
    }

    int start;
    if ((Tcl_GetInt(tcl, argv[0], &start) != TCL_OK) ||
	(start < 0) ||
	(start >= (24*60))) {
	TCL_Error(tcl, "invalid appointment start");
    }
    if (! check_permission(tcl, item)) return TCL_ERROR;

    appt->SetStart(start);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_clone(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    Item_Tcl* clone = new Item_Tcl(tcl, item->value()->Clone(), 0);
    TCL_Return(tcl, (char*) clone->handle());
}

static int item_is(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    if ((strcmp(argv[0], "note") == 0) && (item->value()->AsNotice() != 0)) {
	TCL_Return(tcl, "1");
    }

    if ((strcmp(argv[0], "appt") == 0) && (item->value()->AsAppointment()!=0)){
	TCL_Return(tcl, "1");
    }

    TCL_Return(tcl, "0");
}

static int item_delete(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = ((Item_Tcl*) c);
    if (! check_permission(tcl, item)) return TCL_ERROR;

    CalFile* file = item->calendar();
    if (file != 0) {
	item->set_calendar(0);
	file->GetCalendar()->Remove(item->value());
	file->Modified();

	// XXX Only send triggers when deleting an item from a calendar???
	trigger(tcl, "delete", item->handle());
    }

    delete item->value();
    delete item;

    TCL_Return(tcl, "");
}

static int item_cal(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    CalFile* cal = item->calendar();
    if (cal == 0) {
	TCL_Error(tcl, "item not in calendar");
    }
    TCL_Return(tcl, (char*)(cal->GetName()));
}

static int item_text(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    if (argc == 0) {
	TCL_Return(tcl, (char*) item->value()->GetText());
    }

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->SetText(argv[0]);
    trigger_item(tcl, item, "text");

    TCL_Return(tcl, "");
}

static int item_early(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    if (argc == 0) {
	char buffer[100];

	sprintf(buffer, "%d", item->value()->GetRemindStart());
	Tcl_SetResult(tcl, buffer, TCL_VOLATILE);
	return TCL_OK;
    }

    int warn;
    if (Tcl_GetInt(tcl, argv[0], &warn) != TCL_OK) {
	TCL_Error(tcl, "invalid early warning option");
    }
    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->SetRemindStart(warn);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_owner(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    if (argc == 0) {
	TCL_Return(tcl, (char*) item->value()->GetOwner());
    }

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->SetOwner(argv[0]);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_owned(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    TCL_Return(tcl, (item->value()->IsMine() ? "1" : "0"));
}

static int item_own(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->MakeOwner();
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_hilite(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    if (argc == 0) {
	Tcl_SetResult(tcl, (char*) (item->value()->Hilite()), TCL_VOLATILE);
	return TCL_OK;
    }

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->Hilite(argv[0]);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_todo(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    if (argc == 0) {
	TCL_Return(tcl, (char*)(item->value()->IsTodo() ? "1" : "0"));
    }

    int todo;
    if (Tcl_GetBoolean(tcl, argv[0], &todo) != TCL_OK) {
	TCL_Error(tcl, "invalid value for todo flag");
    }
    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->SetTodo(todo);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_is_done(ClientData c, Tcl_Interp* tcl,int argc,char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    TCL_Return(tcl, (char*)(item->value()->IsDone() ? "1" : "0"));
}

static int item_done(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    if (! check_permission(tcl, item)) return TCL_ERROR;

    int done;
    if (Tcl_GetBoolean(tcl, argv[0], &done) != TCL_OK) {
	TCL_Error(tcl, "invalid value for done flag");
    }

    item->value()->SetDone(done);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_alarms(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    Appointment* appt = item->value()->AsAppointment();
    if (appt == 0) {
	TCL_Error(tcl, "unknown command");
    }

    if (argc == 0) {
	intArray* alarms = appt->GetAlarms();
	if (alarms == 0) {
	    TCL_Error(tcl, "no alarms");
	}

	// Make Tcl string out of integers
	// (We allocate an array one larger than necessary to avoid
	// zero length allocation).

	int i;
	char** str = new char*[alarms->size()+1];
	for (i = 0; i < alarms->size(); i++) {
	    int x = alarms->slot(i);

	    str[i] = new char[100];
	    sprintf(str[i], "%d", x);
	}
	char* list = Tcl_Merge(alarms->size(), str);
	for (i = 0; i < alarms->size(); i++) {
	    delete [] str[i];
	}
	delete [] str;

	Tcl_SetResult(tcl, list, TCL_DYNAMIC);
	return TCL_OK;
    }

    int count;
    char** list;
    if (Tcl_SplitList(tcl, argv[0], &count, &list) != TCL_OK) {
	TCL_Error(tcl, "invalid alarm list");
    }

    intArray* alarms = new intArray(count);
    for (int i = 0; i < count; i++) {
	int x;
	if ((Tcl_GetInt(tcl, list[i], &x) != TCL_OK) || (x < 0) || (x > 60)) {
	    free((char*) list);
	    delete alarms;
	    TCL_Error(tcl, "invalid alarm time");
	}
	alarms->append(x);
    }
    free((char*) list);
	    
    if (! check_permission(tcl, item)) {
	delete alarms;
	return TCL_ERROR;
    }

    appt->SetAlarms(alarms);
    delete alarms;
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_option(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    if (argc == 1) {
	char const* val = item->value()->GetOption(argv[0]);
	if (val == 0) TCL_Error(tcl, "unknown item option");
	Tcl_SetResult(tcl, (char*) val, TCL_VOLATILE);
	return TCL_OK;
    }

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->SetOption(argv[0], argv[1]);
    trigger_item(tcl, item);
    TCL_Return(tcl, "");
}

static int item_doption(ClientData c, Tcl_Interp* tcl, int argc,char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    if (! check_permission(tcl, item)) return TCL_ERROR;

    // Check whether option exists
    char const* val = item->value()->GetOption(argv[0]);
    if (val == 0) TCL_Error(tcl, "unknown item option");

    item->value()->RemoveOption(argv[0]);
    trigger_item(tcl, item);
    TCL_Return(tcl, "");
}

static int item_empty(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    TCL_Return(tcl, (item->value()->empty()?"1":"0"));
}

static int item_repeat(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    TCL_Return(tcl,(item->value()->repeats()?"1":"0"));
}

static int item_first(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    Date d;
    if (! item->value()->first(d)) {
	TCL_Error(tcl, "item does not occur");
    }

    char buffer[100];
    sprintf(buffer, "%d", d.EpochDays());
    Tcl_SetResult(tcl, buffer, TCL_VOLATILE);
    return TCL_OK;
}

static int item_type(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    char* result;
    switch (item->value()->repeat_type()) {
      case DateSet::None:
	result = "";
	break;
      case DateSet::Daily:
	result = "Daily";
	break;
      case DateSet::Weekly:
	result = "Weekly";
	break;
      case DateSet::BiWeekly:
	result = "Every Two Weeks";
	break;
      case DateSet::ThreeWeekly:
	result = "Every Three Weeks";
	break;
      case DateSet::FourWeekly:
	result = "Every Four Weeks";
	break;
      case DateSet::Monthly:
	result = "Monthly";
	break;
      case DateSet::TwoMonthly:
	result = "Every Two Months";
	break;
      case DateSet::ThreeMonthly:
	result = "Every Three Months";
	break;
      case DateSet::FourMonthly:
	result = "Every Four Months";
	break;
      case DateSet::SixMonthly:
	result = "Every Six Months";
	break;
      case DateSet::Annual:
	result = "Annual";
	break;
      default:
	result = "Complex";
	break;
    }
    TCL_Return(tcl, result);
}

static int item_desc(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    charArray buffer;
    item->value()->describe(&buffer);
    buffer.append('\0');
    Tcl_SetResult(tcl, buffer.as_pointer(), TCL_VOLATILE);
    return TCL_OK;
}

static int item_cont(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    int dateDays;
    if (Tcl_GetInt(tcl, argv[0], &dateDays) != TCL_OK) {
	TCL_Error(tcl, "invalid date");
    }
    Date date(dateDays);
    TCL_Return(tcl, (item->value()->contains(date)?"1":"0"));
}

static int item_next(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    int dateDays;
    if (Tcl_GetInt(tcl, argv[0], &dateDays) != TCL_OK) {
	TCL_Error(tcl, "invalid date");
    }
    Date date(dateDays);
    Date next;
    if (! item->value()->next(date, next)) {
	TCL_Error(tcl, "no next occurrence for item");
    }

    char buffer[100];
    sprintf(buffer, "%d", next.EpochDays());
    Tcl_SetResult(tcl, buffer, TCL_VOLATILE);
    return TCL_OK;
}

static int item_range(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    Date s, f;
    if (item->value()->range(s, f)) {
	char buffer[100];
	sprintf(buffer, "%d", s.EpochDays());
	if (Tcl_SetVar(tcl, argv[0], buffer, 0) == NULL)
	    TCL_Error(tcl, "could not set range start variable");
	sprintf(buffer, "%d", f.EpochDays());
	if (Tcl_SetVar(tcl, argv[1], buffer, 0) == NULL)
	    TCL_Error(tcl, "could not set range finish variable");
	TCL_Return(tcl, "1");
    }
    else {
	TCL_Return(tcl, "0");
    }
}

static int item_date(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    int dateDays;
    if (Tcl_GetInt(tcl, argv[0], &dateDays) != TCL_OK) {
	TCL_Error(tcl, "invalid date");
    }
    Date date(dateDays);
    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_date(date);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_start(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    int dateDays;
    if (Tcl_GetInt(tcl, argv[0], &dateDays) != TCL_OK) {
	TCL_Error(tcl, "invalid date");
    }
    Date date(dateDays);
    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_start(date);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_finish(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    int dateDays;
    if (Tcl_GetInt(tcl, argv[0], &dateDays) != TCL_OK) {
	TCL_Error(tcl, "invalid date");
    }
    Date date(dateDays);
    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_finish(date);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_ondel(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;
    int dateDays;
    if (Tcl_GetInt(tcl, argv[0], &dateDays) != TCL_OK) {
	TCL_Error(tcl, "invalid date");
    }
    Date date(dateDays);
    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->delete_occurrence(date);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_dayr(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    int interval;
    if ((Tcl_GetInt(tcl, argv[0], &interval) != TCL_OK) || (interval < 1)) {
	TCL_Error(tcl, "invalid interval");
    }

    int anchorDays;
    if (Tcl_GetInt(tcl, argv[1], &anchorDays) != TCL_OK) {
	TCL_Error(tcl, "invalid anchor date");
    }
    Date anchor(anchorDays);

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_day_based_repeat(interval, anchor);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_monthr(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    int interval;
    if ((Tcl_GetInt(tcl, argv[0], &interval) != TCL_OK) || (interval < 1)) {
	TCL_Error(tcl, "invalid interval");
    }

    int anchorDays;
    if (Tcl_GetInt(tcl, argv[1], &anchorDays) != TCL_OK) {
	TCL_Error(tcl, "invalid anchor date");
    }
    Date anchor(anchorDays);

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_month_based_repeat(interval, anchor);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

// Helper routine for "set_monthly" interfaces.
// modifies	"n", "anchor", "interval".
// effects	Parses "n", "anchor" and "interval" from the command
//		arguments.  Returns TCL_OK iff successful.  If "anchor"
//		and "interval" are not specified in the command arguments,
//		then "anchor" is set to today and "interval" is set to "1".
static int parse_month_args(Tcl_Interp* tcl, int argc, char* argv[],
			    int& n, Date& anchor, int& interval)
{
    if ((argc != 1) && (argc != 3)) TCL_Error(tcl,"wrong number of arguments");
    if ((Tcl_GetInt(tcl, argv[0], &n) != TCL_OK) || (n < 1))
	TCL_Error(tcl, "invalid count");

    // Get anchor and interval
    if (argc == 1) {
	anchor = Date::Today();
	interval = 1;
    }
    else {
	int anchorDays;
	if (Tcl_GetInt(tcl, argv[1], &anchorDays) != TCL_OK)
	    TCL_Error(tcl, "invalid anchor date");
	anchor = Date(anchorDays);

	if ((Tcl_GetInt(tcl, argv[2], &interval) != TCL_OK) || (interval < 1))
	    TCL_Error(tcl, "invalid interval");
    }

    return TCL_OK;
}

static int item_mday(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    int n, interval;
    Date anchor;
    if (parse_month_args(tcl, argc, argv, n, anchor, interval) != TCL_OK)
	return TCL_ERROR;

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_monthly_by_days(n, interval, anchor, 0);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_mlday(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    int n, interval;
    Date anchor;
    if (parse_month_args(tcl, argc, argv, n, anchor, interval) != TCL_OK)
	return TCL_ERROR;

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_monthly_by_days(n, interval, anchor, 1);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_mworkday(ClientData c, Tcl_Interp* tcl,
			 int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    int n, interval;
    Date anchor;
    if (parse_month_args(tcl, argc, argv, n, anchor, interval) != TCL_OK)
	return TCL_ERROR;

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_monthly_by_workdays(n, interval, anchor, 0);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_mlworkday(ClientData c, Tcl_Interp* tcl,
			  int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    int n, interval;
    Date anchor;
    if (parse_month_args(tcl, argc, argv, n, anchor, interval) != TCL_OK)
	return TCL_ERROR;

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_monthly_by_workdays(n, interval, anchor, 1);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_mweekday(ClientData c, Tcl_Interp* tcl,
			 int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    int wday;
    if ((Tcl_GetInt(tcl,argv[0],&wday) != TCL_OK) || (wday < 1) || (wday > 7))
	TCL_Error(tcl, "invalid weekday");
    WeekDay w = WeekDay::First() + (wday - 1);

    int n, interval;
    Date anchor;
    if (parse_month_args(tcl, argc-1, argv+1, n, anchor, interval) != TCL_OK)
	return TCL_ERROR;

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_monthly_by_weeks(n, w, interval, anchor, 0);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_mlweekday(ClientData c, Tcl_Interp* tcl,
			  int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    int wday;
    if ((Tcl_GetInt(tcl,argv[0],&wday) != TCL_OK) || (wday < 1) || (wday > 7))
	TCL_Error(tcl, "invalid weekday");
    WeekDay w = WeekDay::First() + (wday - 1);

    int n, interval;
    Date anchor;
    if (parse_month_args(tcl, argc-1, argv+1, n, anchor, interval) != TCL_OK)
	return TCL_ERROR;

    if (! check_permission(tcl, item)) return TCL_ERROR;
    item->value()->set_monthly_by_weeks(n, w, interval, anchor, 1);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int item_wdays(ClientData c, Tcl_Interp* tcl, int argc, char* argv[]) {
    Item_Tcl* item = (Item_Tcl*) c;

    /* Collect weekdays */
    int i;
    SmallIntSet set;
    set.Clear();
    for (i = 0; i < argc; i++) {
	int weekday;
	if ((Tcl_GetInt(tcl, argv[i], &weekday) != TCL_OK) ||
	    (weekday < 1) ||
	    (weekday > 7)) {
	    TCL_Error(tcl, "invalid weekday");
	}
	set.Insert(weekday);
    }

    if (! check_permission(tcl, item)) return TCL_ERROR;

    /* Repeat every month */
    SmallIntSet months;
    months.Clear();
    for (i = 1; i <= 12; i++) {
	months.Insert(i);
    }

    item->value()->set_week_set(set, months);
    trigger_item(tcl, item);

    TCL_Return(tcl, "");
}

static int check_permission(Tcl_Interp* tcl, Item_Tcl* item) {
    CalFile* file = item->calendar();
    if (file == 0) return 1;

    if (file->GetCalendar()->ReadOnly()) {
	Tcl_SetResult(tcl, "item is in readonly calendar", TCL_STATIC);
	return 0;
    }

    file->Modified();
    return 1;
}

static void trigger_item(Tcl_Interp* tcl, Item_Tcl* item, char const* t) {
    if (item->calendar() != 0)
	trigger(tcl, t, item->handle());
}