// Author : Teddy Valette 
// Link https://github.com/mozilla-comm/ical.js/ with https://github.com/fullcalendar/fullcalendar

recur_events = []

function ical_events(ical, event_callback, recur_event_callback) {
    jcal_events(ICAL.parse(ical), event_callback, recur_event_callback)
}

function jcal_events(jcal, event_callback, recur_event_callback) {
    for (event of new ICAL.Component(jcal).getAllSubcomponents('vevent')) {
        if (event.hasProperty('rrule')) {
            recur_event_callback(event)
        } else {
            event_callback(event)
        }
    }
}

function event_duration(event) {
    return new Date(event.getFirstPropertyValue('dtend').toJSDate() - event.getFirstPropertyValue('dtstart').toJSDate()).getTime()
}

function event_dtend(dtstart, duration) {
    return new ICAL.Time().fromJSDate(new Date(dtstart.toJSDate().getTime() + duration))
}

function expand_recur_event(event, dtstart, dtend, event_callback) {
    exp = new ICAL.RecurExpansion({
        component:event,
        dtstart:event.getFirstPropertyValue('dtstart')
    })
    duration = event_duration(event)
    while (! exp.complete && exp.next() < dtend) {
        if (exp.last >= dtstart) {
            event = new ICAL.Component(event.toJSON())
            event.updatePropertyWithValue('dtstart', exp.last)
            event.updatePropertyWithValue('dtend', event_dtend(exp.last, duration))
            event_callback(event)
        }
    }
}

function an_filter(string) {
    // remove non alphanumeric chars
    return string.replace(/[^\w\s]/gi, '')
}

function moment_icaltime(moment, timezone) {
    // TODO timezone
    return new ICAL.Time().fromJSDate(moment.toDate())
}

function expand_recur_events(start, end, timezone, events_callback) {
    events = []
    for (event of recur_events) {
	event_properties = event.event_properties
        expand_recur_event(event, moment_icaltime(start, timezone), moment_icaltime(end, timezone), function(event){
            fc_event(event, function(event){
                events.push(merge_events(event_properties, merge_events({className:['recur-event']}, event)))
            })
        })
    }
    events_callback(events)
}

function fc_events(ics, event_properties) {
    events = []
    ical_events(
        ics,
        function(event){
            fc_event(event, function(event){
                events.push(merge_events(event_properties, event))
            })
        },
        function(event){
            event.event_properties = event_properties
            recur_events.push(event)
        }
    )
    return events
}

function merge_events(e, f) {
    // f has priority
    for (k in e) {
        if (k == 'className') {
            f[k] = [].concat(f[k]).concat(e[k])
        } else if (! f[k]) {
            f[k] = e[k]
        }
    }
    return f
}

function sanitize_location(location) {
//    return location.replace('Remicourt_', '');
    return location.replace(/Remicourt_/g, '').replace(/,/g, ', ');

}

function sanitize_description(description) {
    return description.trim().replace(/\n/g, "<br />").replace(/\(Modifi. le:.{10} .{5}\)/g, '').slice(0, -8).replace('Remicourt_', '');
}

function fc_event(event, event_callback) {
    e = {
        title:event.getFirstPropertyValue('summary'),
        url:event.getFirstPropertyValue('url'),
        id:event.getFirstPropertyValue('uid'),
        className:['event-'+an_filter(event.getFirstPropertyValue('uid'))],
        room:sanitize_location(event.getFirstPropertyValue('location')),
        description:sanitize_description(event.getFirstPropertyValue('description')),
        color: (() => {
          let title = event.getFirstPropertyValue('summary')
           if (title.toLowerCase().match(/note|noté|examen/)){
             return '#e60000'
           } else if (title.toLowerCase().match(/cm/)){
             return '#ff8000'
           } else if (title.toLowerCase().match(/td/)) {
             return '#008000'
           } else if (title.toLowerCase().match(/tp/)) {
             return '#0066cc'
           } else if (title.toLowerCase().match(/anglais/)) {
             return '#9966ff'
           } else if (title.toLowerCase().match(/période|periode/)) {
             return '#663300'
           } else {
             return '#660066'
           }
        })(),
        allDay:false
    }
    try {
        e['start'] = event.getFirstPropertyValue('dtstart').toJSDate()
    } catch (TypeError) {
        console.debug('Undefined "dtstart", vevent skipped.')
        return
    }
    try {
        e['end'] = event.getFirstPropertyValue('dtend').toJSDate()
    } catch (TypeError) {
        e['allDay'] = true
    }
    event_callback(e)
}