{% extends "base.html" %}

{% block title %}Terminplan konfigurieren - Inventarsystem{% endblock %}

{% block content %}
<div class="container py-4">
    <div class="row justify-content-center">
        <div class="col-12 col-lg-10 col-xl-8">
            <div class="card border-0 shadow-lg rounded-4 overflow-hidden">
                <div class="card-header text-white" style="background: linear-gradient(135deg, #0f4c5c, #16697a);">
                    <h1 class="h3 mb-1 fw-bold">Terminplan konfigurieren</h1>
                    <p class="mb-0 opacity-75">Erstellen Sie einen neuen Plan und verschicken Sie anschließend den Buchungslink.</p>
                </div>
                <div class="card-body p-4 p-md-5 bg-white">
                    <form method="post" action="{{ url_for('terminplaner.configure') }}" class="vstack gap-3">
                        <div class="row g-3">
                            <div class="col-12">
                                <label for="title" class="form-label fw-semibold">Titel des Terminplans</label>
                                <input type="text" id="title" name="title" class="form-control form-control-lg" placeholder="z.B. Elternsprechtag Klasse 10a" value="{{ title or '' }}">
                            </div>
                            <div class="col-12 col-md-6">
                                <label for="start_date" class="form-label fw-semibold">Startdatum</label>
                                <input type="date" id="start_date" name="start_date" class="form-control form-control-lg">
                            </div>
                            <div class="col-12 col-md-6">
                                <label for="end_date" class="form-label fw-semibold">Enddatum</label>
                                <input type="date" id="end_date" name="end_date" class="form-control form-control-lg">
                            </div>
                        </div>

                        <div class="border rounded-4 p-3 p-md-4 bg-light-subtle">
                            <div class="d-flex flex-column flex-md-row justify-content-between align-items-md-center gap-2 mb-2">
                                <div>
                                    <label class="form-label fw-semibold mb-0">Zeitfenster pro Tag</label>
                                    <div class="form-text mb-0">Die Start-, End- und Pausenzeiten werden auf alle erzeugten Tage angewandt.</div>
                                </div>
                                <button type="button" class="btn btn-outline-primary btn-sm" id="build_time_frame">Tage aus Zeitraum erzeugen</button>
                            </div>

                            <div class="row g-3 mb-3">
                                <div class="col-12 col-sm-6 col-lg-3">
                                    <label for="default_day_start" class="form-label fw-semibold">Standard-Start</label>
                                    <input type="time" id="default_day_start" class="form-control" value="08:00">
                                </div>
                                <div class="col-12 col-sm-6 col-lg-3">
                                    <label for="default_day_end" class="form-label fw-semibold">Standard-Ende</label>
                                    <input type="time" id="default_day_end" class="form-control" value="16:00">
                                </div>
                                <div class="col-12 col-sm-6 col-lg-3">
                                    <label for="default_pause_start" class="form-label fw-semibold text-danger">Pause von</label>
                                    <input type="time" id="default_pause_start" class="form-control border-danger-subtle" value="12:00">
                                </div>
                                <div class="col-12 col-sm-6 col-lg-3">
                                    <label for="default_pause_end" class="form-label fw-semibold text-danger">Pause bis</label>
                                    <input type="time" id="default_pause_end" class="form-control border-danger-subtle" value="12:45">
                                </div>
                            </div>

                            <div id="time_frame_days" class="vstack gap-2"></div>

                            <div class="mt-3">
                                <label for="time_frame" class="form-label fw-semibold">Gespeichertes Zeitfenster (Übertragung ans Backend)</label>
                                <textarea id="time_frame" name="time_frame" class="form-control font-monospace" rows="5" placeholder="Wird automatisch aus den Tagen erzeugt" readonly></textarea>
                                <div class="form-text">Pausen teilen den Tag automatisch in zwei buchbare Blöcke, sodass die Pause sicher blockiert ist.</div>
                            </div>
                        </div>

                        <div class="row g-3">
                            <div class="col-12 col-md-6">
                                <label for="slot_length" class="form-label fw-semibold">Slot-Länge in Minuten</label>
                                <input type="number" id="slot_length" name="slot_length" class="form-control" min="1" value="45">
                            </div>
                            <div class="col-12 col-md-6">
                                <label for="slots_amounts" class="form-label fw-semibold text-primary">Automatisch berechnete Slots</label>
                                <input type="number" id="slots_amounts" name="slots_amounts" class="form-control bg-light text-primary fw-bold" min="0" value="0" readonly>
                                <div class="form-text">Wird aus der gebuchten Zeit (abzüglich Pausen) und der Slot-Länge berechnet.</div>
                            </div>
                        </div>

                        {% if mail_service_enabled %}
                            <div>
                                <label for="mail" class="form-label fw-semibold">Empfänger-Mails</label>
                                <input type="text" id="mail" name="mail" class="form-control" placeholder="adresse1@schule.de, adresse2@schule.de">
                            </div>

                            <div>
                                <label for="note" class="form-label fw-semibold">Notiz</label>
                                <textarea id="note" name="note" class="form-control" rows="4" placeholder="Optionaler Einführungstext für die Mail"></textarea>
                            </div>
                        {% endif %}
                        <div class="form-check">
                            <input class="form-check-input" type="checkbox" id="add_to_calendar" name="add_to_calendar" {% if add_to_calendar %}checked{% endif %}>
                            <label class="form-check-label fw-semibold" for="add_to_calendar">Kalendereintrag für den Nutzer erzeugen</label>
                            <div class="form-text">Erzeugt zusätzlich eine .ics-Datei, die in gängige Kalender importiert werden kann.</div>
                        </div>

                        <div class="d-flex flex-column flex-sm-row gap-2 pt-2">
                            <button type="submit" class="btn btn-primary btn-lg">Terminplan erzeugen</button>
                            <a class="btn btn-outline-secondary btn-lg" href="{{ url_for('terminplaner.main') }}">Zur Übersicht</a>
                        </div>
                    </form>
                </div>
            </div>

            {% if generated_link %}
            <div class="alert alert-success mt-4 shadow-sm rounded-4">
                <div class="fw-bold mb-1">Buchungslink erstellt</div>
                <div class="mb-2">
                    {% if mail_service_enabled %}
                        Teilen Sie diesen Link mit den Teilnehmenden oder versenden Sie ihn direkt per E-Mail.
                    {% else %}
                        Der E-Mail-Service ist deaktiviert. Teilen Sie diesen Link manuell mit den Teilnehmenden.
                    {% endif %}
                </div>
                <a href="{{ generated_link }}" class="d-inline-block text-break">{{ generated_link }}</a>
                {% if calendar_link %}
                <div class="mt-3">
                    <div class="fw-semibold mb-1">Kalendereintrag</div>
                    <a href="{{ calendar_link }}" class="btn btn-outline-primary btn-sm">.ics herunterladen</a>
                </div>
                {% endif %}
            </div>
            {% endif %}
        </div>
    </div>
</div>
<script>
(function () {
    const startDateInput = document.getElementById('start_date');
    const endDateInput = document.getElementById('end_date');
    const buildButton = document.getElementById('build_time_frame');
    const daysContainer = document.getElementById('time_frame_days');
    const timeFrameTextarea = document.getElementById('time_frame');
    
    const defaultStartInput = document.getElementById('default_day_start');
    const defaultEndInput = document.getElementById('default_day_end');
    const defaultPauseStartInput = document.getElementById('default_pause_start');
    const defaultPauseEndInput = document.getElementById('default_pause_end');
    
    const slotLengthInput = document.getElementById('slot_length');
    const slotsAmountsInput = document.getElementById('slots_amounts');

    if (!startDateInput || !endDateInput || !buildButton || !daysContainer || !timeFrameTextarea) {
        return;
    }

    const weekdayFormatter = new Intl.DateTimeFormat('de-DE', {
        weekday: 'short',
        day: '2-digit',
        month: '2-digit',
        year: 'numeric',
    });

    function parseDate(value) {
        if (!value) return null;
        const parts = value.split('-').map(Number);
        if (parts.length !== 3 || parts.some(Number.isNaN)) return null;
        return new Date(parts[0], parts[1] - 1, parts[2]);
    }

    function formatDateForRow(date) {
        return weekdayFormatter.format(date);
    }

    function formatDateForValue(date) {
        const year = date.getFullYear();
        const month = String(date.getMonth() + 1).padStart(2, '0');
        const day = String(date.getDate()).padStart(2, '0');
        return `${year}-${month}-${day}`;
    }

    function addDays(date, days) {
        const copy = new Date(date);
        copy.setDate(copy.getDate() + days);
        return copy;
    }

    function timeToMinutes(timeStr) {
        if (!timeStr) return 0;
        const parts = timeStr.split(':').map(Number);
        return parts[0] * 60 + parts[1];
    }

    // Berechnet die Slots basierend auf den konfigurierten Zeiten & Pausen
    function calculateSlots() {
        if (!slotLengthInput || !slotsAmountsInput) return;
        
        const slotLength = parseInt(slotLengthInput.value, 10);
        if (isNaN(slotLength) || slotLength <= 0) {
            slotsAmountsInput.value = 0;
            return;
        }

        let totalSlots = 0;
        const rows = Array.from(daysContainer.querySelectorAll('[data-day-row]'));

        rows.forEach(row => {
            const startTime = row.querySelector('[data-time-start]')?.value;
            const endTime = row.querySelector('[data-time-end]')?.value;
            const pauseStart = row.querySelector('[data-time-pause-start]')?.value;
            const pauseEnd = row.querySelector('[data-time-pause-end]')?.value;

            if (!startTime || !endTime) return;

            const startMins = timeToMinutes(startTime);
            const endMins = timeToMinutes(endTime);
            const pauseStartMins = timeToMinutes(pauseStart);
            const pauseEndMins = timeToMinutes(pauseEnd);

            if (endMins <= startMins) return; // Ungültige Zeit

            // Wenn eine gültige Pause innerhalb der Start/Endzeit existiert
            if (pauseStartMins > 0 && pauseEndMins > 0 && pauseStartMins < pauseEndMins && pauseStartMins > startMins && pauseStartMins < endMins) {
                // Segment 1 (Vor der Pause)
                const segment1 = pauseStartMins - startMins;
                totalSlots += Math.floor(segment1 / slotLength);
                
                // Segment 2 (Nach der Pause)
                const effectivePauseEnd = Math.min(pauseEndMins, endMins);
                const segment2 = endMins - effectivePauseEnd;
                if (segment2 > 0) {
                    totalSlots += Math.floor(segment2 / slotLength);
                }
            } else {
                // Ohne Pause oder ungültige Pause -> Komplett durchrechnen
                totalSlots += Math.floor((endMins - startMins) / slotLength);
            }
        });

        slotsAmountsInput.value = totalSlots;
    }

    // Synchronisiert das Textfeld und fügt den Break-Cut hinzu
    function syncTextarea() {
        const rows = Array.from(daysContainer.querySelectorAll('[data-day-row]'));
        const lines = [];
        
        rows.forEach(function (row) {
            const dayValue = row.getAttribute('data-day-value') || '';
            const startTime = row.querySelector('[data-time-start]')?.value || '';
            const endTime = row.querySelector('[data-time-end]')?.value || '';
            const pauseStart = row.querySelector('[data-time-pause-start]')?.value || '';
            const pauseEnd = row.querySelector('[data-time-pause-end]')?.value || '';
            
            if (!dayValue || !startTime || !endTime) return;

            // Hat der Nutzer eine Pause eingetragen, die innerhalb des Tagesfensters liegt?
            if (pauseStart && pauseEnd && pauseStart < pauseEnd && pauseStart > startTime && pauseStart < endTime) {
                // Zeile am Pausenbeginn aufsplitten -> 2 Blöcke = automatische Pause
                lines.push(`${dayValue} ${startTime}-${pauseStart}`);
                lines.push(`${dayValue} ${pauseEnd}-${endTime}`);
            } else {
                lines.push(`${dayValue} ${startTime}-${endTime}`);
            }
        });

        timeFrameTextarea.value = lines.join('\n');
        calculateSlots(); // Nach jedem Update neu berechnen
    }

    function renderRows() {
        const startDate = parseDate(startDateInput.value);
        const endDate = parseDate(endDateInput.value);

        if (!startDate || !endDate) {
            daysContainer.innerHTML = '<div class="text-muted small">Bitte Start- und Enddatum auswählen, damit die Tageszeilen erzeugt werden.</div>';
            timeFrameTextarea.value = '';
            endDateInput.setCustomValidity('');
            return;
        }

        if (endDate < startDate) {
            daysContainer.innerHTML = '<div class="text-danger small">Das Enddatum muss nach dem Startdatum liegen.</div>';
            timeFrameTextarea.value = '';
            endDateInput.setCustomValidity('Das Enddatum muss nach dem Startdatum liegen.');
            return;
        }

        endDateInput.setCustomValidity('');

        // Bisherige Werte sichern
        const existingValues = new Map();
        Array.from(daysContainer.querySelectorAll('[data-day-row]')).forEach(function (row) {
            const dayValue = row.getAttribute('data-day-value');
            const startTime = row.querySelector('[data-time-start]')?.value || '';
            const endTime = row.querySelector('[data-time-end]')?.value || '';
            const pauseStart = row.querySelector('[data-time-pause-start]')?.value || '';
            const pauseEnd = row.querySelector('[data-time-pause-end]')?.value || '';
            
            if (dayValue) {
                existingValues.set(dayValue, { startTime, endTime, pauseStart, pauseEnd });
            }
        });

        const defaultStart = defaultStartInput.value || '08:00';
        const defaultEnd = defaultEndInput.value || '16:00';
        const defaultPauseStart = defaultPauseStartInput.value || '';
        const defaultPauseEnd = defaultPauseEndInput.value || '';
        const rows = [];

        for (let current = startDate; current <= endDate; current = addDays(current, 1)) {
            const dayValue = formatDateForValue(current);
            const preserved = existingValues.get(dayValue) || {};
            
            const rowStart = preserved.startTime !== undefined ? preserved.startTime : defaultStart;
            const rowEnd = preserved.endTime !== undefined ? preserved.endTime : defaultEnd;
            const rowPauseStart = preserved.pauseStart !== undefined ? preserved.pauseStart : defaultPauseStart;
            const rowPauseEnd = preserved.pauseEnd !== undefined ? preserved.pauseEnd : defaultPauseEnd;

            rows.push(`
                <div class="border rounded-3 bg-white p-3" data-day-row data-day-value="${dayValue}">
                    <div class="row g-2 align-items-end">
                        <div class="col-12 col-lg-4">
                            <label class="form-label fw-semibold mb-1">${formatDateForRow(current)}</label>
                            <div class="text-muted small">${dayValue}</div>
                        </div>
                        <div class="col-6 col-lg-2">
                            <label class="form-label mb-1 text-muted small">Von</label>
                            <input type="time" class="form-control form-control-sm" value="${rowStart}" data-time-start>
                        </div>
                        <div class="col-6 col-lg-2">
                            <label class="form-label mb-1 text-muted small">Bis</label>
                            <input type="time" class="form-control form-control-sm" value="${rowEnd}" data-time-end>
                        </div>
                        <div class="col-6 col-lg-2">
                            <label class="form-label mb-1 text-danger small">Pause ab</label>
                            <input type="time" class="form-control form-control-sm border-danger-subtle" value="${rowPauseStart}" data-time-pause-start>
                        </div>
                        <div class="col-6 col-lg-2">
                            <label class="form-label mb-1 text-danger small">Pause bis</label>
                            <input type="time" class="form-control form-control-sm border-danger-subtle" value="${rowPauseEnd}" data-time-pause-end>
                        </div>
                    </div>
                </div>
            `);
        }

        daysContainer.innerHTML = rows.join('');
        daysContainer.querySelectorAll('input[type="time"]').forEach(function (input) {
            input.addEventListener('input', syncTextarea);
            input.addEventListener('change', syncTextarea);
        });

        syncTextarea();
    }

    // Event Listeners Registration
    buildButton.addEventListener('click', renderRows);
    startDateInput.addEventListener('change', renderRows);
    endDateInput.addEventListener('change', renderRows);
    
    defaultStartInput.addEventListener('change', renderRows);
    defaultEndInput.addEventListener('change', renderRows);
    defaultPauseStartInput.addEventListener('change', renderRows);
    defaultPauseEndInput.addEventListener('change', renderRows);
    
    // Slot Berechnung auf Ändeurng der Länge antriggern
    if(slotLengthInput) {
        slotLengthInput.addEventListener('input', calculateSlots);
        slotLengthInput.addEventListener('change', calculateSlots);
    }

    if (startDateInput.value && endDateInput.value) {
        renderRows();
    }
})();
</script>
{% endblock %}