{% extends "base.html" %}

{% block title %}Episode {{ episode_id }} / {{ num_episodes }}{% endblock %}

{% block description %}
Episode {{ episode_id }} / {{ num_episodes }} - Positronic Dataset Viewer
{% endblock %}

{% block scripts %}
<script async>
    document.addEventListener('DOMContentLoaded', () => {
        initializeSidebar({{ static_data| tojson | safe }});
    });
</script>

<!-- Filtered episode navigation via sessionStorage.
     When users arrive from the episodes table, the table stores the current filtered
     episode ID list and referrer URL in sessionStorage. This lets prev/next cycle through
     only the filtered subset. This state is ephemeral — it doesn't survive a page refresh
     or a shared/bookmarked link, which is acceptable for transient filter UI state. The
     "proper" alternative would be server-side: the /episode/{id} endpoint accepts filter
     query params (reusing the existing matches() helper from /api/episodes), computes the
     filtered list, and passes prev_episode_id/next_episode_id/filtered_count/filtered_index
     in the template context. That gives stable URLs but requires server and template changes. -->
<script>
    let filteredIds = (function() {
        const raw = sessionStorage.getItem(baseScopedKey(FILTERED_EPISODE_IDS));
        if (!raw) return null;

        let ids;
        try { ids = JSON.parse(raw); } catch { return null; }
        const currentId = {{ episode_id }};
        if (!Array.isArray(ids) || ids.indexOf(currentId) === -1) return null;

        const nav = document.getElementById('episode-nav');
        const input = document.getElementById('episode-input');
        const currentIndex = ids.indexOf(currentId);

        // Switch to filtered mode: input shows 1-based position, not episode ID
        nav.classList.add('episode-nav--filtered');
        input.value = currentIndex + 1;
        input.dataset.original = currentIndex + 1;
        input.maxLength = String(ids.length).length;

        const prevId = ids[(currentIndex - 1 + ids.length) % ids.length];
        const nextId = ids[(currentIndex + 1) % ids.length];
        document.getElementById('prev-btn').onclick = () => { window.location.href = episodePageUrl(prevId); };
        document.getElementById('next-btn').onclick = () => { window.location.href = episodePageUrl(nextId); };
        document.getElementById('episode-count').textContent = ` / ${ids.length}`;

        // Add dismiss × and "Filtered" badge inside the nav bar, before "Ep."
        const badge = document.createElement('span');
        badge.className = 'filter-label';
        badge.textContent = 'Filtered';

        const dismiss = document.createElement('button');
        dismiss.className = 'filter-dismiss';
        dismiss.textContent = '\u00d7';
        dismiss.onclick = () => {
            sessionStorage.removeItem(baseScopedKey(FILTERED_EPISODE_IDS));
            sessionStorage.removeItem(baseScopedKey(EPISODES_REFERRER_URL));
            nav.classList.remove('episode-nav--filtered');
            input.value = currentId;
            input.dataset.original = currentId;
            input.maxLength = String({{ num_episodes }}).length;
            document.getElementById('episode-count').textContent = ' / {{ num_episodes }}';
            document.getElementById('prev-btn').onclick = () => { window.location.href = appUrl('{{ prev_link }}'); };
            document.getElementById('next-btn').onclick = () => { window.location.href = appUrl('{{ next_link }}'); };
            document.getElementById('breadcrumb-root').href = appUrl('.');
            filteredIds = null;
            dismiss.remove();
            badge.remove();
        };
        nav.prepend(badge);
        nav.prepend(dismiss);

        const referrerUrl = sessionStorage.getItem(baseScopedKey(EPISODES_REFERRER_URL));
        if (referrerUrl) {
            document.getElementById('breadcrumb-root').href = referrerUrl;
        }

        return ids;
    })();
</script>

<script>
    const episodeForm = document.getElementById('episode-form');
    const episodeInput = document.getElementById('episode-input');
    const maxEpisodes = {{ num_episodes }};

    const maxEpisodeLength = String(maxEpisodes - 1).length;
    episodeInput.style.width = `${maxEpisodeLength + 1.5}ch`;

    episodeForm.addEventListener('submit', (e) => {
        e.preventDefault();
        const value = parseInt(episodeInput.value);
        if (filteredIds) {
            // In filtered mode, input is 1-based position
            if (isNaN(value) || value < 1 || value > filteredIds.length) {
                episodeInput.value = episodeInput.dataset.original;
                return;
            }
            window.location.href = episodePageUrl(filteredIds[value - 1]);
        } else {
            if (isNaN(value) || value < 0 || value >= maxEpisodes) {
                episodeInput.value = episodeInput.dataset.original;
                return;
            }
            window.location.href = episodePageUrl(value);
        }
    });

    episodeInput.addEventListener('blur', () => {
        const value = parseInt(episodeInput.value);
        if (filteredIds) {
            if (isNaN(value) || value < 1 || value > filteredIds.length) {
                episodeInput.value = episodeInput.dataset.original;
            }
        } else {
            if (isNaN(value) || value < 0 || value >= maxEpisodes) {
                episodeInput.value = episodeInput.dataset.original;
            }
        }
    });

    episodeInput.addEventListener('focus', () => {
        episodeInput.select();
    });

    // Seek links use the episode's preferred nanosecond clock, when present.
    window.addEventListener('load', () => {
        const viewerIframe = document.getElementById('viewer-iframe');
        const rrdUrl = appUrl({{ rrd_path | tojson }});
        const viewerUrl = new URL(appUrl({{ viewer_path | tojson }}));
        viewerUrl.searchParams.set('url', rrdUrl);
        viewerUrl.searchParams.set('hide_welcome_screen', '');
        const params = new URLSearchParams(window.location.search);
        const seekTimeline = {{ seek_timeline | tojson }};
        if (seekTimeline !== null) {
            viewerUrl.searchParams.set('seek_timeline', seekTimeline);
            if (params.has('ts_ns')) viewerUrl.searchParams.set('seek_ts_ns', params.get('ts_ns'));
            else if (params.has('t')) viewerUrl.searchParams.set('seek_t', params.get('t'));
        }
        viewerIframe.src = viewerUrl;
    });
</script>
{% endblock %}

{% block content %}
{% from "_attribution.html" import attribution_line %}
<main class="main main--full-screen">
    <div class="header">
        <div class="breadcrumbs">
            <a href="." class="breadcrumb-link" id="breadcrumb-root">{{ title }}</a>
            <span class="breadcrumb-separator">›</span>
            <span id="episode-nav" class="episode-nav">
                <span class="breadcrumb-text">Ep. </span>
                <button id="prev-btn" onclick="window.location.href=appUrl('{{ prev_link }}')"
                    class="btn btn-ghost" title="Previous episode">&lt;</button>
                <form id="episode-form" class="episode-form" style="display: inline; margin: 0;">
                    <input type="text" id="episode-input" class="episode-input" value="{{ episode_id }}"
                        data-original="{{ episode_id }}" maxlength="{{ num_episodes|string|length }}">
                </form>
                <button id="next-btn" onclick="window.location.href=appUrl('{{ next_link }}')"
                    class="btn btn-ghost" title="Next episode">&gt;</button>
                <span class="breadcrumb-text" id="episode-count"> / {{ num_episodes }}</span>
            </span>
            {% if task %}<span class="task-description"> : {{ task }}</span>{% endif %}
        </div>
        {{ attribution_line(attribution) }}
    </div>
    <div class="episode-info-header">
        {% if (show_paths and episode_path) or episode_size_mb %}
        <div class="episode-path">
            {% if show_paths and episode_path %}
            <span class="episode-path-label">Episode path:</span>
            <code class="episode-path-value">{{ episode_path }}</code>
            {% endif %}
            {% if episode_size_mb %}
            <span class="episode-size">({{ episode_size_mb }} MB)</span>
            {% endif %}
        </div>
        {% endif %}

        <button class="sidebar-toggler btn btn-primary">☰ Static Data</button>
    </div>
    <div class="episode-container">
        <div id="viewer-container">
            <iframe id="viewer-iframe"></iframe>
        </div>
        <div class="sidebar">
            <div class="resizer sidebar-resizer"></div>
            <div class="resizer key-column-resizer"></div>
            <div class="sidebar-content">
                <div class="sidebar-content-wrapper">
                    <table class="root-table">
                        <colgroup>
                            <col class="dataset-key-column">
                            <col>
                        </colgroup>
                        <thead>
                            <tr>
                                <th>Dataset Info</th>
                                <th></th>
                            </tr>
                        </thead>
                        <tbody></tbody>
                    </table>
                </div>
            </div>
        </div>
    </div>
</main>
{% endblock %}