/**
 * GoingsOn - Groups (shared-workspace) client cache + badge helpers.
 *
 * A thin, lazily-populated cache of the groups you belong to, keyed by id, so
 * the UI can resolve a project's `groupId` to a human name without a round-trip
 * per render. Sharing is whole-project, so a task's share state is its project's
 * share state; the badge helpers reflect that.
 *
 * The admin/list commands themselves live on `GoingsOn.api.groups`; this module
 * is only the render-side cache. Invalidate it whenever group membership changes
 * (a group is created, joined, or renamed).
 */

(function() {
    'use strict';
    const esc = GoingsOn.utils.escapeHtml;
    const escAttr = GoingsOn.utils.escapeAttrValue;

    let cache = null;      // Array of GroupDto, or null when unloaded.
    let byId = {};         // id -> GroupDto.

    /**
     * Load the group list into the cache if it is not already loaded. Non-fatal:
     * if sync is not configured the cache stays null and names do not
     * resolve (badges still render as a bare "Shared").
     * @returns {Promise<Array>} the cached groups (possibly empty)
     */
    async function ensureLoaded() {
        if (cache) return cache;
        try {
            const list = await GoingsOn.api.groups.list();
            cache = list;
            byId = {};
            list.forEach(g => { byId[g.id] = g; });
        } catch (_) {
            // Leave cache null so a later call retries once sync is ready.
        }
        return cache || [];
    }

    /** Group name for an id, or null when unknown / cache not loaded. */
    function nameFor(groupId) {
        if (!groupId) return null;
        const g = byId[groupId];
        return g ? g.name : null;
    }

    /** Drop the cache so the next ensureLoaded refetches. */
    function invalidate() {
        cache = null;
        byId = {};
    }

    /**
     * Badge HTML for a project's card meta, or '' when the project is personal.
     * Shows the group name when known, otherwise a bare "Shared".
     */
    function projectCardBadge(project) {
        if (!project || !project.groupId) return '';
        const name = nameFor(project.groupId);
        const label = name ? `Shared · ${name}` : 'Shared';
        return `<span class="tag tag-shared" title="${escAttr(label)}">${esc(label)}</span>`;
    }

    /**
     * Small inline marker for a task row whose project is shared, resolved from
     * the projects cache (best-effort; no badge if projects are not loaded).
     */
    function taskSharedBadge(projectId) {
        if (!projectId) return '';
        const project = GoingsOn.getProjectsCache().find(p => p.id === projectId);
        if (!project || !project.groupId) return '';
        const name = nameFor(project.groupId);
        const label = name ? `Shared · ${name}` : 'Shared';
        return `<span class="shared-badge" title="${escAttr(label)}">Shared</span>`;
    }

    GoingsOn.groups = {
        ensureLoaded,
        nameFor,
        invalidate,
        projectCardBadge,
        taskSharedBadge,
        list: () => cache || [],
    };

})();