/**
 * Activity (#249 Activity-1): the concept's Activity page (app.js renderActivity 732–738), its top-bar button
 * (`button#activity-open` with `span.count#activity-count`, index.html 51–52) and its sidebar row (app.js ~341), fed
 * by the session job store (activity-store.mjs).
 *
 * - D52: both counts show the running jobs only and are hidden at 0; the heading has no "Unified activity · proposed"
 *   chip (prototype copy).
 * - D53: while a job runs, the progress pill (`a.activity-pill`, the approved mockup's) sits before the button on every
 *   page: "Scanning · 42% · 8,240 / 19,622" and a mini bar, linking `#/activity/<id>`.
 * - D56: each item's title links its job's own view (activity-job-view.mjs).
 * - D54: each `.activity-item` is a real job. Its chip names the state (green "Completed", or blue "Running",
 *   "Cancelled", "Failed", "Ended"), its line says when and what, and a running job shows its `<progress>` and
 *   "Cancel job" (no "Simulate completion").
 * - D87 (plan D64): an ended scan that recorded Needs review items carries the concept's **Review metadata**
 *   (`go-review`, app.js a738) after its line, which opens `#/review`; its chip still names its state (D54).
 * - D89: an image tagging job's line names its images and, once ended, "N tagged · M errors".
 * - D111: what a line says (scope, counters, what a cancel kept) is the job kind's descriptor (activity-kinds.mjs); a
 *   job without a known total shows an indeterminate `<progress>`, and only a job the server can stop shows Cancel.
 */
import { createButton } from '../shared/toolkit/core.js';
import { navigateTo } from './state.mjs';
import { pageHeading } from './heading.mjs';
import { showWorkspaceToast } from './toast.mjs';
import { pillParts, outcomeLine, LOST_DETAIL } from './activity-store.mjs';
import { viewOf, canCancel, showProgress, indeterminate } from './activity-kinds.mjs';

export const ACTIVITY_DESCRIPTION = 'Scans, tagging, downloads and maintenance share one history.';
export const EMPTY_ACTIVITY = 'No jobs have run since ComfyUI started. Scans and other long operations appear here.';
export const LOAD_FAILED = 'Activity could not be read. It is tried again shortly.';
export const CANCEL_FAILED_TOAST = 'The job could not be cancelled. Try again.';

/** Whether an ended job recorded items for Needs review (a metadata scan's `scope.review_items`). */
export function hasReviewItems(job) {
    const count = job?.scope?.review_items;
    return job?.state !== 'running' && Number.isSafeInteger(count) && count > 0;
}

/** The concept's **Review metadata** (D87): opens Needs review. */
export function createReviewMetadataButton(scope) {
    const button = createButton('Review metadata');
    scope.listen(button, 'click', () => navigateTo('#/review'));
    return button;
}
const CHIPS = Object.freeze({
    running: ['blue', 'Running'], finished: ['green', 'Completed'], cancelled: ['blue', 'Cancelled'],
    failed: ['blue', 'Failed'], lost: ['blue', 'Ended'],
});

function element(tag, text, className) {
    const node = document.createElement(tag);
    if (text !== undefined) node.textContent = text;
    if (className) node.className = className;
    return node;
}

/** "09:41" in the browser's local time; an unknown time is empty. */
export function clockTime(seconds) {
    if (typeof seconds !== 'number' || !Number.isFinite(seconds)) return '';
    const date = new Date(seconds * 1000);
    return `${String(date.getHours()).padStart(2, '0')}:${String(date.getMinutes()).padStart(2, '0')}`;
}

const join = parts => parts.filter(Boolean).join(' · ');

/** What a job covers ("2 output folders", "4 images") and what a cancelled one kept ("N added"), by kind (D111). */
const scopeLine = job => viewOf(job).scope(job);
const keptOf = job => viewOf(job).kept(job);

/** The item's line under its title, by state. */
export function jobDetail(job) {
    const at = clockTime(job.finished_at);
    if (job.state === 'running') {
        return join([`Started ${clockTime(job.started_at)}`, scopeLine(job), 'closing this view does not cancel it']);
    }
    if (job.state === 'lost') return LOST_DETAIL;
    if (job.state === 'cancelled') {
        return join([`Cancelled ${at} at a file boundary`, keptOf(job), 'completed work is kept']);
    }
    if (job.state === 'failed') return join([`Stopped on an error at ${at}`, outcomeLine(job)]);
    return join([`Finished ${at}`, outcomeLine(job)]);
}

/** The shell's Activity indicators: the top-bar count and pill, and the sidebar row's count. */
export function mountActivityTopbar({ store, scope, doc = document }) {
    const button = doc.getElementById('activity-open');
    const count = doc.getElementById('activity-count');
    const pill = doc.getElementById('activity-pill');
    scope.listen(button, 'click', () => navigateTo('#/activity'));
    const label = element('span', '', 'activity-pill-label');
    const files = element('span', '', 'activity-pill-files');
    const bar = element('span', undefined, 'activity-pill-bar');
    const fill = element('i');
    bar.setAttribute('aria-hidden', 'true');
    bar.append(fill);
    pill.replaceChildren(label, files, bar);
    const render = () => {
        const running = store.running();
        count.textContent = String(running.length);
        count.hidden = running.length === 0;
        const row = doc.querySelector('#system-nav a[data-route="activity"]');
        row?.querySelector('.nav-count')?.remove();
        if (row && running.length) row.append(element('span', running.length.toLocaleString(), 'nav-count'));
        const [job] = running;
        pill.hidden = !job;
        if (!job) {
            pill.removeAttribute('href');
            pill.removeAttribute('aria-label');
            return;
        }
        const parts = pillParts(job);
        label.textContent = parts.label;
        files.textContent = parts.files;
        // D111 (S5 review M5): no total, no fill: the bar sweeps instead of showing an empty determinate 0%.
        const unknown = indeterminate(job);
        bar.classList.toggle('indeterminate', unknown);
        fill.style.width = unknown ? '' : `${job.progress}%`;
        pill.href = `#/activity/${job.id}`;
        pill.setAttribute('aria-label', parts.text);
    };
    scope.cleanup(store.subscribe(render));
    render();
}

function itemFor(job, scope) {
    const item = element('div', undefined, 'activity-item');
    item.dataset.jobId = job.id;
    const heading = element('div', undefined, 'panel-heading');
    const title = element('h3');
    // D56: the title opens the job's own view.
    const link = element('a');
    link.href = `#/activity/${job.id}`;
    title.append(link);
    const chip = element('span');
    heading.append(title, chip);
    const detail = element('p');
    const progress = element('progress');
    progress.max = 100;
    const actions = element('div', undefined, 'row-actions');
    const cancel = createButton('Cancel job');
    actions.append(cancel);
    const review = createReviewMetadataButton(scope); // D87
    item.append(heading, detail, progress, actions);
    scope.listen(cancel, 'click', async () => {
        if (cancel.getAttribute('aria-disabled') === 'true') return;
        cancel.setAttribute('aria-disabled', 'true');
        try {
            await item.cancelJob();
        } catch (error) {
            if (scope.signal.aborted) return;
            cancel.removeAttribute('aria-disabled');
            showWorkspaceToast(CANCEL_FAILED_TOAST);
        }
    });
    item.update = next => {
        const [tone, state] = CHIPS[next.state];
        link.textContent = `${next.state === 'finished' ? '✓' : '○'} ${next.title}`;
        chip.className = `chip ${tone}`;
        chip.textContent = state;
        detail.textContent = jobDetail(next);
        const running = next.state === 'running';
        // parentNode, not isConnected: on the first render the item is not in the page yet, so a job that had already
        // ended when Activity opened kept its Cancel job (and a running one's progress moved after its actions).
        if (running) {
            showProgress(progress, next); // D111: no value while the total is unknown
            progress.setAttribute('aria-label', `${next.title} progress`);
            if (!progress.parentNode) item.insertBefore(progress, actions.parentNode ? actions : null);
        } else {
            progress.remove();
        }
        // Truth rule: a job that cannot be cancelled (a held legacy-page job) shows no Cancel job.
        if (canCancel(next)) {
            if (!actions.parentNode) item.append(actions);
        } else if (actions.parentNode) {
            // A focused Cancel job that goes away hands its focus to the item's title link, never to the page body.
            if (actions.contains(document.activeElement)) link.focus();
            actions.remove();
        }
        if (hasReviewItems(next)) { if (!review.isConnected) detail.after(review); } // D87
        else review.remove();
    };
    return item;
}

/** The Activity page: the concept's "Recent work" list of this session's jobs (one job's view is D56). */
export function mountActivityPage(main, { store, scope }) {
    pageHeading(main).description.textContent = ACTIVITY_DESCRIPTION;
    const section = element('section', undefined, 'surface');
    const status = element('p', undefined, 'empty-state');
    section.append(element('h2', 'Recent work'));
    main.append(section);
    const items = new Map();
    const render = () => {
        const jobs = store.jobs();
        for (const [id, item] of items) if (!jobs.some(job => job.id === id)) { item.remove(); items.delete(id); }
        jobs.forEach((job, index) => {
            let item = items.get(job.id);
            if (!item) {
                item = itemFor(job, scope);
                item.cancelJob = () => store.cancel(job.id);
                items.set(job.id, item);
            }
            item.update(job);
            // Only a node out of place moves, so a focused Cancel job keeps its focus across updates.
            const at = section.children[index + 1];
            if (at !== item) section.insertBefore(item, at ?? null);
        });
        const failed = store.status === 'error' && !jobs.length;
        status.textContent = failed ? LOAD_FAILED : EMPTY_ACTIVITY;
        if (failed) status.setAttribute('role', 'alert');
        else status.removeAttribute('role');
        if (jobs.length || store.status === 'idle') status.remove();
        else if (!status.isConnected) section.append(status);
    };
    scope.cleanup(store.subscribe(render));
    render();
    // Opening Activity reads the list at once instead of waiting for the next periodic read.
    store.load();
}