import '../api-client.js';
import { createButton, createScope } from '../shared/toolkit/core.js';
import { routes, mountRouter, summarizeStats, routeTitle, loadNavCounts,
    LIBRARY_WRITE_COUNTS, NAV_COUNT_ROUTES, FAVORITE_WRITE_COUNTS, FAVORITE_COUNT_DELAY_MS, REVIEW_WRITE_COUNTS } from './state.mjs';
import { mountWorkspaceTheme } from './theme.mjs';
import { mountImages, onFavoriteChange } from './images.mjs';
import { mountLibrary, mountNewPromptAction, onLibraryWrite } from './library.mjs';
import { mountVocabulary } from './vocabulary.mjs';
import { createWorkspaceIcon } from './icons.mjs';
import { bindCanvasLink, canvasHref } from './topbar.mjs';
import { renderHeading, pageHeading } from './heading.mjs';
import { closeWorkspaceDialog } from './workspace-dialogs.mjs';
import { createSavedViews, openSaveViewDialog, openEditViewDialog, savedViewHash } from './saved-views.mjs';
import { createActivityStore } from './activity-store.mjs';
import { mountActivityPage, mountActivityTopbar } from './activity.mjs';
import { mountActivityJobView } from './activity-job-view.mjs';
import { mountInspect } from './inspect.mjs';
import { mountReview } from './review.mjs';
import { createPromptSender } from './prompt-sender.mjs';
import { mountSystem } from './system.mjs';
import { mountLibraryBanner } from './library-location.mjs';
import { detectJxlSupport } from './thumbnail-support.mjs';

const { createApiClient, resolveUrl } = window.ApiClient;

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

function legacyLink(route) {
    const link = element('a', route.action, 'workspace-link');
    // A native card (System, Q12) links its workspace hash; a legacy tool's page goes through the mount prefix.
    link.href = route.native ? route.href : resolveUrl(route.href);
    return link;
}

function mountWorkspace() {
    const scope = createScope();
    const api = createApiClient();
    const main = document.getElementById('workspace-main');
    const primaryNav = document.getElementById('primary-nav');
    const savedNav = document.getElementById('saved-nav');
    const systemNav = document.getElementById('system-nav');
    scope.listen(document.querySelector('.skip'), 'click', event => {
        event.preventDefault();
        main.focus();
    });
    // D4: the concept's Theme select; "System" keeps following ComfyUI, then the OS.
    const theme = mountWorkspaceTheme({ root: document.body, scope });
    // #317: learn once whether this browser shows JPEG XL thumbnails (cards fall back to originals otherwise).
    detectJxlSupport();
    const preference = document.getElementById('theme');
    preference.value = theme.preference;
    scope.listen(preference, 'change', () => theme.setPreference(preference.value));
    // D6: ComfyUI ↗ opens the canvas; on Images with a resolved selection it sends that pair (a send is not an Activity job).
    let images = null;
    scope.cleanup(bindCanvasLink(document.querySelector('.topbar .canvas-link'), {
        href: canvasHref(resolveUrl, window.location.pathname),
        getSelectedPair: () => images?.selectedPair?.() ?? null,
        sender: {open: (roles, trigger) => images?.sender.open(roles, trigger)},
    }));
    // The concept's nav(): icon, label text, then a `.nav-count` only for a loaded real count.
    const navLinks = ids => ids.map(([id, icon]) => {
        const route = routes.find(item => item.id === id);
        const link = element('a');
        link.append(createWorkspaceIcon(icon), document.createTextNode(route.label));
        link.href = `#/${route.id}`;
        link.dataset.route = route.id;
        return link;
    });
    primaryNav.replaceChildren(...navLinks([['images', 'images'], ['library', 'library'], ['tags', 'tags'], ['inspect', 'upload']]));
    // The concept's tools-and-system group: Activity, System, then (D28) the production Overview hub.
    systemNav.replaceChildren(...navLinks([['activity', 'activity'], ['system', 'settings'], ['overview', 'overview']]));
    // Activity (#249 Activity-1): one store of this session's jobs feeds the top-bar button and pill, the sidebar
    // row's count and the Activity page, on every route.
    const activity = createActivityStore({ api, scope, connect: url => new EventSource(resolveUrl(url)) });
    mountActivityTopbar({ store: activity, scope });
    activity.load();
    // D129: a node-folder library is offered a move (or "Keep it here") above every page.
    mountLibraryBanner(document.getElementById('library-banner'), { api, activity, scope });
    const sidebar = document.querySelector('aside.sidebar');
    // The route key a nav link carries in `data-route`: a saved view's is `saved/<id>`.
    const routeKey = route => route.id === 'saved' ? `saved/${route.savedId}` : route.id;
    let currentKey = null;
    const markCurrent = () => {
        for (const link of sidebar.querySelectorAll('nav [data-route]')) {
            if (link.dataset.route === currentKey) link.setAttribute('aria-current', 'page');
            else link.removeAttribute('aria-current');
        }
    };
    // SAVED VIEWS (#249 D16): the concept's saved-nav rows (search icon, name, no count), loaded with the shell and
    // re-read after every change. /* D49 */ no "PROPOSED" badge. The first rows are the concept's Favorites (star icon,
    // count, D51) and Needs review (review icon, the exact pending count, ruling R5), kept across every re-read so
    // their counts stay.
    const [favoritesLink, reviewLink] = navLinks([['favorites', 'star'], ['review', 'review']]);
    savedNav.replaceChildren(favoritesLink, reviewLink);
    const savedViews = createSavedViews(api, scope.signal);
    scope.cleanup(savedViews.subscribe(({ views }) => {
        savedNav.replaceChildren(favoritesLink, reviewLink, ...views.map(view => {
            const link = element('a');
            link.append(createWorkspaceIcon('search'), document.createTextNode(view.name));
            link.href = savedViewHash(view.id);
            link.dataset.route = `saved/${view.id}`;
            return link;
        }));
        markCurrent();
    }));
    savedViews.load();
    /** The toolbar's Save view on a page: the concept's name dialog, then the store saves the page's full state. */
    const saveView = (page, view) => (trigger, state) => openSaveViewDialog({ scope: view, trigger, q: state.q,
        onSave: name => savedViews.create(page, name, state) });
    // One read per count, so a write that refreshes Library and Tags never supersedes an Images read in flight.
    const countRequests = new Map();
    function refreshCounts(ids) {
        for (const id of ids) {
            countRequests.get(id)?.abort();
            const request = new AbortController();
            countRequests.set(id, request);
            // Each badge lands as its own read settles; a count that failed to refresh is removed, never left stale.
            loadNavCounts(api, request.signal, (_, count) => {
                if (!request.signal.aborted) showCount(id, count);
            }, [id]);
        }
    }
    function showCount(id, count) {
        const link = sidebar.querySelector(`nav [data-route="${id}"]`);
        link?.querySelector('.nav-count')?.remove();
        if (link && Number.isSafeInteger(count)) link.append(element('span', count.toLocaleString(), 'nav-count'));
    }
    /** A count a page has just read itself: it replaces the badge, and an older read in flight no longer lands. */
    function setCount(id, count) {
        countRequests.get(id)?.abort();
        countRequests.delete(id);
        showCount(id, count);
    }
    scope.cleanup(() => { for (const request of countRequests.values()) request.abort(); });
    // A confirmed Library or vocabulary write cannot change the Images count, so only Library and Tags are re-read.
    scope.cleanup(onLibraryWrite(() => refreshCounts(LIBRARY_WRITE_COUNTS)));
    // Starring or unstarring anywhere (Images, Favorites, Library media) re-reads the Favorites count (D51), once
    // after a run of quick toggles settles rather than once per click (#249 M1).
    let favoriteCountTimer = 0;
    scope.cleanup(onFavoriteChange(() => {
        clearTimeout(favoriteCountTimer);
        favoriteCountTimer = setTimeout(() => refreshCounts(FAVORITE_WRITE_COUNTS), FAVORITE_COUNT_DELAY_MS);
    }));
    scope.cleanup(() => clearTimeout(favoriteCountTimer));
    // A metadata scan that ends may have added items to Needs review: re-read its count once per ended scan.
    const runningScans = new Set();
    scope.cleanup(activity.subscribe(() => {
        let ended = false;
        for (const job of activity.jobs()) {
            if (job.kind !== 'scan') continue;
            if (job.state === 'running') runningScans.add(job.id);
            else if (runningScans.delete(job.id)) ended = true;
        }
        if (ended) refreshCounts(REVIEW_WRITE_COUNTS);
    }));
    refreshCounts(NAV_COUNT_ROUTES);
    let viewScope;
    let firstRender = true;
    // D62: a page whose teardown must wait (Inspect, while a video is still starting) holds the next route until it
    // settles; the latest route wins.
    let leaveGuard = null, renderToken = 0;
    scope.cleanup(() => viewScope?.dispose());

    // The mounted System page: another of its sections is shown in place, keeping the shell and the drafts.
    let system = null;

    function render(route) {
        const token = ++renderToken;
        const hold = leaveGuard?.();
        if (hold) {
            hold.then(() => { if (token === renderToken && !scope.signal.aborted) renderNow(route); });
            return;
        }
        renderNow(route);
    }

    function renderNow(route) {
        leaveGuard = null;
        // A shared page dialog never stays open over the next route.
        closeWorkspaceDialog();
        if (route.id === 'system' && system && currentKey === 'system') {
            system.show(route.section);
            return;
        }
        system = null;
        viewScope?.dispose();
        images = null;
        viewScope = createScope();
        const view = viewScope;
        currentKey = routeKey(route);
        markCurrent();
        if (route.id === 'saved') {
            openSavedView(route, view);
            return;
        }
        renderPage(route, view);
    }

    /** A saved view opens its page with its state; the heading, breadcrumb and title are the view's name. */
    async function openSavedView(route, view) {
        main.replaceChildren();
        await savedViews.settled();
        if (view.signal.aborted) return;
        // A view saved since the list loaded (another tab) is read once more before the link counts as gone.
        if (!savedViews.find(route.savedId) && savedViews.status === 'ready') {
            await savedViews.load();
            if (view.signal.aborted) return;
        }
        const saved = savedViews.find(route.savedId);
        if (saved) {
            const page = routes.find(item => item.id === saved.page);
            renderPage({...page, label:saved.name, title:saved.name}, view, saved);
            mountEditAction(saved, view);
            return;
        }
        if (savedViews.status === 'ready') {
            // A removed or unknown view: the shell's default page, without a history entry for the dead link.
            window.location.replace('#/images');
            return;
        }
        const {description} = renderHeading(main, {title:route.label});
        description.textContent = 'Saved views could not be loaded. Your saved data has not changed.';
        description.setAttribute('role', 'alert');
        const retry = createButton('Retry');
        view.listen(retry, 'click', () => {
            savedViews.load();
            openSavedView(route, view);
        });
        main.append(retry);
    }

    // /* D51 */ The open view's Edit (maintainer ruling): first in the heading's actions. A rename re-reads the list and
    // retitles the open page; a delete re-reads it and replaces the dead route with the view's plain page.
    function mountEditAction(saved, view) {
        // renderPage has just written the heading.
        const edit = createButton('Edit');
        pageHeading(main).actions.prepend(edit);
        view.listen(edit, 'click', () => openEditViewDialog({ scope: view, trigger: edit, view: saved,
            onRename: async name => {
                const renamed = await savedViews.rename(saved.id, name);
                if (view.signal.aborted) return;
                saved = renamed;
                retitle(renamed.name);
            },
            onDelete: async () => {
                await savedViews.remove(saved.id);
                window.location.replace(`#/${saved.page}`);
            } }));
    }

    function retitle(name) {
        // Only the mounted view retitles (its rename returns once aborted), so its heading is present.
        pageHeading(main).h1.textContent = name;
        document.getElementById('workspace-breadcrumb').textContent = name;
        document.title = `${name} · Prompt Manager`;
    }

    function renderPage(route, view, saved = null) {
        document.title = `${routeTitle(route)} · Prompt Manager`;
        // The concept's heading(); each view fills its description and actions.
        // The concept focuses its page title on a hashchange navigation (app.js 1168); the skip link focuses `main`.
        const { description, h1 } = renderHeading(main, { title: route.label });
        if (!firstRender) h1.focus();
        firstRender = false;
        document.getElementById('workspace-breadcrumb').textContent = routeTitle(route);
        if (route.id === 'images' || route.id === 'favorites') {
            mountNewPromptAction(main, api, view);
            images = mountImages(main, api, view, {savedState:saved?.state, favorites:route.id === 'favorites',
                onSaveView:saveView('images', view), activity});
            return;
        }
        if (route.id === 'library') {
            mountLibrary(main, api, view, {positiveId:route.positiveId, savedState:saved?.state, onSaveView:saveView('library', view)});
            return;
        }
        if (route.id === 'tags') {
            mountVocabulary(main, api, view);
            return;
        }
        if (route.id === 'activity') {
            // D56: `#/activity/<id>` is that job's own view; `#/activity` lists the session's jobs.
            if (route.jobId) mountActivityJobView(main, { store: activity, scope: view, api, jobId: route.jobId });
            else mountActivityPage(main, { store: activity, scope: view });
            return;
        }
        if (route.id === 'review') {
            // Needs review (ruling R5): a recorded decision re-reads the row's count, and the open page's total is the
            // count (F3: a change the page hears of costs no count read).
            mountReview(main, { api, scope: view, onDecision: () => refreshCounts(REVIEW_WRITE_COUNTS),
                onTotal: total => setCount('review', total) });
            return;
        }
        if (route.id === 'system') {
            // The concept's System (app.js renderSystem): its heading description, section nav and Save row.
            description.textContent = route.description;
            system = mountSystem(main, api, view, { section: route.section, activity });
            return;
        }
        if (route.id === 'inspect') {
            // The concept's Inspect a file (app.js renderMetadata): a local file, read only in this browser.
            description.textContent = route.description;
            ({ leaveGuard } = mountInspect(main, { parentScope: view, api, sender: createPromptSender({ scope: view }) }));
            return;
        }
        description.textContent = 'A home for your prompts, images and creative history.';
        const stats = element('section', undefined, 'overview-stats');
        stats.setAttribute('aria-label', 'Library statistics');
        main.append(stats);
        const tools = element('section', undefined, 'surface');
        tools.append(element('h2', 'Continue creating'), element('p', 'Your existing tools remain available while the new workspaces take shape.'));
        const cards = element('div', undefined, 'tool-grid');
        for (const target of routes.filter(item => item.href)) {
            const card = element('article', undefined, 'tool-card');
            card.append(element('h3', target.label), element('p', target.description, 'small'), legacyLink(target));
            cards.append(card);
        }
        tools.append(cards);
        main.append(tools);
        async function loadStats() {
            const status = element('p', 'Loading library statistics…');
            status.setAttribute('role', 'status');
            stats.replaceChildren(status);
            try {
                const result = await api.get('/prompt_manager/stats', { signal: view.signal });
                if (view.signal.aborted) return;
                const values = summarizeStats(result.stats);
                const list = element('dl', undefined, 'stat-grid');
                for (const [label, count] of values) {
                    const stat = element('div', undefined, 'stat');
                    stat.append(element('dt', label), element('dd', count.toLocaleString()));
                    list.append(stat);
                }
                stats.replaceChildren(list);
                if (values.every(([, count]) => count === 0)) {
                    stats.append(element('p', 'Your library is empty. Add a prompt in the prompt library or configure sources in System.', 'empty-state'));
                }
            } catch (error) {
                if (view.signal.aborted) return;
                const alert = element('p', 'Library statistics could not be loaded. Your saved data has not changed.');
                alert.setAttribute('role', 'alert');
                const retry = createButton('Retry');
                view.listen(retry, 'click', loadStats);
                stats.replaceChildren(alert, retry);
            }
        }
        loadStats();
    }
    scope.cleanup(mountRouter(window, render));
    scope.listen(window, 'pagehide', () => scope.dispose());
    return () => scope.dispose();
}

mountWorkspace();
window.addEventListener('pageshow', event => {
    if (event.persisted) mountWorkspace();
});