// Panel button that polls the Clash API and renders sing-box status.

import GObject from 'gi://GObject';
import St from 'gi://St';
import Clutter from 'gi://Clutter';
import GLib from 'gi://GLib';
import Gio from 'gi://Gio';

import * as Main from 'resource:///org/gnome/shell/ui/main.js';
import * as PanelMenu from 'resource:///org/gnome/shell/ui/panelMenu.js';
import * as PopupMenu from 'resource:///org/gnome/shell/ui/popupMenu.js';
import { gettext as _ } from 'resource:///org/gnome/shell/extensions/extension.js';

import { ClashApi } from './clashApi.js';
import { formatSpeed, formatSpeedShort } from './format.js';

export const SingBoxIndicator = GObject.registerClass(
class SingBoxIndicator extends PanelMenu.Button {
    _init(extension) {
        super._init(0.0, 'sing-box Status', false);

        this._extension = extension;
        this._settings = extension.getSettings();
        this._api = new ClashApi();

        this._apiUp = null;          // null = connecting, true/false = reachable
        this._connectivity = 'unknown'; // 'unknown' | 'ok' | 'down'
        this._connectivityDelay = null; // ms of last successful outbound ping
        this._activeOutbound = null; // node to probe for connectivity
        this._dotState = 'connecting'; // 'connecting'|'down'|'nocon'|'ok'
        this._prevSample = null;     // { down, up, t } for speed diffing
        this._selectorSignature = null;
        this._selectorItems = new Map();
        this._proxiesMap = {};
        this._delays = new Map();    // node name -> ms number | 'timeout'
        this._probing = new Set();   // nodes with a latency probe in flight
        this._apiUrl = '';
        this._polling = false;
        this._pinging = false;       // connectivity probe in flight
        this._settingsDebounceId = 0;
        this._cancellable = new Gio.Cancellable();

        this._buildPanel();
        this._buildMenu();

        this._settingsChangedId = this._settings.connect('changed', () => this._onSettingsChanged());
        this._applySettings();

        this._startPolling();
        this._startConnectivityCheck();
    }

    // ---- Panel widget -------------------------------------------------

    _buildPanel() {
        const box = new St.BoxLayout({
            style_class: 'panel-status-menu-box sbx-panel-box',
            y_align: Clutter.ActorAlign.CENTER,
        });

        // Monochrome status dot in the panel's text color (adapts to theme):
        //   filled disc      — service up and outbound has connectivity;
        //   bright ring      — service up but no connectivity through the outbound;
        //   dim ring         — service up, connectivity not yet measured;
        //   dashed dim ring  — service (Clash API) unreachable / connecting.
        this._dot = new St.DrawingArea({
            style_class: 'sbx-dot',
            y_align: Clutter.ActorAlign.CENTER,
        });
        this._dot.set_width(16);
        this._dot.set_height(16);
        this._dot.connect('repaint', area => this._drawDot(area));
        box.add_child(this._dot);

        this._outboundLabel = new St.Label({
            style_class: 'sbx-outbound-label',
            y_align: Clutter.ActorAlign.CENTER,
            text: '',
        });
        box.add_child(this._outboundLabel);

        this._speedLabel = new St.Label({
            style_class: 'sbx-speed-label',
            y_align: Clutter.ActorAlign.CENTER,
            text: '',
        });
        box.add_child(this._speedLabel);

        this.add_child(box);
    }

    // ---- Menu ---------------------------------------------------------

    _buildMenu() {
        this._statusItem = new PopupMenu.PopupMenuItem(_('sing-box'), {
            reactive: false,
            can_focus: false,
        });
        this._statusItem.add_style_class_name('sbx-status-item');
        this.menu.addMenuItem(this._statusItem);

        this._speedItem = new PopupMenu.PopupMenuItem('', {
            reactive: false,
            can_focus: false,
        });
        this._speedItem.add_style_class_name('sbx-speed-item');
        this.menu.addMenuItem(this._speedItem);

        this.menu.addMenuItem(new PopupMenu.PopupSeparatorMenuItem());

        // Selector groups (switchable outbounds) are rebuilt into this section.
        this._selectorsSection = new PopupMenu.PopupMenuSection();
        this.menu.addMenuItem(this._selectorsSection);

        // Connections, grouped by outbound.
        this._connItem = new PopupMenu.PopupSubMenuMenuItem(_('Connections: —'));
        this.menu.addMenuItem(this._connItem);

        this.menu.addMenuItem(new PopupMenu.PopupSeparatorMenuItem());

        const dashboardItem = new PopupMenu.PopupMenuItem(_('Open dashboard'));
        dashboardItem.connect('activate', () => this._openDashboard());
        this.menu.addMenuItem(dashboardItem);

        const prefsItem = new PopupMenu.PopupMenuItem(_('Settings'));
        prefsItem.connect('activate', () => this._extension.openPreferences());
        this.menu.addMenuItem(prefsItem);

        // Refresh immediately when the user opens the menu.
        this.menu.connect('open-state-changed', (_menu, open) => {
            if (open)
                this._poll();
        });
    }

    // ---- Settings -----------------------------------------------------

    // Debounce: prefs entry rows emit "changed" per keystroke, and a multi-key
    // reset fires once per key — collapse the burst into a single apply.
    _onSettingsChanged() {
        if (this._settingsDebounceId)
            GLib.Source.remove(this._settingsDebounceId);
        this._settingsDebounceId = GLib.timeout_add(GLib.PRIORITY_DEFAULT, 300, () => {
            this._settingsDebounceId = 0;
            this._reconfigure();
            return GLib.SOURCE_REMOVE;
        });
    }

    _reconfigure() {
        // Latencies measured against one instance are meaningless for another.
        if (this._settings.get_string('api-url') !== this._apiUrl)
            this._delays.clear();
        this._applySettings();
        this._restartPolling();
        this._restartConnectivityCheck();
        if (!this._checkConnectivity) {
            this._connectivity = 'unknown';
            this._connectivityDelay = null;
        }
        this._poll();
        this._updateStatus();
    }

    _applySettings() {
        this._apiUrl = this._settings.get_string('api-url');
        this._api.setEndpoint(
            this._apiUrl,
            this._settings.get_string('api-secret')
        );
        this._interval = this._settings.get_int('refresh-interval');
        this._showOutbound = this._settings.get_boolean('show-outbound');
        this._showSpeed = this._settings.get_boolean('show-speed');
        this._selectorPref = this._settings.get_string('selector-group');
        this._checkConnectivity = this._settings.get_boolean('check-connectivity');
        this._connectivityInterval = this._settings.get_int('connectivity-interval');
        this._connectivityUrl = this._settings.get_string('connectivity-url');
        this._outboundLabel.visible = this._showOutbound;
        this._speedLabel.visible = this._showSpeed;
    }

    // ---- Polling ------------------------------------------------------

    _startPolling() {
        this._poll();
        this._timeoutId = GLib.timeout_add_seconds(
            GLib.PRIORITY_DEFAULT,
            Math.max(1, this._interval),
            () => {
                this._poll();
                return GLib.SOURCE_CONTINUE;
            }
        );
    }

    _restartPolling() {
        if (this._timeoutId) {
            GLib.Source.remove(this._timeoutId);
            this._timeoutId = 0;
        }
        this._timeoutId = GLib.timeout_add_seconds(
            GLib.PRIORITY_DEFAULT,
            Math.max(1, this._interval),
            () => {
                this._poll();
                return GLib.SOURCE_CONTINUE;
            }
        );
    }

    async _poll() {
        if (this._polling)
            return;
        this._polling = true;
        const c = this._cancellable;
        try {
            let conn, proxies;
            try {
                [conn, proxies] = await Promise.all([
                    this._api.getConnections(c),
                    this._api.getProxies(c),
                ]);
            } catch (e) {
                if (c.is_cancelled())
                    return;
                // Service (Clash API) unreachable: connectivity is moot.
                this._apiUp = false;
                this._connectivity = 'unknown';
                this._connectivityDelay = null;
                this._prevSample = null;
                this._clearMenuData();
                this._updateStatus();
                return;
            }
            if (c.is_cancelled())
                return;
            this._apiUp = true;
            // Note: _updateFromData is UI code — keep it out of the API try so
            // a rendering bug isn't misreported as "API unreachable".
            this._updateFromData(conn, proxies);
            this._updateStatus();
            // Resolve unknown connectivity promptly (startup, recovery, switch).
            if (this._checkConnectivity && this._connectivity === 'unknown')
                this._pingConnectivity();
        } finally {
            this._polling = false;
        }
    }

    // ---- Connectivity check (optional active probe) -------------------

    _startConnectivityCheck() {
        if (!this._checkConnectivity)
            return;
        this._connectivityTimeoutId = GLib.timeout_add_seconds(
            GLib.PRIORITY_DEFAULT,
            Math.max(5, this._connectivityInterval),
            () => {
                this._pingConnectivity();
                return GLib.SOURCE_CONTINUE;
            }
        );
        this._pingConnectivity();
    }

    _stopConnectivityCheck() {
        if (this._connectivityTimeoutId) {
            GLib.Source.remove(this._connectivityTimeoutId);
            this._connectivityTimeoutId = 0;
        }
    }

    _restartConnectivityCheck() {
        this._stopConnectivityCheck();
        this._startConnectivityCheck();
    }

    // Probe the active outbound to tell "up but no internet" from "up and OK".
    async _pingConnectivity() {
        if (!this._checkConnectivity || this._apiUp === false || this._pinging)
            return;
        const node = this._activeOutbound;
        if (!node)
            return;
        this._pinging = true;
        const c = this._cancellable;
        try {
            const res = await this._api.getDelay(
                node, { url: this._connectivityUrl || undefined, timeout: 5000 }, c);
            // Discard if cancelled or the active outbound changed mid-flight.
            if (c.is_cancelled() || node !== this._activeOutbound)
                return;
            const d = Number(res?.delay);
            if (Number.isFinite(d) && d > 0) {
                this._connectivity = 'ok';
                this._connectivityDelay = d;
                this._delays.set(node, d);
            } else {
                this._connectivity = 'down';
                this._connectivityDelay = null;
                this._delays.set(node, 'timeout');
            }
            this._updateStatus();
        } catch (e) {
            if (c.is_cancelled() || node !== this._activeOutbound)
                return;
            // A transport/API failure is not an outbound-connectivity verdict.
            this._connectivity = this._apiUp ? 'down' : 'unknown';
            this._connectivityDelay = null;
            if (this._apiUp)
                this._delays.set(node, 'timeout');
            this._updateStatus();
        } finally {
            this._pinging = false;
        }
    }

    // ---- Data → UI ----------------------------------------------------

    _updateFromData(conn, proxies) {
        this._updateSpeed(conn);
        this._updateConnections(conn);
        this._updateSelectors(proxies);
    }

    _updateSpeed(conn) {
        const down = Number(conn?.downloadTotal) || 0;
        const up = Number(conn?.uploadTotal) || 0;
        const now = GLib.get_monotonic_time() / 1e6; // seconds

        let dSpeed = 0;
        let uSpeed = 0;
        if (this._prevSample) {
            const dt = now - this._prevSample.t;
            if (dt > 0) {
                dSpeed = Math.max(0, (down - this._prevSample.down) / dt);
                uSpeed = Math.max(0, (up - this._prevSample.up) / dt);
            }
        }
        this._prevSample = { down, up, t: now };

        this._speedLabel.text = `↓${formatSpeedShort(dSpeed)} ↑${formatSpeedShort(uSpeed)}`;
        this._speedItem.label.text = `↓ ${formatSpeed(dSpeed)}      ↑ ${formatSpeed(uSpeed)}`;
    }

    _updateConnections(conn) {
        const list = Array.isArray(conn?.connections) ? conn.connections : [];
        this._connItem.label.text = `${_('Connections')}: ${list.length}`;

        // Group by the actual outbound node (first element of the chain).
        const counts = new Map();
        for (const item of list) {
            const chain = Array.isArray(item?.chains) ? item.chains : [];
            const node = chain.length ? chain[0] : _('(direct)');
            counts.set(node, (counts.get(node) || 0) + 1);
        }

        this._connItem.menu.removeAll();
        if (counts.size === 0) {
            const empty = new PopupMenu.PopupMenuItem(_('No active connections'), {
                reactive: false,
                can_focus: false,
            });
            this._connItem.menu.addMenuItem(empty);
            return;
        }
        const sorted = [...counts.entries()].sort((a, b) => b[1] - a[1]);
        for (const [node, count] of sorted) {
            const row = new PopupMenu.PopupMenuItem(`${node}`, {
                reactive: false,
                can_focus: false,
            });
            const badge = new St.Label({
                text: String(count),
                style_class: 'sbx-badge',
                x_align: Clutter.ActorAlign.END,
                x_expand: true,
            });
            row.add_child(badge);
            this._connItem.menu.addMenuItem(row);
        }
    }

    _updateSelectors(proxies) {
        const map = proxies?.proxies ?? {};
        this._proxiesMap = map;

        // Outbound groups the extension understands. Selector is switchable
        // (PUT); URLTest/Fallback are shown read-only (sing-box picks the node).
        const groups = [];
        for (const name of Object.keys(map)) {
            const p = map[name];
            if (!p || !Array.isArray(p.all))
                continue;
            if (p.type === 'Selector')
                groups.push({ name, now: p.now, all: p.all, switchable: true });
            else if (p.type === 'URLTest' || p.type === 'Fallback')
                groups.push({ name, now: p.now, all: p.all, switchable: false });
        }

        // Panel outbound label: chosen group's current node.
        const panelGroup = this._pickPanelGroup(groups);
        this._outboundLabel.text = panelGroup ? panelGroup.now ?? '' : '';
        this._activeOutbound = panelGroup ? panelGroup.now ?? null : null;

        // Rebuild the group section only when the structure changes.
        const signature = JSON.stringify(groups.map(g => [g.name, g.all, g.switchable]));
        if (signature !== this._selectorSignature) {
            this._rebuildSelectors(groups);
            this._selectorSignature = signature;
        }

        // Update current selection + latencies every poll.
        for (const g of groups) {
            const stored = this._selectorItems.get(g.name);
            if (!stored)
                continue;
            stored.subMenu.label.text = `${g.name}: ${g.now ?? '—'}`;
            for (const [member, entry] of stored.members) {
                entry.setOrnament(member === g.now
                    ? PopupMenu.Ornament.DOT
                    : PopupMenu.Ornament.NONE);
                // Don't overwrite the "…" placeholder while a probe is running.
                if (this._probing.has(member))
                    continue;
                entry.label.text = this._memberLabelText(member, map[member]);
            }
        }
    }

    _rebuildSelectors(groups) {
        this._selectorsSection.removeAll();
        this._selectorItems.clear();

        if (groups.length === 0) {
            const none = new PopupMenu.PopupMenuItem(_('No outbound groups'), {
                reactive: false,
                can_focus: false,
            });
            this._selectorsSection.addMenuItem(none);
            return;
        }

        for (const g of groups) {
            const subMenu = new PopupMenu.PopupSubMenuMenuItem(`${g.name}: ${g.now ?? '—'}`, true);
            subMenu.icon.icon_name = 'network-workgroup-symbolic';

            // Manual latency probe for all nodes in this group. Override
            // activate() so clicking it runs the probe without closing the menu.
            const testItem = new PopupMenu.PopupImageMenuItem(_('Test latency'), 'view-refresh-symbolic');
            testItem.add_style_class_name('sbx-test-item');
            testItem.activate = () => this._testLatencies(g.name);
            subMenu.menu.addMenuItem(testItem);

            const members = new Map();
            for (const member of g.all) {
                // Switchable groups: click a node to select it. Read-only groups
                // (URLTest/Fallback): show nodes but don't try to PUT-switch.
                const item = g.switchable
                    ? new PopupMenu.PopupMenuItem(member)
                    : new PopupMenu.PopupMenuItem(member, { reactive: false, can_focus: false });
                if (g.switchable)
                    item.connect('activate', () => this._selectOutbound(g.name, member));
                subMenu.menu.addMenuItem(item);
                members.set(member, item);
            }
            this._selectorsSection.addMenuItem(subMenu);
            this._selectorItems.set(g.name, { subMenu, members });
        }
    }

    // Drop menu content that would otherwise stay clickable while offline.
    _clearMenuData() {
        this._selectorsSection.removeAll();
        this._selectorItems.clear();
        this._selectorSignature = null;
        this._probing.clear();
        this._connItem.menu.removeAll();
        this._connItem.label.text = `${_('Connections')}: —`;
    }

    _pickPanelGroup(groups) {
        if (groups.length === 0)
            return null;
        if (this._selectorPref) {
            const match = groups.find(g => g.name === this._selectorPref);
            if (match)
                return match;
        }
        // Default to a switchable (Selector) group; else the first group.
        return groups.find(g => g.switchable) ?? groups[0];
    }

    // Latest known latency: a manual probe result wins over sing-box's own
    // history. Returns a number (ms), the string 'timeout', or null if unknown.
    _delayFor(name, proxy) {
        if (this._delays.has(name))
            return this._delays.get(name);
        return this._latencyOf(proxy);
    }

    _memberLabelText(name, proxy) {
        const d = this._delayFor(name, proxy);
        if (d == null)
            return name;
        if (d === 'timeout')
            return `${name}  ·  ${_('timeout')}`;
        return `${name}  ·  ${d} ms`;
    }

    _latencyOf(proxy) {
        const history = proxy?.history;
        if (Array.isArray(history) && history.length) {
            const last = history[history.length - 1];
            if (last && typeof last.delay === 'number' && last.delay > 0)
                return last.delay;
        }
        return null;
    }

    // Probe every node in a Selector group and update its latency labels.
    _testLatencies(groupName) {
        const stored = this._selectorItems.get(groupName);
        if (!stored)
            return;
        for (const [member, item] of stored.members) {
            this._probing.add(member);
            item.label.text = `${member}  ·  …`;
            this._api.getDelay(member, { url: this._connectivityUrl || undefined }, this._cancellable)
                .then(res => {
                    const d = Number(res?.delay);
                    this._delays.set(member, Number.isFinite(d) && d > 0 ? d : 'timeout');
                })
                .catch(() => {
                    this._delays.set(member, 'timeout');
                })
                .finally(() => {
                    this._probing.delete(member);
                    if (this._cancellable.is_cancelled())
                        return;
                    // Re-resolve the row: the menu may have been rebuilt while
                    // the probe was in flight, disposing the captured actor.
                    const cur = this._selectorItems.get(groupName)?.members.get(member);
                    if (cur)
                        cur.label.text = this._memberLabelText(member, this._proxiesMap?.[member]);
                });
        }
    }

    async _selectOutbound(group, name) {
        try {
            await this._api.selectProxy(group, name, this._cancellable);
            if (this._cancellable.is_cancelled())
                return;
            // The outbound changed: the last connectivity verdict is stale.
            // Reset it; the poll below refreshes the active node and re-probes.
            if (this._checkConnectivity) {
                this._connectivity = 'unknown';
                this._connectivityDelay = null;
            }
            this._poll();
        } catch (e) {
            if (this._cancellable.is_cancelled())
                return;
            Main.notifyError(_('sing-box'), `${_('Failed to switch outbound')}: ${e.message}`);
            logError(e, 'sing-box-status: selectProxy failed');
        }
    }

    // ---- State / visuals ---------------------------------------------

    // Derive the dot state and status text from API + connectivity state.
    _updateStatus() {
        let dot;
        if (this._apiUp === null) {
            dot = 'connecting';
            this._statusItem.label.text = _('sing-box  ·  Connecting…');
        } else if (!this._apiUp) {
            dot = 'down';
            this._statusItem.label.text = _('sing-box  ·  Unreachable');
            this._outboundLabel.text = '';
            this._speedLabel.text = '';
            this._speedItem.label.text = _('API unreachable — check URL and secret in Settings');
        } else if (this._checkConnectivity && this._connectivity === 'unknown') {
            // Service up, connectivity not measured yet — don't claim it works.
            dot = 'checking';
            this._statusItem.label.text = _('sing-box  ·  Active (checking…)');
        } else if (this._checkConnectivity && this._connectivity === 'down') {
            dot = 'nocon';
            this._statusItem.label.text = _('sing-box  ·  No connectivity');
        } else {
            dot = 'ok';
            const ms = this._checkConnectivity && this._connectivityDelay
                ? `  ·  ${this._connectivityDelay} ms` : '';
            this._statusItem.label.text = `${_('sing-box  ·  Active')}${ms}`;
        }

        if (dot !== this._dotState) {
            this._dotState = dot;
            this._dot.queue_repaint();
        }
    }

    _drawDot(area) {
        const cr = area.get_context();
        try {
            const [w, h] = area.get_surface_size();
            const color = area.get_theme_node().get_foreground_color();
            const r = color.red / 255;
            const g = color.green / 255;
            const b = color.blue / 255;
            const a = color.alpha / 255;

            const cx = w / 2;
            const cy = h / 2;
            const radius = Math.min(w, h) / 2 - 2;

            cr.setLineWidth(1.5);
            cr.arc(cx, cy, radius, 0, 2 * Math.PI);

            switch (this._dotState) {
            case 'ok':
                // Filled disc: service up and outbound reachable.
                cr.setSourceRGBA(r, g, b, a);
                cr.fillPreserve();
                cr.stroke();
                break;
            case 'nocon':
                // Bright solid ring: service up but no connectivity.
                cr.setSourceRGBA(r, g, b, a);
                cr.stroke();
                break;
            case 'checking':
                // Dim solid ring: service up, connectivity not measured yet.
                cr.setSourceRGBA(r, g, b, a * 0.5);
                cr.stroke();
                break;
            default:
                // Dashed dim ring: service unreachable ('down') or connecting.
                cr.setDash([2, 2], 0);
                cr.setSourceRGBA(r, g, b, a * 0.5);
                cr.stroke();
                cr.setDash([], 0);
                break;
            }
        } finally {
            cr.$dispose();
        }
    }

    _openDashboard() {
        const url = this._settings.get_string('dashboard-url');
        if (url)
            Gio.AppInfo.launch_default_for_uri(url, null);
    }

    // ---- Teardown -----------------------------------------------------

    destroy() {
        this._cancellable.cancel();
        if (this._timeoutId) {
            GLib.Source.remove(this._timeoutId);
            this._timeoutId = 0;
        }
        this._stopConnectivityCheck();
        if (this._settingsDebounceId) {
            GLib.Source.remove(this._settingsDebounceId);
            this._settingsDebounceId = 0;
        }
        if (this._settingsChangedId) {
            this._settings.disconnect(this._settingsChangedId);
            this._settingsChangedId = 0;
        }
        this._api.destroy();
        super.destroy();
    }
});