/**
 * Dashboard — real-time target status overview.
 */

import { apiKey, _dashboardLoading, set_dashboardLoading, dashboardPollInterval, setDashboardPollInterval } from '../core/state.js';
import { API_BASE, getHeaders, fetchWithAuth } from '../core/api.js';
import { t } from '../core/i18n.js';
import { escapeHtml, handle401Error } from '../core/api.js';
import { showToast } from '../core/ui.js';
import { renderPerfSection, initPerfCharts, startPerfPolling, stopPerfPolling } from './perf-charts.js';
import { startAutoRefresh } from './tabs.js';

const DASHBOARD_COLLAPSED_KEY = 'dashboard_collapsed';
const FPS_HISTORY_KEY = 'dashboard_fps_history';
const MAX_FPS_SAMPLES = 30;

let _fpsHistory = _loadFpsHistory();   // { targetId: number[] }
let _fpsCharts = {};                   // { targetId: Chart }
let _lastRunningIds = [];              // sorted target IDs from previous render
let _uptimeBase = {};                  // { targetId: { seconds, timestamp } }
let _uptimeTimer = null;

function _loadFpsHistory() {
    try {
        const raw = sessionStorage.getItem(FPS_HISTORY_KEY);
        if (raw) return JSON.parse(raw);
    } catch {}
    return {};
}

function _saveFpsHistory() {
    try { sessionStorage.setItem(FPS_HISTORY_KEY, JSON.stringify(_fpsHistory)); }
    catch {}
}

function _pushFps(targetId, value) {
    if (!_fpsHistory[targetId]) _fpsHistory[targetId] = [];
    _fpsHistory[targetId].push(value);
    if (_fpsHistory[targetId].length > MAX_FPS_SAMPLES) _fpsHistory[targetId].shift();
}

function _setUptimeBase(targetId, seconds) {
    _uptimeBase[targetId] = { seconds, timestamp: Date.now() };
}

function _getInterpolatedUptime(targetId) {
    const base = _uptimeBase[targetId];
    if (!base) return null;
    const elapsed = (Date.now() - base.timestamp) / 1000;
    return base.seconds + elapsed;
}

function _startUptimeTimer() {
    if (_uptimeTimer) return;
    _uptimeTimer = setInterval(() => {
        for (const id of _lastRunningIds) {
            const el = document.querySelector(`[data-uptime-text="${id}"]`);
            if (!el) continue;
            const seconds = _getInterpolatedUptime(id);
            if (seconds != null) {
                el.textContent = `🕐 ${formatUptime(seconds)}`;
            }
        }
    }, 1000);
}

function _stopUptimeTimer() {
    if (_uptimeTimer) {
        clearInterval(_uptimeTimer);
        _uptimeTimer = null;
    }
    _uptimeBase = {};
}

function _destroyFpsCharts() {
    for (const id of Object.keys(_fpsCharts)) {
        if (_fpsCharts[id]) { _fpsCharts[id].destroy(); }
    }
    _fpsCharts = {};
}

function _createFpsChart(canvasId, history, fpsTarget) {
    const canvas = document.getElementById(canvasId);
    if (!canvas) return null;
    return new Chart(canvas, {
        type: 'line',
        data: {
            labels: history.map(() => ''),
            datasets: [{
                data: [...history],
                borderColor: '#2196F3',
                backgroundColor: 'rgba(33,150,243,0.12)',
                borderWidth: 1.5,
                tension: 0.3,
                fill: true,
                pointRadius: 0,
            }],
        },
        options: {
            responsive: true,
            maintainAspectRatio: false,
            animation: true,
            plugins: { legend: { display: false }, tooltip: { enabled: false } },
            scales: {
                x: { display: false },
                y: { min: 0, max: fpsTarget * 1.15, display: false },
            },
            layout: { padding: 0 },
        },
    });
}

function _initFpsCharts(runningTargetIds) {
    _destroyFpsCharts();
    // Clean up history for targets that are no longer running
    for (const id of Object.keys(_fpsHistory)) {
        if (!runningTargetIds.includes(id)) delete _fpsHistory[id];
    }
    for (const id of runningTargetIds) {
        const canvas = document.getElementById(`dashboard-fps-${id}`);
        if (!canvas) continue;
        const history = _fpsHistory[id] || [];
        const fpsTarget = parseFloat(canvas.dataset.fpsTarget) || 30;
        _fpsCharts[id] = _createFpsChart(`dashboard-fps-${id}`, history, fpsTarget);
    }
    _saveFpsHistory();
}

/** Update running target metrics in-place (no HTML rebuild). */
function _updateRunningMetrics(enrichedRunning) {
    for (const target of enrichedRunning) {
        const state = target.state || {};
        const metrics = target.metrics || {};
        const fpsActual = state.fps_actual != null ? state.fps_actual.toFixed(1) : '-';
        const fpsTarget = state.fps_target || (target.settings || target.key_colors_settings || {}).fps || '-';
        const errors = metrics.errors_count || 0;

        // Push FPS and update chart
        if (state.fps_actual != null) {
            _pushFps(target.id, state.fps_actual);
        }
        const chart = _fpsCharts[target.id];
        if (chart) {
            const history = _fpsHistory[target.id] || [];
            chart.data.datasets[0].data = [...history];
            chart.data.labels = history.map(() => '');
            chart.update();
        }

        // Refresh uptime base for interpolation
        if (metrics.uptime_seconds != null) {
            _setUptimeBase(target.id, metrics.uptime_seconds);
        }

        // Update text values
        const fpsEl = document.querySelector(`[data-fps-text="${target.id}"]`);
        if (fpsEl) fpsEl.innerHTML = `${fpsActual}<span class="dashboard-fps-target">/${fpsTarget}</span>`;

        const errorsEl = document.querySelector(`[data-errors-text="${target.id}"]`);
        if (errorsEl) errorsEl.textContent = `${errors > 0 ? '⚠️' : '✅'} ${errors}`;

        // Update health dot
        const isLed = target.target_type === 'led' || target.target_type === 'wled';
        if (isLed) {
            const row = document.querySelector(`[data-target-id="${target.id}"]`);
            if (row) {
                const dot = row.querySelector('.health-dot');
                if (dot && state.device_last_checked != null) {
                    dot.className = `health-dot ${state.device_online ? 'health-online' : 'health-offline'}`;
                }
            }
        }
    }
    _saveFpsHistory();
}

function _renderPollIntervalSelect() {
    const sec = Math.round(dashboardPollInterval / 1000);
    return `<span class="dashboard-poll-wrap" onclick="event.stopPropagation()"><input type="range" class="dashboard-poll-slider" min="1" max="10" value="${sec}" oninput="changeDashboardPollInterval(this.value)" title="${t('dashboard.poll_interval')}"><span class="dashboard-poll-value">${sec}s</span></span>`;
}

export function changeDashboardPollInterval(value) {
    const ms = parseInt(value, 10) * 1000;
    setDashboardPollInterval(ms);
    startAutoRefresh();
    stopPerfPolling();
    startPerfPolling();
    const label = document.querySelector('.dashboard-poll-value');
    if (label) label.textContent = `${value}s`;
}

function _getCollapsedSections() {
    try { return JSON.parse(localStorage.getItem(DASHBOARD_COLLAPSED_KEY)) || {}; }
    catch { return {}; }
}

export function toggleDashboardSection(sectionKey) {
    const collapsed = _getCollapsedSections();
    collapsed[sectionKey] = !collapsed[sectionKey];
    localStorage.setItem(DASHBOARD_COLLAPSED_KEY, JSON.stringify(collapsed));
    const header = document.querySelector(`[data-dashboard-section="${sectionKey}"]`);
    if (!header) return;
    const content = header.nextElementSibling;
    const chevron = header.querySelector('.dashboard-section-chevron');
    if (collapsed[sectionKey]) {
        content.style.display = 'none';
        chevron.textContent = '\u25B6';
    } else {
        content.style.display = '';
        chevron.textContent = '\u25BC';
    }
}

function _sectionHeader(sectionKey, label, count, extraHtml = '') {
    const collapsed = _getCollapsedSections();
    const isCollapsed = !!collapsed[sectionKey];
    const chevron = isCollapsed ? '\u25B6' : '\u25BC';
    return `<div class="dashboard-section-header" data-dashboard-section="${sectionKey}" onclick="toggleDashboardSection('${sectionKey}')">
        <span class="dashboard-section-chevron">${chevron}</span>
        ${label}
        <span class="dashboard-section-count">${count}</span>
        ${extraHtml}
    </div>`;
}

function _sectionContent(sectionKey, itemsHtml) {
    const collapsed = _getCollapsedSections();
    const isCollapsed = !!collapsed[sectionKey];
    return `<div class="dashboard-section-content"${isCollapsed ? ' style="display:none"' : ''}>${itemsHtml}</div>`;
}

function formatUptime(seconds) {
    if (!seconds || seconds <= 0) return '-';
    const h = Math.floor(seconds / 3600);
    const m = Math.floor((seconds % 3600) / 60);
    const s = Math.floor(seconds % 60);
    if (h > 0) return `${h}h ${m}m`;
    if (m > 0) return `${m}m ${s}s`;
    return `${s}s`;
}

export async function loadDashboard(forceFullRender = false) {
    if (_dashboardLoading) return;
    set_dashboardLoading(true);
    const container = document.getElementById('dashboard-content');
    if (!container) { set_dashboardLoading(false); return; }

    try {
        const [targetsResp, profilesResp, devicesResp] = await Promise.all([
            fetch(`${API_BASE}/picture-targets`, { headers: getHeaders() }),
            fetch(`${API_BASE}/profiles`, { headers: getHeaders() }).catch(() => null),
            fetch(`${API_BASE}/devices`, { headers: getHeaders() }).catch(() => null),
        ]);
        if (targetsResp.status === 401) { handle401Error(); return; }

        const targetsData = await targetsResp.json();
        const targets = targetsData.targets || [];
        const profilesData = profilesResp && profilesResp.ok ? await profilesResp.json() : { profiles: [] };
        const profiles = profilesData.profiles || [];
        const devicesData = devicesResp && devicesResp.ok ? await devicesResp.json() : { devices: [] };
        const devicesMap = {};
        for (const d of (devicesData.devices || [])) { devicesMap[d.id] = d; }

        // Build dynamic HTML (targets, profiles)
        let dynamicHtml = '';
        let runningIds = [];

        if (targets.length === 0 && profiles.length === 0) {
            dynamicHtml = `<div class="dashboard-no-targets">${t('dashboard.no_targets')}</div>`;
        } else {
            const enriched = await Promise.all(targets.map(async (target) => {
                try {
                    const [stateResp, metricsResp] = await Promise.all([
                        fetch(`${API_BASE}/picture-targets/${target.id}/state`, { headers: getHeaders() }),
                        fetch(`${API_BASE}/picture-targets/${target.id}/metrics`, { headers: getHeaders() }),
                    ]);
                    const state = stateResp.ok ? await stateResp.json() : {};
                    const metrics = metricsResp.ok ? await metricsResp.json() : {};
                    return { ...target, state, metrics };
                } catch {
                    return target;
                }
            }));

            const running = enriched.filter(t => t.state && t.state.processing);
            const stopped = enriched.filter(t => !t.state || !t.state.processing);

            // Check if we can do an in-place metrics update (same targets, not first load)
            const newRunningIds = running.map(t => t.id).sort().join(',');
            const prevRunningIds = [..._lastRunningIds].sort().join(',');
            const hasExistingDom = !!container.querySelector('.dashboard-perf-persistent');
            if (!forceFullRender && hasExistingDom && newRunningIds === prevRunningIds && newRunningIds !== '') {
                _updateRunningMetrics(running);
                set_dashboardLoading(false);
                return;
            }

            if (profiles.length > 0) {
                const activeProfiles = profiles.filter(p => p.is_active);
                const inactiveProfiles = profiles.filter(p => !p.is_active);
                const profileItems = [...activeProfiles, ...inactiveProfiles].map(p => renderDashboardProfile(p)).join('');

                dynamicHtml += `<div class="dashboard-section">
                    ${_sectionHeader('profiles', t('dashboard.section.profiles'), profiles.length)}
                    ${_sectionContent('profiles', profileItems)}
                </div>`;
            }

            if (targets.length > 0) {
                let targetsInner = '';

                if (running.length > 0) {
                    runningIds = running.map(t => t.id);
                    const stopAllBtn = `<button class="btn btn-sm btn-danger dashboard-stop-all" onclick="event.stopPropagation(); dashboardStopAll()" title="${t('dashboard.stop_all')}">⏹️ ${t('dashboard.stop_all')}</button>`;
                    const runningItems = running.map(target => renderDashboardTarget(target, true, devicesMap)).join('');

                    targetsInner += `<div class="dashboard-subsection">
                        ${_sectionHeader('running', t('dashboard.section.running'), running.length, stopAllBtn)}
                        ${_sectionContent('running', runningItems)}
                    </div>`;
                }

                if (stopped.length > 0) {
                    const stoppedItems = stopped.map(target => renderDashboardTarget(target, false, devicesMap)).join('');

                    targetsInner += `<div class="dashboard-subsection">
                        ${_sectionHeader('stopped', t('dashboard.section.stopped'), stopped.length)}
                        ${_sectionContent('stopped', stoppedItems)}
                    </div>`;
                }

                dynamicHtml += `<div class="dashboard-section">
                    ${_sectionHeader('targets', t('dashboard.section.targets'), targets.length)}
                    ${_sectionContent('targets', targetsInner)}
                </div>`;
            }
        }

        // First load: build everything in one innerHTML to avoid flicker
        const isFirstLoad = !container.querySelector('.dashboard-perf-persistent');
        const pollSelect = _renderPollIntervalSelect();
        if (isFirstLoad) {
            container.innerHTML = `<div class="dashboard-perf-persistent dashboard-section">
                ${_sectionHeader('perf', t('dashboard.section.performance'), '', pollSelect)}
                ${_sectionContent('perf', renderPerfSection())}
            </div>
            <div class="dashboard-dynamic">${dynamicHtml}</div>`;
            initPerfCharts();
        } else {
            const dynamic = container.querySelector('.dashboard-dynamic');
            if (dynamic.innerHTML !== dynamicHtml) {
                dynamic.innerHTML = dynamicHtml;
            }
        }
        _lastRunningIds = runningIds;
        _initFpsCharts(runningIds);
        _startUptimeTimer();
        startPerfPolling();

    } catch (error) {
        console.error('Failed to load dashboard:', error);
        container.innerHTML = `<div class="dashboard-no-targets">${t('dashboard.failed')}</div>`;
    } finally {
        set_dashboardLoading(false);
    }
}

function renderDashboardTarget(target, isRunning, devicesMap = {}) {
    const state = target.state || {};
    const metrics = target.metrics || {};
    const isLed = target.target_type === 'led' || target.target_type === 'wled';
    const icon = '⚡';
    const typeLabel = isLed ? 'LED' : 'Key Colors';

    let subtitleParts = [typeLabel];
    if (isLed) {
        const device = target.device_id ? devicesMap[target.device_id] : null;
        if (device) {
            subtitleParts.push((device.device_type || '').toUpperCase());
        }
    }

    if (isRunning) {
        const fpsActual = state.fps_actual != null ? state.fps_actual.toFixed(1) : '-';
        const fpsTarget = state.fps_target || (target.settings || target.key_colors_settings || {}).fps || '-';
        const uptime = formatUptime(metrics.uptime_seconds);
        const errors = metrics.errors_count || 0;

        // Set uptime base for interpolation
        if (metrics.uptime_seconds != null) {
            _setUptimeBase(target.id, metrics.uptime_seconds);
        }

        // Push FPS sample to history
        if (state.fps_actual != null) {
            _pushFps(target.id, state.fps_actual);
        }

        let healthDot = '';
        if (isLed && state.device_last_checked != null) {
            const cls = state.device_online ? 'health-online' : 'health-offline';
            healthDot = `<span class="health-dot ${cls}"></span>`;
        }

        return `<div class="dashboard-target" data-target-id="${target.id}">
            <div class="dashboard-target-info">
                <span class="dashboard-target-icon">${icon}</span>
                <div>
                    <div class="dashboard-target-name">${escapeHtml(target.name)}${healthDot}</div>
                    ${subtitleParts.length ? `<div class="dashboard-target-subtitle">${escapeHtml(subtitleParts.join(' · '))}</div>` : ''}
                </div>
            </div>
            <div class="dashboard-target-metrics">
                <div class="dashboard-metric dashboard-fps-metric">
                    <div class="dashboard-fps-sparkline">
                        <canvas id="dashboard-fps-${target.id}" data-fps-target="${fpsTarget}"></canvas>
                    </div>
                    <div class="dashboard-fps-label">
                        <span class="dashboard-metric-value" data-fps-text="${target.id}">${fpsActual}<span class="dashboard-fps-target">/${fpsTarget}</span></span>
                    </div>
                </div>
                <div class="dashboard-metric" title="${t('dashboard.uptime')}">
                    <div class="dashboard-metric-value" data-uptime-text="${target.id}">🕐 ${uptime}</div>
                </div>
                <div class="dashboard-metric" title="${t('dashboard.errors')}">
                    <div class="dashboard-metric-value" data-errors-text="${target.id}">${errors > 0 ? '⚠️' : '✅'} ${errors}</div>
                </div>
            </div>
            <div class="dashboard-target-actions">
                <button class="btn btn-icon btn-warning" onclick="dashboardStopTarget('${target.id}')" title="${t('device.button.stop')}">⏸</button>
            </div>
        </div>`;
    } else {
        return `<div class="dashboard-target">
            <div class="dashboard-target-info">
                <span class="dashboard-target-icon">${icon}</span>
                <div>
                    <div class="dashboard-target-name">${escapeHtml(target.name)}</div>
                    ${subtitleParts.length ? `<div class="dashboard-target-subtitle">${escapeHtml(subtitleParts.join(' · '))}</div>` : ''}
                </div>
            </div>
            <div class="dashboard-target-metrics"></div>
            <div class="dashboard-target-actions">
                <button class="btn btn-icon btn-success" onclick="dashboardStartTarget('${target.id}')" title="${t('device.button.start')}">▶</button>
            </div>
        </div>`;
    }
}

function renderDashboardProfile(profile) {
    const isActive = profile.is_active;
    const isDisabled = !profile.enabled;

    let condSummary = '';
    if (profile.conditions.length > 0) {
        const parts = profile.conditions.map(c => {
            if (c.condition_type === 'application') {
                const apps = (c.apps || []).join(', ');
                const matchLabel = c.match_type === 'topmost' ? t('profiles.condition.application.match_type.topmost') : t('profiles.condition.application.match_type.running');
                return `${apps} (${matchLabel})`;
            }
            return c.condition_type;
        });
        const logic = profile.condition_logic === 'and' ? ' & ' : ' | ';
        condSummary = parts.join(logic);
    }

    const statusBadge = isDisabled
        ? `<span class="dashboard-badge-stopped">${t('profiles.status.disabled')}</span>`
        : isActive
            ? `<span class="dashboard-badge-active">${t('profiles.status.active')}</span>`
            : `<span class="dashboard-badge-stopped">${t('profiles.status.inactive')}</span>`;

    const targetCount = profile.target_ids.length;
    const activeCount = (profile.active_target_ids || []).length;
    const targetsInfo = isActive ? `${activeCount}/${targetCount}` : `${targetCount}`;

    return `<div class="dashboard-target dashboard-profile">
        <div class="dashboard-target-info">
            <span class="dashboard-target-icon">📋</span>
            <div>
                <div class="dashboard-target-name">${escapeHtml(profile.name)}</div>
                ${condSummary ? `<div class="dashboard-target-subtitle">${escapeHtml(condSummary)}</div>` : ''}
            </div>
            ${statusBadge}
        </div>
        <div class="dashboard-target-metrics">
            <div class="dashboard-metric">
                <div class="dashboard-metric-value">${targetsInfo}</div>
                <div class="dashboard-metric-label">${t('dashboard.targets')}</div>
            </div>
        </div>
        <div class="dashboard-target-actions">
            <button class="btn btn-icon ${profile.enabled ? 'btn-warning' : 'btn-success'}" onclick="dashboardToggleProfile('${profile.id}', ${!profile.enabled})" title="${profile.enabled ? t('profiles.status.disabled') : t('profiles.status.active')}">
                ${profile.enabled ? '⏸' : '▶'}
            </button>
        </div>
    </div>`;
}

export async function dashboardToggleProfile(profileId, enable) {
    try {
        const endpoint = enable ? 'enable' : 'disable';
        const response = await fetch(`${API_BASE}/profiles/${profileId}/${endpoint}`, {
            method: 'POST',
            headers: getHeaders()
        });
        if (response.status === 401) { handle401Error(); return; }
        if (response.ok) {
            loadDashboard();
        }
    } catch (error) {
        showToast('Failed to toggle profile', 'error');
    }
}

export async function dashboardStartTarget(targetId) {
    try {
        const response = await fetch(`${API_BASE}/picture-targets/${targetId}/start`, {
            method: 'POST',
            headers: getHeaders()
        });
        if (response.status === 401) { handle401Error(); return; }
        if (response.ok) {
            showToast(t('device.started'), 'success');
            loadDashboard();
        } else {
            const error = await response.json();
            showToast(`Failed to start: ${error.detail}`, 'error');
        }
    } catch (error) {
        showToast('Failed to start processing', 'error');
    }
}

export async function dashboardStopTarget(targetId) {
    try {
        const response = await fetch(`${API_BASE}/picture-targets/${targetId}/stop`, {
            method: 'POST',
            headers: getHeaders()
        });
        if (response.status === 401) { handle401Error(); return; }
        if (response.ok) {
            showToast(t('device.stopped'), 'success');
            loadDashboard();
        } else {
            const error = await response.json();
            showToast(`Failed to stop: ${error.detail}`, 'error');
        }
    } catch (error) {
        showToast('Failed to stop processing', 'error');
    }
}

export async function dashboardStopAll() {
    try {
        const targetsResp = await fetch(`${API_BASE}/picture-targets`, { headers: getHeaders() });
        if (targetsResp.status === 401) { handle401Error(); return; }
        const data = await targetsResp.json();
        const running = (data.targets || []).filter(t => t.id);
        await Promise.all(running.map(t =>
            fetch(`${API_BASE}/picture-targets/${t.id}/stop`, { method: 'POST', headers: getHeaders() }).catch(() => {})
        ));
        loadDashboard();
    } catch (error) {
        showToast('Failed to stop all targets', 'error');
    }
}

export function stopUptimeTimer() {
    _stopUptimeTimer();
}

// React to global server events when dashboard tab is active
function _isDashboardActive() {
    return (localStorage.getItem('activeTab') || 'dashboard') === 'dashboard';
}

document.addEventListener('server:state_change', () => {
    if (_isDashboardActive()) loadDashboard();
});

document.addEventListener('server:profile_state_changed', () => {
    if (_isDashboardActive()) loadDashboard(true);
});

// Re-render dashboard when language changes
document.addEventListener('languageChanged', () => {
    if (!apiKey) return;
    // Force perf section rebuild with new locale
    const perfEl = document.querySelector('.dashboard-perf-persistent');
    if (perfEl) perfEl.remove();
    loadDashboard();
});