/**
 * Dashboard logic: stats rendering, audit selector, CPU chart, migration table.
 * Expects globals: SKELETON_MODE, CURRENT_CLUSTER, auditData (set by index.html).
 * Depends on: utils.js (formatBytes, getCSSVar, calculateStats)
 */
(function() {
    var cpuDistributionChart = null;

    document.getElementById('auditSelector').addEventListener('change', function(e) {
        var option = this.options[this.selectedIndex];
        if (!option) return;
        document.getElementById('previewCpu').textContent = option.dataset.cpu || '1.0';
        document.getElementById('previewRam').textContent = option.dataset.ram || '1.0';
        document.getElementById('previewScope').textContent = option.dataset.scope || 'Full Cluster';
        document.getElementById('previewStrategy').textContent = option.dataset.strategy || 'Balanced';
    });

    function setStat(key, text) {
        document.querySelectorAll('[data-stats="' + key + '"]').forEach(function(el) {
            el.textContent = text;
            el.classList.remove('animate-pulse');
        });
    }
    function setProgress(key, value) {
        document.querySelectorAll('[data-stats="' + key + '"]').forEach(function(el) {
            if (el.tagName === 'PROGRESS') {
                el.value = value;
                el.classList.remove('animate-pulse');
            }
        });
    }

    function renderStats(data) {
        if (!data) return;
        var el = function(k) { return document.querySelector('[data-stats="' + k + '"]'); };
        var regionBadge = document.getElementById('regionBadge');
        if (regionBadge) regionBadge.textContent = data.region && data.region.name ? data.region.name : '—';
        setStat('pcpu.usage', Number((data.pcpu && data.pcpu.usage) || 0).toFixed(1));
        setStat('pcpu.total', String((data.pcpu && data.pcpu.total) || 0));
        setStat('pcpu.used_percentage', Number((data.pcpu && data.pcpu.used_percentage) || 0).toFixed(1) + '%');
        setStat('pcpu.usage_val', Number((data.pcpu && data.pcpu.usage) || 0).toFixed(1) + ' CPU');
        setProgress('pcpu.progress', (data.pcpu && data.pcpu.used_percentage) || 0);
        setStat('pcpu.free', String((data.pcpu && data.pcpu.free) || 0));
        var pramUsageGb = formatBytes(data.pram && data.pram.usage, 'GB');
        var pramTotalGb = formatBytes(data.pram && data.pram.total, 'GB');
        var pramFreeGb = formatBytes(data.pram && data.pram.free, 'GB');
        setStat('pram.usage_gb', pramUsageGb);
        setStat('pram.total_gb', pramTotalGb);
        setStat('pram.used_percentage', Number((data.pram && data.pram.used_percentage) || 0).toFixed(1) + '%');
        setStat('pram.usage_gb_val', pramUsageGb + ' GB');
        setProgress('pram.progress', (data.pram && data.pram.used_percentage) || 0);
        setStat('pram.free_gb', pramFreeGb + ' GB');
        setStat('vm.active', String(data.vm && data.vm.active));
        setStat('vm.stopped', String(data.vm && data.vm.stopped));
        setStat('vm.count', String(data.vm && data.vm.count));
        setStat('flavors.first_name', data.flavors && data.flavors.first_common_flavor ? data.flavors.first_common_flavor.name : '—');
        setStat('vm.avg_cpu', Number((data.vm && data.vm.avg_cpu) || 0).toFixed(1));
        setStat('vm.density', Number((data.vm && data.vm.density) || 0).toFixed(1) + '/host');
        setStat('vcpu.allocated_total', ((data.vcpu && data.vcpu.allocated) || 0) + ' / ' + ((data.vcpu && data.vcpu.total) || 0) + ' vCPU');
        setProgress('vcpu.progress', (data.vcpu && data.vcpu.allocated_percentage) || 0);
        setStat('vcpu.allocated_percentage', Number((data.vcpu && data.vcpu.allocated_percentage) || 0).toFixed(1) + '%');
        var vcpuOver = el('vcpu.overcommit');
        if (vcpuOver) {
            vcpuOver.textContent = 'overcommit: ' + Number((data.vcpu && data.vcpu.overcommit_ratio) || 0).toFixed(1) + ' / ' + Number((data.vcpu && data.vcpu.overcommit_max) || 0).toFixed(1) + ' — ' + Number((data.vcpu && data.vcpu.allocated_percentage) || 0).toFixed(1) + '% allocated';
            vcpuOver.classList.remove('animate-pulse');
        }
        var vramAllocGb = formatBytes(data.vram && data.vram.allocated, 'GB');
        var vramTotalGb = formatBytes(data.vram && data.vram.total, 'GB');
        setStat('vram.allocated_total', vramAllocGb + ' / ' + vramTotalGb + ' GB');
        setProgress('vram.progress', (data.vram && data.vram.allocated_percentage) || 0);
        setStat('vram.allocated_percentage', Number((data.vram && data.vram.allocated_percentage) || 0).toFixed(1) + '%');
        var vramOver = el('vram.overcommit');
        if (vramOver) {
            vramOver.textContent = 'overcommit: ' + Number((data.vram && data.vram.overcommit_ratio) || 0).toFixed(1) + ' / ' + Number((data.vram && data.vram.overcommit_max) || 0).toFixed(1) + ' — ' + Number((data.vram && data.vram.allocated_percentage) || 0).toFixed(1) + '% allocated';
            vramOver.classList.remove('animate-pulse');
        }
        setStat('flavors.first_count', (data.flavors && data.flavors.first_common_flavor ? data.flavors.first_common_flavor.count : 0) + ' instances');
        var vmCount = data.vm && data.vm.count ? data.vm.count : 0;
        var firstCount = data.flavors && data.flavors.first_common_flavor ? data.flavors.first_common_flavor.count : 0;
        setStat('flavors.first_share', (vmCount ? Math.round(firstCount / vmCount * 100) : 0) + '%');
        setStat('flavors.second_name', data.flavors && data.flavors.second_common_flavor ? data.flavors.second_common_flavor.name : '—');
        setStat('flavors.second_count', data.flavors && data.flavors.second_common_flavor ? String(data.flavors.second_common_flavor.count) : '—');
        setStat('flavors.third_name', data.flavors && data.flavors.third_common_flavor ? data.flavors.third_common_flavor.name : '—');
        setStat('flavors.third_count', data.flavors && data.flavors.third_common_flavor ? String(data.flavors.third_common_flavor.count) : '—');
        document.querySelectorAll('[data-stats]').forEach(function(n) { n.classList.remove('animate-pulse'); });
    }

    function renderAudits(auditsList) {
        if (!auditsList || !auditsList.length) {
            var countEl = document.getElementById('auditsCount');
            if (countEl) countEl.textContent = '0 available';
            var sel = document.getElementById('auditSelector');
            if (sel) { sel.disabled = false; sel.innerHTML = '<option value="">No audits</option>'; }
            return;
        }
        window.auditData = {};
        auditsList.forEach(function(a) {
            window.auditData[a.id] = {
                name: a.name,
                migrations: typeof a.migrations === 'string' ? JSON.parse(a.migrations) : a.migrations,
                hostData: {
                    labels: typeof a.host_labels === 'string' ? JSON.parse(a.host_labels) : a.host_labels,
                    current: typeof a.cpu_current === 'string' ? JSON.parse(a.cpu_current) : a.cpu_current,
                    projected: typeof a.cpu_projected === 'string' ? JSON.parse(a.cpu_projected) : a.cpu_projected
                }
            };
        });
        var sel = document.getElementById('auditSelector');
        if (sel) {
            sel.disabled = false;
            sel.innerHTML = '';
            auditsList.forEach(function(audit) {
                var opt = document.createElement('option');
                opt.value = audit.id;
                opt.setAttribute('data-cpu', audit.cpu_weight || '1.0');
                opt.setAttribute('data-ram', audit.ram_weight || '1.0');
                opt.setAttribute('data-scope', audit.scope || 'Full Cluster');
                opt.setAttribute('data-strategy', audit.strategy || 'Balanced');
                opt.setAttribute('data-goal', audit.goal || '');
                var dateStr = audit.created_at ? new Date(audit.created_at).toLocaleDateString('en-US', { month: 'short', day: 'numeric' }) : '';
                opt.textContent = audit.name + ' (' + dateStr + ')';
                sel.appendChild(opt);
            });
        }
        var countEl = document.getElementById('auditsCount');
        if (countEl) countEl.textContent = auditsList.length + ' available';
        if (auditsList.length > 0) {
            document.getElementById('auditSelector').dispatchEvent(new Event('change'));
            loadSelectedAudit();
        }
    }

    window.loadSelectedAudit = function() {
        var auditId = document.getElementById('auditSelector').value;
        updateMigrationTable(auditId);
        updateCPUCharts(auditId);
    };

    function updateMigrationTable(auditId) {
        var tbody = document.getElementById('migrationTableBody');
        var migrationCount = document.getElementById('migrationCount');
        var data = window.auditData && window.auditData[auditId];

        if (!data || !data.migrations || data.migrations.length === 0) {
            tbody.innerHTML = '<tr><td colspan="4" class="text-center py-6 text-base-content/60">No migration actions recommended</td></tr>';
            migrationCount.textContent = '0 actions';
            return;
        }

        var html = '';
        data.migrations.forEach(function(migration) {
            var impact = migration.impact || 'Low';
            var impactClass = { 'Low': 'badge-success', 'Medium': 'badge-warning', 'High': 'badge-error' }[impact] || 'badge-neutral';
            html += '<tr><td class="font-medium"><div>' + migration.instanceName + '</div></td><td><div class="flex items-center gap-2"><span class="badge badge-outline badge-xs">' + migration.source + '</span><svg class="w-3 h-3 text-base-content/30" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13 7l5 5m0 0l-5 5m5-5H6"/></svg><span class="badge badge-primary badge-outline badge-xs">' + migration.destination + '</span></div></td><td><code class="text-xs bg-base-200 px-2 py-1 rounded">' + migration.flavor + '</code></td><td><span class="badge ' + impactClass + ' badge-xs">' + impact + '</span></td></tr>';
        });
        tbody.innerHTML = html;
        migrationCount.textContent = data.migrations.length + ' action' + (data.migrations.length !== 1 ? 's' : '');
    }

    function updateCPUCharts(auditId) {
        var data = window.auditData && window.auditData[auditId];
        if (!data || !data.hostData) return;

        var ctx = document.getElementById('cpuDistributionChart').getContext('2d');
        var currentStats = calculateStats(data.hostData.current);

        document.getElementById('currentCpuMean').textContent = currentStats.mean.toFixed(1);
        document.getElementById('currentCpuStd').textContent = (currentStats.std * 0.5).toFixed(1);

        if (cpuDistributionChart) cpuDistributionChart.destroy();

        var colors = {
            primary: getCSSVar('--color-primary'),
            secondary: getCSSVar('--color-secondary'),
            accent: getCSSVar('--color-accent'),
            neutral: getCSSVar('--color-neutral'),
            info: getCSSVar('--color-info'),
            success: getCSSVar('--color-success'),
            warning: getCSSVar('--color-warning'),
            error: getCSSVar('--color-error')
        };
        var textColor = getCSSVar('--color-base-content');
        var gridColor = getCSSVar('--chart-grid-color') || textColor;

        cpuDistributionChart = new Chart(ctx, {
            type: 'bar',
            data: {
                labels: data.hostData.labels,
                datasets: [
                    { label: 'Current', data: data.hostData.current.slice(), backgroundColor: colors.info + '40', borderColor: colors.info, borderWidth: 1, borderRadius: 3 },
                    { label: 'Projected', data: data.hostData.projected.slice(), backgroundColor: colors.warning + '40', borderColor: colors.warning, borderWidth: 1, borderRadius: 3 }
                ]
            },
            options: {
                responsive: true,
                maintainAspectRatio: false,
                animation: {
                    onComplete: function() {
                        var chart = this.chart || this;
                        if (chart._hidingDataset === undefined) return;
                        var i = chart._hidingDataset;
                        chart.getDatasetMeta(i).hidden = true;
                        chart.data.datasets[i].data = chart._cpuOriginalData[i].slice();
                        delete chart._hidingDataset;
                        chart.update('none');
                    }
                },
                plugins: {
                    legend: {
                        display: true,
                        position: 'top',
                        align: 'center',
                        onClick: function(e, legendItem, legend) {
                            var i = legendItem.datasetIndex;
                            var chart = legend.chart;
                            var len = chart.data.labels.length;
                            if (chart.isDatasetVisible(i)) {
                                chart._hidingDataset = i;
                                chart.data.datasets[i].data = Array(len).fill(0);
                                chart.update();
                            } else {
                                chart.data.datasets[i].data = Array(len).fill(0);
                                chart.show(i);
                                chart.update('none');
                                chart.data.datasets[i].data = chart._cpuOriginalData[i].slice();
                                chart.update();
                            }
                        },
                        labels: {
                            usePointStyle: true,
                            pointStyle: 'rect',
                            boxWidth: 14,
                            boxHeight: 14,
                            padding: 12,
                            color: textColor,
                            generateLabels: function(chart) {
                                var datasets = chart.data.datasets;
                                var labelColor = getCSSVar('--color-base-content') || textColor;
                                return datasets.map(function(ds, i) {
                                    return { text: ds.label, fillStyle: ds.borderColor, strokeStyle: ds.borderColor, lineWidth: 1, fontColor: labelColor, color: labelColor, hidden: !chart.isDatasetVisible(i), datasetIndex: i };
                                });
                            }
                        }
                    },
                    tooltip: {
                        callbacks: { label: function(ctx) { return ctx.dataset.label + ': ' + Number(ctx.parsed.y).toFixed(2) + '% CPU'; } }
                    },
                    annotation: {
                        annotations: {
                            MeanLine: { type: 'line', yMin: currentStats.mean, yMax: currentStats.mean, borderColor: colors.success, borderWidth: 2, borderDash: [] },
                            upperStdLine: { type: 'line', yMin: currentStats.mean + currentStats.std * 0.5, yMax: currentStats.mean + currentStats.std * 0.5, borderColor: colors.error, borderWidth: 1, borderDash: [5, 5] },
                            lowerStdLine: { type: 'line', yMin: currentStats.mean > currentStats.std * 0.5 ? currentStats.mean - currentStats.std * 0.5 : 0, yMax: currentStats.mean > currentStats.std * 0.5 ? currentStats.mean - currentStats.std * 0.5 : 0, borderColor: colors.error, borderWidth: 1, borderDash: [5, 5] }
                        }
                    }
                },
                scales: {
                    y: { beginAtZero: true, max: 100, grid: { drawBorder: false, color: gridColor }, ticks: { color: textColor, callback: function(value) { return value + '%'; } } },
                    x: { grid: { display: false }, ticks: { display: false }, barPercentage: 1, categoryPercentage: 0.85 }
                }
            }
        });
        cpuDistributionChart._cpuOriginalData = [ data.hostData.current.slice(), data.hostData.projected.slice() ];
    }

    document.addEventListener('DOMContentLoaded', function() {
        if (typeof SKELETON_MODE !== 'undefined' && SKELETON_MODE) {
            Promise.all([
                fetch('/api/stats/').then(function(r) { return r.ok ? r.json() : Promise.reject(r); }),
                fetch('/api/audits/').then(function(r) { return r.ok ? r.json() : Promise.reject(r); })
            ]).then(function(results) {
                renderStats(results[0]);
                renderAudits(results[1].audits);
                if (!results[1].audits || results[1].audits.length === 0) {
                    var cc = results[1].current_cluster;
                    if (cc && cc.host_labels && cc.cpu_current && cc.host_labels.length) {
                        window.auditData = window.auditData || {};
                        window.auditData.current = { hostData: { labels: cc.host_labels, current: cc.cpu_current, projected: cc.cpu_current } };
                        updateCPUCharts('current');
                    }
                }
            }).catch(function(err) {
                var msg = err.status ? 'Failed to load data (' + err.status + ')' : 'Failed to load data';
                var countEl = document.getElementById('auditsCount');
                if (countEl) countEl.textContent = msg;
                fetch('/api/stats/').then(function(r) { return r.ok ? r.json() : null; }).then(function(d) { if (d) renderStats(d); });
                fetch('/api/audits/').then(function(r) { return r.ok ? r.json() : null; }).then(function(d) { if (d && d.audits) renderAudits(d.audits); });
            });
        } else {
            var initialAudit = typeof INITIAL_AUDIT_ID !== 'undefined' ? INITIAL_AUDIT_ID : '';
            if (initialAudit && window.auditData && window.auditData[initialAudit]) {
                document.getElementById('auditSelector').dispatchEvent(new Event('change'));
                loadSelectedAudit();
            } else if (!initialAudit && typeof CURRENT_CLUSTER !== 'undefined' && CURRENT_CLUSTER && CURRENT_CLUSTER.host_labels && CURRENT_CLUSTER.host_labels.length) {
                window.auditData = window.auditData || {};
                window.auditData.current = { hostData: { labels: CURRENT_CLUSTER.host_labels, current: CURRENT_CLUSTER.cpu_current, projected: CURRENT_CLUSTER.cpu_current } };
                updateCPUCharts('current');
            }
        }
    });

    document.addEventListener('themechange', function() {
        if (cpuDistributionChart) {
            var auditId = document.getElementById('auditSelector').value;
            cpuDistributionChart.destroy();
            cpuDistributionChart = null;
            if (auditId) updateCPUCharts(auditId);
        }
    });
})();