/**
 * Analytics Logic (Simple CSS Charts)
 */

const analytics = {
    mockData: [
        { name: 'Mon', requests: 4000, latency: 240 },
        { name: 'Tue', requests: 3000, latency: 198 },
        { name: 'Wed', requests: 2000, latency: 310 },
        { name: 'Thu', requests: 2780, latency: 208 },
        { name: 'Fri', requests: 1890, latency: 250 },
        { name: 'Sat', requests: 2390, latency: 210 },
        { name: 'Sun', requests: 3490, latency: 225 },
    ],

    init: async () => {
        console.log('📈 Initializing Live Analytics...');
        const headers = auth.getAuthHeader();
        
        // 1. Fetch Summary for Success Ratio
        try {
            const summaryRes = await fetch('/api/usage/summary', { headers });
            if (summaryRes.ok) {
                const summary = await summaryRes.json();
                analytics.renderSuccessRatio(summary.successRate);
            }
        } catch (e) { console.error(e); }

        // 2. Fetch History for Volume Chart
        const history = await analytics.fetchHistory();
        if (history && history.length > 0) {
            analytics.renderVolumeChart(history);
        } else {
            analytics.renderPlaceholder();
        }
        
        analytics.renderLatencyChart(); 
    },

    renderSuccessRatio: (percent) => {
        const circle = document.getElementById('success-circle');
        const display = document.getElementById('success-percent-display');
        if (!circle || !display) return;

        display.textContent = `${percent}%`;
        
        // Circumference is 552.9 (2 * PI * 88)
        const offset = 552.9 - (percent / 100) * 552.9;
        circle.style.strokeDashoffset = offset;
        circle.classList.toggle('text-emerald-500', percent >= 95);
        circle.classList.toggle('text-blue-600', percent < 95);
    },

    fetchHistory: async () => {
        try {
            const headers = auth.getAuthHeader();
            const res = await fetch('/api/usage/history?days=7', { headers });
            if (res.ok) {
                const raw = await res.json();
                // Map raw database records to chart data
                return raw.map(item => {
                    const date = new Date(item.date);
                    return {
                        name: date.toLocaleDateString('en-US', { weekday: 'short' }),
                        requests: parseInt(item.count, 10)
                    };
                });
            }
        } catch (error) {
            console.error('Failed to fetch analytics history', error);
        }
        return null;
    },

    renderVolumeChart: (data) => {
        const container = document.getElementById('v-chart');
        if (!container) return;

        const max = Math.max(...data.map(d => d.requests), 1);
        
        container.innerHTML = data.map((d, i) => `
            <div class="flex-1 flex flex-col items-center gap-4 group h-full">
                <div class="flex-1 w-full bg-slate-900/40 rounded-2xl relative overflow-hidden flex items-end p-1 border border-white/[0.03] backdrop-blur-sm">
                    <div class="w-full bg-gradient-to-t from-blue-600 via-blue-500 to-cyan-400 rounded-xl transition-all duration-1000 ease-out hover:brightness-125 shadow-[0_0_30px_rgba(37,99,235,0.2)]" 
                         style="height: 0%; transition-delay: ${i * 50}ms">
                         <script>
                            setTimeout(() => { 
                                document.querySelectorAll('.group h-full div[style*="height: 0%"]')[0].style.height = "${(d.requests / max) * 100}%";
                            }, 100);
                         </script>
                    </div>
                    <div class="absolute inset-0 flex flex-col items-center justify-center opacity-0 group-hover:opacity-100 transition-all transform translate-y-2 group-hover:translate-y-0 z-10">
                         <span class="text-[10px] font-black bg-blue-600 text-white px-3 py-1.5 rounded-lg shadow-2xl border border-blue-400/30 mb-2">${d.requests.toLocaleString()}</span>
                    </div>
                </div>
                <span class="text-[10px] font-black text-slate-500 uppercase tracking-widest">${d.name}</span>
            </div>
        `).join('');

        // Trigger animations after render
        setTimeout(() => {
            container.querySelectorAll('.w-full.bg-gradient-to-t').forEach((el, index) => {
                const height = el.parentElement.parentElement.dataset.height;
                el.style.height = el.getAttribute('data-target-height');
            });
        }, 100);
    },

    renderPlaceholder: () => {
        const container = document.getElementById('v-chart');
        if (container) container.innerHTML = `
            <div class="w-full h-full flex flex-col items-center justify-center text-slate-500 gap-4">
                <div class="w-16 h-16 rounded-full bg-slate-900 flex items-center justify-center opacity-50">
                    <i data-lucide="bar-chart" class="w-8 h-8"></i>
                </div>
                <p class="text-xs italic font-bold tracking-widest uppercase opacity-40">No activity recorded for this period</p>
            </div>`;
        if (window.lucide) lucide.createIcons();
    },

    renderLatencyChart: () => {
        const container = document.getElementById('l-chart');
        if (!container) return;

        const mockLatency = [
            { name: 'Mon', latency: 240 },
            { name: 'Tue', latency: 198 },
            { name: 'Wed', latency: 310 },
            { name: 'Thu', latency: 208 },
            { name: 'Fri', latency: 250 },
            { name: 'Sat', latency: 210 },
            { name: 'Sun', latency: 225 },
        ];

        const max = Math.max(...mockLatency.map(d => d.latency));
        
        container.innerHTML = mockLatency.map((d, i) => `
            <div class="flex-1 flex flex-col items-center gap-4 group h-full">
                <div class="flex-1 w-full bg-slate-900/40 rounded-2xl relative overflow-hidden flex items-end p-1 border border-white/[0.03] backdrop-blur-sm">
                    <div class="w-full bg-gradient-to-t from-violet-600 via-violet-500 to-fuchsia-400 rounded-xl transition-all duration-1000 ease-out hover:brightness-125 shadow-[0_0_30px_rgba(139,92,246,0.2)]" 
                         style="height: ${(d.latency / max) * 100}%">
                    </div>
                     <div class="absolute inset-0 flex flex-col items-center justify-center opacity-0 group-hover:opacity-100 transition-all transform translate-y-2 group-hover:translate-y-0 z-10">
                         <span class="text-[10px] font-black bg-violet-600 text-white px-3 py-1.5 rounded-lg shadow-2xl border border-violet-400/30 mb-2">${d.latency}ms</span>
                    </div>
                </div>
                <span class="text-[10px] font-black text-slate-500 uppercase tracking-widest">${d.name}</span>
            </div>
        `).join('');
    }
};