/**
 * agents-controller.js - Agent Profile Dashboard Controller
 * ==========================================================
 * Handles agent list, detail views, charts, search, and sort.
 * * Hardened for Enterprise MVC:
 * - Uses central `apiFetch` to automatically inherit HTTP-Only Cookies and CSRF headers.
 * - Uses `SecurityUtils` for XSS-safe DOM generation.
 * - Uses `ErrorHandler` for standardized exception recovery.
 */

(function() {
    'use strict';

    let allAgents = [];
    let currentAgentId = null;
    let f1TrendChart = null;
    let qualityRadarChart = null;

    // DOM Elements
    const agentsListView = document.getElementById('agents-list-view');
    const agentDetailView = document.getElementById('agent-detail-view');
    const agentsGrid = document.getElementById('agents-grid');
    const agentsEmptyState = document.getElementById('agents-empty-state');
    const agentSearch = document.getElementById('agent-search');
    const sortSelect = document.getElementById('sort-select');
    const backToListBtn = document.getElementById('back-to-list-btn');
    const reindexAgentBtn = document.getElementById('reindex-agent-btn');

    // Stats elements
    const totalAgentsEl = document.getElementById('total-agents');
    const avgF1ScoreEl = document.getElementById('avg-f1-score');
    const improvingCountEl = document.getElementById('improving-count');
    const decliningCountEl = document.getElementById('declining-count');

    // Detail elements
    const detailAgentName = document.getElementById('detail-agent-name');
    const detailAgentEmail = document.getElementById('detail-agent-email');
    const detailTotalAudits = document.getElementById('detail-total-audits');
    const detailAvgF1 = document.getElementById('detail-avg-f1');
    const detailTrend = document.getElementById('detail-trend');
    const detailRiskFlags = document.getElementById('detail-risk-flags');

    // Safe HTML Escaping (Fallback to native if SecurityUtils isn't loaded yet)
    const escapeHTML = (text) => {
        if (window.SecurityUtils) return window.SecurityUtils.escapeHTML(text);
        const div = document.createElement('div');
        div.textContent = text;
        return div.innerHTML;
    };

    async function init() {
        await loadAgents();
        setupEventListeners();
    }

    async function loadAgents() {
        if (window.toggleLoader) window.toggleLoader(true, 'Synchronizing agent profiles...');
        
        try {
            // Enterprise Architecture: Centralized apiFetch handles CSRF and Cookies automatically
            const data = await window.apiFetch('/agents');

            if (data.success) {
                allAgents = data.agents || [];
                renderAgentsList(allAgents);
                updateStatsBar(allAgents);
            }
        } catch (error) {
            console.error('[Agents] Load failed:', error);
            
            if (window.ErrorHandler) {
                window.ErrorHandler.showError(error);
            } else if (window.SecurityUtils) {
                window.SecurityUtils.showToast('Failed to load agents', 'error');
            }
            
            if (agentsGrid) agentsGrid.innerHTML = '';
            if (agentsEmptyState) agentsEmptyState.hidden = false;
            updateStatsBar([]);
        } finally {
            if (window.toggleLoader) window.toggleLoader(false);
        }
    }

    function renderAgentsList(agents) {
        if (!agentsGrid || !agentsEmptyState) return;

        if (!agents || agents.length === 0) {
            agentsGrid.innerHTML = '';
            agentsEmptyState.hidden = false;
            return;
        }
        
        agentsEmptyState.hidden = true;

        agentsGrid.innerHTML = agents.map(agent => {
            const stats = agent.stats || {};
            const trendIcon = getTrendIcon(stats.trend_direction);
            const trendClass = getTrendClass(stats.trend_direction);
            const f1Score = (stats.avg_f1_score || 0).toFixed(2);
            
            return `
                <div class="agent-card" data-agent-id="${escapeHTML(agent.agent_id)}" role="button" tabindex="0">
                    <div class="agent-card-header">
                        <div class="agent-avatar"><span class="material-symbols-rounded">person</span></div>
                        <div class="agent-info">
                            <h3 class="agent-name">${escapeHTML(agent.name || 'Unknown')}</h3>
                            <p class="agent-email">${escapeHTML(agent.email || '')}</p>
                        </div>
                        <div class="trend-indicator ${trendClass}"><span class="material-symbols-rounded">${trendIcon}</span></div>
                    </div>
                    <div class="agent-stats">
                        <div class="agent-stat-row"><span class="agent-stat-label">F1 Score</span><span class="agent-stat-value f1-score">${f1Score}</span></div>
                        <div class="agent-stat-row"><span class="agent-stat-label">Audits</span><span class="agent-stat-value">${escapeHTML(stats.total_audits || 0)}</span></div>
                        <div class="agent-stat-row"><span class="agent-stat-label">Risk</span><span class="agent-stat-value risk-flags">${escapeHTML((stats.red_risk_count || 0) + (stats.amber_risk_count || 0))}</span></div>
                    </div>
                    <div class="agent-card-footer">
                        <span class="agent-last-audit">Last: ${escapeHTML(formatDate(stats.last_audit_at))}</span>
                    </div>
                </div>
            `;
        }).join('');

        document.querySelectorAll('.agent-card').forEach(card => {
            card.addEventListener('click', () => loadAgentDetail(card.dataset.agentId));
            card.addEventListener('keydown', (e) => {
                if (e.key === 'Enter' || e.key === ' ') {
                    e.preventDefault();
                    loadAgentDetail(card.dataset.agentId);
                }
            });
        });
    }

    function updateStatsBar(agents) {
        const total = agents.length;
        const avg = total > 0 ? (agents.reduce((s, a) => s + (a.stats?.avg_f1_score || 0), 0) / total).toFixed(2) : '0.00';
        
        if (totalAgentsEl) totalAgentsEl.textContent = total;
        if (avgF1ScoreEl) avgF1ScoreEl.textContent = avg;
        if (improvingCountEl) improvingCountEl.textContent = agents.filter(a => a.stats?.trend_direction === 'improving').length;
        if (decliningCountEl) decliningCountEl.textContent = agents.filter(a => a.stats?.trend_direction === 'declining').length;
    }

    async function loadAgentDetail(agentId) {
        currentAgentId = agentId;
        if (window.toggleLoader) window.toggleLoader(true, 'Loading profile...');
        
        try {
            const data = await window.apiFetch(`/agents/${agentId}`);
            if (data.success) {
                renderAgentDetail(data.agent);
                showDetailView();
            }
        } catch (error) {
            console.error('[Agents] Profile load failed:', error);
            if (window.ErrorHandler) {
                window.ErrorHandler.showError(error);
            } else if (window.SecurityUtils) {
                window.SecurityUtils.showToast('Failed to load agent profile', 'error');
            }
        } finally {
            if (window.toggleLoader) window.toggleLoader(false);
        }
    }

    function renderAgentDetail(agent) {
        const s = agent.stats || {};
        
        if (detailAgentName) {
            detailAgentName.textContent = agent.name || 'Unknown';
            // Accessibility / UX: expose the full name on hover via title and aria-label
            detailAgentName.title = agent.name || '';
            detailAgentName.setAttribute('aria-label', agent.name || 'Agent Name');
        }
        if (detailAgentEmail) {
            detailAgentEmail.textContent = agent.email || '';
            detailAgentEmail.title = agent.email || '';
        }
        if (detailTotalAudits) detailTotalAudits.textContent = s.total_audits || 0;
        if (detailAvgF1) detailAvgF1.textContent = (s.avg_f1_score || 0).toFixed(2);
        
        if (detailTrend) {
            detailTrend.textContent = (s.trend_direction || 'stable').toUpperCase();
            detailTrend.className = `detail-stat-value trend-${s.trend_direction || 'stable'}`;
        }
        
        if (detailRiskFlags) detailRiskFlags.textContent = (s.red_risk_count || 0) + (s.amber_risk_count || 0);

        if (window.Chart) {
            renderF1TrendChart(agent.score_history || []);
            renderQualityRadarChart(s);
        }
        
        renderScoreHistoryTable(agent.score_history || []);
        
        if (reindexAgentBtn) reindexAgentBtn.dataset.agentId = agent.agent_id;
    }

    function renderF1TrendChart(history) {
        const ctx = document.getElementById('f1-trend-chart')?.getContext('2d');
        if (!ctx) return;
        if (f1TrendChart) f1TrendChart.destroy();

        // Ensure history is chronological for standard L-to-R line chart
        const data = history.slice().reverse().map(h => h.f1_score || 0);
        const labels = data.map((_, i) => `A${i+1}`);
        
        // CSS Variable support for themes
        const rootStyles = getComputedStyle(document.documentElement);
        const primaryColor = rootStyles.getPropertyValue('--md-primary').trim() || '#14B8A6';
        const primaryLight = 'rgba(20, 184, 166, 0.1)';

        f1TrendChart = new Chart(ctx, {
            type: 'line',
            data: {
                labels,
                datasets: [{
                    label: 'F1 Score',
                    data,
                    borderColor: primaryColor,
                    backgroundColor: primaryLight,
                    fill: true,
                    tension: 0.4
                }]
            },
            options: { 
                responsive: true, 
                plugins: { legend: { display: false } }, 
                scales: { 
                    y: { min: 0, max: 1 },
                    x: { ticks: { maxTicksLimit: 10 } }
                } 
            }
        });
    }

    function renderQualityRadarChart(stats) {
        const ctx = document.getElementById('quality-radar-chart')?.getContext('2d');
        if (!ctx) return;
        if (qualityRadarChart) qualityRadarChart.destroy();

        const rootStyles = getComputedStyle(document.documentElement);
        const accentColor = rootStyles.getPropertyValue('--md-secondary').trim() || '#a78bfa';
        const accentLight = 'rgba(167, 139, 250, 0.2)';

        qualityRadarChart = new Chart(ctx, {
            type: 'radar',
            data: {
                labels: ['Empathy', 'Efficiency', 'Listening', 'Language', 'Bias'],
                datasets: [{
                    data: [stats.avg_empathy||0, stats.avg_efficiency||0, stats.avg_listening||0, stats.avg_language||0, stats.avg_bias||0],
                    borderColor: accentColor,
                    backgroundColor: accentLight,
                    pointBackgroundColor: accentColor
                }]
            },
            options: { 
                responsive: true, 
                plugins: { legend: { display: false } }, 
                scales: { r: { beginAtZero: true, max: 10, ticks: { display: false } } } 
            }
        });
    }

    function renderScoreHistoryTable(history) {
        const table = document.getElementById('score-history-table');
        if (!table) return;
        
        if (!history.length) {
            table.innerHTML = '<p class="empty-message">No history found</p>';
            return;
        }
        
        table.innerHTML = `
            <table class="audit-history-table">
                <thead><tr><th>Date</th><th>F1</th><th>Risk</th><th>Actions</th></tr></thead>
                <tbody>
                    ${history.slice(0, 10).map(h => `
                        <tr>
                            <td>${escapeHTML(formatDate(h.audited_at))}</td>
                            <td><span class="f1-badge">${(h.f1_score || 0).toFixed(2)}</span></td>
                            <td><span class="risk-badge risk-${(h.compliance_risk || 'green').toLowerCase()}">${escapeHTML(h.compliance_risk || 'Green')}</span></td>
                            <td><a href="/audit?id=${escapeHTML(h.audit_id)}" class="view-audit-link">View</a></td>
                        </tr>
                    `).join('')}
                </tbody>
            </table>
        `;

        // Ensure navigation works: if we're already on the Audit workspace,
        // load the audit in-place; otherwise perform a full navigation to
        // `/audit?id=...` so the audit page renders the dashboard exactly
        // as it appears in the archive view.
        const links = table.querySelectorAll('.view-audit-link');
        links.forEach(link => {
            link.addEventListener('click', (e) => {
                // Allow user to open in new tab/window
                if (e.ctrlKey || e.metaKey || e.button === 1) return;
                e.preventDefault();

                try {
                    const href = link.getAttribute('href') || '';
                    const qs = href.split('?')[1] || '';
                    const params = new URLSearchParams(qs);
                    const auditId = params.get('id');

                    // If we're already on the Audit page, prefer the in-page loader.
                    const onAuditPage = !!document.getElementById('page-audit-main');
                    if (onAuditPage && auditId && typeof window.loadAuditDetails === 'function') {
                        window.loadAuditDetails(auditId);
                        return;
                    }

                    // Otherwise navigate to the audit page so it can render the
                    // full audit dashboard (archive-like experience).
                    if (href) window.location.href = href;
                } catch (err) {
                    const href = link.getAttribute('href');
                    if (href) window.location.href = href;
                }
            });
        });
    }

    function searchAgents(term) {
        const t = term.toLowerCase().trim();
        renderAgentsList(t ? allAgents.filter(a => (a.name||'').toLowerCase().includes(t) || (a.email||'').toLowerCase().includes(t)) : allAgents);
    }

    function sortAgents(sortBy) {
        const sorted = [...allAgents].sort((a, b) => {
            if (sortBy === 'f1_desc') return (b.stats?.avg_f1_score || 0) - (a.stats?.avg_f1_score || 0);
            if (sortBy === 'f1_asc') return (a.stats?.avg_f1_score || 0) - (b.stats?.avg_f1_score || 0);
            if (sortBy === 'name_asc') return (a.name || '').localeCompare(b.name || '');
            if (sortBy === 'audits_desc') return (b.stats?.total_audits || 0) - (a.stats?.total_audits || 0);
            return 0;
        });
        renderAgentsList(sorted);
    }

    async function reindexAgent() {
        if (!currentAgentId) return;
        
        if (window.SecurityUtils && reindexAgentBtn) {
            window.SecurityUtils.setButtonLoading(reindexAgentBtn, true);
        }
        
        try {
            const data = await window.apiFetch(`/agents/${currentAgentId}/reindex`, { method: 'POST' });
            if (data.success) {
                if (window.SecurityUtils) window.SecurityUtils.showToast('Profile reindex queued.', 'success');
                setTimeout(() => loadAgentDetail(currentAgentId), 2000);
            }
        } catch (error) {
            if (window.ErrorHandler) {
                window.ErrorHandler.showError(error);
            } else if (window.SecurityUtils) {
                window.SecurityUtils.showToast('Reindex failed', 'error');
            }
        } finally {
            if (window.SecurityUtils && reindexAgentBtn) {
                window.SecurityUtils.setButtonLoading(reindexAgentBtn, false);
            }
        }
    }

    function showDetailView() { 
        if (agentsListView) agentsListView.classList.remove('active'); 
        if (agentDetailView) agentDetailView.classList.add('active'); 
        window.scrollTo(0,0); 
    }
    
    function showListView() { 
        if (agentDetailView) agentDetailView.classList.remove('active'); 
        if (agentsListView) agentsListView.classList.add('active'); 
        currentAgentId = null; 
    }

    function setupEventListeners() {
        if (agentSearch) agentSearch.addEventListener('input', e => searchAgents(e.target.value));
        if (sortSelect) sortSelect.addEventListener('change', e => sortAgents(e.target.value));
        if (backToListBtn) backToListBtn.addEventListener('click', showListView);
        if (reindexAgentBtn) reindexAgentBtn.addEventListener('click', reindexAgent);
        
        // Auto-load when agents tab is clicked
        const agentsTab = document.querySelector('[data-tab="agents"]');
        if (agentsTab) {
            agentsTab.addEventListener('click', () => {
                // Short timeout to allow panel transition
                setTimeout(() => {
                    if (allAgents.length === 0) loadAgents();
                }, 50);
            });
        }
    }

    // Helpers
    function getTrendIcon(t) { return t === 'improving' ? 'trending_up' : t === 'declining' ? 'trending_down' : 'trending_flat'; }
    function getTrendClass(t) { return `trend-${t || 'stable'}`; }
    function formatDate(d) { return d ? new Date(d).toLocaleDateString() : 'Never'; }

    // Init
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', init);
    } else {
        init();
    }
    
    // Expose reload capability globally
    window.AgentsController = {
        reload: () => loadAgents(),
        showList: showListView
    };

})();