/**
 * ORBIT – Educational Research Assistant
 * FULL V-MASTER SCRIPT - WITH VISION (IMAGE), DOCX SUPPORT & THINKING ILLUSION
 */

document.addEventListener('DOMContentLoaded', () => {
    const $ = id => document.getElementById(id);
    const addEvt = (id, event, handler) => { if($(id)) $(id).addEventListener(event, handler); };
    const safeArr = arr => Array.isArray(arr) ? arr : [];

    let currentSid = null;
    let sessions = {};
    let appSettings = null;
    let isBusy = false;
    
    // Penampung File Universal
    let attachedFile = null; 

    const DEFAULT_OR_MODELS = [
        "baidu/cobuddy:free",  
        "poolside/laguna-xs.2:free",  
        "inclusionai/ring-2.6-1t:free",      
        "z-ai/glm-4.5-air:free",        
        "nvidia/nemotron-3-nano-omni-30b-a3b-reasoning:free",
        "google/gemma-4-26b-a4b-it:free",
        "google/gemma-4-31b-it:free",
        "nvidia/llama-nemotron-embed-vl-1b-v2:free",
        "minimax/minimax-m2.5:free",
        "nousresearch/hermes-3-llama-3.1-405b:free",
        "qwen/qwen3-next-80b-a3b-instruct:free",
        "meta-llama/llama-3.3-70b-instruct:free"
    ];

    // TOAST NOTIFICATION
    function showToast(message, isError = false) {
        let toast = $('orbit-toast');
        if (!toast) {
            toast = document.createElement('div');
            toast.id = 'orbit-toast';
            toast.style.cssText = `
                position: fixed; top: 24px; left: 50%; transform: translate(-50%, -20px);
                padding: 12px 24px; border-radius: 50px; box-shadow: 0 10px 25px rgba(0,0,0,0.2);
                font-size: 14px; font-weight: 600; color: white; z-index: 99999;
                opacity: 0; transition: all 0.3s ease-in-out; display: flex; align-items: center; gap: 8px;
                pointer-events: none;
            `;
            document.body.appendChild(toast);
        }
        
        toast.style.backgroundColor = isError ? '#ef4444' : '#10b981';
        toast.innerHTML = isError ? `<span>❌</span> <span>${message}</span>` : `<span>✅</span> <span>${message}</span>`;
        
        setTimeout(() => { toast.style.opacity = '1'; toast.style.transform = 'translate(-50%, 0)'; }, 10);
        setTimeout(() => { toast.style.opacity = '0'; toast.style.transform = 'translate(-50%, -20px)'; }, 4000);
    }

    try {
        const stored = localStorage.getItem('orbit_sessions_v14');
        sessions = stored ? JSON.parse(stored) : {};
        if (typeof sessions !== 'object' || Array.isArray(sessions)) sessions = {};
    } catch(e) { sessions = {}; }

    const isIOS = /iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream;
    let deferredPrompt;
    
    if ($('btn-install-pwa') && !window.matchMedia('(display-mode: standalone)').matches) {
        $('btn-install-pwa').classList.remove('hidden');
    }

    window.addEventListener('beforeinstallprompt', (e) => { e.preventDefault(); deferredPrompt = e; });

    addEvt('btn-install-pwa', 'click', async () => {
        if (isIOS) {
            alert("Apple iOS memblokir install otomatis.\n\nCara Install PWA di iPhone/iPad:\n1. Tekan ikon 'Share' (kotak dengan panah ke atas) di menu bawah Safari.\n2. Geser ke bawah dan pilih 'Add to Home Screen' (Tambahkan ke Layar Utama).");
        } else if (deferredPrompt) {
            deferredPrompt.prompt();
            const { outcome } = await deferredPrompt.userChoice;
            if(outcome === 'accepted' && $('btn-install-pwa')) $('btn-install-pwa').classList.add('hidden');
            deferredPrompt = null;
        } else {
            alert("Chrome memblokir pop-up otomatis.\n\nCara Install:\nKlik ikon Titik-Tiga (⋮) di pojok kanan atas browser, lalu pilih 'Tambahkan ke Layar Utama' (Add to Home screen).");
        }
    });

    async function init() {
        try {
            const me = await fetch('/api/me', { cache: 'no-store' });
            if(me.status === 401) { window.location.href = '/login'; return; }
            if(me.ok) {
                const user = await me.json();
                if($('user-name')) $('user-name').textContent = user.name || user.email;
                if($('user-avatar') && user.picture) $('user-avatar').src = user.picture;
            }

            const setRes = await fetch('/api/settings', { cache: 'no-store' });
            if(setRes.ok) {
                appSettings = await setRes.json();
                
                appSettings.models_nvidia = safeArr(appSettings.models_nvidia);
                appSettings.models_gemini = safeArr(appSettings.models_gemini);
                appSettings.models_agentrouter = safeArr(appSettings.models_agentrouter);
                appSettings.models_openai = safeArr(appSettings.models_openai);

                if (!localStorage.getItem('orbit_force_free_v6')) {
                    appSettings.models_openrouter = [...DEFAULT_OR_MODELS];
                    localStorage.setItem('orbit_force_free_v6', 'true');
                    fetch('/api/settings', { method: 'POST', headers: {'Content-Type': 'application/json'}, body: JSON.stringify(appSettings) }).catch(err => console.error("Auto-save failed", err));
                } else {
                    appSettings.models_openrouter = safeArr(appSettings.models_openrouter);
                }
            }
        } catch (e) {
            console.error("Init err:", e);
        } finally {
            populateModelSelect();
            const ids = Object.keys(sessions).sort((a,b) => b-a);
            if(ids.length) loadSession(ids[0]); else newSession();
        }
    }

    function save() { try { localStorage.setItem('orbit_sessions_v14', JSON.stringify(sessions)); } catch(e){} }
    function newSession() { const id = Date.now().toString(); sessions[id] = { title: "New Chat", messages: [] }; loadSession(id); }
    addEvt('btn-new-chat', 'click', newSession);

    function loadSession(id) {
        if(!sessions[id]) return;
        currentSid = id;
        
        const cm = $('chat-messages'); const ws = $('welcome-msg');
        if(cm) cm.innerHTML = '';
        
        if(sessions[id].messages && sessions[id].messages.length > 0) {
            if(ws) ws.classList.add('hidden');
            sessions[id].messages.forEach(m => renderBubble(m.role, m.displayContent || m.content));
        } else {
            if(ws) ws.classList.remove('hidden');
        }
        
        renderHistory(); 
        const ca = $('chat-area'); if(ca) ca.scrollTop = ca.scrollHeight;
    }

    function renderHistory() {
        const list = $('history-list'); if(!list) return;
        const ids = Object.keys(sessions).sort((a,b) => b-a);
        if(!ids.length) { list.innerHTML = '<p class="text-xs text-gray-400 px-3 py-2 italic">No recent chats.</p>'; return; }
        list.innerHTML = ids.map(id => {
            const active = (id === currentSid) ? 'bg-accent-light text-accent shadow-sm' : 'text-gray-600 hover:bg-white';
            return `<button onclick="window.ls('${id}')" class="w-full text-left px-3 py-2.5 rounded-xl text-xs truncate font-medium ${active}">${sessions[id].title || "New Chat"}</button>`;
        }).join('');
    }
    window.ls = id => { loadSession(id); if(window.innerWidth < 768) toggleSidebar(); };

    function renderBubble(role, content) {
        const isUser = (role === 'user');
        const wrap = document.createElement('div');
        wrap.className = `flex mb-6 ${isUser ? 'justify-end' : 'justify-start'}`;
        if(isUser) {
            wrap.innerHTML = `<div class="bg-accent text-white p-4 rounded-2xl rounded-tr-none max-w-[85%] text-[15px] leading-relaxed shadow-sm">${content}</div>`;
        } else {
            let html = content; try { html = marked.parse(content); } catch(e) { html = content.replace(/\n/g, '<br>'); }
            wrap.innerHTML = `<div class="flex gap-4 items-start w-full"><img src="/static/icon.png" class="w-8 h-8 rounded-full shadow-sm shrink-0" onerror="this.style.display='none'"><div class="bg-[#f8f9fa] border border-slate-200 p-5 rounded-2xl rounded-tl-none max-w-[90%] md:max-w-[85%] prose-orbit w-full shadow-sm">${html}</div></div>`;
        }
        if($('chat-messages')) { 
            $('chat-messages').appendChild(wrap); 
            const ca = $('chat-area'); if(ca) ca.scrollTop = ca.scrollHeight; 
        }
    }

    async function sendChat() {
        if(isBusy) return;
        const raw = $('chat-textarea').value.trim();
        if(!raw && !attachedFile) return;
        
        $('chat-textarea').value = ''; $('chat-textarea').style.height = 'auto';
        if($('welcome-msg')) $('welcome-msg').classList.add('hidden');
        
        let full = raw; let display = raw.replace(/\n/g, '<br>');
        let payloadImage = null;
        let historyContent = raw; // Khusus buat disimpen di memori lokal biar ga overload

        // JIKA ADA FILE ATTACHED
        if (attachedFile) {
            if (attachedFile.type === 'document') {
                full = `[Document: ${attachedFile.filename}]\n${attachedFile.text}\n\nUser: ${raw}`;
                historyContent = full;
                display = `<div class="bg-emerald-500 text-white text-[10px] px-2 py-1 rounded w-fit mb-2 font-bold flex items-center gap-1"><svg class="w-3 h-3" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M15.172 7l-6.586 6.586a2 2 0 102.828 2.828l6.414-6.586a4 4 0 00-5.656-5.656l-6.415 6.585a6 6 0 108.486 8.486L20.5 13"></path></svg>${attachedFile.filename}</div>${display}`;
            } else if (attachedFile.type === 'image') {
                payloadImage = { base64: attachedFile.base64, mime: attachedFile.mime };
                historyContent = `[Gambar Diunggah: ${attachedFile.filename}]\n\n${raw}`; // Base64 ga kita simpen ke localstorage biar ga crash HP user
                display = `<div class="mb-2"><img src="data:${attachedFile.mime};base64,${attachedFile.base64}" class="max-h-[200px] rounded-xl border border-gray-200 shadow-sm bg-white" /></div>${display}`;
            }
            attachedFile = null;
            $('attach-badge').classList.add('hidden');
            $('pdf-input').value = '';
        }

        if(!sessions[currentSid].messages || !sessions[currentSid].messages.length) sessions[currentSid].title = raw.slice(0, 20) || "New Chat";
        sessions[currentSid].messages.push({ role: 'user', content: historyContent, displayContent: display });
        renderBubble('user', display);
        
        isBusy = true; $('btn-send').disabled = true;
        
        // --- ANIMASI KERANGKA BERPIKIR ---
        const loadId = 'load-' + Date.now();
        const textId = 'text-' + Date.now();
        const thinkingSteps = [
            "Memahami konteks pertanyaan...",
            "Memindai literatur dan referensi yang relevan...",
            "Mengekstrak poin-poin penting...",
            "Menyusun kerangka sintesis...",
            "Menyempurnakan tata bahasa..."
        ];

        if($('chat-messages')) { 
            $('chat-messages').insertAdjacentHTML('beforeend', `
                <div id="${loadId}" class="flex mb-8 gap-4 items-start">
                    <img src="/static/icon.png" class="w-8 h-8 rounded-full shadow-sm shrink-0">
                    <div class="bg-white border border-gray-200 px-5 py-4 rounded-[24px] rounded-tl-[8px] shadow-sm flex flex-col gap-2 min-w-[220px]">
                        <div class="flex items-center gap-3 text-accent text-sm font-bold">
                            <svg class="w-4 h-4 animate-spin" fill="none" viewBox="0 0 24 24"><circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle><path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8v8H4z"></path></svg>
                            Thinking Process
                        </div>
                        <div id="${textId}" class="text-xs font-semibold text-gray-500 animate-pulse pl-7 border-l-2 border-gray-200 ml-1.5 mt-1">Memulai inisialisasi...</div>
                    </div>
                </div>
            `); 
            const ca = $('chat-area'); if(ca) ca.scrollTop = ca.scrollHeight; 
        }

        let stepIndex = 0;
        const thinkingInterval = setInterval(() => {
            const txtEl = $(textId);
            if(txtEl) {
                txtEl.textContent = thinkingSteps[stepIndex % thinkingSteps.length];
                stepIndex++;
            }
        }, 2200);

        try {
            const res = await fetch('/api/chat', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ 
                    prompt: full, 
                    model: $('model-select').value, 
                    messages: sessions[currentSid].messages.slice(0,-1),
                    image: payloadImage // Ngirim payload ke backend
                })
            });
            const data = await res.json();
            
            clearInterval(thinkingInterval);
            if($(loadId)) $(loadId).remove();
            
            if(!res.ok) throw new Error(data.error || "Server error");
            sessions[currentSid].messages.push({ role: 'assistant', content: data.reply });
            renderBubble('assistant', data.reply);
            save(); renderHistory();
        } catch(e) {
            clearInterval(thinkingInterval);
            if($(loadId)) $(loadId).remove();
            renderBubble('assistant', `**Error:** ${e.message}`);
        } finally { isBusy = false; $('btn-send').disabled = false; }
    }

    addEvt('btn-send', 'click', sendChat);
    addEvt('chat-textarea', 'keydown', e => { if(e.key === 'Enter' && !e.shiftKey) { e.preventDefault(); sendChat(); } });
    if($('chat-textarea')) $('chat-textarea').addEventListener('input', function() { this.style.height = 'auto'; this.style.height = Math.min(this.scrollHeight, 160) + 'px'; });

    const provMap = { "OpenRouter": "or", "Nvidia NIM": "nv", "Google Gemini": "gem", "AgentRouter": "ar", "Custom OpenAI": "oai" };

    function syncProviderUI() {
        const prov = $('settings-provider').value;
        document.querySelectorAll('.prov-sec').forEach(el => el.classList.add('hidden'));
        const secId = provMap[prov];
        if(secId && $(`sec-${secId}`)) $(`sec-${secId}`).classList.remove('hidden');
    }

    function populateModelSelect() {
        const ms = $('model-select'); if(!ms) return;
        ms.innerHTML = "";
        let list = ["gemini-1.5-pro-latest", "gemini-1.5-flash-latest"];
        if(appSettings) {
            const mapKey = { "OpenRouter": "models_openrouter", "Nvidia NIM": "models_nvidia", "Google Gemini": "models_gemini", "AgentRouter": "models_agentrouter", "Custom OpenAI": "models_openai" };
            const k = mapKey[appSettings.provider];
            if(appSettings[k] && appSettings[k].length > 0) list = appSettings[k];
        }
        list.forEach(m => { const opt = document.createElement('option'); opt.value = m; opt.textContent = m; if(appSettings && m === appSettings.current_model) opt.selected = true; ms.appendChild(opt); });
    }

    function renderDynamicLists() {
        if(!appSettings) return;
        const draw = (arr, listId, k) => {
            const lst = $(listId); if(!lst) return;
            lst.innerHTML = safeArr(arr).map((m,i) => `<div class="flex items-center justify-between px-2 py-1.5 rounded hover:bg-white group"><span class="text-xs truncate flex-1">${m}</span><button data-i="${i}" data-k="${k}" class="btn-del text-red-400 font-bold ml-2">✕</button></div>`).join('');
            lst.querySelectorAll('.btn-del').forEach(b => {
                b.addEventListener('click', function() { appSettings[this.dataset.k].splice(Number(this.dataset.i), 1); renderDynamicLists(); });
            });
        };
        draw(appSettings.models_openrouter, 'list-or', 'models_openrouter');
        draw(appSettings.models_nvidia, 'list-nv', 'models_nvidia');
        draw(appSettings.models_gemini, 'list-gem', 'models_gemini');
        draw(appSettings.models_agentrouter, 'list-ar', 'models_agentrouter');
        draw(appSettings.models_openai, 'list-oai', 'models_openai');
    }

    addEvt('btn-settings', 'click', () => {
        if(appSettings) {
            $('settings-provider').value = appSettings.provider || "OpenRouter";
            $('settings-apikey').value = appSettings.api_key || "";
            $('settings-url').value = appSettings.base_url || "";
            renderDynamicLists();
            syncProviderUI();
        }
        $('settings-modal').classList.remove('hidden');
        if(window.innerWidth < 768) toggleSidebar();
    });
    addEvt('btn-close-settings', 'click', () => $('settings-modal').classList.add('hidden'));
    addEvt('btn-cancel-settings', 'click', () => $('settings-modal').classList.add('hidden'));

    addEvt('settings-provider', 'change', () => {
        const prov = $('settings-provider').value;
        const urls = { "OpenRouter": "https://openrouter.ai/api/v1/chat/completions", "Nvidia NIM": "https://integrate.api.nvidia.com/v1/chat/completions", "Google Gemini": "https://generativelanguage.googleapis.com/v1beta/models/", "AgentRouter": "https://agentrouter.org/v1/chat/completions" };
        if (urls[prov] && $('settings-url')) $('settings-url').value = urls[prov];
        syncProviderUI();
    });

    addEvt('btn-toggle-key', 'click', () => { const inp = $('settings-apikey'); if(inp) inp.type = inp.type === 'password' ? 'text' : 'password'; });

    const bindAdd = (btnId, inpId, listKey) => {
        const f = () => {
            const val = $(inpId)?.value.trim();
            if(!val || !appSettings) return;
            if(!Array.isArray(appSettings[listKey])) appSettings[listKey] = [];
            if(!appSettings[listKey].includes(val)) { appSettings[listKey].push(val); $(inpId).value = ""; renderDynamicLists(); }
        };
        addEvt(btnId, 'click', f);
        if($(inpId)) $(inpId).addEventListener('keydown', e => { if(e.key==='Enter') f(); });
    };
    bindAdd('btn-add-or', 'inp-or', 'models_openrouter');
    bindAdd('btn-add-nv', 'inp-nv', 'models_nvidia');
    bindAdd('btn-add-gem', 'inp-gem', 'models_gemini');
    bindAdd('btn-add-ar', 'inp-ar', 'models_agentrouter');
    bindAdd('btn-add-oai', 'inp-oai', 'models_openai');

    addEvt('btn-save-settings', 'click', async () => {
        const btn = $('btn-save-settings');
        const originalText = btn.textContent;
        
        btn.innerHTML = `<svg class="w-4 h-4 animate-spin inline mr-2" fill="none" viewBox="0 0 24 24"><circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle><path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8v8H4z"></path></svg>Saving...`;
        btn.disabled = true;

        const payload = {
            provider: $('settings-provider').value,
            base_url: $('settings-url').value,
            api_key: $('settings-apikey').value,
            models_openrouter: safeArr(appSettings.models_openrouter),
            models_nvidia: safeArr(appSettings.models_nvidia),
            models_gemini: safeArr(appSettings.models_gemini),
            models_agentrouter: safeArr(appSettings.models_agentrouter),
            models_openai: safeArr(appSettings.models_openai),
            current_model: $('model-select').value
        };

        try {
            const res = await fetch('/api/settings', { 
                method: 'POST', 
                headers: {'Content-Type': 'application/json'}, 
                body: JSON.stringify(payload) 
            });
            
            if(res.ok) { 
                appSettings = await res.json(); 
                populateModelSelect(); 
                
                setTimeout(() => {
                    $('settings-modal').classList.add('hidden');
                    showToast("Settings saved successfully!");
                }, 300);

            } else {
                throw new Error("Gagal terhubung ke database server");
            }
        } catch(e) { 
            console.error(e);
            showToast(`Error: ${e.message}`, true); 
        } finally {
            setTimeout(() => { btn.textContent = originalText; btn.disabled = false; }, 300);
        }
    });

    // 7. DOI MODAL
    addEvt('btn-doi', 'click', () => {
        $('doi-modal').classList.remove('hidden');
        if($('doi-input')) { $('doi-input').value = ""; $('doi-input').focus(); }
        if($('doi-result')) $('doi-result').classList.add('hidden');
        if(window.innerWidth < 768) toggleSidebar();
    });
    addEvt('btn-close-doi', 'click', () => $('doi-modal').classList.add('hidden'));
    
    if($('doi-input')) {
        $('doi-input').addEventListener('keydown', e => {
            if(e.key === 'Enter') {
                e.preventDefault();
                if($('btn-validate-doi-submit')) $('btn-validate-doi-submit').click();
            }
        });
    }

    addEvt('btn-validate-doi-submit', 'click', async () => {
        const doi = $('doi-input').value.trim(); if(!doi) return;
        $('doi-result').classList.remove('hidden'); $('doi-result').innerHTML = "Validating...";
        try {
            const res = await fetch('/api/validate_doi', { method: 'POST', headers: {'Content-Type': 'application/json'}, body: JSON.stringify({doi}) });
            const d = await res.json();
            if(!res.ok || d.error) $('doi-result').innerHTML = `<p class="text-red-500 font-medium">Error: ${d.error || "Gagal"}</p>`; 
            else $('doi-result').innerHTML = `<div class="space-y-2"><div><p class="text-[10px] font-semibold text-gray-400 uppercase">Title</p><p class="font-medium text-gray-800 text-sm">${d.title}</p></div><div><p class="text-[10px] font-semibold text-gray-400 uppercase">Authors</p><p class="text-sm text-gray-700">${d.authors}</p></div><div class="flex gap-6"><div><p class="text-[10px] font-semibold text-gray-400 uppercase">Year</p><p class="text-sm text-gray-700">${d.year}</p></div><div><p class="text-[10px] font-semibold text-gray-400 uppercase">Type</p><p class="text-sm text-gray-700">${d.type}</p></div></div><div><p class="text-[10px] font-semibold text-gray-400 uppercase">Source</p><p class="text-sm text-gray-700">${d.journal}</p></div></div>`;
        } catch(e) {
            $('doi-result').innerHTML = `<p class="text-red-500 font-medium">Error: ${e.message}</p>`; 
        }
    });

    function toggleSidebar() { $('sidebar').classList.toggle('-translate-x-full'); $('sidebar-overlay').classList.toggle('hidden'); }
    addEvt('btn-hamburger', 'click', toggleSidebar); addEvt('btn-close-sidebar', 'click', toggleSidebar); addEvt('sidebar-overlay', 'click', toggleSidebar);

    function clr() {
        if(!currentSid) return; sessions[currentSid].messages = []; sessions[currentSid].title = "New Chat"; save(); loadSession(currentSid);
    }
    addEvt('btn-clear-chat-top', 'click', clr); addEvt('btn-clear-chat-mobile', 'click', clr);

    // 8. LOGIKA UPLOAD MULTI-FILE 
    addEvt('btn-attach', 'click', () => $('pdf-input').click());
    addEvt('btn-remove-attach', 'click', () => { attachedFile = null; $('attach-badge').classList.add('hidden'); $('pdf-input').value = ''; });
    
    if($('pdf-input')) {
        $('pdf-input').addEventListener('change', async e => {
            const f = e.target.files[0]; if(!f) return; 
            
            // VALIDASI EKSTENSI (GUE TAMBAHIN DISINI SESUAI MINTA LU)
            const allowed = ['pdf', 'doc', 'docx', 'jpg', 'jpeg', 'png'];
            const ext = f.name.split('.').pop().toLowerCase();
            
            if(!allowed.includes(ext)) {
                showToast("Error: Ekstensi file tidak valid atau tidak diterima!", true);
                $('pdf-input').value = ''; // Reset inputnya
                return;
            }

            const fd = new FormData(); fd.append('file', f);
            $('attach-badge').classList.remove('hidden'); 
            $('attach-name').textContent = "Memproses file...";
            
            try {
                // Tembak ke endpoint yang udah gue update di app.py
                const res = await fetch('/api/upload_file', { method: 'POST', body: fd });
                const d = await res.json();
                
                if(res.ok) { 
                    attachedFile = d; // Nampung data (text atau gambar base64)
                    $('attach-name').textContent = d.filename; 
                } else { 
                    showToast(d.error || "Gagal mengunggah file.", true); 
                    $('attach-badge').classList.add('hidden'); 
                    $('pdf-input').value = '';
                }
            } catch(e) { 
                showToast(e.message, true); 
                $('attach-badge').classList.add('hidden'); 
                $('pdf-input').value = '';
            }
        });
    }

    init();
});