import os
import logging
import time
import random
from datetime import timedelta
import secrets
from functools import wraps
from flask import Flask, render_template, request, jsonify, session, redirect, url_for
from flask_cors import CORS
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address
from flask_wtf.csrf import CSRFProtect
from openai import OpenAI
from scripts.database import DatabaseManager
from scripts.rag_helper import RAGHelper

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = Flask(__name__)

# ------------------------------------------------------------
# Critical session cookie settings for HTTPS (Hugging Face Spaces)
# ------------------------------------------------------------
app.config.update(
    SECRET_KEY=os.environ.get('SECRET_KEY', secrets.token_urlsafe(32)),
    SESSION_COOKIE_SECURE=True,               # Required for HTTPS
    SESSION_COOKIE_HTTPONLY=True,
    SESSION_COOKIE_SAMESITE='None',           # Allow cross-site (needed for Spaces)
    PERMANENT_SESSION_LIFETIME=timedelta(hours=24),
    SESSION_COOKIE_NAME='tmc_session',
    WTF_CSRF_CHECK_DEFAULT=False              # Disable global CSRF (we use per‑route exemption)
)

# CORS with credentials support – allow your Space domain or '*' for testing
CORS(app, supports_credentials=True, origins=["https://moderator404-chatbot.hf.space"])
csrf = CSRFProtect(app)
limiter = Limiter(key_func=get_remote_address, app=app, default_limits=["1000 per hour", "100 per minute"])

db = DatabaseManager()
rag_helper = RAGHelper(use_vector_search=True)

# ---------- Hugging Face Inference Providers (OpenAI-compatible) ----------
HF_TOKEN = os.environ.get('HF_TOKEN')
HUGGINGFACE_MODEL = "google/gemma-4-26B-A4B-it:novita"   # or any other supported model
API_BASE_URL = "https://router.huggingface.co/v1"

if HF_TOKEN and HF_TOKEN != "dummy":
    hf_client = OpenAI(base_url=API_BASE_URL, api_key=HF_TOKEN)
else:
    hf_client = None
    logger.warning("HF_TOKEN not set. Using mock responses only.")

# ---------- Mock response fallback (for when HF API is unavailable) ----------
def mock_response(message, rag_context, ticket_context):
    msg_lower = message.lower()
    if rag_context:
        first_line = rag_context.split('\n')[0]
        if len(first_line) > 20:
            return f"Based on our knowledge base: {first_line[:200]}"
    if any(w in msg_lower for w in ['cable','usb-c','hdmi','lightning']):
        return "We offer high-quality cables with lifetime warranty. Check our products page for details."
    if any(w in msg_lower for w in ['return','refund','warranty']):
        return "30-day money-back guarantee and lifetime warranty on all cables. Contact support for returns."
    if any(w in msg_lower for w in ['shipping','delivery']):
        return "Free shipping on orders over $25. Most orders ship same-day."
    if any(w in msg_lower for w in ['hello','hi','hey']):
        return "Hello! I'm TMCBot. How can I help you today?"
    return "I'm here to help with cables, orders, and technical support. Could you provide more details?"

# -------------------------------------------------------------------
# ChatBot class
# -------------------------------------------------------------------
class ChatBot:
    def __init__(self, db_manager):
        self.db_manager = db_manager

    def get_configured_model(self):
        return HUGGINGFACE_MODEL

    def send_message(self, message, conversation_id=None, user_id=None, session_id=None):
        if conversation_id is None:
            conversation_id = self.db_manager.create_conversation(user_id=user_id, session_id=session_id)
        self.db_manager.add_message(conversation_id, 'user', message)

        # Get RAG and ticket context
        rag_context = rag_helper.get_relevant_context(message)
        ticket_context, tickets_found = self.get_controlled_ticket_context(message, user_id)

        # Build system prompt
        system_msg = "You are a helpful customer service agent for Too Many Cables. Answer concisely in 1-2 sentences."
        if rag_context:
            system_msg += f"\nRelevant info: {rag_context[:400]}"
        if ticket_context and tickets_found:
            system_msg += f"\nTicket info: {ticket_context}"

        bot_response = None
        api_worked = False

        # Try Hugging Face API if client available
        if hf_client:
            try:
                completion = hf_client.chat.completions.create(
                    model=HUGGINGFACE_MODEL,
                    messages=[
                        {"role": "system", "content": system_msg},
                        {"role": "user", "content": message}
                    ],
                    temperature=0.3,
                    max_tokens=150,
                    top_p=0.9,
                )
                bot_response = completion.choices[0].message.content.strip()
                if bot_response:
                    api_worked = True
                    logger.info("HF Router API returned a response")
                else:
                    bot_response = None
            except Exception as e:
                logger.warning(f"HF Router API exception: {e}")

        # Fallback to mock
        if not api_worked:
            bot_response = mock_response(message, rag_context, ticket_context)
            logger.info("Using mock response (API unavailable)")

        self.db_manager.add_message(conversation_id, 'assistant', bot_response, model_used=HUGGINGFACE_MODEL)
        return {
            'success': True,
            'response': bot_response,
            'conversation_id': conversation_id,
            'response_time_ms': 0,
            'rag_used': bool(rag_context),
            'rag_context_length': len(rag_context),
            'tickets_used': tickets_found
        }

    def get_conversation(self, conversation_id):
        return self.db_manager.get_conversation_history(conversation_id)

    def clear_conversation(self, conversation_id):
        with self.db_manager.get_connection() as conn:
            conn.execute("UPDATE conversations SET is_active = 0 WHERE id = ?", (conversation_id,))
            conn.commit()
        return True

    def get_controlled_ticket_context(self, message, user_id):
        import re
        ticket_matches = re.findall(r'TMC-\d{6}', message.upper())
        if not ticket_matches and not any(k in message.lower() for k in ['ticket','tickets']):
            return None, False
        if not user_id:
            return "Please log in to view your tickets.", True
        conn = self.db_manager.get_connection()
        cursor = conn.cursor()
        if ticket_matches:
            tn = ticket_matches[0]
            cursor.execute("SELECT ticket_number, status, priority, category, description, created_at FROM support_tickets WHERE ticket_number=? AND user_id=?", (tn, user_id))
            t = cursor.fetchone()
            conn.close()
            if t:
                return f"Ticket {t['ticket_number']}: {t['status']}, {t['priority']} priority. Created {t['created_at']}. Description: {t['description']}", True
            return f"Ticket {tn} not found.", True
        else:
            cursor.execute("SELECT ticket_number, status, priority, category, created_at FROM support_tickets WHERE user_id=? AND status!='closed' ORDER BY created_at DESC LIMIT 5", (user_id,))
            tickets = cursor.fetchall()
            conn.close()
            if not tickets:
                return "You have no open tickets.", True
            result = "Your recent tickets:\n" + "\n".join(f"- {t['ticket_number']}: {t['status']} ({t['priority']}) - {t['category']}" for t in tickets)
            return result, True

    def get_user_ticket_context(self, user_id):
        if not user_id:
            return None
        conn = self.db_manager.get_connection()
        cursor = conn.cursor()
        cursor.execute("SELECT ticket_number, subject, status, priority, category, created_at FROM support_tickets WHERE user_id=? AND status!='closed' ORDER BY created_at DESC", (user_id,))
        tickets = cursor.fetchall()
        conn.close()
        return {"tickets": [dict(t) for t in tickets], "user_name": "Customer"}

    def create_ticket_from_chat(self, user_id, subject, description, category, priority, conversation_id):
        return self.db_manager.create_support_ticket(user_id, subject, description, category, conversation_id, priority)

    def add_conversation_summary_to_tickets(self, conversation_id):
        logger.info(f"Summary for conversation {conversation_id} would be added here.")
        return True

chatbot = ChatBot(db)

# -------------------------------------------------------------------
# Authentication helpers
# -------------------------------------------------------------------
def is_authenticated():
    sid = session.get('session_id')
    uid = session.get('user_id')
    if not sid or not uid:
        return False
    user = db.get_user_by_session(sid)
    return user and user['id'] == uid

def require_auth(f):
    @wraps(f)
    def decorated(*args, **kwargs):
        if not is_authenticated():
            return jsonify({'success': False, 'error': 'Authentication required'}), 401
        return f(*args, **kwargs)
    return decorated

def require_role(role):
    def decorator(f):
        @wraps(f)
        def decorated(*args, **kwargs):
            uid = session.get('user_id')
            if not uid:
                return jsonify({'error': 'Auth required'}), 401
            user_role = db.get_user_role(uid)
            if user_role != role:
                return jsonify({'error': 'Insufficient privileges'}), 403
            return f(*args, **kwargs)
        return decorated
    return decorator

# -------------------------------------------------------------------
# Web Routes
# -------------------------------------------------------------------
@app.route('/')
def homepage():
    return render_template('homepage.html')

@app.route('/products')
def products():
    return render_template('products.html')

@app.route('/chat')
def chat():
    cache_bust = int(time.time())
    return render_template('chat.html', configured_model=chatbot.get_configured_model(), cache_bust=cache_bust)

@app.route('/tickets')
def tickets():
    return render_template('tickets.html')

@app.route('/admin')
def admin():
    return redirect(url_for('admin_tickets'))

@app.route('/admin/tickets')
@require_role('admin')
def admin_tickets():
    return render_template('admin_tickets.html')

# -------------------------------------------------------------------
# API Endpoints (all exempt from CSRF)
# -------------------------------------------------------------------
@app.route('/api/chat', methods=['POST'])
@csrf.exempt
def api_chat():
    data = request.get_json()
    message = data.get('message')
    conv_id = data.get('conversation_id')
    if not message:
        return jsonify({'success': False, 'error': 'Message required'}), 400
    result = chatbot.send_message(message, conv_id, session.get('user_id'), session.get('session_id'))
    return jsonify(result)

@app.route('/api/conversation/<conversation_id>')
def get_conversation(conversation_id):
    return jsonify({'success': True, 'messages': chatbot.get_conversation(conversation_id)})

@app.route('/api/conversation/<conversation_id>/clear', methods=['POST'])
@csrf.exempt
def clear_conversation(conversation_id):
    return jsonify({'success': chatbot.clear_conversation(conversation_id)})

@app.route('/api/conversation/end', methods=['POST'])
@csrf.exempt
def end_conversation():
    data = request.get_json()
    conv_id = data.get('conversation_id')
    if conv_id:
        chatbot.add_conversation_summary_to_tickets(conv_id)
    return jsonify({'success': True, 'message': 'Conversation ended'})

@app.route('/api/login', methods=['POST'])
@csrf.exempt
def login():
    data = request.get_json()
    user = db.authenticate_user(data.get('email'), data.get('password'))
    if user:
        sid = db.create_session(user['id'], request.remote_addr, request.headers.get('User-Agent', ''))
        session['user_id'] = user['id']
        session['session_id'] = sid
        return jsonify({'success': True, 'user': {'id': user['id'], 'email': user['email'], 'name': f"{user['first_name']} {user['last_name']}"}})
    return jsonify({'success': False, 'error': 'Invalid credentials'}), 401

@app.route('/api/register', methods=['POST'])
@csrf.exempt
def register():
    data = request.get_json()
    uid = db.create_user(data['email'], data['first_name'], data['last_name'], data['password'], data.get('phone'), data.get('company'))
    if uid:
        return jsonify({'success': True})
    return jsonify({'success': False, 'error': 'Email exists'}), 409

@app.route('/api/user')
def get_user():
    if not is_authenticated():
        return jsonify({'authenticated': False})
    uid = session['user_id']
    conn = db.get_connection()
    cur = conn.cursor()
    cur.execute("SELECT id, email, first_name, last_name FROM users WHERE id = ?", (uid,))
    u = cur.fetchone()
    conn.close()
    if u:
        return jsonify({'authenticated': True, 'user': {'id': u[0], 'email': u[1], 'name': f"{u[2]} {u[3]}"}})
    return jsonify({'authenticated': False})

@app.route('/api/logout', methods=['POST'])
@csrf.exempt
def logout():
    session.clear()
    return jsonify({'success': True})

@app.route('/api/tickets/create', methods=['POST'])
@require_auth
@csrf.exempt
def create_ticket():
    data = request.get_json()
    tn = db.create_support_ticket(
        session['user_id'], data['subject'], data['description'],
        data.get('category', 'General'), data.get('conversation_id'), data.get('priority', 'medium')
    )
    return jsonify({'success': True, 'ticket_number': tn})

@app.route('/api/tickets/user')
@require_auth
def get_user_tickets():
    tickets = db.get_user_tickets(session['user_id'])
    return jsonify({'success': True, 'tickets': tickets})

@app.route('/api/tickets/<ticket_number>')
@require_auth
def get_ticket(ticket_number):
    ticket = db.get_ticket_by_number(ticket_number)
    if not ticket or ticket['user_id'] != session['user_id']:
        return jsonify({'error': 'Not found'}), 404
    updates = db.get_ticket_updates(ticket['id'])
    return jsonify({'success': True, 'ticket': ticket, 'updates': updates})

@app.route('/api/tickets/<int:ticket_id>/update', methods=['POST'])
@require_auth
@csrf.exempt
def add_ticket_update(ticket_id):
    data = request.get_json()
    db.add_ticket_update(ticket_id, session['user_id'], data['message'], 'note')
    return jsonify({'success': True})

@app.route('/api/chat/user-tickets')
@require_auth
def chat_user_tickets():
    ctx = chatbot.get_user_ticket_context(session['user_id'])
    return jsonify({'success': True, 'tickets': ctx['tickets'] if ctx else []})

@app.route('/api/chat/create-ticket', methods=['POST'])
@require_auth
@csrf.exempt
def chat_create_ticket():
    data = request.get_json()
    tn = chatbot.create_ticket_from_chat(
        session['user_id'],
        data['subject'],
        data['description'],
        data.get('category', 'General'),
        data.get('priority', 'medium'),
        data.get('conversation_id')
    )
    return jsonify({'success': True, 'ticket_number': tn, 'message': f'Ticket {tn} created'})

@app.route('/api/health')
def health():
    return jsonify({'status': 'healthy', 'model': HUGGINGFACE_MODEL})

@app.route('/api/knowledge-base/stats')
def kb_stats():
    return jsonify(rag_helper.get_knowledge_base_stats())

@app.route('/api/admin/tickets')
@require_role('admin')
def admin_get_tickets():
    tickets = db.get_tickets_by_status('', limit=100)
    return jsonify({'success': True, 'tickets': tickets})

@app.route('/api/admin/tickets/stats')
@require_role('admin')
def admin_ticket_stats():
    with db.get_connection() as conn:
        cur = conn.cursor()
        cur.execute("SELECT COUNT(*) as total FROM support_tickets")
        total = cur.fetchone()['total']
        cur.execute("SELECT COUNT(*) as open FROM support_tickets WHERE status='open'")
        open_t = cur.fetchone()['open']
        cur.execute("SELECT COUNT(*) as in_progress FROM support_tickets WHERE status='in_progress'")
        in_prog = cur.fetchone()['in_progress']
        cur.execute("SELECT COUNT(*) as resolved FROM support_tickets WHERE status='resolved'")
        resolved = cur.fetchone()['resolved']
        return jsonify({'success': True, 'stats': {'overall': {'total_tickets': total, 'open_tickets': open_t, 'in_progress_tickets': in_prog, 'resolved_tickets': resolved}}})

@app.route('/api/tickets/categories')
def ticket_categories():
    with db.get_connection() as conn:
        cur = conn.cursor()
        cur.execute("SELECT name, description FROM ticket_categories WHERE is_active=1")
        cats = [dict(row) for row in cur.fetchall()]
        return jsonify({'success': True, 'categories': cats})

@app.route('/api/admin/tickets/<int:ticket_id>/assign', methods=['PUT'])
@require_role('admin')
@csrf.exempt
def admin_assign_ticket(ticket_id):
    data = request.get_json()
    agent = data.get('assigned_agent')
    with db.get_connection() as conn:
        conn.execute("UPDATE support_tickets SET assigned_agent = ? WHERE id = ?", (agent, ticket_id))
        conn.commit()
    return jsonify({'success': True})

@app.route('/api/admin/tickets/<int:ticket_id>/status', methods=['PUT'])
@require_role('admin')
@csrf.exempt
def admin_update_status(ticket_id):
    data = request.get_json()
    new_status = data.get('status')
    notes = data.get('resolution_notes', '')
    with db.get_connection() as conn:
        conn.execute("UPDATE support_tickets SET status = ?, resolution_notes = ? WHERE id = ?", (new_status, notes, ticket_id))
        conn.commit()
    return jsonify({'success': True})

@app.route('/api/admin/tickets/<int:ticket_id>/reply', methods=['POST'])
@require_role('admin')
@csrf.exempt
def admin_add_reply(ticket_id):
    data = request.get_json()
    message = data.get('message')
    is_internal = data.get('is_internal', False)
    db.add_ticket_update(ticket_id, session['user_id'], message, 'admin_reply', is_internal)
    return jsonify({'success': True})

@app.route('/api/product/<product_name>')
def get_product_specs(product_name):
    import os
    path = f"knowledge_base/product_manuals/{product_name}.md"
    if os.path.exists(path):
        with open(path, 'r', encoding='utf-8') as f:
            return jsonify({'success': True, 'specifications': f.read()})
    return jsonify({'success': False, 'error': 'Product not found'}), 404

# -------------------------------------------------------------------
# Debug endpoint (optional)
# -------------------------------------------------------------------
@app.route('/api/debug-headers')
def debug_headers():
    return jsonify(dict(request.headers))

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=7860, debug=False)