import os
import logging

from flask import (Blueprint, render_template, redirect, url_for,
                   flash, request, current_app, jsonify, abort)
from flask_login import login_required, current_user

from app import db
from app.models.support import (SupportTicket, SupportTicketReply,
                                SupportChatSession, SupportChatMessage)
from app.models.user import User
from app.models.facility import Facility
from app.utils.decorators import supervisor_required
from app.utils.scope import get_customer_scope
from app.utils.audit import log_action, ACTION_CREATE, ACTION_UPDATE
from app.utils.time_utils import now_eastern
from app.utils.notifications import notify

bp = Blueprint('support', __name__, url_prefix='/support')
logger = logging.getLogger(__name__)

# ── Groq system prompt ────────────────────────────────────────────────────────

_SYSTEM_PROMPT = """\
You are JQC Support, a friendly assistant for customers of JQC (Janitorial Quality Control), \
a commercial cleaning quality management platform.

Help customers with:
- Navigating the portal: Dashboard, Inspections, Issues, Reports pages
- Inspection scores: 90%+ = Excellent, 70-89% = Satisfactory, below 70% = Needs Improvement
- SLA timelines: Critical issues = 4 h, High = 24 h, Medium = 72 h, Low = 168 h
- Issue statuses: Open → In Progress → Pending Verification → Resolved
- Following issues to receive email/in-app update notifications
- Reporting new cleaning concerns via the Issues > Log Issue page
- Understanding facility scorecards and trend charts in Reports

Rules:
- Keep answers concise (3-5 sentences max) and friendly.
- Never invent specific staff names, contract prices, schedules, or contact numbers.
- If the customer has an access problem, billing question, or a concern you genuinely \
cannot resolve through guidance, say so clearly and suggest they click \
"Submit to Support" to reach the admin team directly.\
"""

# Preset FAQ questions shown as quick-reply chips on first load
FAQS = [
    {'icon': 'bi-clipboard-check',  'text': 'How do I view my inspection reports?'},
    {'icon': 'bi-graph-up',         'text': 'What do inspection scores mean?'},
    {'icon': 'bi-exclamation-circle','text': 'How do I track an open issue?'},
    {'icon': 'bi-megaphone',        'text': 'How do I report a cleaning concern?'},
    {'icon': 'bi-alarm',            'text': 'What is SLA and how does it work?'},
    {'icon': 'bi-bell',             'text': 'How do I get notified on issue updates?'},
]


# ── Customer chat page ────────────────────────────────────────────────────────

@bp.route('/chat')
@login_required
def chat():
    if current_user.role != 'customer':
        return redirect(url_for('support.admin_tickets'))

    cids = get_customer_scope(current_user) or []
    facilities = (Facility.query
                  .filter(Facility.id.in_(cids), Facility.active == True)
                  .order_by(Facility.name).all()) if cids else []

    # Load the customer's most recent conversation so it continues on return.
    # A ?new=1 param (New conversation button) starts a fresh, empty window.
    start_new = request.args.get('new')
    session = None
    if not start_new:
        session = (SupportChatSession.query
                   .filter_by(customer_id=current_user.id)
                   .order_by(SupportChatSession.updated_at.desc())
                   .first())
    chat_history = []
    if session:
        chat_history = [
            {'role': m.role, 'content': m.content}
            for m in session.messages.order_by(SupportChatMessage.created_at.asc()).all()
        ]

    groq_ready = bool(os.environ.get('GROQ_API_KEY'))
    return render_template('support/chat.html',
                           faqs=FAQS,
                           facilities=facilities,
                           groq_ready=groq_ready,
                           chat_session_id=(session.id if session else None),
                           chat_history=chat_history)


# ── Groq chat AJAX endpoint ───────────────────────────────────────────────────

@bp.route('/chat/message', methods=['POST'])
@login_required
def chat_message():
    if current_user.role != 'customer':
        return jsonify({'error': 'Forbidden'}), 403

    data         = request.get_json(silent=True) or {}
    history      = data.get('messages', [])   # list of {role, content} dicts
    user_message = data.get('message', '').strip()
    session_id   = data.get('session_id')

    if not user_message:
        return jsonify({'error': 'Empty message'}), 400

    # ── Generate the reply ────────────────────────────────────────────────
    api_key = os.environ.get('GROQ_API_KEY')
    if not api_key:
        reply = ("I'm sorry, the AI assistant isn't configured right now. "
                 "Please use the **Submit to Support** form to reach our team directly.")
    else:
        try:
            from groq import Groq
            client = Groq(api_key=api_key)

            messages = [{'role': 'system', 'content': _SYSTEM_PROMPT}]
            # Append prior conversation (cap at last 20 turns to control token usage)
            for m in history[-20:]:
                if m.get('role') in ('user', 'assistant') and m.get('content'):
                    messages.append({'role': m['role'], 'content': m['content']})
            messages.append({'role': 'user', 'content': user_message})

            model = os.environ.get('GROQ_MODEL', 'llama-3.3-70b-versatile')
            completion = client.chat.completions.create(
                model=model,
                messages=messages,
                max_tokens=512,
                temperature=0.5,
            )
            reply = completion.choices[0].message.content.strip()
        except Exception as exc:
            logger.error('SUPPORT | Groq error: %s', exc)
            reply = ("I ran into a problem reaching the AI assistant. "
                     "Please try again, or use **Submit to Support** to contact our team.")

    # ── Persist the turn (user message + assistant reply) ─────────────────
    now = now_eastern()
    session = None
    if session_id:
        session = db.session.get(SupportChatSession, session_id)
        if session is not None and session.customer_id != current_user.id:
            session = None   # never write into someone else's session
    if session is None:
        session = SupportChatSession(customer_id=current_user.id,
                                     created_at=now, updated_at=now)
        db.session.add(session)
        db.session.flush()   # assign session.id

    db.session.add(SupportChatMessage(session_id=session.id, role='user',
                                      content=user_message, created_at=now))
    db.session.add(SupportChatMessage(session_id=session.id, role='assistant',
                                      content=reply, created_at=now))
    session.updated_at = now
    db.session.commit()

    return jsonify({'reply': reply, 'session_id': session.id})


# ── Customer: saved chat conversations ────────────────────────────────────────

@bp.route('/my-conversations')
@login_required
def my_conversations():
    if current_user.role != 'customer':
        abort(403)
    sessions = (SupportChatSession.query
                .filter_by(customer_id=current_user.id)
                .order_by(SupportChatSession.updated_at.desc())
                .all())
    return render_template('support/my_conversations.html', sessions=sessions)


@bp.route('/my-conversations/<int:session_id>')
@login_required
def conversation_detail(session_id):
    if current_user.role != 'customer':
        abort(403)
    session = db.session.get(SupportChatSession, session_id)
    if session is None or session.customer_id != current_user.id:
        abort(404)
    messages = session.messages.order_by(SupportChatMessage.created_at.asc()).all()
    return render_template('support/conversation_detail.html',
                           session=session, messages=messages)


# ── Submit support ticket ─────────────────────────────────────────────────────

@bp.route('/tickets', methods=['POST'])
@login_required
def submit_ticket():
    if current_user.role != 'customer':
        abort(403)

    subject     = request.form.get('subject', '').strip()
    body        = request.form.get('body', '').strip()
    facility_id = request.form.get('facility_id', type=int)

    if not subject or not body:
        flash('Please fill in both subject and description.', 'warning')
        return redirect(url_for('support.chat'))

    # Validate facility belongs to this customer
    cids = get_customer_scope(current_user) or []
    if facility_id and facility_id not in cids:
        facility_id = None

    ticket = SupportTicket(
        customer_id = current_user.id,
        facility_id = facility_id,
        subject     = subject,
        body        = body,
        status      = 'open',
        created_at  = now_eastern(),
    )
    db.session.add(ticket)
    db.session.commit()

    log_action(ACTION_CREATE, 'SupportTicket', ticket.id,
               f'#{ticket.id}: {subject[:60]}',
               f'customer={current_user.username}')

    _notify_admins_new_ticket(ticket)

    flash('Your message has been submitted. Our team will get back to you soon.', 'success')
    return redirect(url_for('support.my_tickets'))


# ── Customer: my tickets list ─────────────────────────────────────────────────

@bp.route('/my-tickets')
@login_required
def my_tickets():
    if current_user.role != 'customer':
        abort(403)

    tickets = (SupportTicket.query
               .filter_by(customer_id=current_user.id)
               .order_by(SupportTicket.created_at.desc())
               .all())
    return render_template('support/my_tickets.html', tickets=tickets)


# ── Customer: ticket detail ───────────────────────────────────────────────────

@bp.route('/my-tickets/<int:ticket_id>', methods=['GET', 'POST'])
@login_required
def my_ticket_detail(ticket_id):
    if current_user.role != 'customer':
        abort(403)

    ticket = db.session.get(SupportTicket, ticket_id)
    if ticket is None or ticket.customer_id != current_user.id:
        abort(404)

    if request.method == 'POST':
        if ticket.status == 'closed':
            flash('This ticket is closed and cannot receive new replies.', 'warning')
            return redirect(url_for('support.my_ticket_detail', ticket_id=ticket_id))

        body = request.form.get('body', '').strip()
        if not body:
            flash('Reply cannot be empty.', 'warning')
            return redirect(url_for('support.my_ticket_detail', ticket_id=ticket_id))

        reply = SupportTicketReply(
            ticket_id  = ticket.id,
            user_id    = current_user.id,
            body       = body,
            created_at = now_eastern(),
        )
        db.session.add(reply)
        # Reopen if it was answered so admin sees there's a follow-up
        if ticket.status == 'answered':
            ticket.status = 'open'
        db.session.commit()

        log_action(ACTION_CREATE, 'SupportTicketReply', reply.id,
                   f'ticket #{ticket.id}',
                   f'customer reply by {current_user.username}')

        _notify_admins_customer_reply(ticket, reply)
        flash('Your reply has been sent.', 'success')
        return redirect(url_for('support.my_ticket_detail', ticket_id=ticket_id))

    replies = ticket.replies.order_by(SupportTicketReply.created_at.asc()).all()
    return render_template('support/my_ticket_detail.html',
                           ticket=ticket, replies=replies)


def _notify_admins_new_ticket(ticket):
    """Create in-app notifications and send emails to all active admin users."""
    admins = User.query.filter_by(role='admin', active=True).all()
    if not admins:
        return

    customer_label = ticket.customer.display_name if ticket.customer else 'Unknown'
    facility_label = ticket.facility.name if ticket.facility else 'N/A'
    link = url_for('support.admin_ticket_detail', ticket_id=ticket.id)
    title = f'New support ticket #{ticket.id} from {customer_label}'
    body  = (f'Subject: {ticket.subject}\n'
             f'Facility: {facility_label}\n\n'
             f'{ticket.body[:300]}{"…" if len(ticket.body) > 300 else ""}')

    for admin in admins:
        notify(
            recipient   = admin,
            title       = title,
            body        = body,
            link        = link,
            send_email  = True,
        )
    db.session.commit()


# ── Admin: ticket list ────────────────────────────────────────────────────────

@bp.route('/admin/tickets')
@login_required
@supervisor_required
def admin_tickets():
    status_filter = request.args.get('status', '')
    page          = request.args.get('page', 1, type=int)

    q = SupportTicket.query.order_by(SupportTicket.created_at.desc())
    if status_filter:
        q = q.filter(SupportTicket.status == status_filter)

    tickets = q.paginate(page=page, per_page=25, error_out=False)
    return render_template('support/admin_tickets.html',
                           tickets=tickets,
                           status_filter=status_filter)


# ── Admin: ticket detail + reply ──────────────────────────────────────────────

@bp.route('/admin/tickets/<int:ticket_id>', methods=['GET', 'POST'])
@login_required
@supervisor_required
def admin_ticket_detail(ticket_id):
    ticket = db.session.get(SupportTicket, ticket_id)
    if ticket is None:
        abort(404)

    if request.method == 'POST':
        action = request.form.get('action')

        if action == 'reply':
            body = request.form.get('body', '').strip()
            if not body:
                flash('Reply cannot be empty.', 'warning')
                return redirect(url_for('support.admin_ticket_detail', ticket_id=ticket_id))

            reply = SupportTicketReply(
                ticket_id  = ticket.id,
                user_id    = current_user.id,
                body       = body,
                created_at = now_eastern(),
            )
            db.session.add(reply)
            # Auto-advance status to answered if still open
            if ticket.status == 'open':
                ticket.status = 'answered'
            db.session.commit()

            log_action(ACTION_UPDATE, 'SupportTicket', ticket.id,
                       f'#{ticket.id}: {ticket.subject[:60]}',
                       f'reply added by {current_user.username}')

            _notify_customer_reply(ticket, reply)
            flash('Reply sent.', 'success')

        elif action == 'status':
            new_status = request.form.get('status', '')
            if new_status in ('open', 'answered', 'closed'):
                ticket.status = new_status
                db.session.commit()
                log_action(ACTION_UPDATE, 'SupportTicket', ticket.id,
                           f'#{ticket.id}: {ticket.subject[:60]}',
                           f'status={new_status}')
                flash(f'Ticket marked as {new_status}.', 'success')

        return redirect(url_for('support.admin_ticket_detail', ticket_id=ticket_id))

    replies = ticket.replies.order_by(SupportTicketReply.created_at.asc()).all()
    return render_template('support/admin_ticket_detail.html',
                           ticket=ticket,
                           replies=replies)


# ── Admin: view saved chat conversations (read-only) ──────────────────────────

@bp.route('/admin/conversations')
@login_required
@supervisor_required
def admin_conversations():
    page = request.args.get('page', 1, type=int)
    sessions = (SupportChatSession.query
                .order_by(SupportChatSession.updated_at.desc())
                .paginate(page=page, per_page=25, error_out=False))
    return render_template('support/admin_conversations.html', sessions=sessions)


@bp.route('/admin/conversations/<int:session_id>')
@login_required
@supervisor_required
def admin_conversation_detail(session_id):
    session = db.session.get(SupportChatSession, session_id)
    if session is None:
        abort(404)
    messages = session.messages.order_by(SupportChatMessage.created_at.asc()).all()
    return render_template('support/admin_conversation_detail.html',
                           session=session, messages=messages)


def _notify_customer_reply(ticket, reply):
    """Create an in-app notification and send an email to the customer."""
    if not ticket.customer:
        return

    admin_name = reply.author.display_name if reply.author else 'Support Team'
    title = f'Reply to your support request #{ticket.id}'
    body  = (f'{admin_name} replied to your ticket "{ticket.subject}":\n\n'
             f'{reply.body[:400]}{"…" if len(reply.body) > 400 else ""}')
    link  = url_for('support.my_ticket_detail', ticket_id=ticket.id)

    notify(
        recipient  = ticket.customer,
        title      = title,
        body       = body,
        link       = link,
        send_email = True,
    )
    db.session.commit()


def _notify_admins_customer_reply(ticket, reply):
    """Notify admins when a customer adds a follow-up reply to their ticket."""
    admins = User.query.filter_by(role='admin', active=True).all()
    if not admins:
        return

    customer_label = ticket.customer.display_name if ticket.customer else 'Unknown'
    link  = url_for('support.admin_ticket_detail', ticket_id=ticket.id)
    title = f'Customer reply on ticket #{ticket.id} from {customer_label}'
    body  = (f'Re: {ticket.subject}\n\n'
             f'{reply.body[:400]}{"…" if len(reply.body) > 400 else ""}')

    for admin in admins:
        notify(
            recipient  = admin,
            title      = title,
            body       = body,
            link       = link,
            send_email = True,
        )
    db.session.commit()