"""
Reactions + Pins API Routes
============================

Add/remove emoji reactions to messages and pin/unpin messages.
"""

import re
import logging

from flask import jsonify, request
from flask_login import login_required, current_user
from sqlalchemy.exc import IntegrityError

from . import bp
from database import (
    SessionLocal, ConvMessage, MessageReaction, MessagePin,
    ConversationMember, User,
)
from utils.decorators import member_required
from redis_service import publish_event

logger = logging.getLogger(__name__)

ALLOWED_REACTIONS = ['👍', '❤️', '😂', '😮', '😢', '✅']


# ============================================================
# HELPERS
# ============================================================

def strip_html(text):
    """Strip HTML tags for plain-text previews."""
    return re.sub(r'<[^>]+>', '', text or '').strip()


def _verify_membership(db, conversation_id, user_id):
    """Return ConversationMember or None."""
    return db.query(ConversationMember).filter_by(
        conversation_id=conversation_id,
        user_id=user_id,
    ).first()


def _publish_to_conv(db, conversation_id, event_type, data):
    """Publish SSE event to all conversation members."""
    members = db.query(ConversationMember).filter_by(
        conversation_id=conversation_id,
    ).all()
    for m in members:
        publish_event(m.user_id, event_type, data)


# ============================================================
# 1. POST /api/messages/<message_id>/reactions — Add reaction
# ============================================================

@bp.route('/api/messages/<int:message_id>/reactions', methods=['POST'])
@login_required
@member_required
def add_reaction(message_id):
    """Add an emoji reaction to a message."""
    db = SessionLocal()
    try:
        message = db.query(ConvMessage).get(message_id)
        if not message:
            return jsonify({'error': 'Wiadomość nie znaleziona'}), 404

        # Verify membership
        membership = _verify_membership(db, message.conversation_id, current_user.id)
        if not membership:
            return jsonify({'error': 'Brak dostępu do konwersacji'}), 403

        data = request.get_json(silent=True) or {}
        emoji = data.get('emoji', '').strip()

        if emoji not in ALLOWED_REACTIONS:
            return jsonify({'error': 'Niedozwolona reakcja'}), 400

        reaction = MessageReaction(
            message_id=message_id,
            user_id=current_user.id,
            emoji=emoji,
        )
        db.add(reaction)
        try:
            db.commit()
        except IntegrityError:
            db.rollback()
            # Duplicate — reaction already exists, that's fine

        # Build SSE payload
        user_name = current_user.name or current_user.email.split('@')[0]
        _publish_to_conv(db, message.conversation_id, 'reaction', {
            'message_id': message_id,
            'conversation_id': message.conversation_id,
            'user_id': current_user.id,
            'user_name': user_name,
            'emoji': emoji,
            'action': 'add',
        })

        return jsonify({'ok': True, 'emoji': emoji})

    except Exception as e:
        db.rollback()
        logger.error(f"add_reaction error: {e}")
        return jsonify({'error': 'Błąd serwera'}), 500
    finally:
        db.close()


# ============================================================
# 2. DELETE /api/messages/<message_id>/reactions/<emoji> — Remove reaction
# ============================================================

@bp.route('/api/messages/<int:message_id>/reactions/<path:emoji>', methods=['DELETE'])
@login_required
@member_required
def remove_reaction(message_id, emoji):
    """Remove an emoji reaction from a message."""
    db = SessionLocal()
    try:
        message = db.query(ConvMessage).get(message_id)
        if not message:
            return jsonify({'error': 'Wiadomość nie znaleziona'}), 404

        # Verify membership
        membership = _verify_membership(db, message.conversation_id, current_user.id)
        if not membership:
            return jsonify({'error': 'Brak dostępu do konwersacji'}), 403

        reaction = db.query(MessageReaction).filter_by(
            message_id=message_id,
            user_id=current_user.id,
            emoji=emoji,
        ).first()

        if not reaction:
            return jsonify({'error': 'Reakcja nie znaleziona'}), 404

        db.delete(reaction)
        db.commit()

        # Build SSE payload
        user_name = current_user.name or current_user.email.split('@')[0]
        _publish_to_conv(db, message.conversation_id, 'reaction', {
            'message_id': message_id,
            'conversation_id': message.conversation_id,
            'user_id': current_user.id,
            'user_name': user_name,
            'emoji': emoji,
            'action': 'remove',
        })

        return jsonify({'ok': True})

    except Exception as e:
        db.rollback()
        logger.error(f"remove_reaction error: {e}")
        return jsonify({'error': 'Błąd serwera'}), 500
    finally:
        db.close()


# ============================================================
# 3. POST /api/messages/<message_id>/pin — Pin message
# ============================================================

@bp.route('/api/messages/<int:message_id>/pin', methods=['POST'])
@login_required
@member_required
def pin_message(message_id):
    """Pin a message in its conversation."""
    db = SessionLocal()
    try:
        message = db.query(ConvMessage).get(message_id)
        if not message:
            return jsonify({'error': 'Wiadomość nie znaleziona'}), 404

        # Verify membership
        membership = _verify_membership(db, message.conversation_id, current_user.id)
        if not membership:
            return jsonify({'error': 'Brak dostępu do konwersacji'}), 403

        pin = MessagePin(
            conversation_id=message.conversation_id,
            message_id=message_id,
            pinned_by_id=current_user.id,
        )
        db.add(pin)
        db.commit()

        _publish_to_conv(db, message.conversation_id, 'message_pinned', {
            'message_id': message_id,
            'conversation_id': message.conversation_id,
            'pinned_by_id': current_user.id,
        })

        return jsonify({'ok': True})

    except Exception as e:
        db.rollback()
        logger.error(f"pin_message error: {e}")
        return jsonify({'error': 'Błąd serwera'}), 500
    finally:
        db.close()


# ============================================================
# 4. DELETE /api/messages/<message_id>/pin — Unpin message
# ============================================================

@bp.route('/api/messages/<int:message_id>/pin', methods=['DELETE'])
@login_required
@member_required
def unpin_message(message_id):
    """Unpin a message from its conversation."""
    db = SessionLocal()
    try:
        message = db.query(ConvMessage).get(message_id)
        if not message:
            return jsonify({'error': 'Wiadomość nie znaleziona'}), 404

        # Verify membership
        membership = _verify_membership(db, message.conversation_id, current_user.id)
        if not membership:
            return jsonify({'error': 'Brak dostępu do konwersacji'}), 403

        pin = db.query(MessagePin).filter_by(message_id=message_id).first()
        if not pin:
            return jsonify({'error': 'Wiadomość nie jest przypięta'}), 404

        conversation_id = pin.conversation_id
        db.delete(pin)
        db.commit()

        _publish_to_conv(db, conversation_id, 'message_unpinned', {
            'message_id': message_id,
            'conversation_id': conversation_id,
        })

        return jsonify({'ok': True})

    except Exception as e:
        db.rollback()
        logger.error(f"unpin_message error: {e}")
        return jsonify({'error': 'Błąd serwera'}), 500
    finally:
        db.close()


# ============================================================
# 5. GET /api/conversations/<conv_id>/pins — List pins
# ============================================================

@bp.route('/api/conversations/<int:conv_id>/pins', methods=['GET'])
@login_required
@member_required
def list_pins(conv_id):
    """List all pinned messages in a conversation."""
    db = SessionLocal()
    try:
        # Verify membership
        membership = _verify_membership(db, conv_id, current_user.id)
        if not membership:
            return jsonify({'error': 'Brak dostępu do konwersacji'}), 403

        pins = db.query(MessagePin).filter_by(
            conversation_id=conv_id,
        ).order_by(MessagePin.created_at.desc()).all()

        result = []
        for pin in pins:
            msg = pin.message

            # Sender name
            sender_name = None
            if msg and msg.sender:
                sender_name = msg.sender.name or msg.sender.email.split('@')[0]

            # Content preview (strip HTML, truncate)
            content_preview = ''
            if msg and not msg.is_deleted:
                content_preview = strip_html(msg.content)[:100]

            # Pinned-by name
            pinned_by_name = None
            if pin.pinned_by:
                pinned_by_name = pin.pinned_by.name or pin.pinned_by.email.split('@')[0]

            result.append({
                'id': pin.id,
                'message_id': pin.message_id,
                'content_preview': content_preview,
                'sender_name': sender_name,
                'pinned_by_name': pinned_by_name,
                'pinned_at': pin.created_at.isoformat() if pin.created_at else None,
                'created_at': msg.created_at.isoformat() if msg and msg.created_at else None,
            })

        return jsonify(result)

    except Exception as e:
        logger.error(f"list_pins error: {e}")
        return jsonify({'error': 'Błąd serwera'}), 500
    finally:
        db.close()