from flask import Blueprint, render_template, request, redirect, url_for, flash, jsonify
from flask_login import login_required
from app import db
from app.models.classroom import Classroom, ClassroomResource
from app.models.reservation import Reservation, ReservationStatus
from app.forms.classroom import ClassroomForm, ClassroomResourceForm
from datetime import datetime

classrooms_bp = Blueprint('classrooms', __name__, url_prefix='/classrooms')

@classrooms_bp.route('/')
@login_required
def list_classrooms():
    """List all classrooms"""
    page = request.args.get('page', 1, type=int)
    search = request.args.get('search', '')
    campus = request.args.get('campus', '')
    
    query = Classroom.query.filter_by(is_active=True)
    
    if search:
        query = query.filter(
            Classroom.code.contains(search) |
            Classroom.name.contains(search) |
            Classroom.building.contains(search)
        )
    
    if campus:
        query = query.filter(Classroom.campus_location == campus)
    
    classrooms = query.paginate(
        page=page, 
        per_page=20, 
        error_out=False
    )
    
    return render_template('classrooms/list.html', 
                         classrooms=classrooms, 
                         search=search, 
                         campus=campus)

@classrooms_bp.route('/add', methods=['GET', 'POST'])
@login_required
def add_classroom():
    """Add new classroom"""
    form = ClassroomForm()
    
    if form.validate_on_submit():
        classroom = Classroom(
            code=form.code.data,
            name=form.name.data,
            building=form.building.data,
            floor=form.floor.data,
            capacity=form.capacity.data,
            description=form.description.data,
            campus_location=form.campus_location.data
        )
        
        try:
            db.session.add(classroom)
            db.session.commit()
            flash(f'Classroom {classroom.code} added successfully!', 'success')
            return redirect(url_for('classrooms.list_classrooms'))
        except Exception as e:
            db.session.rollback()
            flash('Error adding classroom. Classroom code might already exist.', 'error')
    
    return render_template('classrooms/add.html', form=form)

@classrooms_bp.route('/edit/<int:Id>', methods=['GET', 'POST'])
@login_required
def edit_classroom(Id):
    """Edit classroom"""
    classroom = Classroom.query.get_or_404(Id)
    
    if not classroom.is_active:
        flash('This classroom has been deactivated.', 'warning')
        return redirect(url_for('classrooms.list_classrooms'))
    
    form = ClassroomForm(obj=classroom)
    
    if form.validate_on_submit():
        try:
            classroom.code = form.code.data
            classroom.name = form.name.data
            classroom.building = form.building.data
            classroom.floor = form.floor.data
            classroom.capacity = form.capacity.data
            classroom.description = form.description.data
            classroom.campus_location = form.campus_location.data
            classroom.updated_at = datetime.utcnow()
            
            db.session.commit()
            flash(f'Classroom {classroom.code} updated successfully!', 'success')
            return redirect(url_for('classrooms.view_classroom', Id=classroom.id))
        except Exception as e:
            db.session.rollback()
            flash('Error updating classroom.', 'error')
    
    return render_template('classrooms/edit.html', form=form, classroom=classroom)

@classrooms_bp.route('/view/<int:Id>')
@login_required
def view_classroom(Id):
    """View classroom details"""
    classroom = Classroom.query.get_or_404(Id)
    
    if not classroom.is_active:
        flash('This classroom has been deactivated.', 'warning')
        return redirect(url_for('classrooms.list_classrooms'))
    
    # Get classroom resources
    resources = ClassroomResource.query.filter_by(classroom_id=Id).all()
    
    # Get upcoming reservations
    upcoming_reservations = Reservation.query.filter(
        Reservation.classroom_id == Id,
        Reservation.start_time >= datetime.utcnow(),
        Reservation.status.in_([ReservationStatus.CONFIRMED, ReservationStatus.PENDING])
    ).order_by(Reservation.start_time).limit(10).all()
    
    return render_template('classrooms/view.html', 
                         classroom=classroom, 
                         resources=resources,
                         upcoming_reservations=upcoming_reservations)

@classrooms_bp.route('/delete/<int:Id>')
@login_required
def delete_classroom(Id):
    """Delete/deactivate classroom"""
    classroom = Classroom.query.get_or_404(Id)
    
    # Check for active reservations
    active_reservations = Reservation.query.filter(
        Reservation.classroom_id == Id,
        Reservation.status.in_([ReservationStatus.CONFIRMED, ReservationStatus.PENDING])
    ).count()
    
    if active_reservations > 0:
        flash('Cannot delete classroom with active reservations.', 'error')
        return redirect(url_for('classrooms.view_classroom', Id=Id))
    
    try:
        classroom.is_active = False
        classroom.updated_at = datetime.utcnow()
        db.session.commit()
        flash(f'Classroom {classroom.code} has been deactivated.', 'success')
    except Exception as e:
        db.session.rollback()
        flash('Error deactivating classroom.', 'error')
    
    return redirect(url_for('classrooms.list_classrooms'))

@classrooms_bp.route('/<int:classroom_id>/add_resource', methods=['GET', 'POST'])
@login_required
def add_resource(classroom_id):
    """Add resource to classroom"""
    classroom = Classroom.query.get_or_404(classroom_id)
    form = ClassroomResourceForm()
    
    if form.validate_on_submit():
        resource = ClassroomResource(
            classroom_id=classroom_id,
            resource_type=form.resource_type.data,
            brand=form.brand.data,
            model=form.model.data,
            specifications=form.specifications.data,
            quantity=form.quantity.data
        )
        
        try:
            db.session.add(resource)
            db.session.commit()
            flash(f'{resource.resource_type} added to {classroom.code} successfully!', 'success')
            return redirect(url_for('classrooms.view_classroom', Id=classroom_id))
        except Exception as e:
            db.session.rollback()
            flash('Error adding resource.', 'error')
    
    return render_template('classrooms/add_resource.html', form=form, classroom=classroom)

@classrooms_bp.route('/api/available')
@login_required
def api_available_classrooms():
    """API endpoint to get available classrooms"""
    start_time = request.args.get('start_time')
    end_time = request.args.get('end_time')
    min_capacity = request.args.get('min_capacity', 0, type=int)
    
    if not start_time or not end_time:
        return jsonify({'error': 'start_time and end_time are required'}), 400
    
    try:
        start_dt = datetime.fromisoformat(start_time)
        end_dt = datetime.fromisoformat(end_time)
    except ValueError:
        return jsonify({'error': 'Invalid datetime format'}), 400
    
    # Find available classrooms (without conflicts)
    conflicting_classroom_ids = [
        r.classroom_id for r in Reservation.query.filter(
            Reservation.start_time < end_dt,
            Reservation.end_time > start_dt,
            Reservation.status == ReservationStatus.CONFIRMED
        ).all()
    ]
    
    available_classrooms = Classroom.query.filter(
        Classroom.is_active == True,
        Classroom.capacity >= min_capacity,
        ~Classroom.id.in_(conflicting_classroom_ids)
    ).all()
    
    return jsonify([classroom.to_dict() for classroom in available_classrooms])