"""
routes/dashboard.py
===================
Dashboard and related API routes.

Routes: /dashboard, /project/<id>/qr-codes, /dashboard/search,
        /api/dashboard/stats, /api/dashboard/realtime
"""
from flask import abort, Blueprint, render_template, request, redirect, flash, session, jsonify, url_for
from datetime import datetime, timedelta, date, time
from sqlalchemy import and_

from extensions import db, logger_handler
from models.attendance import AttendanceData
from models.project import Project
from models.qrcode import QRCode
from models.user import User
from logger_handler import log_user_activity, log_database_operations
from utils.helpers import login_required, load_project_manager_scope


def _project_manager_qr_filter():
    """
    (is_pm, qr_filter) for the session user — the QR codes a Project Manager may
    see (§4). qr_filter is None for everyone else, and a never-true condition for
    a PM with no assignments.
    """
    is_pm, allowed_project_ids, allowed_location_names = load_project_manager_scope()
    if not is_pm:
        return False, None

    # AND, not OR — the same rule the Attendance Report applies
    # (_attendance_filter_conditions in routes/attendance.py): the assigned
    # projects, narrowed to the assigned locations when there are any.
    # With OR, a PM assigned location "Bldg A" also saw every OTHER project's
    # QR codes that happened to use that same location name (Set 28).
    scope = []
    if allowed_project_ids:
        scope.append(QRCode.project_id.in_(allowed_project_ids))
    if allowed_location_names:
        scope.append(QRCode.location.in_(allowed_location_names))
    if not scope:
        return True, QRCode.id.is_(None)  # assigned nothing → sees nothing
    return True, and_(*scope)

bp = Blueprint('dashboard', __name__)



@bp.route('/dashboard', endpoint='dashboard')
@login_required
def dashboard():
    """Enhanced project-centric dashboard with search filters"""
    try:
        user = db.session.get(User, session['user_id'])
        
        # Get search parameters from URL
        search_name = request.args.get('search_name', '').strip()
        search_status = request.args.get('search_status', '').strip()
        
        # Build QR codes query with filters
        qr_query = QRCode.query

        # Project Managers only see QR codes in their assigned projects/locations
        is_pm, pm_qr_filter = _project_manager_qr_filter()
        if pm_qr_filter is not None:
            qr_query = qr_query.filter(pm_qr_filter)

        # Apply name filter if provided
        if search_name:
            qr_query = qr_query.filter(QRCode.name.ilike(f'%{search_name}%'))
        
        # Apply status filter if provided
        if search_status == 'active':
            qr_query = qr_query.filter(QRCode.active_status == True)
        elif search_status == 'inactive':
            qr_query = qr_query.filter(QRCode.active_status == False)
        
        # Execute query
        qr_codes = qr_query.order_by(QRCode.created_date.desc()).all()

        project_query = Project.query
        if is_pm:
            # Only the projects the PM is assigned to, plus those behind their locations
            visible_project_ids = {qr.project_id for qr in qr_codes if qr.project_id}
            _, allowed_project_ids, _ = load_project_manager_scope()
            visible_project_ids.update(allowed_project_ids)
            project_query = (project_query.filter(Project.id.in_(sorted(visible_project_ids)))
                             if visible_project_ids else project_query.filter(Project.id.is_(None)))
        projects = project_query.order_by(Project.name.asc()).all()
        
        # Log dashboard access with filter info
        filter_info = []
        if search_name:
            filter_info.append(f"name contains '{search_name}'")
        if search_status:
            filter_info.append(f"status is {search_status}")
        
        log_message = f"User {session['username']} accessed dashboard: {len(qr_codes)} QR codes"
        if filter_info:
            log_message += f" (filtered: {', '.join(filter_info)})"
        
        logger_handler.logger.info(log_message)
        
        return render_template('dashboard.html',
                             user=user,
                             qr_codes=qr_codes,
                             projects=projects,
                             search_name=search_name,
                             search_status=search_status)
    
    except Exception as e:
        db.session.rollback()
        logger_handler.log_database_error('dashboard_load', e)
        flash('Error loading dashboard. Please try again.', 'error')
        return redirect(url_for('auth.login'))

@bp.route('/project/<int:project_id>/qr-codes', endpoint='project_qr_codes')
@login_required
def project_qr_codes(project_id):
    """
    View all QR codes for a specific project with search filters
    Allows filtering by name and status within the project
    """
    try:
        # Get the project
        project = db.session.get(Project, project_id)
        if project is None:
            abort(404)

        # Project Managers may only open their own projects (§4)
        is_pm, allowed_project_ids, _ = load_project_manager_scope()
        if is_pm and project_id not in allowed_project_ids:
            logger_handler.logger.warning(
                f"Project Manager {session.get('username')} tried to open project {project_id}"
            )
            flash('You do not have permission to view that project.', 'error')
            return redirect(url_for('dashboard.dashboard'))

        # Get search parameters from URL
        search_name = request.args.get('search_name', '').strip()
        search_status = request.args.get('search_status', '').strip()
        
        # Build QR codes query with filters for this project only
        qr_query = QRCode.query.filter_by(project_id=project_id)
        
        # Apply name filter if provided
        if search_name:
            qr_query = qr_query.filter(QRCode.name.ilike(f'%{search_name}%'))
        
        # Apply status filter if provided
        if search_status == 'active':
            qr_query = qr_query.filter(QRCode.active_status == True)
        elif search_status == 'inactive':
            qr_query = qr_query.filter(QRCode.active_status == False)
        
        # Execute query
        qr_codes = qr_query.order_by(QRCode.created_date.desc()).all()
        
        # Log access with filter info
        filter_info = []
        if search_name:
            filter_info.append(f"name contains '{search_name}'")
        if search_status:
            filter_info.append(f"status is {search_status}")
        
        log_message = f"User {session['username']} viewed project '{project.name}' QR codes: {len(qr_codes)} QR codes"
        if filter_info:
            log_message += f" (filtered: {', '.join(filter_info)})"
        
        logger_handler.logger.info(log_message)
        
        return render_template('project_qr_codes.html',
                             project=project,
                             qr_codes=qr_codes,
                             search_name=search_name,
                             search_status=search_status)
    
    except Exception as e:
        db.session.rollback()
        logger_handler.log_database_error('project_qr_codes_view', e)
        flash('Error loading project QR codes. Please try again.', 'error')
        return redirect(url_for('dashboard.dashboard'))
    
@bp.route('/dashboard/search', methods=['GET'], endpoint='search_qr_codes')
@login_required
def search_qr_codes():
    """Search QR codes - redirect to dashboard with filters"""
    search_name = request.args.get('search_name', '').strip()
    search_status = request.args.get('search_status', '').strip()
    
    # Log search activity
    logger_handler.logger.info(
        f"User {session['username']} searched QR codes: "
        f"name='{search_name}', status='{search_status}'"
    )
    
    # Redirect to dashboard with search parameters
    return redirect(url_for('dashboard.dashboard', search_name=search_name, search_status=search_status))

@bp.route('/api/dashboard/stats', endpoint='dashboard_stats_api')
@login_required
def dashboard_stats_api():
    """API endpoint for dashboard statistics"""
    try:
        # Project Manager scope (§4): every count below is restricted to the QR
        # codes / locations they are assigned to.
        is_pm, allowed_project_ids, allowed_location_names = load_project_manager_scope()
        _, pm_qr_filter = _project_manager_qr_filter()

        qr_base_query = QRCode.query.filter_by(active_status=True)
        attendance_base_query = AttendanceData.query
        location_base_query = db.session.query(AttendanceData.location_name)
        project_base_query = Project.query.filter_by(active_status=True)

        if is_pm:
            qr_base_query = qr_base_query.filter(pm_qr_filter)
            attendance_scope = []
            if allowed_project_ids:
                attendance_scope.append(AttendanceData.qr_code_id.in_(
                    db.session.query(QRCode.id).filter(QRCode.project_id.in_(allowed_project_ids))
                ))
                project_base_query = project_base_query.filter(Project.id.in_(allowed_project_ids))
            else:
                project_base_query = project_base_query.filter(Project.id.is_(None))
            if allowed_location_names:
                attendance_scope.append(AttendanceData.location_name.in_(allowed_location_names))
            attendance_condition = and_(*attendance_scope) if attendance_scope else AttendanceData.id.is_(None)
            attendance_base_query = attendance_base_query.filter(attendance_condition)
            location_base_query = location_base_query.filter(attendance_condition)

        # Get current stats
        total_qr_codes = qr_base_query.count()

        # Today's check-ins — local date, matching how check-ins are stored
        today = datetime.now().date()
        today_checkins = attendance_base_query.filter(
            AttendanceData.check_in_date == today
        ).count()

        # Active projects
        active_projects = project_base_query.count()

        # Unique locations
        unique_locations = location_base_query.distinct().count()

        # Calculate trends (compared to last month)
        last_month = datetime.now() - timedelta(days=30)

        # QR codes trend
        old_qr_count = qr_base_query.filter(
            QRCode.created_date <= last_month
        ).count()
        qr_change = ((total_qr_codes - old_qr_count) / max(old_qr_count, 1)) * 100
        
        # Check-ins trend (yesterday)
        yesterday = today - timedelta(days=1)
        yesterday_checkins = attendance_base_query.filter(
            AttendanceData.check_in_date == yesterday
        ).count()
        checkin_change = ((today_checkins - yesterday_checkins) / max(yesterday_checkins, 1)) * 100
        
        return jsonify({
            'success': True,
            'total_qr_codes': total_qr_codes,
            'today_checkins': today_checkins,
            'active_projects': active_projects,
            'unique_locations': unique_locations,
            'qr_change': round(qr_change, 1),
            'checkin_change': round(checkin_change, 1),
            'project_change': 0,  # You can calculate this based on your needs
            'location_change': 0   # You can calculate this based on your needs
        })
        
    except Exception as e:
        db.session.rollback()
        logger_handler.log_database_error('dashboard_stats_api', e)
        return jsonify({
            'success': False,
            'error': 'Failed to fetch dashboard statistics'
        }), 500

@bp.route('/api/dashboard/realtime', endpoint='dashboard_realtime_api')
@login_required
def dashboard_realtime_api():
    """API endpoint for real-time dashboard data"""
    try:
        # Get recent activity (last 10 check-ins)
        recent_query = db.session.query(
            AttendanceData.employee_id,
            AttendanceData.location_name,
            AttendanceData.check_in_time,
            AttendanceData.check_in_date
        )

        # Project Managers only see activity at their own projects/locations (§4)
        is_pm, allowed_project_ids, allowed_location_names = load_project_manager_scope()
        if is_pm:
            recent_scope = []
            if allowed_project_ids:
                recent_scope.append(AttendanceData.qr_code_id.in_(
                    db.session.query(QRCode.id).filter(QRCode.project_id.in_(allowed_project_ids))
                ))
            if allowed_location_names:
                recent_scope.append(AttendanceData.location_name.in_(allowed_location_names))
            recent_query = recent_query.filter(and_(*recent_scope) if recent_scope
                                                else AttendanceData.id.is_(None))

        recent_activity = recent_query.order_by(
            AttendanceData.check_in_date.desc(),
            AttendanceData.check_in_time.desc()
        ).limit(10).all()
        
        activity_data = [
            {
                'employee_id': activity.employee_id,
                'location': activity.location_name,
                'time': activity.check_in_time.strftime('%H:%M'),
                'date': activity.check_in_date.strftime('%Y-%m-%d')
            }
            for activity in recent_activity
        ]
        
        return jsonify({
            'success': True,
            'recent_activity': activity_data
        })
        
    except Exception as e:
        db.session.rollback()
        logger_handler.log_database_error('dashboard_realtime_api', e)
        return jsonify({
            'success': False,
            'error': 'Failed to fetch real-time data'
        }), 500
    
# USER MANAGEMENT ROUTES