import logging
from flask import Blueprint, render_template, redirect, url_for, flash, request, abort
from flask_login import login_required, current_user
from app import db
from app.models.facility import Facility, Area
from app.models.project import Project
from app.utils.forms import FacilityForm, AreaForm
from app.utils.decorators import supervisor_required, admin_required
from app.utils.audit import log_action, ACTION_CREATE, ACTION_UPDATE, ACTION_DELETE
from app.utils.scope import get_customer_scope, get_inspector_scope

bp = Blueprint('facilities', __name__, url_prefix='/facilities')

logger = logging.getLogger(__name__)

@bp.route('/')
@login_required
def list_facilities():
    if current_user.role == 'customer':
        cids = get_customer_scope(current_user) or []
        facilities = Facility.query.filter(
            Facility.id.in_(cids), Facility.active == True
        ).order_by(Facility.name).all()
    elif current_user.role == 'inspector':
        fids = get_inspector_scope(current_user) or []
        facilities = Facility.query.filter(
            Facility.id.in_(fids), Facility.active == True
        ).order_by(Facility.name).all()
    else:
        facilities = Facility.query.order_by(Facility.name).all()

    # Group facilities by Contract (Project) for the collapsible list view.
    # Facilities with no contract are collected under key '__none__' and
    # rendered last as "No Contract Assigned".
    from collections import OrderedDict
    grouped = OrderedDict()
    ungrouped = []
    for f in facilities:
        if f.project:
            key = f.project.name
            grouped.setdefault(key, {'project': f.project, 'facilities': []})
            grouped[key]['facilities'].append(f)
        else:
            ungrouped.append(f)

    grouped = OrderedDict(sorted(grouped.items()))
    if ungrouped:
        grouped['__none__'] = {'project': None, 'facilities': ungrouped}

    logger.info('FACILITIES | list | user=%s | total=%s | groups=%s',
                current_user.username, len(facilities), len(grouped))
    return render_template('facilities/list.html', facilities=facilities, grouped=grouped)

@bp.route('/new', methods=['GET', 'POST'])
@login_required
@supervisor_required
def create_facility():
    form = FacilityForm()
    projects = Project.query.filter_by(active=True).order_by(Project.name).all()
    form.project_id.choices = [(0, '— None —')] + [(p.id, p.name) for p in projects]

    if form.validate_on_submit():
        project_id = form.project_id.data if form.project_id.data else None
        facility = Facility(
            name=form.name.data,
            address=form.address.data,
            contact_person=form.contact_person.data,
            contact_phone=form.contact_phone.data,
            project_id=project_id if project_id else None,
            active=form.active.data
        )

        facility.ensure_public_token()   # QR landing-page token
        db.session.add(facility)
        db.session.commit()
        logger.info('FACILITIES | create | user=%s | facility_id=%s name=%r',
                    current_user.username, facility.id, facility.name)
        log_action(ACTION_CREATE, 'Facility', facility.id, facility.name,
                   f'contact={facility.contact_person or ""}; project_id={facility.project_id}; active={facility.active}')
        flash(f'Facility "{facility.name}" created successfully.', 'success')
        return redirect(url_for('facilities.view_facility', facility_id=facility.id))

    return render_template('facilities/form.html', form=form, title='Create Facility')

@bp.route('/<int:facility_id>')
@login_required
def view_facility(facility_id):
    facility = db.session.get(Facility, facility_id)
    if facility is None:
        abort(404)
    if current_user.role == 'customer':
        cids = get_customer_scope(current_user) or []
        if facility_id not in cids:
            flash('Access denied.', 'danger')
            return redirect(url_for('facilities.list_facilities'))
    areas = facility.areas.order_by(Area.name).all()
    return render_template('facilities/view.html', facility=facility, areas=areas)


# ── Public QR code ────────────────────────────────────────────────────────────
# Staff (admin/director/pm/inspector) may access QR for any facility; customers
# may access QR only for facilities in their assigned scope.

def _public_facility_url(facility):
    """Absolute URL the QR encodes — the login-free occupant summary page."""
    facility.ensure_public_token()
    if not facility.public_token:
        return None
    return url_for('public.facility_summary',
                   token=facility.public_token, _external=True)


def _facility_for_qr_or_403(facility_id):
    """Load a facility for a QR action, enforcing customer facility scope.

    Customers may only touch QR codes for facilities they are assigned to; all
    other (staff) roles have unrestricted QR access.
    """
    facility = db.session.get(Facility, facility_id)
    if facility is None:
        abort(404)
    if current_user.role == 'customer':
        cids = get_customer_scope(current_user) or []
        if facility.id not in cids:
            abort(403)
    return facility


@bp.route('/<int:facility_id>/qr.png')
@login_required
def facility_qr_png(facility_id):
    """Return the facility's QR code as a PNG image."""
    facility = _facility_for_qr_or_403(facility_id)

    # Token may not exist for pre-phase34 rows viewed before any commit.
    created = not facility.public_token
    url = _public_facility_url(facility)
    if created:
        db.session.commit()

    import io
    import qrcode
    img = qrcode.make(url, box_size=10, border=2)
    buf = io.BytesIO()
    img.save(buf, format='PNG')
    buf.seek(0)

    from flask import Response
    return Response(buf.getvalue(), mimetype='image/png', headers={
        'Cache-Control': 'private, max-age=3600',
    })


@bp.route('/<int:facility_id>/qr')
@login_required
def facility_qr_page(facility_id):
    """Printable page: facility name + QR + public URL + posting instructions."""
    facility = _facility_for_qr_or_403(facility_id)
    public_url = _public_facility_url(facility)
    db.session.commit()   # persist token if it was just generated
    return render_template('facilities/qr.html',
                           facility=facility, public_url=public_url)


@bp.route('/<int:facility_id>/qr/regenerate', methods=['POST'])
@login_required
def facility_qr_regenerate(facility_id):
    """Mint a NEW public token, invalidating any previously printed QR code.

    Allowed for admin/director, and for customers on their own assigned
    facilities. Project managers and inspectors cannot regenerate.
    """
    facility = _facility_for_qr_or_403(facility_id)
    if current_user.role not in ('admin', 'director', 'customer'):
        abort(403)

    facility.public_token = Facility.generate_public_token()
    db.session.commit()

    logger.info('FACILITIES | qr_regenerate | user=%s | facility_id=%s',
                current_user.username, facility.id)
    log_action(ACTION_UPDATE, 'Facility', facility.id, facility.name,
               'regenerated public QR token (old code invalidated)')
    flash('QR code regenerated. Any previously printed codes for this facility no '
          'longer work — reprint and repost.', 'warning')
    return redirect(url_for('facilities.facility_qr_page', facility_id=facility.id))


@bp.route('/qr/print-all')
@login_required
def facility_qr_print_all():
    """Printable sheet of QR codes for all facilities the user can see.

    Optional ?contract_id=<id> limits the sheet to one contract. Inspectors are
    scoped to their contracted facilities; customers to their assigned
    facilities; managers see all active facilities.
    """
    contract_id = request.args.get('contract_id', type=int)

    if current_user.role == 'inspector':
        fids = get_inspector_scope(current_user) or []
        query = Facility.query.filter(Facility.id.in_(fids), Facility.active == True)
    elif current_user.role == 'customer':
        fids = get_customer_scope(current_user) or []
        query = Facility.query.filter(Facility.id.in_(fids), Facility.active == True)
    else:
        query = Facility.query.filter(Facility.active == True)

    if contract_id:
        query = query.filter(Facility.project_id == contract_id)

    facilities = query.order_by(Facility.name).all()

    # Ensure every facility on the sheet has a token so its qr.png renders.
    changed = False
    for f in facilities:
        if not f.public_token:
            f.ensure_public_token()
            changed = True
    if changed:
        db.session.commit()

    selected_contract = db.session.get(Project, contract_id) if contract_id else None
    return render_template('facilities/qr_print_all.html',
                           facilities=facilities,
                           selected_contract=selected_contract)

@bp.route('/<int:facility_id>/edit', methods=['GET', 'POST'])
@login_required
@supervisor_required
def edit_facility(facility_id):
    facility = db.session.get(Facility, facility_id)
    if facility is None:
        abort(404)
    form = FacilityForm(obj=facility)
    projects = Project.query.filter_by(active=True).order_by(Project.name).all()
    form.project_id.choices = [(0, '— None —')] + [(p.id, p.name) for p in projects]

    if form.validate_on_submit():
        project_id = form.project_id.data if form.project_id.data else None
        facility.name = form.name.data
        facility.address = form.address.data
        facility.contact_person = form.contact_person.data
        facility.contact_phone = form.contact_phone.data
        facility.project_id = project_id if project_id else None
        facility.active = form.active.data

        db.session.commit()
        logger.info('FACILITIES | edit | user=%s | facility_id=%s name=%r',
                    current_user.username, facility.id, facility.name)
        log_action(ACTION_UPDATE, 'Facility', facility.id, facility.name,
                   f'project_id={facility.project_id}; active={facility.active}')
        flash(f'Facility "{facility.name}" updated successfully.', 'success')
        return redirect(url_for('facilities.view_facility', facility_id=facility.id))

    return render_template('facilities/form.html', form=form, facility=facility, title='Edit Facility')

@bp.route('/<int:facility_id>/delete', methods=['POST'])
@login_required
@admin_required
def delete_facility(facility_id):
    facility = db.session.get(Facility, facility_id)
    if facility is None:
        abort(404)
    
    if facility.inspections.count() > 0:
        flash(f'Cannot delete "{facility.name}" — it has existing inspection records.', 'danger')
        return redirect(url_for('facilities.view_facility', facility_id=facility.id))
    
    facility_name = facility.name
    facility_id_snap = facility.id
    db.session.delete(facility)
    db.session.commit()
    logger.info('FACILITIES | delete | user=%s | facility_id=%s name=%r',
                current_user.username, facility_id_snap, facility_name)
    log_action(ACTION_DELETE, 'Facility', facility_id_snap, facility_name)
    flash(f'Facility "{facility_name}" has been permanently deleted.', 'success')
    return redirect(url_for('facilities.list_facilities'))

# Area Management Routes

@bp.route('/<int:facility_id>/areas/new', methods=['GET', 'POST'])
@login_required
@supervisor_required
def create_area(facility_id):
    facility = db.session.get(Facility, facility_id)
    if facility is None:
        abort(404)
    form = AreaForm()
    form.facility_id.choices = [(facility.id, facility.name)]
    form.facility_id.data = facility.id
    
    if form.validate_on_submit():
        area = Area(
            name=form.name.data,
            area_type=form.area_type.data,
            facility_id=facility.id
        )
        
        db.session.add(area)
        db.session.commit()
        logger.info('FACILITIES | create_area | user=%s | area_id=%s name=%r facility=%r',
                    current_user.username, area.id, area.name, facility.name)
        log_action(ACTION_CREATE, 'Area', area.id, area.name,
                   f'facility={facility.name}; type={area.area_type or ""}')
        flash(f'Area "{area.name}" created successfully.', 'success')
        return redirect(url_for('facilities.view_facility', facility_id=facility.id))
    
    return render_template('facilities/area_form.html', form=form, facility=facility, title='Create Area')

@bp.route('/areas/<int:area_id>/edit', methods=['GET', 'POST'])
@login_required
@supervisor_required
def edit_area(area_id):
    area = db.session.get(Area, area_id)
    if area is None:
        abort(404)
    form = AreaForm(obj=area)
    
    facilities = Facility.query.filter_by(active=True).order_by(Facility.name).all()
    form.facility_id.choices = [(f.id, f.name) for f in facilities]
    
    if form.validate_on_submit():
        area.name = form.name.data
        area.area_type = form.area_type.data
        area.facility_id = form.facility_id.data
        
        db.session.commit()
        logger.info('FACILITIES | edit_area | user=%s | area_id=%s name=%r',
                    current_user.username, area.id, area.name)
        log_action(ACTION_UPDATE, 'Area', area.id, area.name,
                   f'facility_id={area.facility_id}; type={area.area_type or ""}')
        flash(f'Area "{area.name}" updated successfully.', 'success')
        return redirect(url_for('facilities.view_facility', facility_id=area.facility_id))
    
    return render_template('facilities/area_form.html', form=form, area=area, facility=area.facility, title='Edit Area')

@bp.route('/areas/<int:area_id>/delete', methods=['POST'])
@login_required
@supervisor_required
def delete_area(area_id):
    area = db.session.get(Area, area_id)
    if area is None:
        abort(404)
    facility_id = area.facility_id
    
    if area.inspections.count() > 0:
        flash('Cannot delete area with existing inspections.', 'danger')
        return redirect(url_for('facilities.view_facility', facility_id=facility_id))

    issue_count = area.issues.count()
    if issue_count > 0:
        flash(
            f'Cannot delete area "{area.name}" — it has {issue_count} issue record(s) on file. '
            f'Resolve or reassign those issues first.',
            'danger'
        )
        return redirect(url_for('facilities.view_facility', facility_id=facility_id))

    area_name = area.name
    area_id_snap = area.id
    db.session.delete(area)
    db.session.commit()
    logger.info('FACILITIES | delete_area | user=%s | area_id=%s name=%r',
                current_user.username, area_id_snap, area_name)
    log_action(ACTION_DELETE, 'Area', area_id_snap, area_name)
    flash(f'Area "{area_name}" deleted successfully.', 'success')
    return redirect(url_for('facilities.view_facility', facility_id=facility_id))