Code reviewed and issue fixed.

app/__init__.py

@@ -112,7 +112,10 @@ def create_app(config_name=None):
 
     @login_manager.user_loader
     def load_user(user_id):
-        return User.query.get(int(user_id))
+        # db.session.get() is the SQLAlchemy 2.x successor to the deprecated
+        # Model.query.get(). Both hit the identity map first (no SQL if the
+        # object is already in session), then fall back to a SELECT by PK.
+        return db.session.get(User, int(user_id))
 
     # ── Context processors ────────────────────────────────────────────────────
     @app.context_processor

app/models.py

@@ -124,11 +124,34 @@ class Ticket(db.Model):
     history      = db.relationship('TicketHistory', backref='ticket', lazy='dynamic', cascade='all, delete-orphan')
 
     def generate_ticket_number(self):
-        """Generate unique ticket number like TKT-20240101-0001"""
+        """Generate a unique ticket number like TKT-20240101-0001.
+
+        Concurrency safety
+        ------------------
+        The naive approach — query the last ticket, increment its sequence,
+        then insert — has a TOCTOU race: two concurrent requests can both read
+        the same "last" ticket and generate the same next number, causing an
+        IntegrityError at commit time.
+
+        We eliminate the race by appending FOR UPDATE to the SELECT. This
+        acquires a row-level write lock on the last matching ticket for the
+        duration of the current transaction, serialising concurrent callers
+        through the database rather than through application code. The lock is
+        released automatically when the transaction commits or rolls back.
+
+        MySQL / MariaDB: with_for_update() emits SELECT … FOR UPDATE.
+        SQLite (dev/test): SELECT … FOR UPDATE is silently ignored, which is
+        acceptable because SQLite's connection-level locking already prevents
+        concurrent writes in practice.
+        """
         date_str = datetime.utcnow().strftime('%Y%m%d')
-        last = Ticket.query.filter(
+        last = (
-            Ticket.ticket_number.like(f'TKT-{date_str}-%')
+            Ticket.query
-        ).order_by(Ticket.id.desc()).first()
+            .filter(Ticket.ticket_number.like(f'TKT-{date_str}-%'))
+            .order_by(Ticket.id.desc())
+            .with_for_update()   # acquires a write lock; serialises concurrent callers
+            .first()
+        )
         if last:
             seq = int(last.ticket_number.split('-')[-1]) + 1
         else:

app/routes/admin.py

@@ -11,6 +11,7 @@ from app import db
 from app.models import (User, Ticket, Comment, ActivityLog, KnowledgeBase,
                         KBAttachment, UserRole, TicketStatus)
 from app.services.log_service import log_action
+from app.services.validation_service import validate_password, validate_file
 
 admin_bp = Blueprint('admin', __name__, url_prefix='/admin')
 logger   = logging.getLogger(__name__)
@@ -73,6 +74,13 @@ def it_required(f):
 @login_required
 @it_required
 def index():
+    from sqlalchemy import func, case
+
+    now = datetime.utcnow()
+    day7  = now - timedelta(days=7)
+    day30 = now - timedelta(days=30)
+
+    # ── Headline stats ────────────────────────────────────────────────────────
     stats = {
         'total_tickets' : Ticket.query.count(),
         'open'          : Ticket.query.filter_by(status=TicketStatus.OPEN).count(),
@@ -85,8 +93,177 @@ def index():
                               User.role.in_([UserRole.IT_STAFF, UserRole.ADMIN]),
                               User.is_active == True).count(),
     }
-    recent_logs = ActivityLog.query.order_by(ActivityLog.created_at.desc()).limit(20).all()
+
-    return render_template('admin/index.html', stats=stats, recent_logs=recent_logs)
+    # ── IT performance metrics ────────────────────────────────────────────────
+    # Avg resolution time (hours) — resolved tickets only
+    resolved_tickets = Ticket.query.filter(
+        Ticket.resolved_at.isnot(None),
+        Ticket.created_at.isnot(None),
+    ).all()
+    if resolved_tickets:
+        total_hours = sum(
+            (t.resolved_at - t.created_at).total_seconds() / 3600
+            for t in resolved_tickets
+        )
+        avg_resolution_hours = round(total_hours / len(resolved_tickets), 1)
+    else:
+        avg_resolution_hours = None
+
+    # Resolved last 7 / 30 days
+    resolved_7d  = Ticket.query.filter(Ticket.resolved_at >= day7).count()
+    resolved_30d = Ticket.query.filter(Ticket.resolved_at >= day30).count()
+
+    # New tickets last 7 / 30 days
+    new_7d  = Ticket.query.filter(Ticket.created_at >= day7).count()
+    new_30d = Ticket.query.filter(Ticket.created_at >= day30).count()
+
+    # Unassigned open tickets
+    unassigned = Ticket.query.filter(
+        Ticket.assigned_to_id.is_(None),
+        Ticket.status.in_([TicketStatus.OPEN, TicketStatus.IN_PROGRESS]),
+    ).count()
+
+    # SLA at-risk: open/in-progress tickets older than 3 days
+    sla_breach = Ticket.query.filter(
+        Ticket.status.in_([TicketStatus.OPEN, TicketStatus.IN_PROGRESS]),
+        Ticket.created_at < now - timedelta(days=3),
+    ).count()
+
+    # Open tickets by priority
+    priority_breakdown = {}
+    for priority in ('critical', 'high', 'medium', 'low'):
+        priority_breakdown[priority] = Ticket.query.filter(
+            Ticket.priority == priority,
+            Ticket.status.in_([TicketStatus.OPEN, TicketStatus.IN_PROGRESS, TicketStatus.PENDING]),
+        ).count()
+
+    # Open tickets by category (top 6)
+    from app.models import TicketCategory
+    category_breakdown = []
+    for cat in (TicketCategory.SOFTWARE, TicketCategory.HARDWARE, TicketCategory.NETWORK,
+                TicketCategory.ACCESS, TicketCategory.EMAIL, TicketCategory.OTHER):
+        count = Ticket.query.filter(
+            Ticket.category == cat,
+            Ticket.status.in_([TicketStatus.OPEN, TicketStatus.IN_PROGRESS]),
+        ).count()
+        category_breakdown.append((cat.replace('_', ' ').title(), count))
+    category_breakdown.sort(key=lambda x: x[1], reverse=True)
+
+    # ── Staff performance ─────────────────────────────────────────────────────
+    # Replaced N×5 per-member query loop with two aggregated SQL queries so
+    # that the dashboard cost is constant regardless of IT team size.
+    #
+    # Query 1: grouped counts per assignee (open workload, totals, urgent).
+    # Query 2: resolution timestamps for avg-hours calculation (one row per
+    #          resolved ticket, grouped in Python to avoid TIMESTAMPDIFF
+    #          dialect differences between MySQL and SQLite).
+    it_members = User.query.filter(
+        User.role.in_([UserRole.IT_STAFF, UserRole.ADMIN]),
+        User.is_active == True,
+    ).order_by(User.full_name).all()
+
+    it_member_ids = [m.id for m in it_members]
+
+    # ── Aggregated count query ────────────────────────────────────────────────
+    # Produces one row per assignee with all needed counts computed in SQL.
+    count_rows = (
+        db.session.query(
+            Ticket.assigned_to_id,
+            func.sum(case(
+                (Ticket.status.in_([TicketStatus.OPEN, TicketStatus.IN_PROGRESS, TicketStatus.PENDING]), 1),
+                else_=0,
+            )).label('assigned_open'),
+            func.sum(case(
+                (Ticket.status.in_([TicketStatus.RESOLVED, TicketStatus.CLOSED]), 1),
+                else_=0,
+            )).label('resolved_total'),
+            func.sum(case(
+                (Ticket.resolved_at >= day30, 1),
+                else_=0,
+            )).label('resolved_30d'),
+            func.sum(case(
+                (
+                    (Ticket.priority.in_(['critical', 'high'])) &
+                    (Ticket.status.in_([TicketStatus.OPEN, TicketStatus.IN_PROGRESS])),
+                    1,
+                ),
+                else_=0,
+            )).label('urgent_open'),
+        )
+        .filter(Ticket.assigned_to_id.in_(it_member_ids))
+        .group_by(Ticket.assigned_to_id)
+        .all()
+    )
+    counts_by_id = {row.assigned_to_id: row for row in count_rows}
+
+    # ── Resolution-time query ─────────────────────────────────────────────────
+    # Fetches only the two timestamp columns needed for avg-hours per assignee.
+    # Using Python arithmetic avoids TIMESTAMPDIFF / strftime dialect issues.
+    res_rows = (
+        db.session.query(
+            Ticket.assigned_to_id,
+            Ticket.created_at,
+            Ticket.resolved_at,
+        )
+        .filter(
+            Ticket.assigned_to_id.in_(it_member_ids),
+            Ticket.resolved_at.isnot(None),
+            Ticket.created_at.isnot(None),
+        )
+        .all()
+    )
+    # Group timestamps by assignee in Python for the avg-hours calculation.
+    res_by_id: dict[int, list[float]] = {}
+    for row in res_rows:
+        hours = (row.resolved_at - row.created_at).total_seconds() / 3600
+        res_by_id.setdefault(row.assigned_to_id, []).append(hours)
+
+    # ── Assemble staff_stats from pre-fetched data ────────────────────────────
+    staff_stats = []
+    for member in it_members:
+        row   = counts_by_id.get(member.id)
+        hours = res_by_id.get(member.id, [])
+        staff_stats.append({
+            'name'          : member.full_name,
+            'assigned_open' : int(row.assigned_open)   if row else 0,
+            'resolved_total': int(row.resolved_total)  if row else 0,
+            'resolved_30d'  : int(row.resolved_30d)    if row else 0,
+            'avg_hours'     : round(sum(hours) / len(hours), 1) if hours else None,
+            'urgent_open'   : int(row.urgent_open)     if row else 0,
+        })
+
+    # Sort by open workload desc
+    staff_stats.sort(key=lambda x: x['assigned_open'], reverse=True)
+
+    # ── 5 most urgent open tickets ────────────────────────────────────────────
+    urgent_tickets = Ticket.query.filter(
+        Ticket.status.in_([TicketStatus.OPEN, TicketStatus.IN_PROGRESS]),
+    ).order_by(
+        # critical first, then high, then by age
+        case(
+            (Ticket.priority == 'critical', 0),
+            (Ticket.priority == 'high',     1),
+            (Ticket.priority == 'medium',   2),
+            else_=3,
+        ),
+        Ticket.created_at.asc(),
+    ).limit(8).all()
+
+    return render_template('admin/index.html',
+        stats               = stats,
+        avg_resolution_hours= avg_resolution_hours,
+        resolved_7d         = resolved_7d,
+        resolved_30d        = resolved_30d,
+        new_7d              = new_7d,
+        new_30d             = new_30d,
+        unassigned          = unassigned,
+        sla_breach          = sla_breach,
+        priority_breakdown  = priority_breakdown,
+        category_breakdown  = category_breakdown,
+        staff_stats         = staff_stats,
+        urgent_tickets      = urgent_tickets,
+        now                 = now,
+    )
 
 
 # ─── User Management ─────────────────────────────────────────────────────────
@@ -127,12 +304,9 @@ def create_user():
             flash('That username is already taken.', 'danger')
             return render_template('admin/create_user.html', roles=_roles(), form=request.form)
 
-        if password != confirm:
+        pw_error = validate_password(password, confirm)
-            flash('Passwords do not match.', 'danger')
+        if pw_error:
-            return render_template('admin/create_user.html', roles=_roles(), form=request.form)
+            flash(pw_error, 'danger')
-
-        if len(password) < 8:
-            flash('Password must be at least 8 characters.', 'danger')
             return render_template('admin/create_user.html', roles=_roles(), form=request.form)
 
         # ── Create ────────────────────────────────────────────────────────────
@@ -147,6 +321,10 @@ def create_user():
         )
         user.set_password(password)
         db.session.add(user)
+        # Flush to obtain user.id from the DB sequence before logging.
+        # Without this flush, user.id is None and the activity log entry
+        # records entity_id=None, making the log entry unlinkable.
+        db.session.flush()
         log_action(current_user.id, 'admin_user_create', 'user', user.id,
                    f'email={email} role={role}')
         db.session.commit()
@@ -172,6 +350,11 @@ def edit_user(user_id):
         user.is_active = bool(request.form.get('is_active'))
         new_pw         = request.form.get('new_password', '')
         if new_pw:
+            confirm_pw = request.form.get('confirm_password', '')
+            pw_error   = validate_password(new_pw, confirm_pw)
+            if pw_error:
+                flash(pw_error, 'danger')
+                return render_template('admin/edit_user.html', user=user, roles=_roles())
             user.set_password(new_pw)
             logger.info(f'[ADMIN PASSWORD RESET] target_user_id={user.id} by admin_id={current_user.id}')
         log_action(current_user.id, 'admin_user_edit', 'user', user.id,
@@ -314,10 +497,13 @@ def kb_upload_image():
     if not f or not f.filename:
         return jsonify({'error': 'No file provided'}), 400
 
-    ext = f.filename.rsplit('.', 1)[-1].lower() if '.' in f.filename else ''
+    _image_exts = {'png', 'jpg', 'jpeg', 'gif', 'webp'}
-    if ext not in {'png', 'jpg', 'jpeg', 'gif', 'webp'}:
+    file_error = validate_file(f, _image_exts)
-        return jsonify({'error': 'Only image files are accepted (PNG, JPG, GIF, WEBP)'}), 400
+    if file_error:
+        logger.warning(f'[KB IMAGE UPLOAD REJECTED] {file_error} filename="{f.filename}" user_id={current_user.id}')
+        return jsonify({'error': file_error}), 400
 
+    ext         = f.filename.rsplit('.', 1)[-1].lower()
     stored_name = f"{uuid.uuid4().hex}.{ext}"
     upload_dir  = current_app.config['UPLOAD_FOLDER']
     os.makedirs(upload_dir, exist_ok=True)
@@ -329,10 +515,20 @@ def kb_upload_image():
 
 # ── File-serve route (images embedded in articles + attachment downloads) ─────
 
-@admin_bp.route('/kb/files/<path:stored_name>')
+@admin_bp.route('/kb/files/<string:stored_name>')
 @login_required
 def kb_serve_file(stored_name):
-    """Serve a KB attachment file. Login required — no public access."""
+    """Serve a KB attachment file. Login required — no public access.
+
+    Security note
+    -------------
+    The <string:> converter is used deliberately instead of <path:>.
+    The <path:> converter permits forward slashes in the captured segment,
+    which would allow a crafted URL like /kb/files/../../etc/passwd to
+    traverse outside the upload directory. <string:> disallows slashes,
+    restricting the value to a flat filename — matching the UUID-based
+    stored_name format (e.g. 'a1b2c3d4e5f6....png') used by all upload helpers.
+    """
     upload_dir = current_app.config['UPLOAD_FOLDER']
     return send_from_directory(upload_dir, stored_name)
 
@@ -400,7 +596,11 @@ def kb_new():
             db.session.flush()
 
             for f in request.files.getlist('attachments'):
-                if f and f.filename and _kb_allowed(f.filename):
+                if f and f.filename:
+                    file_error = validate_file(f, _KB_ALLOWED_EXT)
+                    if file_error:
+                        logger.warning(f'[KB NEW UPLOAD REJECTED] {file_error} filename="{f.filename}" user_id={current_user.id}')
+                        continue
                     att = _save_kb_file(f, article.id)
                     db.session.add(att)
 
@@ -433,7 +633,11 @@ def kb_edit(article_id):
             article.is_published= bool(request.form.get('is_published')) and not bool(request.form.get('_save_as_draft'))
 
             for f in request.files.getlist('attachments'):
-                if f and f.filename and _kb_allowed(f.filename):
+                if f and f.filename:
+                    file_error = validate_file(f, _KB_ALLOWED_EXT)
+                    if file_error:
+                        logger.warning(f'[KB EDIT UPLOAD REJECTED] {file_error} filename="{f.filename}" user_id={current_user.id}')
+                        continue
                     att = _save_kb_file(f, article.id)
                     db.session.add(att)
 

app/routes/auth.py

@@ -6,6 +6,7 @@ from flask_login import login_user, logout_user, login_required, current_user
 from app import db, limiter
 from app.models import User, UserRole
 from app.services.log_service import log_action
+from app.services.validation_service import validate_password
 
 auth_bp = Blueprint('auth', __name__, url_prefix='/auth')
 logger  = logging.getLogger(__name__)
@@ -75,10 +76,10 @@ def register():
             flash('Email already registered.', 'danger')
         elif User.query.filter_by(username=username).first():
             flash('Username already taken.', 'danger')
-        elif password != confirm:
+        else:
-            flash('Passwords do not match.', 'danger')
+            pw_error = validate_password(password, confirm)
-        elif len(password) < 8:
+            if pw_error:
-            flash('Password must be at least 8 characters.', 'danger')
+                flash(pw_error, 'danger')
             else:
                 user = User(
                     email      = email,
@@ -90,6 +91,10 @@ def register():
                 )
                 user.set_password(password)
                 db.session.add(user)
+                # Flush to obtain user.id from the DB sequence before logging.
+                # Without this flush, user.id is None and the activity log entry
+                # records entity_id=None, making the log entry unlinkable.
+                db.session.flush()
                 log_action(user.id, 'user_register', 'user', user.id, f'email={email}')
                 db.session.commit()
                 logger.info(f'[AUTH REGISTER] user_id={user.id} email={email}')
@@ -128,11 +133,9 @@ def profile():
         current_user.web_notif  = web_notif
 
         if new_pw:
-            if new_pw != confirm_pw:
+            pw_error = validate_password(new_pw, confirm_pw)
-                flash('Passwords do not match.', 'danger')
+            if pw_error:
-                return render_template('auth/profile.html')
+                flash(pw_error, 'danger')
-            if len(new_pw) < 8:
-                flash('Password must be at least 8 characters.', 'danger')
                 return render_template('auth/profile.html')
             current_user.set_password(new_pw)
             logger.info(f'[AUTH PASSWORD CHANGE] user_id={current_user.id}')

app/routes/chatbot.py

@@ -3,7 +3,7 @@ import logging
 import requests
 from flask import Blueprint, request, jsonify, current_app
 from flask_login import login_required, current_user
-from app import db
+from app import db, limiter
 from app.models import Ticket, TicketStatus, TicketPriority, TicketCategory
 from app.services.notification_service import notify_new_ticket
 from app.services.log_service import log_action
@@ -79,6 +79,7 @@ def _call_groq(api_key, history, user_msg):
 
 @chatbot_bp.route('/message', methods=['POST'])
 @login_required
+@limiter.limit('20 per minute; 100 per hour')
 def chat():
     data     = request.get_json(force=True)
     history  = data.get('history', [])   # [{role, content}, ...]
@@ -146,6 +147,10 @@ def chat():
                 )
                 ticket.ticket_number = ticket.generate_ticket_number()
                 db.session.add(ticket)
+                # Flush to obtain ticket.id from the DB sequence before logging.
+                # Without this flush, ticket.id is None and the activity log
+                # entry records entity_id=None, making the log entry unlinkable.
+                db.session.flush()
                 log_action(current_user.id, 'ticket_create_chatbot', 'ticket', ticket.id,
                            f'ticket_number={ticket.ticket_number} ai_generated=True')
                 db.session.commit()

app/routes/tickets.py

@@ -15,17 +15,16 @@ from app.services.notification_service import (
     notify_comment_added, notify_assignment,
 )
 from app.services.log_service import log_action, log_ticket_history
+from app.services.validation_service import validate_file
 
 tickets_bp = Blueprint('tickets', __name__)
 logger     = logging.getLogger(__name__)
 
+# Allowed extensions for ticket and comment attachments.
+# validate_file() uses this set for both extension and magic-byte checks.
 ALLOWED_EXT = {'png', 'jpg', 'jpeg', 'gif', 'pdf', 'doc', 'docx', 'txt', 'zip', 'log'}
 
 
-def allowed_file(filename):
-    return '.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_EXT
-
-
 def save_attachment(file, ticket_id=None, comment_id=None, uploader_id=None):
     filename    = secure_filename(file.filename)
     ext         = filename.rsplit('.', 1)[1].lower() if '.' in filename else ''
@@ -114,7 +113,11 @@ def create_ticket():
 
         # Handle file uploads
         for f in request.files.getlist('attachments'):
-            if f and f.filename and allowed_file(f.filename):
+            if f and f.filename:
+                file_error = validate_file(f, ALLOWED_EXT)
+                if file_error:
+                    logger.warning(f'[TICKET UPLOAD REJECTED] {file_error} filename="{f.filename}" user_id={current_user.id}')
+                    continue
                 save_attachment(f, ticket_id=ticket.id, uploader_id=current_user.id)
 
         log_action(current_user.id, 'ticket_create', 'ticket', ticket.id,
@@ -193,7 +196,11 @@ def ticket_detail(ticket_id):
             db.session.flush()
 
             for f in request.files.getlist('attachments'):
-                if f and f.filename and allowed_file(f.filename):
+                if f and f.filename:
+                    file_error = validate_file(f, ALLOWED_EXT)
+                    if file_error:
+                        logger.warning(f'[COMMENT UPLOAD REJECTED] {file_error} filename="{f.filename}" user_id={current_user.id}')
+                        continue
                     save_attachment(f, ticket_id=ticket.id,
                                     comment_id=comment.id, uploader_id=current_user.id)
 
@@ -266,7 +273,7 @@ def update_ticket(ticket_id):
         def _user_label(uid):
             if uid is None:
                 return 'Unassigned'
-            u = User.query.get(uid)
+            u = db.session.get(User, uid)
             return u.full_name if u else f'User #{uid}'
 
         ticket.assigned_to_id = new_assigned
@@ -275,7 +282,7 @@ def update_ticket(ticket_id):
                            _user_label(new_assigned),
                            current_user.id)
         changes.append(f'assigned_to: {old_assigned} → {new_assigned}')
-        notify_assignment(ticket, current_user)
+        # notify_assignment is called AFTER commit below — see Fix #13.
 
     ticket.internal_notes    = internal_notes
     ticket.resolution_notes  = resolution
@@ -291,6 +298,13 @@ def update_ticket(ticket_id):
     db.session.commit()
     logger.info(f'[TICKET UPDATE] ticket_id={ticket.id} changes={changes} by user_id={current_user.id}')
 
+    # Both notification calls are placed after commit so that create_notification's
+    # independent commit never races against an uncommitted ticket state. If the
+    # parent commit above had failed, neither notification would be sent — which
+    # is the correct behaviour (no notification for a change that did not persist).
+    if new_assigned != old_assigned:
+        notify_assignment(ticket, current_user)
+
     if new_status != old_status:
         notify_status_change(ticket, old_status, current_user)
 
@@ -322,6 +336,18 @@ def delete_comment(comment_id):
 @login_required
 def download_attachment(att_id):
     att = Attachment.query.get_or_404(att_id)
+    # Authorization: employees may only download attachments belonging to
+    # their own tickets. IT staff have unrestricted access across all tickets.
+    # att.ticket_id is the authoritative link — comment attachments also carry
+    # the parent ticket_id, so this check covers both ticket and comment files.
+    if not current_user.is_it_staff:
+        ticket = Ticket.query.get_or_404(att.ticket_id)
+        if ticket.created_by_id != current_user.id:
+            logger.warning(
+                f'[ATTACHMENT ACCESS DENIED] att_id={att_id} ticket_id={att.ticket_id} '
+                f'user_id={current_user.id}'
+            )
+            abort(403)
     upload_dir = current_app.config['UPLOAD_FOLDER']
     return send_from_directory(upload_dir, att.stored_name, as_attachment=True,
                                download_name=att.filename)
@@ -385,8 +411,20 @@ def knowledge_base():
 @login_required
 def kb_article(article_id):
     article = KnowledgeBase.query.get_or_404(article_id)
-    article.view_count += 1
+    # Increment view_count atomically at the SQL level. A Python-level
+    # read-modify-write (article.view_count += 1) is not safe under concurrent
+    # requests: two simultaneous reads both see the same value and one
+    # increment is silently lost. The SQL expression KnowledgeBase.view_count + 1
+    # delegates the addition to the database, which serialises it correctly.
+    from sqlalchemy import update as sa_update
+    db.session.execute(
+        sa_update(KnowledgeBase)
+        .where(KnowledgeBase.id == article_id)
+        .values(view_count=KnowledgeBase.view_count + 1)
+    )
     db.session.commit()
+    # Re-fetch so the template receives the post-increment value.
+    db.session.refresh(article)
     return render_template('tickets/kb_article.html', article=article)
 
 

app/services/log_service.py

@@ -54,8 +54,16 @@ def log_action(user_id, action, entity_type=None, entity_id=None, details=None):
     own business objects. This ensures the log entry is only persisted when
     the parent operation succeeds — an independent commit here would leave
     orphaned log entries for operations that were subsequently rolled back.
+
+    Error isolation
+    ---------------
+    On failure, only the log entry itself is expelled from the session via
+    expunge(). db.session.rollback() is intentionally NOT called here because
+    that would wipe the entire session — silently undoing the parent business
+    operation (ticket creation, user update, etc.) that triggered this log call.
     """
     ip = _get_real_ip()
+    entry = None
 
     try:
         entry = ActivityLog(
@@ -74,8 +82,14 @@ def log_action(user_id, action, entity_type=None, entity_id=None, details=None):
             f'user_id={user_id} ip={ip}'
         )
     except Exception as exc:
-        db.session.rollback()
+        # Expunge only the failed log entry — do NOT roll back the full session,
-        logger.error(f'[ACTIVITY LOG ERROR] {exc}')
+        # as that would undo the parent operation that called this function.
+        if entry is not None:
+            try:
+                db.session.expunge(entry)
+            except Exception:
+                pass
+        logger.error(f'[ACTIVITY LOG ERROR] action={action} entity={entity_type}:{entity_id} error={exc}')
 
 
 def log_ticket_history(ticket, field_name, old_value, new_value, changed_by_id):
@@ -85,8 +99,15 @@ def log_ticket_history(ticket, field_name, old_value, new_value, changed_by_id):
     ----------------
     Like log_action, this function does NOT commit — the caller is responsible
     for committing the session after all field changes have been recorded.
+
+    Error isolation
+    ---------------
+    On failure, only the failed history entry is expelled from the session.
+    db.session.rollback() is intentionally NOT called here — that would undo
+    the parent ticket update that triggered this history recording.
     """
     from app.models import TicketHistory
+    entry = None
     try:
         entry = TicketHistory(
             ticket_id  = ticket.id,
@@ -102,5 +123,11 @@ def log_ticket_history(ticket, field_name, old_value, new_value, changed_by_id):
             f'"{old_value}" -> "{new_value}" by user_id={changed_by_id}'
         )
     except Exception as exc:
-        db.session.rollback()
+        # Expunge only the failed history entry — do NOT roll back the full
-        logger.error(f'[TICKET HISTORY ERROR] {exc}')
+        # session, as that would undo the parent ticket update.
+        if entry is not None:
+            try:
+                db.session.expunge(entry)
+            except Exception:
+                pass
+        logger.error(f'[TICKET HISTORY ERROR] ticket_id={ticket.id} field={field_name} error={exc}')

app/services/notification_service.py

@@ -251,7 +251,7 @@ def notify_comment_added(comment):
             ticket_id = ticket.id,
             link      = f'/tickets/{ticket.id}#comment-{comment.id}',
         )
-        user = User.query.get(user_id)
+        user = db.session.get(User, user_id)
         if user and user.email_notif and not is_internal:
             html = render_template_string(_STATUS_UPDATE_EMAIL,
                 ticket_number = ticket.ticket_number,

app/services/validation_service.py

@@ -0,0 +1,179 @@
+"""
+Shared validation helpers used across multiple route modules.
+
+Centralising these here prevents logic divergence that arises from
+copy-pasting validation code into auth.py, admin.py, and future modules.
+"""
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+# ─── Password Validation ──────────────────────────────────────────────────────
+
+def validate_password(password: str, confirm: str) -> str | None:
+    """Validate a new password and its confirmation field.
+
+    Returns an error message string if validation fails, or None if the
+    password is acceptable. Callers should flash the returned message with
+    the 'danger' category and return early.
+
+    Rules
+    -----
+    - Password and confirmation must match.
+    - Minimum length: 8 characters.
+
+    Parameters
+    ----------
+    password : str  – the candidate password (plain text)
+    confirm  : str  – the confirmation field value
+    """
+    if password != confirm:
+        return 'Passwords do not match.'
+    if len(password) < 8:
+        return 'Password must be at least 8 characters.'
+    return None
+
+
+# ─── File MIME-Type Validation ────────────────────────────────────────────────
+
+# Magic-byte signatures for every extension in ALLOWED_EXT / _KB_ALLOWED_EXT.
+# Format: extension → list of (offset, bytes) tuples that must ALL be present.
+# Using raw magic bytes avoids a dependency on python-magic / libmagic while
+# still catching the "renamed shell.php → shell.pdf" class of attack.
+#
+# References: https://en.wikipedia.org/wiki/List_of_file_signatures
+_MAGIC: dict[str, list[tuple[int, bytes]]] = {
+    'png' : [(0, b'\x89PNG\r\n\x1a\n')],
+    'jpg' : [(0, b'\xff\xd8\xff')],
+    'jpeg': [(0, b'\xff\xd8\xff')],
+    'gif' : [(0, b'GIF87a'), (0, b'GIF89a')],          # either signature is valid
+    'webp': [(0, b'RIFF'), (8, b'WEBP')],
+    'pdf' : [(0, b'%PDF')],
+    'zip' : [(0, b'PK\x03\x04')],
+    # Office Open XML (.docx, .xlsx, .pptx) are ZIP archives internally
+    'docx': [(0, b'PK\x03\x04')],
+    'xlsx': [(0, b'PK\x03\x04')],
+    'pptx': [(0, b'PK\x03\x04')],
+    # Legacy OLE2 compound document (.doc, .xls, .ppt)
+    'doc' : [(0, b'\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1')],
+    'xls' : [(0, b'\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1')],
+    'ppt' : [(0, b'\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1')],
+    # Plain-text formats — no reliable magic bytes; skip byte check
+    'txt' : [],
+    'csv' : [],
+    'log' : [],
+}
+
+# Maximum number of bytes to read for magic-byte inspection.
+# 12 bytes covers all signatures above (WEBP needs offset 8 + 4 = 12).
+_MAGIC_READ_BYTES = 12
+
+# Per-file size cap (bytes). Mirrors MAX_CONTENT_LENGTH so a single
+# large file cannot saturate the total-request budget on its own.
+_MAX_FILE_BYTES = 16 * 1024 * 1024   # 16 MB
+
+
+def validate_file(file, allowed_extensions: set[str]) -> str | None:
+    """Validate an uploaded file object by extension, size, and magic bytes.
+
+    Returns an error message string if validation fails, or None on success.
+    The file stream seek position is reset to 0 after inspection so callers
+    can still read or save the file normally.
+
+    Parameters
+    ----------
+    file               : werkzeug FileStorage object
+    allowed_extensions : set of lowercase extension strings (without leading dot)
+
+    Checks performed
+    ----------------
+    1. Extension is in the allowed set.
+    2. File does not exceed the per-file size cap (_MAX_FILE_BYTES).
+    3. Magic bytes in the file content match the declared extension, where
+       a known signature exists. Plain-text types (txt, csv, log) are
+       accepted on extension alone since they have no reliable magic bytes.
+    """
+    filename = file.filename or ''
+    if '.' not in filename:
+        return 'File has no extension.'
+
+    ext = filename.rsplit('.', 1)[1].lower()
+
+    # ── 1. Extension check ────────────────────────────────────────────────────
+    if ext not in allowed_extensions:
+        return f'File type ".{ext}" is not permitted.'
+
+    # ── 2. Size check ─────────────────────────────────────────────────────────
+    # Read the file in chunks to measure size without loading it all into RAM,
+    # then seek back to the start so the caller can still save it.
+    file.stream.seek(0, 2)           # seek to end
+    file_size = file.stream.tell()   # position == size
+    file.stream.seek(0)              # rewind
+
+    if file_size > _MAX_FILE_BYTES:
+        mb = _MAX_FILE_BYTES // (1024 * 1024)
+        return f'File exceeds the {mb} MB per-file size limit.'
+
+    # ── 3. Magic-byte check ───────────────────────────────────────────────────
+    signatures = _MAGIC.get(ext)
+    if signatures is None:
+        # Extension is allowed but has no entry in _MAGIC — treat as safe.
+        # This handles future extensions added to ALLOWED_EXT without a
+        # corresponding _MAGIC entry; log a warning for visibility.
+        logger.warning(f'[FILE VALIDATION] No magic signature defined for ext="{ext}"; skipping byte check.')
+        return None
+
+    if not signatures:
+        # Explicit empty list means "no magic bytes available for this type"
+        # (txt, csv, log) — accepted on extension alone.
+        return None
+
+    header = file.stream.read(_MAGIC_READ_BYTES)
+    file.stream.seek(0)   # rewind after inspection
+
+    # For extensions with multiple valid signatures (e.g. GIF87a / GIF89a)
+    # the file is valid if ANY of the listed signatures matches.
+    matched = False
+    for sigs in _group_by_alternative(signatures):
+        # Each alternative is a list of (offset, bytes) pairs that must ALL match.
+        if all(header[offset:offset + len(magic)] == magic for offset, magic in sigs):
+            matched = True
+            break
+
+    if not matched:
+        logger.warning(
+            f'[FILE VALIDATION] Magic-byte mismatch: filename="{filename}" ext="{ext}" '
+            f'header={header.hex()}'
+        )
+        return f'File content does not match its declared type (.{ext}).'
+
+    return None
+
+
+def _group_by_alternative(
+    signatures: list[tuple[int, bytes]],
+) -> list[list[tuple[int, bytes]]]:
+    """Split a flat signature list into per-alternative groups.
+
+    For most extensions there is a single signature, so this returns
+    [[sig1, sig2, ...]]. For GIF (two valid headers) it returns
+    [[gif87_sig], [gif89_sig]] so the caller can treat each inner list as
+    a complete match candidate.
+
+    The rule: each entry with offset=0 starts a new alternative group.
+    Entries with offset>0 are appended to the current group (they are
+    additional constraints on the same file type, e.g. WEBP needs both
+    offset-0 'RIFF' and offset-8 'WEBP').
+    """
+    groups: list[list[tuple[int, bytes]]] = []
+    for offset, magic in signatures:
+        if offset == 0:
+            groups.append([(offset, magic)])
+        else:
+            if groups:
+                groups[-1].append((offset, magic))
+            else:
+                groups.append([(offset, magic)])
+    return groups if groups else [[]]

app/templates/admin/index.html

@@ -3,15 +3,16 @@
 {% block page_title %}IT Operations Overview{% endblock %}
 
 {% block content %}
-<!-- Stats grid -->
+
+{# ── Headline stat cards ───────────────────────────────────────────────────── #}
 <div class="row g-3 mb-4">
   {% for label, value, icon, color, bg in [
     ('Total Tickets',  stats.total_tickets, 'bi-collection',  'var(--text)',    'rgba(255,255,255,.05)'),
     ('Open',           stats.open,          'bi-circle',      'var(--info)',    'rgba(96,165,250,.1)'),
-    ('In Progress', stats.in_progress, 'bi-arrow-repeat', 'var(--accent3)', 'rgba(0,180,216,.1)'),
+    ('In Progress',    stats.in_progress,   'bi-arrow-repeat','var(--accent3)','rgba(0,180,216,.1)'),
-    ('Resolved', stats.resolved, 'bi-check-circle', 'var(--success)', 'rgba(45,212,191,.1)'),
+    ('Resolved',       stats.resolved,      'bi-check-circle','var(--success)','rgba(45,212,191,.1)'),
     ('Closed',         stats.closed,        'bi-archive',     'var(--muted)',  'rgba(112,112,160,.1)'),
-    ('Active Users', stats.total_users, 'bi-people', 'var(--accent2)', 'rgba(123,94,167,.1)'),
+    ('Active Users',   stats.total_users,   'bi-people',      'var(--accent2)','rgba(123,94,167,.1)'),
   ] %}
   <div class="col-6 col-xl-2">
     <div class="stat-card">
@@ -25,44 +26,236 @@
   {% endfor %}
 </div>
 
-<!-- Activity log -->
+{# ── Row 1: Performance KPIs + Priority breakdown ─────────────────────────── #}
-<div class="card">
+<div class="row g-3 mb-4">
-  <div class="card-header d-flex align-items-center justify-content-between">
+
-    <span><i class="bi bi-activity me-2"></i>Recent Activity</span>
+  {# KPI cards #}
-    {% if current_user.is_admin %}
+  <div class="col-lg-8">
-    <a href="{{ url_for('admin.activity_logs') }}" style="font-size:12px;color:var(--accent3);">Full log →</a>
+    <div class="card h-100">
-    {% endif %}
+      <div class="card-header"><i class="bi bi-speedometer2 me-2"></i>IT Performance — Last 30 Days</div>
+      <div class="card-body">
+        <div class="row g-3">
+
+          {# Avg resolution time #}
+          <div class="col-6 col-lg-3">
+            <div style="text-align:center;padding:12px;background:var(--surface2);border-radius:10px;">
+              <div style="font-size:26px;font-weight:700;
+                color:{% if avg_resolution_hours is none %}var(--muted)
+                      {% elif avg_resolution_hours <= 24 %}var(--success)
+                      {% elif avg_resolution_hours <= 72 %}var(--warning)
+                      {% else %}var(--danger){% endif %};">
+                {% if avg_resolution_hours is none %}—
+                {% elif avg_resolution_hours >= 24 %}{{ (avg_resolution_hours / 24)|round(1) }}d
+                {% else %}{{ avg_resolution_hours }}h{% endif %}
               </div>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px;">Avg Resolution Time</div>
+            </div>
+          </div>
+
+          {# Resolved last 7d #}
+          <div class="col-6 col-lg-3">
+            <div style="text-align:center;padding:12px;background:var(--surface2);border-radius:10px;">
+              <div style="font-size:26px;font-weight:700;color:var(--success);">{{ resolved_7d }}</div>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px;">Resolved (7 days)</div>
+            </div>
+          </div>
+
+          {# New last 7d #}
+          <div class="col-6 col-lg-3">
+            <div style="text-align:center;padding:12px;background:var(--surface2);border-radius:10px;">
+              <div style="font-size:26px;font-weight:700;color:var(--info);">{{ new_7d }}</div>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px;">New (7 days)</div>
+            </div>
+          </div>
+
+          {# Resolution rate 30d #}
+          <div class="col-6 col-lg-3">
+            {% set rate = ((resolved_30d / new_30d * 100)|int) if new_30d > 0 else 0 %}
+            <div style="text-align:center;padding:12px;background:var(--surface2);border-radius:10px;">
+              <div style="font-size:26px;font-weight:700;
+                color:{% if rate >= 80 %}var(--success){% elif rate >= 50 %}var(--warning){% else %}var(--danger){% endif %};">
+                {{ rate }}%
+              </div>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px;">Resolution Rate (30d)</div>
+            </div>
+          </div>
+
+          {# Unassigned #}
+          <div class="col-6 col-lg-3">
+            <a href="{{ url_for('admin.all_tickets', assigned='unassigned') }}" style="text-decoration:none;">
+              <div style="text-align:center;padding:12px;background:var(--surface2);border-radius:10px;cursor:pointer;">
+                <div style="font-size:26px;font-weight:700;color:{% if unassigned > 0 %}var(--warning){% else %}var(--success){% endif %};">
+                  {{ unassigned }}
+                </div>
+                <div style="font-size:11px;color:var(--muted);margin-top:4px;">Unassigned Open</div>
+              </div>
+            </a>
+          </div>
+
+          {# SLA at-risk #}
+          <div class="col-6 col-lg-3">
+            <div style="text-align:center;padding:12px;background:var(--surface2);border-radius:10px;">
+              <div style="font-size:26px;font-weight:700;color:{% if sla_breach > 0 %}var(--danger){% else %}var(--success){% endif %};">
+                {{ sla_breach }}
+              </div>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px;">SLA At-Risk (&gt;3 days)</div>
+            </div>
+          </div>
+
+          {# Resolved 30d #}
+          <div class="col-6 col-lg-3">
+            <div style="text-align:center;padding:12px;background:var(--surface2);border-radius:10px;">
+              <div style="font-size:26px;font-weight:700;color:var(--success);">{{ resolved_30d }}</div>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px;">Resolved (30 days)</div>
+            </div>
+          </div>
+
+          {# New 30d #}
+          <div class="col-6 col-lg-3">
+            <div style="text-align:center;padding:12px;background:var(--surface2);border-radius:10px;">
+              <div style="font-size:26px;font-weight:700;color:var(--info);">{{ new_30d }}</div>
+              <div style="font-size:11px;color:var(--muted);margin-top:4px;">New (30 days)</div>
+            </div>
+          </div>
+
+        </div>
+      </div>
+    </div>
+  </div>
+
+  {# Priority breakdown #}
+  <div class="col-lg-4">
+    <div class="card h-100">
+      <div class="card-header"><i class="bi bi-bar-chart me-2"></i>Open by Priority</div>
+      <div class="card-body">
+        {% set total_open = priority_breakdown.values()|sum %}
+        {% for priority, count in [
+          ('critical', priority_breakdown.critical),
+          ('high',     priority_breakdown.high),
+          ('medium',   priority_breakdown.medium),
+          ('low',      priority_breakdown.low),
+        ] %}
+        <div class="mb-3">
+          <div class="d-flex justify-content-between align-items-center mb-1">
+            <span class="badge badge-{{ priority }}" style="font-size:11px;">{{ priority.upper() }}</span>
+            <span style="font-size:13px;font-weight:600;">{{ count }}</span>
+          </div>
+          <div style="height:6px;background:var(--surface2);border-radius:3px;overflow:hidden;">
+            <div style="height:100%;width:{{ ((count / total_open * 100)|int) if total_open > 0 else 0 }}%;
+              background:{% if priority=='critical' %}#374151{% elif priority=='high' %}var(--danger){% elif priority=='medium' %}var(--warning){% else %}var(--success){% endif %};
+              border-radius:3px;transition:width .4s;"></div>
+          </div>
+        </div>
+        {% endfor %}
+
+        <hr style="border-color:var(--border);margin:12px 0;">
+        <div style="font-size:12px;color:var(--muted);">Open by Category</div>
+        <div class="mt-2">
+          {% for cat, count in category_breakdown %}
+          {% if count > 0 %}
+          <div class="d-flex justify-content-between" style="font-size:12px;padding:3px 0;border-bottom:1px solid var(--border);">
+            <span style="color:var(--muted);">{{ cat }}</span>
+            <span style="font-weight:600;">{{ count }}</span>
+          </div>
+          {% endif %}
+          {% endfor %}
+        </div>
+      </div>
+    </div>
+  </div>
+</div>
+
+{# ── Row 2: Staff performance + Urgent queue ──────────────────────────────── #}
+<div class="row g-3">
+
+  {# Staff performance table #}
+  <div class="col-lg-7">
+    <div class="card">
+      <div class="card-header"><i class="bi bi-people me-2"></i>IT Staff Performance</div>
       <div class="card-body p-0">
+        {% if staff_stats %}
         <table class="table mb-0">
           <thead>
             <tr>
-          <th>Action</th>
+              <th>Staff Member</th>
-          <th>User</th>
+              <th style="text-align:center;">Open</th>
-          <th>Entity</th>
+              <th style="text-align:center;">Urgent</th>
-          <th>Details</th>
+              <th style="text-align:center;">Resolved (30d)</th>
-          <th>Time</th>
+              <th style="text-align:center;">Avg Time</th>
+              <th style="text-align:center;">Total Resolved</th>
             </tr>
           </thead>
           <tbody>
-        {% for log in recent_logs %}
+            {% for s in staff_stats %}
             <tr>
-          <td>
+              <td style="font-size:13px;font-weight:500;">{{ s.name }}</td>
-            <span class="mono" style="font-size:11px;
+              <td style="text-align:center;">
-              color:{% if 'create' in log.action %}var(--success){% elif 'delete' in log.action %}var(--danger){% elif 'update' in log.action or 'edit' in log.action %}var(--warning){% else %}var(--muted){% endif %};">
+                <span style="font-size:13px;font-weight:600;color:{% if s.assigned_open > 5 %}var(--danger){% elif s.assigned_open > 2 %}var(--warning){% else %}var(--success){% endif %};">
-              {{ log.action }}
+                  {{ s.assigned_open }}
                 </span>
               </td>
-          <td style="font-size:13px;">
+              <td style="text-align:center;">
-            {% if log.user %}{{ log.user.full_name }}{% else %}<span style="color:var(--muted);">System</span>{% endif %}
+                {% if s.urgent_open > 0 %}
+                <span style="font-size:12px;font-weight:600;color:var(--danger);">{{ s.urgent_open }}</span>
+                {% else %}
+                <span style="font-size:12px;color:var(--success);"><i class="bi bi-check2"></i></span>
+                {% endif %}
               </td>
-          <td style="font-size:12px;color:var(--muted);">{{ log.entity_type or '—' }} {% if log.entity_id %}#{{ log.entity_id }}{% endif %}</td>
+              <td style="text-align:center;font-size:13px;color:var(--success);font-weight:600;">{{ s.resolved_30d }}</td>
-          <td style="font-size:12px;color:var(--muted);max-width:220px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;">{{ log.details or '—' }}</td>
+              <td style="text-align:center;font-size:12px;color:var(--muted);">
-          <td style="font-size:11px;color:var(--muted);font-family:'Space Mono',monospace;">{{ log.created_at.strftime('%b %d %H:%M') }}</td>
+                {% if s.avg_hours is none %}—
+                {% elif s.avg_hours >= 24 %}{{ (s.avg_hours / 24)|round(1) }}d
+                {% else %}{{ s.avg_hours }}h{% endif %}
+              </td>
+              <td style="text-align:center;font-size:12px;color:var(--muted);">{{ s.resolved_total }}</td>
             </tr>
             {% endfor %}
           </tbody>
         </table>
+        {% else %}
+        <div class="p-4 text-center" style="color:var(--muted);font-size:13px;">No IT staff found.</div>
+        {% endif %}
       </div>
+    </div>
+  </div>
+
+  {# Urgent open tickets queue #}
+  <div class="col-lg-5">
+    <div class="card">
+      <div class="card-header d-flex align-items-center justify-content-between">
+        <span><i class="bi bi-exclamation-triangle me-2"></i>Needs Attention</span>
+        <a href="{{ url_for('admin.all_tickets', status='open') }}" style="font-size:12px;color:var(--accent3);">View all →</a>
+      </div>
+      <div class="card-body p-0">
+        {% if urgent_tickets %}
+        {% for t in urgent_tickets %}
+        <a href="{{ url_for('tickets.ticket_detail', ticket_id=t.id) }}"
+           style="display:flex;align-items:center;gap:10px;padding:10px 16px;border-bottom:1px solid var(--border);color:var(--text);text-decoration:none;">
+          <span class="badge badge-{{ t.priority }}" style="flex-shrink:0;font-size:10px;">{{ t.priority.upper() }}</span>
+          <div style="flex:1;min-width:0;">
+            <div style="font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;">{{ t.title }}</div>
+            <div style="font-size:11px;color:var(--muted);">
+              {{ t.ticket_number }} · {{ t.creator.full_name.split()[0] }} ·
+              {% set age = ((now - t.created_at).total_seconds() / 3600)|int %}
+              {% if age >= 24 %}{{ (age / 24)|int }}d ago{% else %}{{ age }}h ago{% endif %}
+            </div>
+          </div>
+          {% if t.assignee %}
+          <span style="font-size:11px;color:var(--muted);flex-shrink:0;">{{ t.assignee.full_name.split()[0] }}</span>
+          {% else %}
+          <span style="font-size:11px;color:var(--warning);flex-shrink:0;font-style:italic;">Unassigned</span>
+          {% endif %}
+        </a>
+        {% endfor %}
+        {% else %}
+        <div class="p-4 text-center" style="color:var(--success);font-size:13px;">
+          <i class="bi bi-check2-all" style="font-size:28px;display:block;margin-bottom:8px;"></i>
+          All caught up — no urgent open tickets.
+        </div>
+        {% endif %}
+      </div>
+    </div>
+  </div>
+
 </div>
 {% endblock %}