Update app.py

app.py

@@ -1,753 +1,748 @@
-import os
-import re
-import csv
-import secrets
-import unicodedata
-from datetime import datetime, timedelta
-from io import BytesIO
-
-from flask import (
-    Flask,
-    render_template,
-    request,
-    redirect,
-    url_for,
-    send_file,
-    flash,
-    session,
-    abort,
-)
-from flask_sqlalchemy import SQLAlchemy
-from flask_login import (
-    LoginManager,
-    UserMixin,
-    login_user,
-    login_required,
-    current_user,
-    logout_user,
-)
-from werkzeug.security import generate_password_hash, check_password_hash
-from reportlab.pdfgen import canvas
-from reportlab.lib.pagesizes import letter
-
-from sendgrid import SendGridAPIClient
-from sendgrid.helpers.mail import Mail
-
-# your HF-based classifier
-from model import classify_tone_rich
-
-
-# =========================================================
-# APP CONFIG
-# =========================================================
-
-app = Flask(__name__)
-
-app.config["SECRET_KEY"] = os.getenv("SECRET_KEY", "change-this-in-prod")
-app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///data.db"
-app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
-
-# cookie security
-app.config["SESSION_COOKIE_HTTPONLY"] = True
-app.config["SESSION_COOKIE_SAMESITE"] = "Lax"
-
-db = SQLAlchemy(app)
-login_manager = LoginManager(app)
-login_manager.login_view = "login"
-
-# Email (SendGrid)
-SENDGRID_API_KEY = os.getenv("SENDGRID_API_KEY")
-SENDER_EMAIL = os.getenv("SENDER_EMAIL", "no-reply@example.com")
-
-# simple email regex
-EMAIL_RE = re.compile(r"^[^@\s]+@[^@\s]+\.[^@\s]+$")
-
-os.makedirs("exports", exist_ok=True)
-
-
-# =========================================================
-# HELPER FUNCTIONS – SANITIZATION, CSRF, PASSWORDS
-# =========================================================
-
-def normalize_text(value: str) -> str:
-    if not value:
-        return ""
-    value = unicodedata.normalize("NFKC", value)
-    value = value.replace("\u200b", "").replace("\u200c", "").replace("\u200d", "")
-    return value.strip()
-
-
-def sanitize_string(value: str, max_len: int = 255) -> str:
-    value = normalize_text(value)
-    if len(value) > max_len:
-        value = value[:max_len]
-    return value
-
-
-def sanitize_long_text(value: str, max_len: int = 4000) -> str:
-    value = normalize_text(value)
-    if len(value) > max_len:
-        value = value[:max_len]
-    return value
-
-
-def is_valid_email(email: str) -> bool:
-    return bool(email and EMAIL_RE.match(email))
-
-
-def is_strong_password(pw: str) -> bool:
-    if not pw or len(pw) < 8:
-        return False
-    has_letter = any(c.isalpha() for c in pw)
-    has_digit = any(c.isdigit() for c in pw)
-    return has_letter and has_digit
-
-
-def generate_code() -> str:
-    """6-digit numeric code used for verify + reset."""
-    return f"{secrets.randbelow(1000000):06d}"
-
-
-def generate_csrf_token() -> str:
-    token = session.get("csrf_token")
-    if not token:
-        token = secrets.token_hex(16)
-        session["csrf_token"] = token
-    return token
-
-
-@app.before_request
-def csrf_protect():
-    # ensure CSRF token exists
-    generate_csrf_token()
-
-    if request.method == "POST":
-        form_token = request.form.get("csrf_token", "")
-        sess_token = session.get("csrf_token", "")
-        if not form_token or form_token != sess_token:
-            abort(400, description="Invalid CSRF token")
-
-
-@app.context_processor
-def inject_csrf():
-    return {"csrf_token": session.get("csrf_token", "")}
-
-
-# =========================================================
-# MODELS
-# =========================================================
-
-class User(UserMixin, db.Model):
-    id = db.Column(db.Integer, primary_key=True)
-    email = db.Column(db.String(255), unique=True, nullable=False)
-    password_hash = db.Column(db.String(255), nullable=False)
-    created_at = db.Column(db.DateTime, default=datetime.utcnow)
-
-    # login security
-    failed_logins = db.Column(db.Integer, default=0)
-    lock_until = db.Column(db.DateTime, nullable=True)
-
-    # email verification
-    is_verified = db.Column(db.Boolean, default=False)
-    verification_code = db.Column(db.String(6), nullable=True)
-    verification_expires = db.Column(db.DateTime, nullable=True)
-
-    # password reset
-    reset_code = db.Column(db.String(6), nullable=True)
-    reset_expires = db.Column(db.DateTime, nullable=True)
-
-    # activity (for possible retention rules)
-    last_active_at = db.Column(db.DateTime, nullable=True)
-
-
-class Entry(db.Model):
-    id = db.Column(db.Integer, primary_key=True)
-    created_at = db.Column(db.DateTime, default=datetime.utcnow)
-    text = db.Column(db.Text, nullable=False)
-    label = db.Column(db.String(32))
-    confidence = db.Column(db.Float)
-    severity = db.Column(db.Integer)
-    threat_score = db.Column(db.Integer)
-    politeness_score = db.Column(db.Integer)
-    friendly_score = db.Column(db.Integer)
-    has_threat = db.Column(db.Boolean, default=False)
-    has_profanity = db.Column(db.Boolean, default=False)
-    has_sarcasm = db.Column(db.Boolean, default=False)
-    user_id = db.Column(db.Integer, db.ForeignKey("user.id"), nullable=False)
-
-    user = db.relationship("User", backref="entries")
-
-
-@login_manager.user_loader
-def load_user(user_id):
-    try:
-        return User.query.get(int(user_id))
-    except Exception:
-        return None
-
-
-# =========================================================
-# EMAIL HELPERS
-# =========================================================
-
-def send_email(to_email: str, subject: str, html: str):
-    if not SENDGRID_API_KEY:
-        print("[WARN] SENDGRID_API_KEY not set. Skipping email send.")
-        print(f"Subject: {subject}\nTo: {to_email}\n{html}")
-        return
-
-    message = Mail(
-        from_email=SENDER_EMAIL,
-        to_emails=to_email,
-        subject=subject,
-        html_content=html,
-    )
-    try:
-        sg = SendGridAPIClient(SENDGRID_API_KEY)
-        sg.send(message)
-        print(f"[INFO] Sent email to {to_email}: {subject}")
-    except Exception as e:
-        print(f"[ERROR] Failed to send email to {to_email}: {e}")
-
-
-def send_verification_email(to_email: str, code: str):
-    html = f"""
-    <p>Thanks for signing up for the AI Email Tone Classifier.</p>
-    <p>Your verification code is: <strong>{code}</strong></p>
-    <p>This code will expire in 15 minutes.</p>
-    """
-    send_email(to_email, "Verify your email", html)
-
-
-def send_password_reset_email(to_email: str, code: str):
-    html = f"""
-    <p>You requested to reset your password for the AI Email Tone Classifier.</p>
-    <p>Your password reset code is: <strong>{code}</strong></p>
-    <p>This code will expire in 15 minutes.</p>
-    <p>If you did not request this, you can ignore this email.</p>
-    """
-    send_email(to_email, "Password reset code", html)
-
-
-# =========================================================
-# AUTH ROUTES: REGISTER / LOGIN / LOGOUT / VERIFY
-# =========================================================
-
-@app.route("/register", methods=["GET", "POST"])
-def register():
-    if current_user.is_authenticated:
-        return redirect(url_for("index"))
-
-    if request.method == "POST":
-        email = sanitize_string(request.form.get("email", ""), 255).lower()
-        password = normalize_text(request.form.get("password", ""))
-        consent = request.form.get("consent_privacy") == "on"
-
-        if not email or not password:
-            flash("Email and password are required.", "error")
-            return redirect(url_for("register"))
-
-        if not is_valid_email(email):
-            flash("Please enter a valid email address.", "error")
-            return redirect(url_for("register"))
-
-        if not is_strong_password(password):
-            flash("Password must be at least 8 characters and contain letters and numbers.", "error")
-            return redirect(url_for("register"))
-
-        if not consent:
-            flash("You must agree to the Privacy Policy to create an account.", "error")
-            return redirect(url_for("register"))
-
-        existing = User.query.filter_by(email=email).first()
-        if existing:
-            flash("An account with that email already exists.", "error")
-            return redirect(url_for("register"))
-
-        user = User(
-            email=email,
-            password_hash=generate_password_hash(password),
-            last_active_at=datetime.utcnow(),
-        )
-
-        code = generate_code()
-        user.verification_code = code
-        user.verification_expires = datetime.utcnow() + timedelta(minutes=15)
-        user.is_verified = False
-
-        db.session.add(user)
-        db.session.commit()
-
-        send_verification_email(email, code)
-        session["pending_email"] = email
-
-        flash("Account created. Check your email for the verification code.", "success")
-        return redirect(url_for("verify"))
-
-    return render_template("login.html", mode="register", title="Register")
-
-
-@app.route("/login", methods=["GET", "POST"])
-def login():
-    if current_user.is_authenticated:
-        return redirect(url_for("index"))
-
-    if request.method == "POST":
-        email = sanitize_string(request.form.get("email", ""), 255).lower()
-        password = normalize_text(request.form.get("password", ""))
-
-        if not email or not password:
-            flash("Email and password are required.", "error")
-            return redirect(url_for("login"))
-
-        user = User.query.filter_by(email=email).first()
-        if not user:
-            flash("Invalid email or password.", "error")
-            return redirect(url_for("login"))
-
-        now = datetime.utcnow()
-
-        # lockout check
-        if user.lock_until and user.lock_until > now:
-            remaining = int((user.lock_until - now).total_seconds() // 60) + 1
-            flash(f"Account locked due to too many failed attempts. Try again in ~{remaining} minutes.", "error")
-            return redirect(url_for("login"))
-
-        if not check_password_hash(user.password_hash, password):
-            user.failed_logins = (user.failed_logins or 0) + 1
-            if user.failed_logins >= 5:
-                user.lock_until = now + timedelta(minutes=10)
-                user.failed_logins = 0
-            db.session.commit()
-            flash("Invalid email or password.", "error")
-            return redirect(url_for("login"))
-
-        # reset counters
-        user.failed_logins = 0
-        user.lock_until = None
-        user.last_active_at = now
-        db.session.commit()
-
-        if not user.is_verified:
-            session["pending_email"] = user.email
-            flash("Please verify your email before logging in.", "error")
-            return redirect(url_for("verify"))
-
-        login_user(user)
-        flash("Logged in successfully.", "success")
-        return redirect(url_for("index"))
-
-    return render_template("login.html", mode="login", title="Login")
-
-
-@app.route("/logout")
-@login_required
-def logout():
-    logout_user()
-    flash("You have been logged out.", "success")
-    return redirect(url_for("login"))
-
-
-@app.route("/verify", methods=["GET", "POST"])
-def verify():
-    email = sanitize_string(
-        request.args.get("email", "") or session.get("pending_email", ""), 255
-    ).lower()
-
-    if not email:
-        flash("No email specified for verification. Please register or log in again.", "error")
-        return redirect(url_for("register"))
-
-    user = User.query.filter_by(email=email).first()
-    if not user:
-        flash("Account not found. Please register again.", "error")
-        return redirect(url_for("register"))
-
-    if user.is_verified:
-        flash("Your email is already verified. You can log in.", "success")
-        return redirect(url_for("login"))
-
-    if request.method == "POST":
-        action = request.form.get("action", "verify")
-
-        if action == "resend":
-            code = generate_code()
-            user.verification_code = code
-            user.verification_expires = datetime.utcnow() + timedelta(minutes=15)
-            db.session.commit()
-            send_verification_email(user.email, code)
-            flash("A new verification code has been sent.", "success")
-            return redirect(url_for("verify", email=user.email))
-
-        code_input = sanitize_string(request.form.get("code", ""), 6)
-
-        if not code_input:
-            flash("Please enter the verification code.", "error")
-            return redirect(url_for("verify", email=user.email))
-
-        if not user.verification_code or not user.verification_expires:
-            flash("No active verification code. Please resend.", "error")
-            return redirect(url_for("verify", email=user.email))
-
-        if datetime.utcnow() > user.verification_expires:
-            flash("Verification code expired. Please request a new one.", "error")
-            return redirect(url_for("verify", email=user.email))
-
-        if code_input != user.verification_code:
-            flash("Invalid verification code.", "error")
-            return redirect(url_for("verify", email=user.email))
-
-        user.is_verified = True
-        user.verification_code = None
-        user.verification_expires = None
-        user.last_active_at = datetime.utcnow()
-        db.session.commit()
-
-        flash("Email verified successfully. You can now log in.", "success")
-        return redirect(url_for("login"))
-
-    session["pending_email"] = email
-    return render_template("verify.html", email=email, title="Verify Email")
-
-
-# =========================================================
-# FORGOT PASSWORD + RESET
-# =========================================================
-
-@app.route("/forgot", methods=["GET", "POST"])
-def forgot_password():
-    if request.method == "POST":
-        email = sanitize_string(request.form.get("email", ""), 255).lower()
-
-        if not is_valid_email(email):
-            flash("If that email exists, a reset code has been sent. Check your email, then enter the code below.", "success")
-            return redirect(url_for("reset_password"))
-
-        user = User.query.filter_by(email=email).first()
-        if user:
-            code = generate_code()
-            user.reset_code = code
-            user.reset_expires = datetime.utcnow() + timedelta(minutes=15)
-            db.session.commit()
-            send_password_reset_email(user.email, code)
-
-        flash("If that email exists, a reset code has been sent. Check your email, then enter the code below.", "success")
-        return redirect(url_for("reset_password"))
-
-    return render_template("forgot.html", title="Forgot Password")
-
-
-
-@app.route("/reset", methods=["GET", "POST"])
-def reset_password():
-    if request.method == "POST":
-        email = sanitize_string(request.form.get("email", ""), 255).lower()
-        code_input = sanitize_string(request.form.get("code", ""), 6)
-        new_pw = normalize_text(request.form.get("password", ""))
-        confirm_pw = normalize_text(request.form.get("confirm_password", ""))
-
-        if not email or not code_input or not new_pw or not confirm_pw:
-            flash("All fields are required.", "error")
-            return redirect(url_for("reset_password"))
-
-        if new_pw != confirm_pw:
-            flash("Passwords do not match.", "error")
-            return redirect(url_for("reset_password"))
-
-        if not is_strong_password(new_pw):
-            flash("Password must be at least 8 characters and contain letters and numbers.", "error")
-            return redirect(url_for("reset_password"))
-
-        user = User.query.filter_by(email=email).first()
-        if (
-            not user
-            or not user.reset_code
-            or not user.reset_expires
-            or datetime.utcnow() > user.reset_expires
-            or code_input != user.reset_code
-        ):
-            flash("Invalid or expired reset code.", "error")
-            return redirect(url_for("reset_password"))
-
-        user.password_hash = generate_password_hash(new_pw)
-        user.reset_code = None
-        user.reset_expires = None
-        db.session.commit()
-
-        flash("Password reset successfully. You can now log in.", "success")
-        return redirect(url_for("login"))
-
-    return render_template("reset_password.html", title="Reset Password")
-
-
-# =========================================================
-# MAIN CLASSIFIER
-# =========================================================
-
-@app.route("/", methods=["GET", "POST"])
-@login_required
-def index():
-    if not current_user.is_verified:
-        flash("Please verify your email to use the classifier.", "error")
-        return redirect(url_for("verify", email=current_user.email))
-
-    result = None
-    text = ""
-
-    if request.method == "POST":
-        text = sanitize_long_text(request.form.get("email_text", ""))
-        if text:
-            result = classify_tone_rich(text)
-
-            entry = Entry(
-                text=text,
-                label=result["label"],
-                confidence=float(result["confidence"]),
-                severity=int(result["severity"]),
-                threat_score=int(result["threat_score"]),
-                politeness_score=int(result["politeness_score"]),
-                friendly_score=int(result["friendly_score"]),
-                has_threat=bool(result["has_threat"]),
-                has_profanity=bool(result["has_profanity"]),
-                has_sarcasm=bool(result["has_sarcasm"]),
-                user_id=current_user.id,
-            )
-            db.session.add(entry)
-            db.session.commit()
-
-    return render_template(
-        "index.html",
-        title="Analyze Email",
-        email_text=text,
-        result=result,
-    )
-
-
-# =========================================================
-# HISTORY + EXPORTS
-# =========================================================
-
-@app.route("/history")
-@login_required
-def history_view():
-    if not current_user.is_verified:
-        flash("Please verify your email to view history.", "error")
-        return redirect(url_for("verify", email=current_user.email))
-
-    q = sanitize_string(request.args.get("q", ""), 255).lower()
-    filter_label = sanitize_string(request.args.get("label", ""), 32).lower()
-
-    query = Entry.query.filter_by(user_id=current_user.id)
-
-    if q:
-        query = query.filter(Entry.text.ilike(f"%{q}%"))
-
-    if filter_label:
-        query = query.filter(Entry.label.ilike(filter_label))
-
-    entries = query.order_by(Entry.created_at.desc()).all()
-
-    return render_template(
-        "history.html",
-        title="History",
-        history=entries,
-        search=q,
-        active_filter=filter_label,
-    )
-
-
-@app.route("/export/csv")
-@login_required
-def export_csv():
-    if not current_user.is_verified:
-        flash("Please verify your email to export data.", "error")
-        return redirect(url_for("verify", email=current_user.email))
-
-    filepath = os.path.join("exports", f"history_{current_user.id}.csv")
-    entries = Entry.query.filter_by(user_id=current_user.id).order_by(Entry.created_at.asc())
-
-    with open(filepath, "w", newline="", encoding="utf-8") as f:
-        writer = csv.writer(f)
-        writer.writerow(
-            [
-                "Time UTC",
-                "Label",
-                "Confidence",
-                "Severity",
-                "ThreatScore",
-                "PolitenessScore",
-                "FriendlyScore",
-                "HasThreat",
-                "HasProfanity",
-                "HasSarcasm",
-                "Text",
-            ]
-        )
-        for e in entries:
-            writer.writerow(
-                [
-                    e.created_at.isoformat(),
-                    e.label,
-                    f"{e.confidence:.1f}",
-                    e.severity,
-                    e.threat_score,
-                    e.politeness_score,
-                    e.friendly_score,
-                    int(e.has_threat),
-                    int(e.has_profanity),
-                    int(e.has_sarcasm),
-                    e.text,
-                ]
-            )
-
-    return send_file(filepath, as_attachment=True)
-
-
-@app.route("/export/pdf")
-@login_required
-def export_pdf():
-    if not current_user.is_verified:
-        flash("Please verify your email to export data.", "error")
-        return redirect(url_for("verify", email=current_user.email))
-
-    buffer = BytesIO()
-    c = canvas.Canvas(buffer, pagesize=letter)
-    width, height = letter
-
-    c.setFillColorRGB(0.12, 0.15, 0.20)
-    c.rect(0, height - 60, width, 60, fill=1)
-    c.setFillColorRGB(1, 1, 1)
-    c.setFont("Helvetica-Bold", 18)
-    c.drawString(40, height - 35, "Tone Classifier – History Report")
-
-    entries = (
-        Entry.query.filter_by(user_id=current_user.id)
-        .order_by(Entry.created_at.desc())
-        .all()
-    )
-
-    y = height - 80
-    for e in entries:
-        if y < 90:
-            c.showPage()
-            y = height - 60
-
-        c.setFont("Helvetica-Bold", 10)
-        c.setFillColorRGB(0, 0, 0)
-        c.drawString(
-            40,
-            y,
-            f"{e.created_at.isoformat()} | {e.label} | Severity {e.severity}",
-        )
-        y -= 12
-
-        meta = f"Threat:{e.threat_score}  Polite:{e.politeness_score}  Friendly:{e.friendly_score}"
-        c.setFont("Helvetica", 9)
-        c.drawString(40, y, meta)
-        y -= 12
-
-        text = e.text
-        while len(text) > 90:
-            idx = text.rfind(" ", 0, 90)
-            if idx == -1:
-                idx = 90
-            c.drawString(50, y, text[:idx])
-            text = text[idx:].strip()
-            y -= 11
-
-        c.drawString(50, y, text)
-        y -= 20
-
-    c.showPage()
-    c.save()
-
-    buffer.seek(0)
-    filepath = os.path.join("exports", f"history_{current_user.id}.pdf")
-    with open(filepath, "wb") as f:
-        f.write(buffer.getvalue())
-
-    return send_file(filepath, as_attachment=True)
-
-
-@app.route("/history/clear", methods=["POST"])
-@login_required
-def clear_history():
-    if not current_user.is_verified:
-        flash("Please verify your email to clear history.", "error")
-        return redirect(url_for("verify", email=current_user.email))
-
-    Entry.query.filter_by(user_id=current_user.id).delete()
-    db.session.commit()
-    flash("History cleared.", "success")
-    return redirect(url_for("history_view"))
-
-
-# =========================================================
-# DELETE ACCOUNT + GDPR PAGES
-# =========================================================
-
-@app.route("/account/delete", methods=["GET", "POST"])
-@login_required
-def delete_account():
-    if request.method == "POST":
-        password = normalize_text(request.form.get("password", ""))
-
-        if not check_password_hash(current_user.password_hash, password):
-            flash("Incorrect password. Account not deleted.", "error")
-            return redirect(url_for("delete_account"))
-
-        try:
-            uid = current_user.id
-            Entry.query.filter_by(user_id=uid).delete()
-            user = User.query.get(uid)
-            logout_user()
-            db.session.delete(user)
-            db.session.commit()
-            flash("Your account and all data have been deleted.", "success")
-        except Exception as e:
-            db.session.rollback()
-            flash("Error deleting account. Please try again.", "error")
-            print(f"[ERROR] delete_account failed: {e}")
-            return redirect(url_for("delete_account"))
-
-        return redirect(url_for("register"))
-
-    return render_template("delete_account.html", title="Delete Account")
-
-
-@app.route("/privacy")
-def privacy():
-    # pass datetime for template display
-    from datetime import datetime as dt
-    return render_template("privacy.html", title="Privacy Policy", datetime=dt)
-
-
-@app.route("/do-not-sell")
-def do_not_sell():
-    return render_template("do_not_sell.html", title="Do Not Sell My Info")
-
-
-# =========================================================
-# INIT DB & RUN (LOCAL)
-# =========================================================
-
-with app.app_context():
-    db.create_all()
-
-if __name__ == "__main__":
-    # local dev
-    app.run(debug=True, host="0.0.0.0", port=7860)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
+import os
+import re
+import csv
+import secrets
+import unicodedata
+from datetime import datetime, timedelta
+from io import BytesIO
+
+from flask import (
+    Flask,
+    render_template,
+    request,
+    redirect,
+    url_for,
+    send_file,
+    flash,
+    session,
+    abort,
+)
+from flask_sqlalchemy import SQLAlchemy
+from flask_login import (
+    LoginManager,
+    UserMixin,
+    login_user,
+    login_required,
+    current_user,
+    logout_user,
+)
+from werkzeug.security import generate_password_hash, check_password_hash
+from reportlab.pdfgen import canvas
+from reportlab.lib.pagesizes import letter
+
+from sendgrid import SendGridAPIClient
+from sendgrid.helpers.mail import Mail
+
+# your HF-based classifier
+from model import classify_tone_rich
+
+
+# =========================================================
+# APP CONFIG
+# =========================================================
+
+app = Flask(__name__)
+
+app.config["SECRET_KEY"] = os.getenv("SECRET_KEY", "change-this-in-prod")
+app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///data.db"
+app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
+
+# Detect if running on Hugging Face Spaces (they set SPACE_ID)
+IS_HF = os.getenv("SPACE_ID") is not None
+
+# cookie security
+app.config["SESSION_COOKIE_HTTPONLY"] = True
+
+if IS_HF:
+    # Needed because app runs inside an iframe on huggingface.co
+    app.config["SESSION_COOKIE_SAMESITE"] = "None"
+    app.config["SESSION_COOKIE_SECURE"] = True
+else:
+    # Local dev / normal hosting
+    app.config["SESSION_COOKIE_SAMESITE"] = "Lax"
+    app.config["SESSION_COOKIE_SECURE"] = False
+
+db = SQLAlchemy(app)
+login_manager = LoginManager(app)
+login_manager.login_view = "login"
+
+# Email (SendGrid)
+SENDGRID_API_KEY = os.getenv("SENDGRID_API_KEY")
+SENDER_EMAIL = os.getenv("SENDER_EMAIL", "no-reply@example.com")
+
+# simple email regex
+EMAIL_RE = re.compile(r"^[^@\s]+@[^@\s]+\.[^@\s]+$")
+
+os.makedirs("exports", exist_ok=True)
+
+
+# =========================================================
+# HELPER FUNCTIONS – SANITIZATION, CSRF, PASSWORDS
+# =========================================================
+
+def normalize_text(value: str) -> str:
+    if not value:
+        return ""
+    value = unicodedata.normalize("NFKC", value)
+    value = value.replace("\u200b", "").replace("\u200c", "").replace("\u200d", "")
+    return value.strip()
+
+
+def sanitize_string(value: str, max_len: int = 255) -> str:
+    value = normalize_text(value)
+    if len(value) > max_len:
+        value = value[:max_len]
+    return value
+
+
+def sanitize_long_text(value: str, max_len: int = 4000) -> str:
+    value = normalize_text(value)
+    if len(value) > max_len:
+        value = value[:max_len]
+    return value
+
+
+def is_valid_email(email: str) -> bool:
+    return bool(email and EMAIL_RE.match(email))
+
+
+def is_strong_password(pw: str) -> bool:
+    if not pw or len(pw) < 8:
+        return False
+    has_letter = any(c.isalpha() for c in pw)
+    has_digit = any(c.isdigit() for c in pw)
+    return has_letter and has_digit
+
+
+def generate_code() -> str:
+    """6-digit numeric code used for verify + reset."""
+    return f"{secrets.randbelow(1000000):06d}"
+
+
+def generate_csrf_token() -> str:
+    token = session.get("csrf_token")
+    if not token:
+        token = secrets.token_hex(16)
+        session["csrf_token"] = token
+    return token
+
+
+@app.before_request
+def csrf_protect():
+    # ensure CSRF token exists
+    generate_csrf_token()
+
+    if request.method == "POST":
+        form_token = request.form.get("csrf_token", "")
+        sess_token = session.get("csrf_token", "")
+        if not form_token or form_token != sess_token:
+            abort(400, description="Invalid CSRF token")
+
+
+@app.context_processor
+def inject_csrf():
+    return {"csrf_token": session.get("csrf_token", "")}
+
+
+# =========================================================
+# MODELS
+# =========================================================
+
+class User(UserMixin, db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    email = db.Column(db.String(255), unique=True, nullable=False)
+    password_hash = db.Column(db.String(255), nullable=False)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+
+    # login security
+    failed_logins = db.Column(db.Integer, default=0)
+    lock_until = db.Column(db.DateTime, nullable=True)
+
+    # email verification
+    is_verified = db.Column(db.Boolean, default=False)
+    verification_code = db.Column(db.String(6), nullable=True)
+    verification_expires = db.Column(db.DateTime, nullable=True)
+
+    # password reset
+    reset_code = db.Column(db.String(6), nullable=True)
+    reset_expires = db.Column(db.DateTime, nullable=True)
+
+    # activity (for possible retention rules)
+    last_active_at = db.Column(db.DateTime, nullable=True)
+
+
+class Entry(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+    text = db.Column(db.Text, nullable=False)
+    label = db.Column(db.String(32))
+    confidence = db.Column(db.Float)
+    severity = db.Column(db.Integer)
+    threat_score = db.Column(db.Integer)
+    politeness_score = db.Column(db.Integer)
+    friendly_score = db.Column(db.Integer)
+    has_threat = db.Column(db.Boolean, default=False)
+    has_profanity = db.Column(db.Boolean, default=False)
+    has_sarcasm = db.Column(db.Boolean, default=False)
+    user_id = db.Column(db.Integer, db.ForeignKey("user.id"), nullable=False)
+
+    user = db.relationship("User", backref="entries")
+
+
+@login_manager.user_loader
+def load_user(user_id):
+    try:
+        return User.query.get(int(user_id))
+    except Exception:
+        return None
+
+
+# =========================================================
+# EMAIL HELPERS
+# =========================================================
+
+def send_email(to_email: str, subject: str, html: str):
+    if not SENDGRID_API_KEY:
+        print("[WARN] SENDGRID_API_KEY not set. Skipping email send.")
+        print(f"Subject: {subject}\nTo: {to_email}\n{html}")
+        return
+
+    message = Mail(
+        from_email=SENDER_EMAIL,
+        to_emails=to_email,
+        subject=subject,
+        html_content=html,
+    )
+    try:
+        sg = SendGridAPIClient(SENDGRID_API_KEY)
+        sg.send(message)
+        print(f"[INFO] Sent email to {to_email}: {subject}")
+    except Exception as e:
+        print(f"[ERROR] Failed to send email to {to_email}: {e}")
+
+
+def send_verification_email(to_email: str, code: str):
+    html = f"""
+    <p>Thanks for signing up for the AI Email Tone Classifier.</p>
+    <p>Your verification code is: <strong>{code}</strong></p>
+    <p>This code will expire in 15 minutes.</p>
+    """
+    send_email(to_email, "Verify your email", html)
+
+
+def send_password_reset_email(to_email: str, code: str):
+    html = f"""
+    <p>You requested to reset your password for the AI Email Tone Classifier.</p>
+    <p>Your password reset code is: <strong>{code}</strong></p>
+    <p>This code will expire in 15 minutes.</p>
+    <p>If you did not request this, you can ignore this email.</p>
+    """
+    send_email(to_email, "Password reset code", html)
+
+
+# =========================================================
+# AUTH ROUTES: REGISTER / LOGIN / LOGOUT / VERIFY
+# =========================================================
+
+@app.route("/register", methods=["GET", "POST"])
+def register():
+    if current_user.is_authenticated:
+        return redirect(url_for("index"))
+
+    if request.method == "POST":
+        email = sanitize_string(request.form.get("email", ""), 255).lower()
+        password = normalize_text(request.form.get("password", ""))
+        consent = request.form.get("consent_privacy") == "on"
+
+        if not email or not password:
+            flash("Email and password are required.", "error")
+            return redirect(url_for("register"))
+
+        if not is_valid_email(email):
+            flash("Please enter a valid email address.", "error")
+            return redirect(url_for("register"))
+
+        if not is_strong_password(password):
+            flash("Password must be at least 8 characters and contain letters and numbers.", "error")
+            return redirect(url_for("register"))
+
+        if not consent:
+            flash("You must agree to the Privacy Policy to create an account.", "error")
+            return redirect(url_for("register"))
+
+        existing = User.query.filter_by(email=email).first()
+        if existing:
+            flash("An account with that email already exists.", "error")
+            return redirect(url_for("register"))
+
+        user = User(
+            email=email,
+            password_hash=generate_password_hash(password),
+            last_active_at=datetime.utcnow(),
+        )
+
+        code = generate_code()
+        user.verification_code = code
+        user.verification_expires = datetime.utcnow() + timedelta(minutes=15)
+        user.is_verified = False
+
+        db.session.add(user)
+        db.session.commit()
+
+        send_verification_email(email, code)
+        session["pending_email"] = email
+
+        flash("Account created. Check your email for the verification code.", "success")
+        return redirect(url_for("verify"))
+
+    return render_template("login.html", mode="register", title="Register")
+
+
+@app.route("/login", methods=["GET", "POST"])
+def login():
+    if current_user.is_authenticated:
+        return redirect(url_for("index"))
+
+    if request.method == "POST":
+        email = sanitize_string(request.form.get("email", ""), 255).lower()
+        password = normalize_text(request.form.get("password", ""))
+
+        if not email or not password:
+            flash("Email and password are required.", "error")
+            return redirect(url_for("login"))
+
+        user = User.query.filter_by(email=email).first()
+        if not user:
+            flash("Invalid email or password.", "error")
+            return redirect(url_for("login"))
+
+        now = datetime.utcnow()
+
+        # lockout check
+        if user.lock_until and user.lock_until > now:
+            remaining = int((user.lock_until - now).total_seconds() // 60) + 1
+            flash(f"Account locked due to too many failed attempts. Try again in ~{remaining} minutes.", "error")
+            return redirect(url_for("login"))
+
+        if not check_password_hash(user.password_hash, password):
+            user.failed_logins = (user.failed_logins or 0) + 1
+            if user.failed_logins >= 5:
+                user.lock_until = now + timedelta(minutes=10)
+                user.failed_logins = 0
+            db.session.commit()
+            flash("Invalid email or password.", "error")
+            return redirect(url_for("login"))
+
+        # reset counters
+        user.failed_logins = 0
+        user.lock_until = None
+        user.last_active_at = now
+        db.session.commit()
+
+        if not user.is_verified:
+            session["pending_email"] = user.email
+            flash("Please verify your email before logging in.", "error")
+            return redirect(url_for("verify"))
+
+        login_user(user)
+        flash("Logged in successfully.", "success")
+        return redirect(url_for("index"))
+
+    return render_template("login.html", mode="login", title="Login")
+
+
+@app.route("/logout")
+@login_required
+def logout():
+    logout_user()
+    flash("You have been logged out.", "success")
+    return redirect(url_for("login"))
+
+
+@app.route("/verify", methods=["GET", "POST"])
+def verify():
+    email = sanitize_string(
+        request.args.get("email", "") or session.get("pending_email", ""), 255
+    ).lower()
+
+    if not email:
+        flash("No email specified for verification. Please register or log in again.", "error")
+        return redirect(url_for("register"))
+
+    user = User.query.filter_by(email=email).first()
+    if not user:
+        flash("Account not found. Please register again.", "error")
+        return redirect(url_for("register"))
+
+    if user.is_verified:
+        flash("Your email is already verified. You can log in.", "success")
+        return redirect(url_for("login"))
+
+    if request.method == "POST":
+        action = request.form.get("action", "verify")
+
+        if action == "resend":
+            code = generate_code()
+            user.verification_code = code
+            user.verification_expires = datetime.utcnow() + timedelta(minutes=15)
+            db.session.commit()
+            send_verification_email(user.email, code)
+            flash("A new verification code has been sent.", "success")
+            return redirect(url_for("verify", email=user.email))
+
+        code_input = sanitize_string(request.form.get("code", ""), 6)
+
+        if not code_input:
+            flash("Please enter the verification code.", "error")
+            return redirect(url_for("verify", email=user.email))
+
+        if not user.verification_code or not user.verification_expires:
+            flash("No active verification code. Please resend.", "error")
+            return redirect(url_for("verify", email=user.email))
+
+        if datetime.utcnow() > user.verification_expires:
+            flash("Verification code expired. Please request a new one.", "error")
+            return redirect(url_for("verify", email=user.email))
+
+        if code_input != user.verification_code:
+            flash("Invalid verification code.", "error")
+            return redirect(url_for("verify", email=user.email))
+
+        user.is_verified = True
+        user.verification_code = None
+        user.verification_expires = None
+        user.last_active_at = datetime.utcnow()
+        db.session.commit()
+
+        flash("Email verified successfully. You can now log in.", "success")
+        return redirect(url_for("login"))
+
+    session["pending_email"] = email
+    return render_template("verify.html", email=email, title="Verify Email")
+
+
+# =========================================================
+# FORGOT PASSWORD + RESET
+# =========================================================
+
+@app.route("/forgot", methods=["GET", "POST"])
+def forgot_password():
+    if request.method == "POST":
+        email = sanitize_string(request.form.get("email", ""), 255).lower()
+
+        if not is_valid_email(email):
+            flash("If that email exists, a reset code has been sent. Check your email, then enter the code below.", "success")
+            return redirect(url_for("reset_password"))
+
+        user = User.query.filter_by(email=email).first()
+        if user:
+            code = generate_code()
+            user.reset_code = code
+            user.reset_expires = datetime.utcnow() + timedelta(minutes=15)
+            db.session.commit()
+            send_password_reset_email(user.email, code)
+
+        flash("If that email exists, a reset code has been sent. Check your email, then enter the code below.", "success")
+        return redirect(url_for("reset_password"))
+
+    return render_template("forgot.html", title="Forgot Password")
+
+
+@app.route("/reset", methods=["GET", "POST"])
+def reset_password():
+    if request.method == "POST":
+        email = sanitize_string(request.form.get("email", ""), 255).lower()
+        code_input = sanitize_string(request.form.get("code", ""), 6)
+        new_pw = normalize_text(request.form.get("password", ""))
+        confirm_pw = normalize_text(request.form.get("confirm_password", ""))
+
+        if not email or not code_input or not new_pw or not confirm_pw:
+            flash("All fields are required.", "error")
+            return redirect(url_for("reset_password"))
+
+        if new_pw != confirm_pw:
+            flash("Passwords do not match.", "error")
+            return redirect(url_for("reset_password"))
+
+        if not is_strong_password(new_pw):
+            flash("Password must be at least 8 characters and contain letters and numbers.", "error")
+            return redirect(url_for("reset_password"))
+
+        user = User.query.filter_by(email=email).first()
+        if (
+            not user
+            or not user.reset_code
+            or not user.reset_expires
+            or datetime.utcnow() > user.reset_expires
+            or code_input != user.reset_code
+        ):
+            flash("Invalid or expired reset code.", "error")
+            return redirect(url_for("reset_password"))
+
+        user.password_hash = generate_password_hash(new_pw)
+        user.reset_code = None
+        user.reset_expires = None
+        db.session.commit()
+
+        flash("Password reset successfully. You can now log in.", "success")
+        return redirect(url_for("login"))
+
+    return render_template("reset_password.html", title="Reset Password")
+
+
+# =========================================================
+# MAIN CLASSIFIER
+# =========================================================
+
+@app.route("/", methods=["GET", "POST"])
+@login_required
+def index():
+    if not current_user.is_verified:
+        flash("Please verify your email to use the classifier.", "error")
+        return redirect(url_for("verify", email=current_user.email))
+
+    result = None    # dict from classify_tone_rich
+    text = ""
+
+    if request.method == "POST":
+        text = sanitize_long_text(request.form.get("email_text", ""))
+        if text:
+            result = classify_tone_rich(text)
+
+            entry = Entry(
+                text=text,
+                label=result["label"],
+                confidence=float(result["confidence"]),
+                severity=int(result["severity"]),
+                threat_score=int(result["threat_score"]),
+                politeness_score=int(result["politeness_score"]),
+                friendly_score=int(result["friendly_score"]),
+                has_threat=bool(result["has_threat"]),
+                has_profanity=bool(result["has_profanity"]),
+                has_sarcasm=bool(result["has_sarcasm"]),
+                user_id=current_user.id,
+            )
+            db.session.add(entry)
+            db.session.commit()
+
+    return render_template(
+        "index.html",
+        title="Analyze Email",
+        email_text=text,
+        result=result,
+    )
+
+
+# =========================================================
+# HISTORY + EXPORTS
+# =========================================================
+
+@app.route("/history")
+@login_required
+def history_view():
+    if not current_user.is_verified:
+        flash("Please verify your email to view history.", "error")
+        return redirect(url_for("verify", email=current_user.email))
+
+    q = sanitize_string(request.args.get("q", ""), 255).lower()
+    filter_label = sanitize_string(request.args.get("label", ""), 32).lower()
+
+    query = Entry.query.filter_by(user_id=current_user.id)
+
+    if q:
+        query = query.filter(Entry.text.ilike(f"%{q}%"))
+
+    if filter_label:
+        query = query.filter(Entry.label.ilike(filter_label))
+
+    entries = query.order_by(Entry.created_at.desc()).all()
+
+    return render_template(
+        "history.html",
+        title="History",
+        history=entries,
+        search=q,
+        active_filter=filter_label,
+    )
+
+
+@app.route("/export/csv")
+@login_required
+def export_csv():
+    if not current_user.is_verified:
+        flash("Please verify your email to export data.", "error")
+        return redirect(url_for("verify", email=current_user.email))
+
+    filepath = os.path.join("exports", f"history_{current_user.id}.csv")
+    entries = Entry.query.filter_by(user_id=current_user.id).order_by(Entry.created_at.asc())
+
+    with open(filepath, "w", newline="", encoding="utf-8") as f:
+        writer = csv.writer(f)
+        writer.writerow(
+            [
+                "Time UTC",
+                "Label",
+                "Confidence",
+                "Severity",
+                "ThreatScore",
+                "PolitenessScore",
+                "FriendlyScore",
+                "HasThreat",
+                "HasProfanity",
+                "HasSarcasm",
+                "Text",
+            ]
+        )
+        for e in entries:
+            writer.writerow(
+                [
+                    e.created_at.isoformat(),
+                    e.label,
+                    f"{e.confidence:.1f}",
+                    e.severity,
+                    e.threat_score,
+                    e.politeness_score,
+                    e.friendly_score,
+                    int(e.has_threat),
+                    int(e.has_profanity),
+                    int(e.has_sarcasm),
+                    e.text,
+                ]
+            )
+
+    return send_file(filepath, as_attachment=True)
+
+
+@app.route("/export/pdf")
+@login_required
+def export_pdf():
+    if not current_user.is_verified:
+        flash("Please verify your email to export data.", "error")
+        return redirect(url_for("verify", email=current_user.email))
+
+    buffer = BytesIO()
+    c = canvas.Canvas(buffer, pagesize=letter)
+    width, height = letter
+
+    c.setFillColorRGB(0.12, 0.15, 0.20)
+    c.rect(0, height - 60, width, 60, fill=1)
+    c.setFillColorRGB(1, 1, 1)
+    c.setFont("Helvetica-Bold", 18)
+    c.drawString(40, height - 35, "Tone Classifier – History Report")
+
+    entries = (
+        Entry.query.filter_by(user_id=current_user.id)
+        .order_by(Entry.created_at.desc())
+        .all()
+    )
+
+    y = height - 80
+    for e in entries:
+        if y < 90:
+            c.showPage()
+            y = height - 60
+
+        c.setFont("Helvetica-Bold", 10)
+        c.setFillColorRGB(0, 0, 0)
+        c.drawString(
+            40,
+            y,
+            f"{e.created_at.isoformat()} | {e.label} | Severity {e.severity}",
+        )
+        y -= 12
+
+        meta = f"Threat:{e.threat_score}  Polite:{e.politeness_score}  Friendly:{e.friendly_score}"
+        c.setFont("Helvetica", 9)
+        c.drawString(40, y, meta)
+        y -= 12
+
+        text = e.text
+        while len(text) > 90:
+            idx = text.rfind(" ", 0, 90)
+            if idx == -1:
+                idx = 90
+            c.drawString(50, y, text[:idx])
+            text = text[idx:].strip()
+            y -= 11
+
+        c.drawString(50, y, text)
+        y -= 20
+
+    c.showPage()
+    c.save()
+
+    buffer.seek(0)
+    filepath = os.path.join("exports", f"history_{current_user.id}.pdf")
+    with open(filepath, "wb") as f:
+        f.write(buffer.getvalue())
+
+    return send_file(filepath, as_attachment=True)
+
+
+@app.route("/history/clear", methods=["POST"])
+@login_required
+def clear_history():
+    if not current_user.is_verified:
+        flash("Please verify your email to clear history.", "error")
+        return redirect(url_for("verify", email=current_user.email))
+
+    Entry.query.filter_by(user_id=current_user.id).delete()
+    db.session.commit()
+    flash("History cleared.", "success")
+    return redirect(url_for("history_view"))
+
+
+# =========================================================
+# DELETE ACCOUNT + GDPR PAGES
+# =========================================================
+
+@app.route("/account/delete", methods=["GET", "POST"])
+@login_required
+def delete_account():
+    if request.method == "POST":
+        password = normalize_text(request.form.get("password", ""))
+
+        if not check_password_hash(current_user.password_hash, password):
+            flash("Incorrect password. Account not deleted.", "error")
+            return redirect(url_for("delete_account"))
+
+        try:
+            uid = current_user.id
+            Entry.query.filter_by(user_id=uid).delete()
+            user = User.query.get(uid)
+            logout_user()
+            db.session.delete(user)
+            db.session.commit()
+            flash("Your account and all data have been deleted.", "success")
+        except Exception as e:
+            db.session.rollback()
+            flash("Error deleting account. Please try again.", "error")
+            print(f"[ERROR] delete_account failed: {e}")
+            return redirect(url_for("delete_account"))
+
+        return redirect(url_for("register"))
+
+    return render_template("delete_account.html", title="Delete Account")
+
+
+@app.route("/privacy")
+def privacy():
+    from datetime import datetime as dt
+    return render_template("privacy.html", title="Privacy Policy", datetime=dt)
+
+
+@app.route("/do-not-sell")
+def do_not_sell():
+    return render_template("do_not_sell.html", title="Do Not Sell My Info")
+
+
+# =========================================================
+# INIT DB & RUN (LOCAL)
+# =========================================================
+
+with app.app_context():
+    db.create_all()
+
+if __name__ == "__main__":
+    # local dev
+    app.run(debug=True, host="0.0.0.0", port=7860)