"""
app.py
======
Main Flask application for the Theme Song Booth.

This module defines all HTTP routes, helper functions, the email layer,
runtime settings persistence, MP3 metadata tagging, rate limiting, and
database health/maintenance helpers.

It is meant to be served by gunicorn inside a Docker container (see Dockerfile).

Public routes (customers):
- /                      -> redirects to /request
- /request               -> customer submits their info
- /thanks/<id>           -> confirmation page after submission
- /play/<token>          -> private player page with Version A and B
- /play/<token>/approve  -> customer picks a version
- /play/<token>/revise   -> customer asks for changes
- /audio/<token>/<v>.mp3 -> serves the uploaded MP3 files

Admin routes:
- /admin/login              -> password login
- /admin/logout             -> clears session
- /admin                    -> dashboard queue with status filters and auto-refresh
- /admin/settings           -> runtime settings, health check, DB stats, backup/restore, reset
- /admin/request/<id>       -> detail/edit page for a single request
- /admin/request/<id>/delete -> deletes one request and its uploaded files
- /admin/reset              -> deletes ALL requests and ALL files
"""

# Standard library imports
import os
import re
import shutil
import smtplib
import ssl
import time
from email.message import EmailMessage
from pathlib import Path

import json

from cryptography.fernet import Fernet
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
import base64

import hmac
import hashlib
import secrets

# Flask and related imports
from flask import Flask, request, render_template, redirect, url_for, flash, session, send_from_directory, abort, current_app, send_file, jsonify
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address
from werkzeug.utils import secure_filename

# Project imports
from config import Config
from models import init_db, close_db, create_request, get_request_by_id, get_request_by_token, list_requests, update_request, now_utc, delete_request, reset_all_requests, get_db
from models import SCHEMA, get_requests_by_email, log_revision, list_revision_history

# Audio metadata import
from mutagen.mp3 import MP3
from mutagen.easyid3 import EasyID3

# ---------------------------------------------------------------------------
# App setup
# ---------------------------------------------------------------------------

# Create the Flask app and load configuration from Config class.
app = Flask(__name__)
app.config.from_object(Config)

# Global request rate limiting by remote IP (default 60/min). The public form is further limited to 5/min.
limiter = Limiter(get_remote_address, app=app, default_limits=["60 per minute"])

# Ensure the SQLite connection is closed at the end of each request.
app.teardown_appcontext(close_db)

# Human-readable labels for each status value stored in the database.
STATUS_LABELS = {
    'pending': 'Pending',
    'prompt_ready': 'Prompt Ready',
    'songs_uploaded': 'Songs Uploaded — Awaiting Approval',
    'revisions_requested': 'Revisions Requested',
    'awaiting_payment': 'Awaiting Payment',
    'paid': 'Paid',
    'delivered': 'Delivered',
}

# ---------------------------------------------------------------------------
# Helper functions
# ---------------------------------------------------------------------------

def is_admin():
    """Return True if the current browser session is logged in as admin."""
    return session.get('admin') is True


def require_admin():
    """Redirect to the admin login page if the user is not logged in."""
    if not is_admin():
        return redirect(url_for('admin_login'))


def admin_password_ok(pw):
    """Check the submitted admin password against the configured one."""
    return pw and pw == current_app.config['ADMIN_PASSWORD']


def allowed_file(filename):
    """Return True if the uploaded filename has an allowed extension (mp3)."""
    return '.' in filename and filename.rsplit('.', 1)[1].lower() in current_app.config['ALLOWED_EXTENSIONS']


def upload_path(request_id):
    """Return the per-request upload directory path, creating it if necessary."""
    p = Path(current_app.config['UPLOAD_FOLDER']) / str(request_id)
    p.mkdir(parents=True, exist_ok=True)
    return p


def save_upload(request_id, file_obj, version, song_title=None):
    """
    Save an uploaded MP3 file for a request, preserving the original filename
    with a version prefix (e.g. A - MySong.mp3 / B - MySong.mp3).
    Applies the configured metadata tags (title, artist, album, year, comment).
    """
    if not file_obj or file_obj.filename == '':
        return None
    if not allowed_file(file_obj.filename):
        flash('Only MP3 files are allowed.', 'error')
        return None
    original = secure_filename(file_obj.filename)
    filename = f"{version.upper()} - {original}"
    p = upload_path(request_id)
    dest = p / filename
    file_obj.save(dest)
    apply_mp3_tags(str(dest), song_title)
    return str(dest)


def apply_mp3_tags(path, title=None):
    """
    Write common ID3 tags on an uploaded MP3 using the runtime metadata defaults.
    Writes title, artist, album, and date via EasyID3, plus a comment using both
    a COMM frame and a TXXX:Comment frame for broad reader compatibility.
    Failures are logged as a warning and do not block the upload.
    """
    cfg = load_booth_settings()
    try:
        audio = MP3(path)
        if audio.tags is None:
            audio.add_tags()
        if not isinstance(audio.tags, EasyID3):
            audio.tags = EasyID3()
        tags = audio.tags
        if title:
            tags['title'] = title
        if cfg.get('artist'):
            tags['artist'] = cfg['artist']
        if cfg.get('album'):
            tags['album'] = cfg['album']
        if cfg.get('year'):
            tags['date'] = str(cfg['year'])
        audio.save()
        if cfg.get('comment'):
            from mutagen.id3 import COMM, TXXX
            audio2 = MP3(path)
            if audio2.tags is None:
                audio2.add_tags()
            audio2.tags["COMM"] = COMM(encoding=3, lang='eng', desc='Comment', text=cfg['comment'])
            audio2.tags["TXXX:Comment"] = TXXX(encoding=3, desc='Comment', text=cfg['comment'])
            audio2.save()
    except Exception as e:
        try:
            flash(f'Warning: could not tag MP3: {e}', 'error')
        except RuntimeError:
            import logging
            logging.getLogger('app').warning('Could not tag MP3 %s: %s', path, e)


def _get_fernet():
    """Derive a Fernet key from the Flask SECRET_KEY so stored values are encrypted."""
    secret = current_app.config['SECRET_KEY'].encode()
    kdf = PBKDF2HMAC(
        algorithm=hashes.SHA256(),
        length=32,
        salt=b'theme-song-booth-v1',
        iterations=480000,
    )
    key = base64.urlsafe_b64encode(kdf.derive(secret))
    return Fernet(key)


def encrypt_value(value):
    """Encrypt a string using the Flask SECRET_KEY. Returns base64 ciphertext."""
    if not value:
        return ''
    return _get_fernet().encrypt(value.encode()).decode()


def decrypt_value(ciphertext):
    """Decrypt a string previously encrypted by encrypt_value."""
    if not ciphertext:
        return ''
    try:
        return _get_fernet().decrypt(ciphertext.encode()).decode()
    except Exception:
        return ''


def decrypt_value_legacy(ciphertext):
    """Decrypt or return plaintext. Tolerates unencrypted legacy values."""
    if not ciphertext:
        return ''
    plaintext = decrypt_value(ciphertext)
    if plaintext:
        return plaintext
    # If decryption failed, the value might already be plaintext.
    # A Fernet token is base64 and ends with '='; a plain API key does not.
    if not ciphertext.endswith('='):
        return ciphertext
    return ''


def settings_file_path():
    """Return the path to the persistent runtime settings JSON file."""
    return Path(current_app.config['DATABASE']).parent / current_app.config['SETTINGS_FILE']


def load_booth_settings():
    """Load persistent runtime settings from JSON file inside the upload parent."""
    cfg_path = settings_file_path()
    if cfg_path.exists():
        try:
            cfg = json.loads(cfg_path.read_text())
            # Normalize any legacy None metadata/email values to empty strings
            # so form fields repopulate correctly after reload.
            for key in ('artist', 'album', 'year', 'comment', 'smtp_host', 'smtp_port', 'smtp_user', 'smtp_from'):
                if cfg.get(key) is None:
                    cfg[key] = ''
            return cfg
        except (json.JSONDecodeError, OSError):
            pass
    return {}


def save_booth_settings(settings):
    """Persist runtime settings to JSON file."""
    cfg_path = settings_file_path()
    try:
        cfg_path.write_text(json.dumps(settings, indent=2))
    except OSError as e:
        flash(f'Warning: could not save settings: {e}', 'error')


def get_email_config():
    """
    Return the effective SMTP configuration.
    Runtime settings in booth_settings.json override environment defaults.
    The SMTP password is decrypted from the encrypted value stored on disk.
    """
    cfg = load_booth_settings()
    return {
        'SMTP_HOST': cfg.get('smtp_host', current_app.config['SMTP_HOST']),
        'SMTP_PORT': int(cfg.get('smtp_port') or current_app.config['SMTP_PORT']),
        'SMTP_USER': cfg.get('smtp_user', current_app.config['SMTP_USER']),
        'SMTP_PASS': decrypt_value(cfg.get('smtp_pass', '')) or current_app.config['SMTP_PASS'],
        'SMTP_FROM': cfg.get('smtp_from', current_app.config['SMTP_FROM']),
    }


def get_refresh_seconds():
    """Return the dashboard auto-refresh interval in seconds (10, 20, or 30)."""
    cfg = load_booth_settings()
    try:
        val = int(cfg.get('refresh_seconds', 10))
    except (ValueError, TypeError):
        val = 10
    return val if val in (10, 20, 30) else 10


def get_hermes_api_key():
    """
    Return the effective Hermes API key.
    Environment variable HERMES_API_KEY overrides any runtime setting.
    """
    env_key = current_app.config.get('HERMES_API_KEY', '')
    if env_key:
        return env_key
    cfg = load_booth_settings()
    return decrypt_value_legacy(cfg.get('hermes_api_key', ''))


def set_hermes_api_key(key):
    """Persist a new Hermes API key (encrypted) to runtime settings."""
    cfg = load_booth_settings()
    cfg['hermes_api_key'] = encrypt_value(key)
    save_booth_settings(cfg)


def generate_hermes_api_key():
    """Generate a new random API key for Hermes callback authentication."""
    return secrets.token_urlsafe(32)


def mask_api_key(key):
    """Return a masked version of the API key showing only the last 6 characters."""
    if not key:
        return 'Not set'
    if len(key) <= 6:
        return '*' * len(key)
    return '*' * (len(key) - 6) + key[-6:]


def sign_prompt_callback(rid, expires_at=None):
    """
    Create a signed callback token for a specific request ID.
    The signature is HMAC-SHA256 over "rid:expires_at" using APP_SECRET_KEY.
    Returns a URL-safe token string.
    """
    secret = current_app.config['SECRET_KEY'].encode()
    if expires_at is None:
        # Default expiry: 1 hour.
        expires_at = int(time.time()) + 3600
    payload = f"{rid}:{expires_at}"
    sig = hmac.new(secret, payload.encode(), hashlib.sha256).hexdigest()[:16]
    return f"{rid}:{expires_at}:{sig}"


def verify_prompt_callback(token):
    """
    Verify a signed callback token. Returns (rid, ok) tuple.
    The token must match the HMAC signature and not be expired.
    """
    if not token:
        return None, False
    parts = token.split(':')
    if len(parts) != 3:
        return None, False
    try:
        rid = int(parts[0])
        expires_at = int(parts[1])
    except ValueError:
        return None, False
    if int(time.time()) > expires_at:
        return None, False
    expected = sign_prompt_callback(rid, expires_at)
    if not hmac.compare_digest(expected, token):
        return None, False
    return rid, True


def build_prompt_callback_url(rid):
    """Build the full callback URL an operator pastes into Hermes for a request."""
    token = sign_prompt_callback(rid)
    return f"{current_app.config['PUBLIC_BASE_URL']}/api/prompt/{rid}?token={token}"


def send_email(to, subject, body, attachments=None, inline_images=None):
    """Send an email using the configured or runtime SMTP settings."""
    cfg = get_email_config()
    if not cfg['SMTP_PASS']:
        raise RuntimeError('SMTP password is not configured')

    msg = EmailMessage()
    msg['From'] = cfg['SMTP_FROM']
    msg['To'] = to
    msg['Subject'] = subject
    msg.set_content(body)

    html_body = body.replace('\n', '<br>\n')
    if inline_images:
        for _, cid in inline_images:
            html_body += f'<br><img src="cid:{cid}" alt="Dionysis Media" style="max-width:200px;margin-top:1rem;"/>'
    html_body += f'<br><br><hr style="border:none;border-top:1px solid #ddd;"/><p style="font-size:0.9rem;color:#555;">Dionysis Media: stories, sound, and a little divine chaos — <a href="https://dionysismedia.ca/">https://dionysismedia.ca/</a></p>'
    msg.add_alternative(html_body, subtype='html')

    if inline_images:
        for path, cid in inline_images:
            with open(path, 'rb') as f:
                data = f.read()
            ext = Path(path).suffix.lower().lstrip('.')
            subtype = ext if ext in ('png', 'jpg', 'jpeg', 'gif', 'webp') else 'png'
            msg.get_payload()[1].add_related(data, maintype='image', subtype=subtype, cid=f'<{cid}>')

    if attachments:
        for path, name in attachments:
            with open(path, 'rb') as f:
                data = f.read()
            msg.add_attachment(data, maintype='audio', subtype='mpeg', filename=name)

    with smtplib.SMTP_SSL(cfg['SMTP_HOST'], cfg['SMTP_PORT'], context=ssl.create_default_context()) as server:
        server.login(cfg['SMTP_USER'], cfg['SMTP_PASS'])
        server.send_message(msg)

def build_signature_images():
    """Return inline image tuple list for static/DM-Logo_email.png (Dionysis Media logo)."""
    logo_path = Path(current_app.root_path) / 'static' / 'DM-Logo_email.png'
    if not logo_path.exists():
        return []
    return [(str(logo_path), 'dm-logo')]


def get_booth_open():
    """Return True if the booth is currently marked as open in runtime settings."""
    cfg = load_booth_settings()
    return cfg.get('booth_open', True)


# ---------------------------------------------------------------------------
# Public customer routes
# ---------------------------------------------------------------------------

@app.route('/')
def index():
    """Root route: redirect customers straight to the request form."""
    return redirect(url_for('request_form'))


@app.route('/request', methods=['GET', 'POST'])
@limiter.limit("5 per minute")
def request_form():
    """
    Public request form.
    GET  -> shows the form with the banner image, or a closed message if the booth is closed.
    POST -> validates the email, creates a database record, sends a
            confirmation email, and redirects to the thanks page.
    Rate limited to 5 submissions per minute per IP.
    """
    if not get_booth_open():
        return render_template('closed.html')

    if request.method == 'POST':
        form_data = {
            'name': request.form.get('name', '').strip(),
            'email': request.form.get('email', '').strip().lower(),
            'hobbies': request.form.get('hobbies', '').strip(),
            'notable_facts': request.form.get('notable_facts', '').strip(),
            'style_genre': request.form.get('style_genre', '').strip(),
            'extra_requests': request.form.get('extra_requests', '').strip(),
            'vocal_gender': request.form.get('vocal_gender', '').strip(),
        }
        if not is_valid_email(form_data['email']):
            flash('Please enter a valid email address.', 'error')
            return render_template('request.html', form=form_data), 400
        rid = create_request(**form_data)

        # Send confirmation email with a summary of what the customer asked for.
        req = get_request_by_id(rid)
        if req:
            try:
                body_lines = [
                    f"Hi {req['name']},",
                    "",
                    "Thanks for stopping by the Trollgorithm Theme Song Booth! We've received your request and will start crafting your custom song soon.",
                    "",
                    "Here's what we have on file:",
                    f"Name: {req['name']}",
                    f"Email: {req['email']}",
                    f"Style / genre: {req['style_genre'] or '-'}",
                    f"Preferred singer voice / gender: {req['vocal_gender'] or 'No preference'}",
                    f"Hobbies: {req['hobbies'] or '-'}",
                    f"Notable facts: {req['notable_facts'] or '-'}",
                    f"Extra requests: {req['extra_requests'] or '-'}",
                    "",
                    "You'll get another email with a private link to preview two versions of your song when they're ready.",
                    "",
                    "— Trollgorithm / Dionysis Media"
                ]
                send_email(req['email'], 'Your theme song request is received', '\n'.join(body_lines), inline_images=build_signature_images())
            except Exception as e:
                flash(f'Your request was saved, but we could not send a confirmation email: {e}', 'error')

        flash('Your request has been submitted! Check your email soon.', 'success')
        return redirect(url_for('thanks', rid=rid))
    return render_template('request.html', form=None)


@app.route('/api/prompt/<int:rid>', methods=['POST'])
def api_update_prompt(rid):
    """
    Hermes callback endpoint.

    Accepts a JSON POST with generated Suno prompt fields and updates the
    matching request. Two layers of auth:
      1) A per-request signed callback token in the query string.
      2) A Hermes API key in the Authorization header (Bearer).

    Only records in 'pending' status can be updated. On success, status is set
    to 'prompt_ready'.
    """
    # Layer 1: verify the signed callback URL token.
    callback_token = request.args.get('token', '').strip()
    token_rid, token_ok = verify_prompt_callback(callback_token)
    if not token_ok or token_rid != rid:
        abort(401)

    # Layer 2: verify the Hermes API key from the Authorization header.
    expected_key = get_hermes_api_key()
    if not expected_key:
        abort(500, description='Hermes API key is not configured')
    auth_header = request.headers.get('Authorization', '').strip()
    if not auth_header.startswith('Bearer '):
        abort(401)
    provided_key = auth_header[7:].strip()
    if not hmac.compare_digest(expected_key, provided_key):
        abort(401)

    req = get_request_by_id(rid)
    if not req:
        abort(404)
    if req['status'] != 'pending':
        abort(409, description='Request is no longer pending')

    data = request.get_json(silent=True) or {}

    # Optional email verification to make sure clipboard matches record.
    provided_email = data.get('email', '').strip().lower()
    if provided_email and provided_email != req['email'].lower():
        abort(400, description='Email mismatch')

    update_request(rid,
        suno_title=data.get('suno_title', '').strip(),
        suno_style=data.get('suno_style', '').strip(),
        suno_lyrics=data.get('suno_lyrics', '').strip(),
        status='prompt_ready'
    )

    return jsonify({'ok': True, 'request_id': rid, 'status': 'prompt_ready'}), 200


@app.route('/thanks/<int:rid>')
def thanks(rid):
    """Confirmation page shown after a customer submits a request."""
    req = get_request_by_id(rid)
    if not req:
        abort(404)
    return render_template('thanks.html', req=req)


@app.route('/status', methods=['GET', 'POST'])
def status_lookup():
    """
    Public order status lookup page.
    Customers enter their email to see all their requests and their current
    statuses, plus the private player link once songs have been uploaded.
    """
    requests_list = []
    email = ''
    searched = False
    if request.method == 'POST':
        email = request.form.get('email', '').strip().lower()
        if not is_valid_email(email):
            flash('Please enter a valid email address.', 'error')
        else:
            requests_list = get_requests_by_email(email)
            searched = True
    return render_template('status.html', email=email, requests=requests_list, searched=searched, statuses=STATUS_LABELS)


@app.route('/faq')
def faq():
    """Customer-facing frequently asked questions page."""
    return render_template('faq.html')


@app.route('/play/<token>')
def play(token):
    """
    Private player page for a customer.
    The token is a cryptographically random URL-safe string generated at request time.
    Shows A/B audio players, approval buttons, or a revision note depending on status.
    """
    req = get_request_by_token(token)
    if not req:
        abort(404)

    # Load runtime max revisions setting.
    runtime_settings = load_booth_settings()
    max_revisions = runtime_settings.get('max_revisions', current_app.config['MAX_REVISIONS'])
    revisions_left = max(0, max_revisions - (req.get('revision_count') or 0))

    return render_template('player.html', req=req, revisions_left=revisions_left)


@app.route('/play/<token>/approve', methods=['POST'])
def approve(token):
    """
    Customer has chosen Version A, Version B, or both.
    Updates the request status to 'awaiting_payment' so the operator can collect payment.
    Operator email alerts are intentionally disabled; the dashboard is the single queue.
    """
    req = get_request_by_token(token)
    if not req:
        abort(404)
    choice = request.form.get('choice')
    if choice not in ('a', 'b', 'both'):
        flash('Invalid selection.', 'error')
        return redirect(url_for('play', token=token))

    update_request(req['id'], customer_approved=choice, status='awaiting_payment', approval_notified_at=now_utc())

    flash('Thanks! Please return to the booth to finalize payment.', 'success')
    return redirect(url_for('play', token=token))


@app.route('/play/<token>/revise', methods=['POST'])
def revise(token):
    """
    Customer asked for changes.
    Enforces the runtime max revisions limit, archives the current A/B MP3 files,
    stores the revision note, and resets status to 'revisions_requested'.
    """
    note = request.form.get('revision_note', '').strip()
    req = get_request_by_token(token)
    if not req:
        abort(404)

    # Enforce max revisions limit for customer-submitted revisions.
    runtime_settings = load_booth_settings()
    max_revisions = runtime_settings.get('max_revisions', current_app.config['MAX_REVISIONS'])
    current_count = req.get('revision_count') or 0
    if current_count >= max_revisions:
        flash('Revision limit reached. Please speak to the booth operator if you need further changes.', 'error')
        return redirect(url_for('play', token=token))

    # Increment revision counter and archive current files before new versions are uploaded.
    new_count = current_count + 1
    upload_dir = Path(current_app.config['UPLOAD_FOLDER']) / str(req['id'])
    old_a, old_b = req.get('song_a_path'), req.get('song_b_path')
    new_a, new_b = old_a, old_b
    if upload_dir.exists():
        for field, version in (('song_a_path', 'A'), ('song_b_path', 'B')):
            path = req.get(field)
            if path and Path(path).exists():
                old = Path(path)
                archived = upload_dir / f"Rev{new_count}-{old.name}"
                try:
                    old.rename(archived)
                    if field == 'song_a_path':
                        new_a = str(archived)
                    else:
                        new_b = str(archived)
                    req[field] = str(archived)
                except OSError:
                    pass
    log_revision(req['id'], new_count, note, old_a=old_a, old_b=old_b, new_a=new_a, new_b=new_b)
    update_request(req['id'], revision_note=note, status='revisions_requested',
                   song_a_path=req.get('song_a_path'), song_b_path=req.get('song_b_path'),
                   customer_approved='none', revision_count=new_count)

    # NOTE: No operator email is sent; the dashboard is the single queue.
    flash('Your feedback has been saved. We will regenerate and update you.', 'success')
    return redirect(url_for('play', token=token))


@app.route('/api/stream/<token>/<version>.mp3')
def stream_audio(token, version):
    """
    Stream an uploaded MP3 through a backend proxy endpoint.

    This hides the real file path from the customer. The endpoint checks the
    player token and serves bytes with Range request support so the HTML audio
    player can seek. The URL is still interceptable in-browser, but it is not a
    direct file path and can be gated or expired later.
    """
    req = get_request_by_token(token)
    if not req:
        abort(404)
    if version not in ('a', 'b'):
        abort(404)

    # Both versions must exist before any streaming happens.
    a_path = req.get('song_a_path')
    b_path = req.get('song_b_path')
    if not a_path or not b_path:
        abort(404)
    for p in (a_path, b_path):
        if not Path(p).exists():
            abort(404)

    path = a_path if version == 'a' else b_path
    file_path = Path(path)
    file_size = file_path.stat().st_size

    range_header = request.headers.get('Range', '')
    start = 0
    end = file_size - 1
    status_code = 200

    if range_header and range_header.startswith('bytes='):
        try:
            range_value = range_header[len('bytes='):].strip()
            if '-' in range_value:
                parts = range_value.split('-')
                if parts[0]:
                    start = int(parts[0])
                if parts[1]:
                    end = min(int(parts[1]), file_size - 1)
            if start >= file_size or start > end:
                abort(416)
            status_code = 206
        except ValueError:
            start = 0
            end = file_size - 1
            status_code = 200

    def generate():
        with open(file_path, 'rb') as f:
            f.seek(start)
            remaining = end - start + 1
            chunk_size = 64 * 1024
            while remaining > 0:
                to_read = min(chunk_size, remaining)
                data = f.read(to_read)
                if not data:
                    break
                yield data
                remaining -= len(data)

    response = current_app.response_class(generate(), mimetype='audio/mpeg')
    response.status_code = status_code
    response.headers['Accept-Ranges'] = 'bytes'
    response.headers['Content-Disposition'] = 'inline'
    response.headers['Content-Length'] = str(end - start + 1)
    if status_code == 206:
        response.headers['Content-Range'] = f'bytes {start}-{end}/{file_size}'
    return response


@app.route('/audio/<token>/<version>.mp3')
def audio(token, version):
    """
    Legacy audio endpoint. Replaced by /api/stream/<token>/<version>.mp3.
    Returns 404 so old direct links do not work.
    """
    abort(404)


# ---------------------------------------------------------------------------
# Admin routes
# ---------------------------------------------------------------------------

@app.route('/admin/login', methods=['GET', 'POST'])
def admin_login():
    """Simple session-based admin login. Password is set via ADMIN_PASSWORD env var."""
    if is_admin():
        return redirect(url_for('admin_dashboard'))
    if request.method == 'POST':
        if admin_password_ok(request.form.get('password', '')):
            session['admin'] = True
            return redirect(url_for('admin_dashboard'))
        flash('Invalid password.', 'error')
    return render_template('admin/login.html')


def is_valid_email(email):
    """Return True if the given string looks like a valid email address."""
    if not email:
        return False
    # Very loose regex: local@domain.tld, no spaces, with a real TLD part.
    pattern = r"^[^\s@]+@[^\s@]+\.[^\s@]+$"
    return re.match(pattern, email) is not None


@app.route('/admin/logout')
def admin_logout():
    """Clear the admin session."""
    session.pop('admin', None)
    return redirect(url_for('admin_login'))


@app.route('/admin')
def admin_dashboard():
    """
    Main operator queue.
    Optional ?status= filter lets operators focus on one state at a time.
    Auto-refresh interval is controlled from /admin/settings.
    """
    redir = require_admin()
    if redir:
        return redir
    status_filter = request.args.get('status')
    requests = list_requests(status_filter)
    return render_template('admin/dashboard.html', requests=requests, statuses=STATUS_LABELS, current_status=status_filter, refresh_seconds=get_refresh_seconds())


@app.route('/admin/sales')
def admin_sales():
    """
    Sales report: delivered requests only.
    Shows customer email, name, chosen version, and Square payment reference.
    """
    redir = require_admin()
    if redir:
        return redir
    sales = list_requests(status='delivered')
    return render_template('admin/sales.html', sales=sales, statuses=STATUS_LABELS)


@app.route('/admin/pricing', methods=['GET', 'POST'])
def admin_pricing():
    """
    Pricing configuration page.
    Fixed items: one_song, both_songs, wav_per_song, stems_per_song.
    Plus up to 5 custom name/price pairs.
    """
    redir = require_admin()
    if redir:
        return redir

    fixed_keys = ['one_song', 'both_songs', 'wav_per_song', 'stems_per_song']
    custom_count = 5

    cfg = load_booth_settings()
    if 'pricing' not in cfg:
        cfg['pricing'] = {}

    if request.method == 'POST':
        pricing = {}
        for key in fixed_keys:
            pricing[key] = request.form.get(key, '').strip()
        for i in range(1, custom_count + 1):
            name = request.form.get(f'custom_name_{i}', '').strip()
            price = request.form.get(f'custom_price_{i}', '').strip()
            if name:
                pricing[f'custom_{i}'] = {'name': name, 'price': price}
            else:
                pricing[f'custom_{i}'] = None
        cfg['pricing'] = pricing
        save_booth_settings(cfg)
        flash('Pricing saved.', 'success')
        return redirect(url_for('admin_pricing'))

    pricing = cfg.get('pricing', {})
    fixed = {key: pricing.get(key, '') for key in fixed_keys}
    customs = []
    for i in range(1, custom_count + 1):
        entry = pricing.get(f'custom_{i}')
        customs.append({
            'name': entry.get('name', '') if isinstance(entry, dict) else '',
            'price': entry.get('price', '') if isinstance(entry, dict) else ''
        })
    return render_template('admin/pricing.html', fixed=fixed, customs=customs)


@app.route('/admin/request/<int:rid>', methods=['GET', 'POST'])
def admin_request(rid):
    """
    Detail/edit page for a single request.
    GET  -> render customer info (email editable), prompt, upload status,
            email status, operator notes, and delivery forms.
    POST -> handle one of six actions:
            update_customer_email, save_operator_notes, save_prompt, upload_songs,
            notify_customer, mark_paid_deliver
    Uploaded MP3s are tagged with metadata defaults from /admin/settings.
    """
    redir = require_admin()
    if redir:
        return redir
    req = get_request_by_id(rid)
    if not req:
        abort(404)

    # Small helpers exposed to the template for status badges.
    def file_exists(path):
        return bool(path and Path(path).exists())

    def basename(path):
        return Path(path).name if path else ''

    # Collect any extra MP3 files in the request folder (archived revisions).
    upload_dir = Path(current_app.config['UPLOAD_FOLDER']) / str(rid)
    current_paths = {req['song_a_path'], req['song_b_path']}
    extra_files = []
    if upload_dir.exists():
        for f in upload_dir.iterdir():
            if f.is_file() and f.suffix.lower() == '.mp3' and str(f) not in current_paths:
                extra_files.append(str(f))
    extra_files.sort()

    if request.method == 'POST':
        action = request.form.get('action')

        if action == 'update_customer_email':
            new_email = request.form.get('email', '').strip().lower()
            if not is_valid_email(new_email):
                flash('Please enter a valid email address.', 'error')
                return redirect(url_for('admin_request', rid=rid))
            update_request(rid, email=new_email)
            flash('Customer email updated.', 'success')
            return redirect(url_for('admin_request', rid=rid))

        elif action == 'update_customer_info':
            new_email = request.form.get('email', '').strip().lower()
            if not is_valid_email(new_email):
                flash('Please enter a valid email address.', 'error')
                return redirect(url_for('admin_request', rid=rid))
            update_request(rid,
                email=new_email,
                name=request.form.get('name', '').strip(),
                hobbies=request.form.get('hobbies', '').strip(),
                notable_facts=request.form.get('notable_facts', '').strip(),
                style_genre=request.form.get('style_genre', '').strip(),
                vocal_gender=request.form.get('vocal_gender', '').strip(),
                extra_requests=request.form.get('extra_requests', '').strip()
            )
            flash('Customer info updated.', 'success')
            return redirect(url_for('admin_request', rid=rid))

        elif action == 'save_operator_notes':
            update_request(rid, operator_notes=request.form.get('operator_notes', '').strip())
            flash('Operator notes saved.', 'success')
            return redirect(url_for('admin_request', rid=rid))

        elif action == 'save_stems_link':
            update_request(rid, stems_link=request.form.get('stems_link', '').strip())
            flash('Stems share link saved.', 'success')
            return redirect(url_for('admin_request', rid=rid))

        elif action == 'save_prompt':
            # Store the generated title/style/lyrics and mark prompt ready.
            update_request(rid,
                suno_title=request.form.get('suno_title', '').strip(),
                suno_style=request.form.get('suno_style', '').strip(),
                suno_lyrics=request.form.get('suno_lyrics', '').strip(),
                status='prompt_ready'
            )
            flash('Prompt saved.', 'success')

        elif action == 'upload_songs':
            # Save uploaded MP3 files for Version A and/or Version B.
            # Use the saved Suno title as the MP3 title tag if available.
            song_title = req.get('suno_title') or None
            a_path = save_upload(rid, request.files.get('song_a'), 'a', song_title)
            b_path = save_upload(rid, request.files.get('song_b'), 'b', song_title)
            fields = {}
            if a_path:
                fields['song_a_path'] = a_path
            if b_path:
                fields['song_b_path'] = b_path
            if fields:
                fields['status'] = 'songs_uploaded'
                update_request(rid, **fields)
                flash('Songs uploaded.', 'success')

        elif action == 'notify_customer':
            # Email the customer a private player link. Both songs must be uploaded first.
            if not (req['song_a_path'] and req['song_b_path']):
                flash('Both songs must be uploaded first.', 'error')
            else:
                player_link = f"{current_app.config['PUBLIC_BASE_URL']}/play/{req['player_token']}"
                body = f"Hi {req['name']},\n\nYour custom theme song has been created. Listen to both versions and let us know which one you want:\n\n{player_link}\n\n- Version A\n- Version B\n- Or both versions\n\nOnce you make your choice, we'll send you to the booth to finalize payment and deliver your files.\n\nThanks for stopping by!\n\n— {current_app.config['BOOTH_NAME']}"
                try:
                    send_email(req['email'], 'Your custom theme song is ready — listen and pick your version', body, inline_images=build_signature_images())
                    update_request(rid, preview_sent_at=now_utc(), status='songs_uploaded')
                    flash('Preview email sent.', 'success')
                except Exception as e:
                    flash(f'Failed to send preview email: {e}', 'error')

        elif action == 'mark_paid_deliver':
            # Finalize: record Square payment ref, attach approved MP3s, email customer.
            if req.get('customer_approved', 'none') == 'none':
                flash('Customer must approve a version before you can mark paid or deliver.', 'error')
                return redirect(url_for('admin_request', rid=rid))

            payment_ref = request.form.get('square_payment_ref', '').strip()
            if not payment_ref:
                flash('Square payment reference is required.', 'error')
                return redirect(url_for('admin_request', rid=rid))

            # Build list of selected files from checkboxes.
            selected = request.form.getlist('deliver_file')
            if not selected:
                flash('Select at least one file to deliver.', 'error')
                return redirect(url_for('admin_request', rid=rid))

            # Record payment immediately so the reference is preserved even if email fails.
            update_request(rid, square_payment_ref=payment_ref, status='delivered')

            attachments = []
            for path in selected:
                p = Path(path)
                if p.exists():
                    attachments.append((str(p), p.name))

            # Compute 3-month expiry date for any stems share link.
            from datetime import datetime, timedelta
            expiry_date = (datetime.utcnow() + timedelta(days=90)).strftime('%B %d, %Y')

            player_link = f"{current_app.config['PUBLIC_BASE_URL']}/play/{req['player_token']}"
            body_lines = [
                f"Hi {req['name']},",
                "",
                "Thanks for your payment! Your selected song(s) are attached to this email.",
                f"You can also keep streaming them here: {player_link}",
                "",
                "Enjoy!",
                "",
                f"— {current_app.config['BOOTH_NAME']}"
            ]
            if req.get('stems_link'):
                body_lines.insert(4, f"Your stems / extras are available here: {req['stems_link']}")
                body_lines.insert(5, f"This share link expires on {expiry_date} (3 months from today). Please download before then.")
                body_lines.insert(6, "")
            body = '\n'.join(body_lines)
            try:
                send_email(req['email'], 'Your theme song files are here!', body, attachments=attachments, inline_images=build_signature_images())
                update_request(rid, delivery_sent_at=now_utc())
                flash('Delivery email sent with MP3 attachments.', 'success')
            except Exception as e:
                flash(f'Payment recorded, but delivery email failed: {e}', 'error')

        return redirect(url_for('admin_request', rid=rid))

    return render_template('admin/request.html', req=req, statuses=STATUS_LABELS, file_exists=file_exists, basename=basename, extra_files=extra_files, callback_url=build_prompt_callback_url(rid), revision_history=list_revision_history(rid))


@app.route('/admin/request/<int:rid>/delete', methods=['POST'])
def admin_delete_request(rid):
    """Delete a single request and remove its uploaded MP3 files."""
    redir = require_admin()
    if redir:
        return redir
    req = get_request_by_id(rid)
    if not req:
        abort(404)

    # Delete uploaded files if they exist.
    for field in ('song_a_path', 'song_b_path'):
        path = req.get(field)
        if path and Path(path).exists():
            try:
                Path(path).unlink()
            except OSError:
                pass
    # Remove empty upload directory.
    upload_dir = Path(current_app.config['UPLOAD_FOLDER']) / str(rid)
    if upload_dir.exists():
        try:
            upload_dir.rmdir()
        except OSError:
            pass

    delete_request(rid)
    flash(f'Request #{rid} deleted.', 'success')
    return redirect(url_for('admin_dashboard'))


@app.route('/admin/settings', methods=['GET', 'POST'])
def admin_settings():
    """
    Settings / maintenance page for operators.
    GET  -> show database health, statistics, disk usage, runtime settings forms,
            booth open/closed switch, SMTP/email config, MP3 metadata defaults, backup/restore, and reset.
    POST -> handle one of: fix_db, reset_system, save_max_revisions, save_metadata,
            save_email_config, send_test_email, save_refresh, save_booth_open, download_db, restore_db.
    """
    redir = require_admin()
    if redir:
        return redir

    db_path = Path(current_app.config['DATABASE'])
    upload_root = Path(current_app.config['UPLOAD_FOLDER'])

    # Compute database stats.
    db_size = db_path.stat().st_size if db_path.exists() else 0
    all_requests = list_requests()
    total_records = len(all_requests)
    status_counts = {}
    for req in all_requests:
        status_counts[req['status']] = status_counts.get(req['status'], 0) + 1

    # Load persistent runtime settings (max_revisions overrides env var if set).
    runtime_settings = load_booth_settings()
    current_max_revisions = runtime_settings.get('max_revisions', current_app.config.get('MAX_REVISIONS', 2))
    current_refresh_seconds = runtime_settings.get('refresh_seconds', 10)
    booth_open = runtime_settings.get('booth_open', True)

    # Effective email config to show in the form (non-sensitive only; password left blank).
    email_form = {
        'smtp_host': runtime_settings.get('smtp_host', current_app.config['SMTP_HOST']),
        'smtp_port': runtime_settings.get('smtp_port', str(current_app.config['SMTP_PORT'])),
        'smtp_user': runtime_settings.get('smtp_user', current_app.config['SMTP_USER']),
        'smtp_from': runtime_settings.get('smtp_from', current_app.config['SMTP_FROM']),
        'smtp_pass_set': bool(runtime_settings.get('smtp_pass', '')),
    }

    # Hermes API key state for the settings page.
    hermes_key = get_hermes_api_key()
    hermes_key_masked = mask_api_key(hermes_key)
    hermes_key_set = bool(hermes_key)
    hermes_key_just_generated = session.pop('hermes_key_just_generated', None)

    # Compute upload folder stats.
    total_upload_size = 0
    upload_file_count = 0
    request_dir_count = 0
    if upload_root.exists():
        for entry in upload_root.iterdir():
            if entry.is_dir():
                request_dir_count += 1
                for f in entry.iterdir():
                    if f.is_file():
                        total_upload_size += f.stat().st_size
                        upload_file_count += 1
            elif entry.is_file():
                total_upload_size += entry.stat().st_size
                upload_file_count += 1

    def format_bytes(n):
        for unit in ['B', 'KB', 'MB', 'GB']:
            if n < 1024:
                return f"{n:.2f} {unit}"
            n /= 1024
        return f"{n:.2f} TB"

    # Health check: verify expected columns exist and expected tables exist.
    expected_cols = {
        'id', 'created_at', 'name', 'email', 'hobbies', 'notable_facts',
        'style_genre', 'extra_requests', 'vocal_gender', 'status', 'suno_title', 'suno_style',
        'suno_lyrics', 'song_a_path', 'song_b_path', 'customer_approved',
        'approval_notified_at', 'preview_sent_at', 'delivery_sent_at',
        'square_payment_ref', 'admin_alert_email', 'player_token', 'revision_note', 'revision_count', 'operator_notes', 'stems_link'
    }
    expected_tables = {'requests', 'revision_history'}
    health = {'ok': True, 'missing_columns': [], 'missing_tables': [], 'message': 'Database schema looks good.'}
    try:
        db = get_db()
        cur = db.execute("SELECT name FROM sqlite_master WHERE type='table'")
        existing_tables = {row['name'] for row in cur.fetchall()}
        missing_tables = sorted(expected_tables - existing_tables)

        cur = db.execute('PRAGMA table_info(requests)')
        existing_cols = {row['name'] for row in cur.fetchall()}
        missing_cols = sorted(expected_cols - existing_cols)

        if missing_tables or missing_cols:
            parts = []
            if missing_tables:
                parts.append(f"missing tables: {', '.join(missing_tables)}")
            if missing_cols:
                parts.append(f"missing columns: {', '.join(missing_cols)}")
            health = {'ok': False, 'missing_columns': missing_cols, 'missing_tables': missing_tables, 'message': 'Database schema issues: ' + '; '.join(parts)}
    except Exception as e:
        health = {'ok': False, 'missing_columns': [], 'missing_tables': [], 'message': f'Could not inspect database: {e}'}

    if request.method == 'POST':
        action = request.form.get('action')

        if action == 'fix_db':
            # Attempt to create missing tables and add missing columns via ALTER TABLE.
            try:
                db = get_db()
                db.executescript(SCHEMA)
                if not health['ok'] and health['missing_columns']:
                    for col in health['missing_columns']:
                        # Default to TEXT columns; adequate for current schema.
                        db.execute(f'ALTER TABLE requests ADD COLUMN {col} TEXT')
                    flash(f'Created missing tables and added columns: {", ".join(health["missing_columns"])}. Please refresh the page.', 'success')
                else:
                    flash('Database schema is up to date.', 'success')
                db.commit()
            except Exception as e:
                flash(f'Failed to fix database: {e}', 'error')
            return redirect(url_for('admin_settings'))

        elif action == 'reset_system':
            # Same nuclear reset logic as the old /admin/reset endpoint.
            if upload_root.exists():
                for entry in upload_root.iterdir():
                    try:
                        if entry.is_file():
                            entry.unlink()
                        elif entry.is_dir():
                            shutil.rmtree(entry)
                    except OSError:
                        pass
            reset_all_requests()
            flash('System reset complete. All orders and files have been cleared.', 'success')
            return redirect(url_for('admin_settings'))

        elif action == 'save_max_revisions':
            # Update the MAX_REVISIONS config from the settings form.
            try:
                val = int(request.form.get('max_revisions', '2').strip())
                if val < 0:
                    raise ValueError
                cfg = load_booth_settings()
                cfg['max_revisions'] = val
                save_booth_settings(cfg)
                flash(f'Maximum revisions set to {val}.', 'success')
            except ValueError:
                flash('Invalid revision limit. Please enter a non-negative number.', 'error')
            return redirect(url_for('admin_settings'))

        elif action == 'save_metadata':
            # Update MP3 metadata defaults from the settings form.
            # Store empty strings (not None) so fields repopulate correctly on reload.
            cfg = load_booth_settings()
            for key in ('artist', 'album', 'year', 'comment'):
                cfg[key] = request.form.get(key, '').strip()
            save_booth_settings(cfg)
            flash('MP3 metadata defaults saved.', 'success')
            return redirect(url_for('admin_settings'))

        elif action == 'save_email_config':
            # Update SMTP settings from the settings form. Password is encrypted.
            # Empty values are stored as empty strings so the form repopulates.
            cfg = load_booth_settings()
            cfg['smtp_host'] = request.form.get('smtp_host', '').strip()
            cfg['smtp_port'] = request.form.get('smtp_port', '').strip()
            cfg['smtp_user'] = request.form.get('smtp_user', '').strip()
            cfg['smtp_from'] = request.form.get('smtp_from', '').strip()
            new_pass = request.form.get('smtp_pass', '').strip()
            # Only overwrite the stored password if a new value was provided.
            if new_pass:
                cfg['smtp_pass'] = encrypt_value(new_pass)
            save_booth_settings(cfg)
            flash('Email (SMTP) settings saved. Password stored encrypted.', 'success')
            return redirect(url_for('admin_settings'))

        elif action == 'send_test_email':
            # Send a test email to the address provided in the form.
            test_to = request.form.get('test_email_address', '').strip()
            if not test_to:
                flash('Enter a test email address first.', 'error')
                return redirect(url_for('admin_settings'))
            try:
                body = "Hi,\n\nThis is a test email from the Trollgorithm Theme Song Booth. If you're seeing this, SMTP is configured correctly."
                send_email(test_to, 'SMTP Test from Theme Song Booth', body, inline_images=build_signature_images())
                flash(f'Test email sent to {test_to}.', 'success')
            except Exception as e:
                flash(f'Failed to send test email: {e}', 'error')
            return redirect(url_for('admin_settings'))

        elif action == 'save_refresh':
            # Update dashboard auto-refresh interval.
            val = request.form.get('refresh_seconds', '10').strip()
            if val not in ('0', '10', '20', '30'):
                val = '10'
            cfg = load_booth_settings()
            cfg['refresh_seconds'] = int(val)
            save_booth_settings(cfg)
            flash(f'Dashboard auto-refresh set to {val} seconds.', 'success')
            return redirect(url_for('admin_settings'))

        elif action == 'save_booth_open':
            # Toggle whether the public request form is accepting submissions.
            cfg = load_booth_settings()
            cfg['booth_open'] = request.form.get('booth_open', '1') == '1'
            save_booth_settings(cfg)
            state = 'open' if cfg['booth_open'] else 'closed'
            flash(f'Booth is now {state}.', 'success')
            return redirect(url_for('admin_settings'))

        elif action == 'download_db':
            # Send the SQLite database file as a download.
            if db_path.exists():
                return send_file(str(db_path), as_attachment=True, download_name='theme-song-booth.db')
            flash('Database file not found.', 'error')
            return redirect(url_for('admin_settings'))

        elif action == 'download_uploads_zip':
            # Zip all files under UPLOAD_FOLDER and send as a download.
            import zipfile
            zip_path = db_path.with_suffix('.uploads-' + str(int(time.time())) + '.zip')
            try:
                with zipfile.ZipFile(zip_path, 'w', zipfile.ZIP_DEFLATED) as zf:
                    if upload_root.exists():
                        for entry in upload_root.rglob('*'):
                            if entry.is_file():
                                zf.write(str(entry), str(entry.relative_to(upload_root)))
                return send_file(str(zip_path), as_attachment=True, download_name='theme-song-booth-uploads.zip')
            except Exception as e:
                flash(f'Failed to create uploads ZIP: {e}', 'error')
                return redirect(url_for('admin_settings'))
            finally:
                if zip_path.exists():
                    zip_path.unlink()

        elif action == 'restore_db':
            # Replace the current database file with an uploaded SQLite backup.
            file_obj = request.files.get('db_backup')
            if not file_obj or file_obj.filename == '':
                flash('No database backup file selected.', 'error')
                return redirect(url_for('admin_settings'))
            backup_path = db_path.with_suffix('.backup-restore')
            try:
                # Stream uploaded file directly to disk to avoid memory issues with large DBs.
                file_obj.save(backup_path)
                # Quick sanity check: try to open as SQLite and query sqlite_master.
                import sqlite3
                conn = sqlite3.connect(str(backup_path))
                conn.execute("SELECT name FROM sqlite_master WHERE type='table'")
                conn.close()
                # Replace old database with backup.
                old_backup = db_path.with_suffix('.backup-' + str(int(time.time())))
                db_path.rename(old_backup)
                backup_path.rename(db_path)
                flash('Database restored successfully. Old database kept at ' + old_backup.name, 'success')
            except Exception as e:
                if backup_path.exists():
                    backup_path.unlink()
                flash(f'Database restore failed: {e}', 'error')
            return redirect(url_for('admin_settings'))

        elif action == 'regenerate_hermes_key':
            # Legacy action: no longer exposed in UI. Key is managed via HERMES_API_KEY env var.
            flash('Hermes API key is managed via the HERMES_API_KEY environment variable.', 'info')
            return redirect(url_for('admin_settings'))

    return render_template(
        'admin/settings.html',
        health=health,
        db_size=format_bytes(db_size),
        total_records=total_records,
        status_counts=status_counts,
        statuses=STATUS_LABELS,
        upload_file_count=upload_file_count,
        upload_dir_count=request_dir_count,
        upload_size=format_bytes(total_upload_size),
        db_path=str(db_path),
        upload_path=str(upload_root),
        current_max_revisions=current_max_revisions,
        current_refresh_seconds=current_refresh_seconds,
        booth_open=booth_open,
        email_form=email_form,
        metadata={
            'artist': runtime_settings.get('artist', ''),
            'album': runtime_settings.get('album', ''),
            'year': runtime_settings.get('year', ''),
            'comment': runtime_settings.get('comment', ''),
        },
        hermes_key_masked=hermes_key_masked,
        hermes_key_set=hermes_key_set,
        hermes_key_just_generated=hermes_key_just_generated,
    )


@app.route('/admin/reset', methods=['POST'])
def admin_reset_system():
    """
    Nuclear reset for the start of an event.
    Deletes all database rows and all files/directories under UPLOAD_FOLDER.
    Requires clicking through a browser confirm dialog.
    """
    redir = require_admin()
    if redir:
        return redir

    upload_root = Path(current_app.config['UPLOAD_FOLDER'])
    if upload_root.exists():
        for entry in upload_root.iterdir():
            try:
                if entry.is_file():
                    entry.unlink()
                elif entry.is_dir():
                    shutil.rmtree(entry)
            except OSError:
                pass

    reset_all_requests()
    flash('System reset complete. All orders and files have been cleared.', 'success')
    return redirect(url_for('admin_dashboard'))


# ---------------------------------------------------------------------------
# CLI and entry point
# ---------------------------------------------------------------------------

@app.cli.command('init-db')
def init_db_command():
    """Flask CLI command: flask --app app init-db"""
    init_db()
    print('Database initialized.')


if __name__ == '__main__':
    # Development-only entry point. Production uses gunicorn (see Dockerfile).
    app.run(debug=True, host='0.0.0.0')