# app/routes/devices.py
# ----------------------
# Admin-only page for viewing registered iOS devices and pushing
# "please update" notifications to users on outdated app versions.

import logging
from flask import Blueprint, render_template, request, redirect, url_for, flash
from flask_login import login_required, current_user

from app import db
from app.models.device_registration import DeviceRegistration
from app.models.notification import Notification
from app.utils.decorators import admin_required
from app.utils.audit import log_action, ACTION_CREATE

logger = logging.getLogger(__name__)

bp = Blueprint('devices', __name__, url_prefix='/admin/devices')


@bp.route('/', methods=['GET'])
@login_required
@admin_required
def index():
    """Show all registered devices, most-recently-seen first."""
    devices = (
        DeviceRegistration.query
        .order_by(DeviceRegistration.last_seen_at.desc())
        .all()
    )
    return render_template('admin/devices.html', devices=devices)


@bp.route('/notify', methods=['POST'])
@login_required
@admin_required
def notify_update():
    """
    Send an in-app update notice to all users whose app_version is below
    the version string entered by the admin.

    Form fields
    -----------
    current_version  str  The version string to treat as current (e.g. "1.3.0")
    message          str  Optional custom message body (default provided)
    """
    current_version = (request.form.get('current_version') or '').strip()
    custom_message  = (request.form.get('message') or '').strip()

    if not current_version:
        flash('Current version is required.', 'danger')
        return redirect(url_for('devices.index'))

    def version_tuple(v: str):
        """Convert "1.3.0" → (1, 3, 0) for comparison. Non-numeric parts → 0."""
        try:
            return tuple(int(x) for x in v.strip().split('.'))
        except ValueError:
            return (0,)

    target_v = version_tuple(current_version)

    # Find all devices running an older version
    all_devices = DeviceRegistration.query.all()
    outdated = [d for d in all_devices if version_tuple(d.app_version) < target_v]

    if not outdated:
        flash(f'No devices found running a version older than {current_version}.', 'info')
        return redirect(url_for('devices.index'))

    # Deduplicate by user_id — one notification per user even if they have
    # multiple devices registered (e.g. primary + secondary server devices).
    seen_users = set()
    notified   = 0
    for device in outdated:
        if device.user_id in seen_users:
            continue
        seen_users.add(device.user_id)

        body = custom_message or (
            f'A new version of JanitorialQC ({current_version}) is available. '
            f'Please update from the App Store to get the latest features and fixes.'
        )
        notif = Notification(
            user_id    = device.user_id,
            title      = f'App Update Available — v{current_version}',
            body       = body,
            link       = None,
            event_type = 'admin_broadcast',
            is_read    = False,
        )
        db.session.add(notif)
        notified += 1

    db.session.commit()

    log_action(ACTION_CREATE, 'DeviceUpdateNotice', 0,
               f'v{current_version} notice → {notified} user(s)',
               f'outdated_devices={len(outdated)}; sent_by={current_user.username}')

    logger.info('DEVICES | update_notice | version=%s | users_notified=%d | devices_outdated=%d | by=%s',
                current_version, notified, len(outdated), current_user.username)

    flash(
        f'Update notice sent to {notified} user(s) on {len(outdated)} outdated device(s).',
        'success'
    )
    return redirect(url_for('devices.index'))