"""
gui_app.py — vSphere Backup Manager
Flask web UI: login → VM browser → create jobs → schedule backups
"""
import os
import sys
import uuid
import threading
import time
import json
from datetime import datetime
from functools import wraps
from pathlib import Path

from flask import (
    Flask, request, redirect, url_for, session,
    flash, jsonify, abort, render_template
)

from backup_core import run_backup, list_vms

# ── APScheduler (optional graceful degradation) ──────────────────────────────
try:
    from apscheduler.schedulers.background import BackgroundScheduler
    from apscheduler.triggers.cron import CronTrigger
    from apscheduler.triggers.interval import IntervalTrigger
    HAS_SCHEDULER = True
except ImportError:
    HAS_SCHEDULER = False
    print("WARNING: APScheduler not installed — recurring schedules disabled. "
          "Install with: pip install APScheduler", file=sys.stderr)

# ── App setup ─────────────────────────────────────────────────────────────────
app = Flask(__name__)
app.secret_key = os.environ.get('SECRET_KEY', 'vsphere-backup-dev-key-change-me')

BASE_DIR  = Path(__file__).resolve().parent
JOBS_DIR  = BASE_DIR / 'jobs'
JOBS_DIR.mkdir(exist_ok=True)

# In-memory job store: {job_id: job_dict}
# job_dict keys: id, label, vm_name, status, started, dest, compress,
#                no_verify_ssl, sftp_host, sftp_user, sftp_password,
#                log, schedule_type, schedule_time, schedule_id
jobs: dict = {}

# APScheduler instance
scheduler = None
if HAS_SCHEDULER:
    scheduler = BackgroundScheduler(daemon=True)
    scheduler.start()


# ── Helpers ───────────────────────────────────────────────────────────────────
def login_required(f):
    @wraps(f)
    def decorated(*args, **kwargs):
        if not session.get('host'):
            flash('Please log in first.', 'info')
            return redirect(url_for('login'))
        return f(*args, **kwargs)
    return decorated


def fmt_time(ts):
    return datetime.fromtimestamp(ts).strftime('%Y-%m-%d %H:%M:%S') if ts else '—'


def job_to_display(jid, info):
    """Convert internal job dict to template-friendly dict."""
    return {
        'id':            jid,
        'label':         info.get('label', ''),
        'vm_name':       info.get('vm_name', '—'),
        'status':        info.get('status', 'unknown'),
        'started_fmt':   fmt_time(info.get('started')),
        'dest':          info.get('dest', ''),
        'compress':      info.get('compress', False),
        'sftp_host':     info.get('sftp_host', ''),
        'schedule_type': info.get('schedule_type', 'now'),
        'schedule_time': info.get('schedule_time', ''),
        'schedule_id':   info.get('schedule_id'),
    }


def run_job_thread(jid):
    """Worker executed in a thread (and by APScheduler)."""
    info = jobs.get(jid)
    if not info:
        return
    info['status'] = 'running'
    info['started'] = time.time()
    log_path = str(JOBS_DIR / jid / 'backup.log')
    try:
        run_backup(
            host=info['host'],
            user=info['user'],
            password=info['password'],
            vm_name=info['vm_name'],
            dest=info['dest'],
            compress=info.get('compress', False),
            no_verify_ssl=info.get('no_verify_ssl', False),
            sftp_host=info.get('sftp_host') or None,
            sftp_user=info.get('sftp_user') or None,
            sftp_password=info.get('sftp_password') or None,
            sftp_key=None,
            log_path=log_path,
        )
        info['status'] = 'finished'
    except Exception as e:
        info['status'] = f'failed ({e})'


def create_and_start_job(
    vm_name, dest, compress, no_verify_ssl,
    sftp_host, sftp_user, sftp_password,
    schedule_type, schedule_time, weekly_day, interval_hours,
    label=''
):
    """Create a job entry and either run immediately or register schedule."""
    jid = datetime.now().strftime('%Y%m%d%H%M%S') + '-' + uuid.uuid4().hex[:6]
    job_dir = JOBS_DIR / jid
    job_dir.mkdir(parents=True, exist_ok=True)

    info = {
        'id':            jid,
        'label':         label,
        'host':          session['host'],
        'user':          session['user'],
        'password':      session['password'],
        'vm_name':       vm_name,
        'dest':          dest,
        'compress':      compress,
        'no_verify_ssl': no_verify_ssl,
        'sftp_host':     sftp_host,
        'sftp_user':     sftp_user,
        'sftp_password': sftp_password,
        'started':       time.time(),
        'status':        'queued',
        'schedule_type': schedule_type,
        'schedule_time': schedule_time,
        'schedule_id':   None,
    }
    jobs[jid] = info

    if schedule_type == 'now' or not HAS_SCHEDULER:
        t = threading.Thread(target=run_job_thread, args=(jid,), daemon=True)
        t.start()
    else:
        # Build APScheduler trigger
        trigger = None
        if schedule_type == 'daily':
            hour, minute = (schedule_time.split(':') + ['00'])[:2]
            trigger = CronTrigger(hour=int(hour), minute=int(minute))
        elif schedule_type == 'weekly':
            hour, minute = (schedule_time.split(':') + ['00'])[:2]
            trigger = CronTrigger(
                day_of_week=int(weekly_day),
                hour=int(hour), minute=int(minute)
            )
        elif schedule_type == 'interval':
            trigger = IntervalTrigger(hours=max(1, int(interval_hours or 24)))

        if trigger:
            # Capture jid in closure
            def make_runner(j):
                def _runner():
                    run_job_thread(j)
                return _runner

            sched_job = scheduler.add_job(
                make_runner(jid),
                trigger=trigger,
                id=f'backup-{jid}',
                name=f'Backup {vm_name} ({label or jid[:8]})',
                misfire_grace_time=3600,
                max_instances=1,
            )
            info['schedule_id'] = sched_job.id
            info['status'] = 'scheduled'
        else:
            # Fallback: run now
            t = threading.Thread(target=run_job_thread, args=(jid,), daemon=True)
            t.start()

    return jid


# ── Routes ────────────────────────────────────────────────────────────────────

@app.route('/')
def index():
    if session.get('host'):
        return redirect(url_for('vms'))
    return redirect(url_for('login'))


# ── Login / Logout ────────────────────────────────────────────────────────────

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        host         = request.form.get('host', '').strip()
        user         = request.form.get('user', '').strip()
        password     = request.form.get('password', '')
        no_verify_ssl = 'no_verify_ssl' in request.form

        if not (host and user and password):
            flash('Host, username and password are required.', 'danger')
            return render_template('login.html')

        # Verify credentials by listing VMs
        try:
            list_vms(host, user, password, no_verify_ssl=no_verify_ssl)
        except Exception as e:
            flash(f'Connection failed: {e}', 'danger')
            return render_template('login.html')

        session['host']          = host
        session['user']          = user
        session['password']      = password
        session['no_verify_ssl'] = no_verify_ssl
        flash(f'Connected to {host} successfully.', 'success')
        return redirect(url_for('vms'))

    return render_template('login.html')


@app.route('/logout')
def logout():
    session.clear()
    flash('Logged out.', 'info')
    return redirect(url_for('login'))


# ── VM Browser ────────────────────────────────────────────────────────────────

@app.route('/vms')
@login_required
def vms():
    error = None
    vm_list = []
    try:
        vm_list = list_vms(
            session['host'], session['user'], session['password'],
            no_verify_ssl=session.get('no_verify_ssl', False)
        )
        # Sort: powered on first, then alphabetical
        order = {'poweredOn': 0, 'suspended': 1, 'poweredOff': 2}
        vm_list.sort(key=lambda v: (order.get(v['power_state'], 3), v['name'].lower()))
    except Exception as e:
        error = str(e)
    return render_template('vms.html', vms=vm_list, error=error)


@app.route('/api/vms')
@login_required
def api_vms():
    try:
        vm_list = list_vms(
            session['host'], session['user'], session['password'],
            no_verify_ssl=session.get('no_verify_ssl', False)
        )
        return jsonify(vm_list)
    except Exception as e:
        return jsonify({'error': str(e)}), 500


# ── Create Job ────────────────────────────────────────────────────────────────

@app.route('/jobs/create', methods=['GET', 'POST'])
@login_required
def create_job():
    if request.method == 'POST':
        vm_name       = request.form.get('vm_name', '').strip()
        dest          = request.form.get('dest', './backups').strip()
        compress      = 'compress' in request.form
        no_verify_ssl = 'no_verify_ssl' in request.form
        sftp_host     = request.form.get('sftp_host', '').strip() or None
        sftp_user     = request.form.get('sftp_user', '').strip() or None
        sftp_password = request.form.get('sftp_password', '') or None
        schedule_type = request.form.get('schedule_type', 'now')
        daily_time    = request.form.get('daily_time', '02:00')
        weekly_day    = request.form.get('weekly_day', '0')
        weekly_time   = request.form.get('weekly_time', '02:00')
        interval_hrs  = request.form.get('interval_hours', '24')
        label         = request.form.get('job_label', '').strip()

        if not vm_name:
            flash('Please select a virtual machine.', 'danger')
            return redirect(url_for('create_job'))

        # Determine schedule_time string for display
        if schedule_type == 'daily':
            sched_time = daily_time
        elif schedule_type == 'weekly':
            sched_time = weekly_time
        else:
            sched_time = ''

        jid = create_and_start_job(
            vm_name=vm_name,
            dest=dest,
            compress=compress,
            no_verify_ssl=no_verify_ssl,
            sftp_host=sftp_host,
            sftp_user=sftp_user,
            sftp_password=sftp_password,
            schedule_type=schedule_type,
            schedule_time=sched_time,
            weekly_day=weekly_day,
            interval_hours=interval_hrs,
            label=label,
        )
        flash(f'Job created successfully!', 'success')
        return redirect(url_for('job_detail', jobid=jid))

    # GET: load VM list for the dropdown
    selected_vm  = request.args.get('vm', '')
    show_schedule = bool(request.args.get('schedule', ''))
    vm_list = []
    try:
        vm_list = list_vms(
            session['host'], session['user'], session['password'],
            no_verify_ssl=session.get('no_verify_ssl', False)
        )
        vm_list.sort(key=lambda v: v['name'].lower())
    except Exception as e:
        flash(f'Could not load VM list: {e}', 'danger')

    return render_template(
        'create_job.html',
        vms=vm_list,
        selected_vm=selected_vm,
        show_schedule=show_schedule,
    )


# ── Jobs Dashboard ────────────────────────────────────────────────────────────

@app.route('/jobs')
@login_required
def list_jobs():
    job_list = [
        job_to_display(jid, info)
        for jid, info in sorted(jobs.items(), key=lambda x: x[1].get('started', 0), reverse=True)
    ]
    scheduled_count = sum(1 for j in job_list if j['schedule_id'])
    return render_template('jobs.html', jobs=job_list, scheduled_count=scheduled_count)


# ── Job Detail ────────────────────────────────────────────────────────────────

@app.route('/job/<jobid>')
@login_required
def job_detail(jobid):
    info = jobs.get(jobid)
    if not info:
        abort(404)
    return render_template('job_detail.html', job=job_to_display(jobid, info))


@app.route('/job/<jobid>/log')
@login_required
def job_log(jobid):
    info = jobs.get(jobid)
    if not info:
        abort(404)
    log_path = JOBS_DIR / jobid / 'backup.log'
    if not log_path.exists():
        return '(No log output yet)', 200
    with open(log_path, 'rb') as f:
        lines = f.read().splitlines()[-300:]
    return '\n'.join(line.decode('utf-8', errors='replace') for line in lines)


@app.route('/api/job/<jobid>/status')
@login_required
def api_job_status(jobid):
    info = jobs.get(jobid)
    if not info:
        return jsonify({'error': 'not found'}), 404
    return jsonify({'status': info.get('status', 'unknown'), 'id': jobid})


@app.route('/job/<jobid>/cancel-schedule', methods=['POST'])
@login_required
def cancel_schedule(jobid):
    info = jobs.get(jobid)
    if not info:
        abort(404)
    sched_id = info.get('schedule_id')
    if sched_id and scheduler:
        try:
            scheduler.remove_job(sched_id)
        except Exception:
            pass
    info['schedule_id'] = None
    info['status'] = info.get('status', 'finished') if info.get('status') not in ('queued', 'running') else info['status']
    flash('Recurring schedule cancelled.', 'success')
    return redirect(url_for('job_detail', jobid=jobid))


# ── Template filter ───────────────────────────────────────────────────────────
@app.template_filter('startswith')
def startswith_filter(value, prefix):
    return str(value).startswith(prefix)


# ── Main ──────────────────────────────────────────────────────────────────────
if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000, debug=False)