from flask import Blueprint, request, redirect, flash
from auth import require_level
from config_utils import load_config, save_config, verify_config_hash, queued_msg
import sanitize
import validation as validate

bp = Blueprint('action_upstreamdns', __name__)

_VIEW = '/view/view_upstream_dns'


@bp.route('/action/upstreamdns_cardupstreamdns_save', methods=['POST'])
@require_level('administrator')
def upstreamdns_cardupstreamdns_save():
    strict_order = 'strict_order' in request.form
    submitted    = request.form.getlist('upstream_servers')

    for s in submitted:
        if not s.strip():
            flash('Remove blank server entries before saving.', 'error')
            return redirect(_VIEW)

    upstream_servers = []
    for s in submitted:
        clean = sanitize.ip(s.strip())
        if not clean:
            flash(f"'{s.strip()}' is not a valid IP address.", 'error')
            return redirect(_VIEW)
        upstream_servers.append(clean)

    if not verify_config_hash(request.form.get('config_hash', '')):
        flash('Configuration was modified by another session. Please refresh and try again.', 'error')
        return redirect(_VIEW)

    cfg    = load_config()
    current = cfg.get('upstream_dns', {})
    if (strict_order == bool(current.get('strict_order', False)) and
            upstream_servers == current.get('upstream_servers', [])):
        flash('No changes detected.', 'info')
        return redirect(_VIEW)

    cfg.setdefault('upstream_dns', {}).update({
        'strict_order':     strict_order,
        'upstream_servers': upstream_servers,
    })
    errors = validate.validate_config(cfg)
    if errors:
        for msg in errors:
            flash(msg, 'error')
        return redirect(_VIEW)
    save_config(cfg)
    flash(queued_msg('core apply'), 'success')
    return redirect(_VIEW)


@bp.route('/action/upstreamdns_cardforwardingdnsservice_save', methods=['POST'])
@require_level('administrator')
def upstreamdns_cardforwardingdnsservice_save():
    cache_size = validate.int_range(request.form.get('cache_size', '').strip(), 0, None)
    if cache_size is None:
        flash('Cache Size must be a non-negative integer.', 'error')
        return redirect(_VIEW)

    if not verify_config_hash(request.form.get('config_hash', '')):
        flash('Configuration was modified by another session. Please refresh and try again.', 'error')
        return redirect(_VIEW)

    cfg    = load_config()
    current = cfg.get('upstream_dns', {})
    if cache_size == int(current.get('cache_size', 0)):
        flash('No changes detected.', 'info')
        return redirect(_VIEW)

    cfg.setdefault('upstream_dns', {})['cache_size'] = cache_size
    errors = validate.validate_config(cfg)
    if errors:
        for msg in errors:
            flash(msg, 'error')
        return redirect(_VIEW)
    save_config(cfg)
    flash(queued_msg('core apply'), 'success')
    return redirect(_VIEW)