/**
 * Hoover — components/applyconfirm.js
 *
 * Apply button with cross-subsystem confirmation modal.
 * Fetches pending changes from /api/status/pending, shows them in an
 * expandable modal, then applies all via /api/status/apply-all.
 */

import { h } from '../vdom.js?v=8';
import { html } from '../html.js?v=8';
import { reactive } from '../reactivity.js?v=8';
import { apiFetch, toast } from '../api.js?v=8';
import { modelFetch } from '../model.js?v=8';
import { openModal, closeModal, modalVNodes } from './modal.js?v=8';

export const SUBSYSTEM_LIST = [
    { key: 'firewall', label: 'Firewall' },
    { key: 'dnsmasq', label: 'DHCP/DNS' },
    { key: 'nginx', label: 'Nginx' },
    { key: 'wireguard', label: 'WireGuard' },
    { key: 'networkd', label: 'Network' },
];

/**
 * Extract pending state from a subsystem result.
 * Handles firewall's `needs_apply` vs hash subsystems' `pending_changes`.
 */
export function isPending(ss) {
    return (ss.needs_apply || ss.pending_changes || false);
}

/**
 * Build the VNode array for modal rows given pending data and expanded state.
 */
export function buildRows(pendingData, expanded) {
    const vnodeList = [];

    for (const sub of SUBSYSTEM_LIST) {
        const ss = pendingData[sub.key] || {};
        const changes = ss.changes || [];
        const hasPending = isPending(ss) && changes.length > 0;
        const isExpanded = !!expanded[sub.key];

        vnodeList.push(html`<div class="apply-subsystem-row${hasPending ? ' pending' : ''}">
<span class="apply-subsystem-name">${sub.label}</span>
<span class="apply-subsystem-status${hasPending ? ' pending' : ''}">${hasPending ? changes.length + ' pending changes' : 'Up to date'}</span>
${hasPending ? html`<span class="apply-expand-icon${isExpanded ? ' expanded' : ''}">\u25B6</span>` : ''}
</div>`);

        if (hasPending && isExpanded) {
            vnodeList.push(html`<div class="apply-detail-section">${changes.map(c => html`<div class="apply-detail-item">${c.summary || c.detail || c}</div>`)}</div>`);
        }
    }

    return vnodeList;
}

/**
 * POST apply-all, toast result, close modal, refresh models.
 */
async function doApply(successMsg, refreshTargets) {
    const resp = await apiFetch('/api/status/apply-all', { method: 'POST' });
    if (resp.ok) {
        toast(successMsg, 'success');
        closeModal();
        if (refreshTargets) {
            const names = Array.isArray(refreshTargets) ? refreshTargets : [refreshTargets];
            names.forEach(n => modelFetch(n));
        }
    } else {
        toast(resp.error || 'Apply failed', 'error');
    }
}

/**
 * Fetch pending state, then open the confirmation modal.
 */
async function openApplyModal(successMsg, refreshTargets) {
    const pendingResp = await apiFetch('/api/status/pending');
    if (!pendingResp.ok) {
        toast(pendingResp.error || 'Could not fetch pending changes', 'error');
        return;
    }

    const pendingData = pendingResp.data || {};
    const totalChanges = pendingData.total_changes || 0;

    const expanded = reactive({});

    openModal((inner) => {
        const rows = buildRows(pendingData, expanded);

        if (totalChanges === 0) {
            modalVNodes(inner, html`<div>
<h2 class="modal-title">Confirm: Apply All Changes</h2>
<div class="apply-no-changes">No pending changes to apply.</div>
<div class="apply-modal-actions"><button class="btn btn-outline" onClick="${() => closeModal()}">Cancel</button></div>
</div>`);
            return;
        }

        modalVNodes(inner, html`<div>
<h2 class="modal-title">Confirm: Apply All Changes</h2>
<div class="modal-body">${rows}</div>
<div class="apply-modal-actions"><button class="btn btn-outline" onClick="${() => closeModal()}">Cancel</button><button class="btn btn-primary" onClick="${() => doApply(successMsg, refreshTargets)}">Apply All</button></div>
</div>`);
    });
}

/**
 * Apply button with cross-subsystem confirmation modal.
 *
 * @param {object} props
 * @param {boolean} props.pending              - Whether any subsystem has pending changes
 * @param {string}  [props.label]              - Apply button text (default: 'Apply')
 * @param {string}  [props.syncedLabel]        - Synced button text (default: 'Synced')
 * @param {string}  [props.cls]                - Button CSS classes (default: 'btn btn-primary' when pending, 'btn btn-outline' when synced)
 * @param {string}  [props.successMsg]         - Success toast message (default: 'All changes applied')
 * @param {string|string[]} [props.refresh]    - Model name(s) to refresh after apply
 */
export function ApplyConfirm(props = {}) {
    const label = props.label || 'Apply';
    const syncedLabel = props.syncedLabel || 'Synced';
    const successMsg = props.successMsg || 'All changes applied';

    return h('button', {
        class: props.cls !== undefined
            ? props.cls
            : (props.pending ? 'btn btn-primary' : 'btn btn-outline'),
        'on:click': () => {
            if (!props.pending) {
                toast(successMsg || 'All synced', 'info');
                return;
            }
            openApplyModal(successMsg, props.refresh);
        },
    }, props.pending ? label : syncedLabel);
}