<?php
/**
 * ajax/networks.php
 *
 * Backs the Networks panel. See docs/ARCHITECTURE.md section 8 for why
 * networks created here are netavark-backed and deliberately isolated
 * from Docker's own docker0/custom-network space.
 *
 * Actions (?action=...):
 *   list                  GET  -> normalized network list with subnet/gateway/usage
 *   list_parent_interfaces GET -> host bridge/VLAN interfaces available as a macvlan parent
 *   create                POST {"name": "...", "driver": "bridge"|"macvlan", "subnet": "...",
 *                                "gateway": "...", "parentInterface": "br0"}
 *   remove                POST {"name": "...", "force": false}
 */

declare(strict_types=1);

require __DIR__ . '/../include/bootstrap.php';

$action = $_GET['action'] ?? '';

switch ($action) {
    case 'list':
        podman_json_response(networks_list($client));
        break;

    case 'list_parent_interfaces':
        podman_json_response(macvlan_parent_interfaces());
        break;

    case 'create':
        $body = podman_read_json_body();
        $name = (string) ($body['name'] ?? '');
        if ($name === '') {
            podman_json_error('Missing name in request body', 400);
        }
        $driver = (string) ($body['driver'] ?? 'bridge');

        $parentInterface = null;
        if ($driver === 'macvlan') {
            $parentInterface = (string) ($body['parentInterface'] ?? '');
            // Only ever accept an interface this same host reported via
            // macvlan_parent_interfaces() — the boundary preventing a
            // tampered request from asking podman to attach to an
            // arbitrary/unexpected interface name.
            $known = array_column(macvlan_parent_interfaces(), 'interface');
            if (!in_array($parentInterface, $known, true)) {
                podman_json_error('Unknown parent interface — refresh the page and try again.', 400);
            }
            if (!isset($body['subnet']) || (string) $body['subnet'] === '') {
                podman_json_error('Subnet is required for a macvlan network.', 400);
            }
        }

        podman_json_response($client->createNetwork(
            $name,
            $driver,
            isset($body['subnet']) ? (string) $body['subnet'] : null,
            isset($body['gateway']) ? (string) $body['gateway'] : null,
            $parentInterface
        ));
        break;

    case 'remove':
        $body = podman_read_json_body();
        $name = (string) ($body['name'] ?? '');
        if ($name === '') {
            podman_json_error('Missing name in request body', 400);
        }
        // podman0, the default bridge, refuses removal API-side — no
        // special-casing needed here, PodmanApiException surfaces podman's
        // own rejection message as-is.
        $client->removeNetwork($name, (bool) ($body['force'] ?? false));
        podman_json_response(['status' => 'removed']);
        break;

    default:
        podman_json_error("Unknown action '{$action}'", 400);
}

/**
 * Reads Unraid's own /boot/config/network.cfg (BRNAME[i]/VLANID[i,j]/
 * DESCRIPTION[i,j]) to list the same host bridge + VLAN interfaces
 * Unraid's own Docker Manager offers as "Custom: br0" / "Custom: br0.3
 * (VPN)" network types — reusing Unraid's own config instead of guessing
 * from raw `ip link` output, so the list always matches what Docker
 * Manager shows for the same host. Verified live: this host's
 * network.cfg has BRNAME[0]="br0" and VLANID[0,1]="3"/DESCRIPTION[0,1]=
 * "VPN", producing "br0" and "br0.3 (VPN)" — matching the interface
 * names shown in that other plugin's own network-type dropdown exactly.
 * Each candidate is confirmed to actually exist in /sys/class/net before
 * being offered, in case network.cfg mentions an interface that isn't
 * currently up.
 *
 * @return array<int,array{interface:string,label:string}>
 */
function macvlan_parent_interfaces(): array
{
    $cfgFile = '/boot/config/network.cfg';
    if (!is_file($cfgFile)) {
        return [];
    }

    $cfg = [];
    foreach (file($cfgFile, FILE_IGNORE_NEW_LINES) ?: [] as $line) {
        if (preg_match('/^([A-Z0-9_]+)\[(\d+)(?:,(\d+))?\]="([^"]*)"$/', $line, $m) !== 1) {
            continue;
        }
        [, $key, $i, $j, $value] = $m + [3 => ''];
        $i = (int) $i;
        if ($j === '') {
            $cfg[$key][$i] = $value;
        } else {
            $cfg[$key][$i][(int) $j] = $value;
        }
    }

    $out = [];
    foreach (($cfg['BRNAME'] ?? []) as $i => $brname) {
        if (!is_string($brname) || $brname === '' || !is_dir("/sys/class/net/{$brname}")) {
            continue;
        }
        $out[] = ['interface' => $brname, 'label' => $brname];
        foreach (($cfg['VLANID'][$i] ?? []) as $j => $vlanId) {
            $iface = "{$brname}.{$vlanId}";
            if (!is_dir("/sys/class/net/{$iface}")) {
                continue;
            }
            $desc = $cfg['DESCRIPTION'][$i][$j] ?? '';
            $out[] = ['interface' => $iface, 'label' => $iface . ($desc !== '' ? " ({$desc})" : '')];
        }
    }
    return $out;
}

/** @return array<int,array<string,mixed>> */
function networks_list(PodmanClient $client): array
{
    $raw = $client->listNetworks();

    $usageCounts = [];
    foreach ($client->listContainers(true) as $c) {
        $nets = $c['Networks'] ?? [];
        if (is_array($nets)) {
            foreach ($nets as $netName) {
                if (is_string($netName)) {
                    $usageCounts[$netName] = ($usageCounts[$netName] ?? 0) + 1;
                }
            }
        }
    }

    $out = [];
    foreach ($raw as $n) {
        $name = (string) ($n['name'] ?? '');
        $subnets = $n['subnets'] ?? [];
        $subnet = is_array($subnets) && count($subnets) > 0 ? (string) ($subnets[0]['subnet'] ?? '') : '';
        $gateway = is_array($subnets) && count($subnets) > 0 ? (string) ($subnets[0]['gateway'] ?? '') : '';

        $out[] = [
            'name' => $name,
            'driver' => (string) ($n['driver'] ?? 'bridge'),
            'subnet' => $subnet,
            'gateway' => $gateway,
            'isDefault' => $name === 'podman',
            'containers' => $usageCounts[$name] ?? 0,
        ];
    }

    usort($out, static fn($a, $b) => strcmp($a['name'], $b['name']));
    return $out;
}