<?php
/**
 * GET /api/hub/channels/get.php
 *
 * Get a single channel by ID or Name.
 *
 * Query params:
 *   ID    int     get by ID
 *   Name  string  get by name (if ID not provided)
 *
 * Response: { OK: true, Channel: { ... }, Members: [...] }
 */

require_once __DIR__ . '/../../helpers.php';

if ($_SERVER['REQUEST_METHOD'] !== 'GET') {
    jsonResponse(['OK' => false, 'ERROR' => 'method_not_allowed'], 405);
}

$id = (int) ($_GET['ID'] ?? 0);
$name = trim($_GET['Name'] ?? '');

if ($id <= 0 && $name === '') {
    jsonResponse(['OK' => false, 'ERROR' => 'id_or_name_required']);
}

if ($id > 0) {
    $channel = queryOne("SELECT * FROM Hub_Channels WHERE ID = ?", [$id]);
} else {
    $channel = queryOne("SELECT * FROM Hub_Channels WHERE Name = ?", [$name]);
}

if (!$channel) {
    jsonResponse(['OK' => false, 'ERROR' => 'channel_not_found'], 404);
}

// Fetch members
$members = queryTimed(
    "SELECT m.*, a.AgentName, a.AgentType, a.Role AS AgentRole
     FROM Hub_ChannelMembers m
     LEFT JOIN Sprinter_Agents a ON a.FullAddress = m.AgentAddress
     WHERE m.ChannelID = ?
     ORDER BY m.JoinedAt ASC",
    [(int) $channel['ID']]
);

$memberList = [];
foreach ($members as $m) {
    $memberList[] = [
        'AgentAddress' => $m['AgentAddress'],
        'AgentName'    => $m['AgentName'] ?? '',
        'AgentType'    => $m['AgentType'] ?? '',
        'Role'         => $m['Role'],
        'JoinedAt'     => toISO8601($m['JoinedAt']),
        'LastViewedAt' => $m['LastViewedAt'] ? toISO8601($m['LastViewedAt']) : null,
    ];
}

jsonResponse([
    'OK' => true,
    'Channel' => [
        'ID'          => (int) $channel['ID'],
        'Name'        => $channel['Name'],
        'DisplayName' => $channel['DisplayName'],
        'Purpose'     => $channel['Purpose'],
        'ChannelType' => $channel['ChannelType'],
        'CreatedBy'   => $channel['CreatedBy'],
        'IsArchived'  => (bool) $channel['IsArchived'],
        'CreatedAt'   => toISO8601($channel['CreatedAt']),
        'UpdatedAt'   => toISO8601($channel['UpdatedAt']),
        'MemberCount' => count($memberList),
    ],
    'Members' => $memberList,
]);