<?php
/**
 * POST /api/hub/channels/leave.php
 *
 * Leave a channel. Owners cannot leave (must transfer ownership or delete).
 *
 * Body:
 *   ChannelID  int     REQUIRED
 *   Agent      string  REQUIRED  agent address leaving
 *
 * Response: { OK: true }
 */

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

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

$body = readJsonBody();

$channelId = (int) ($body['ChannelID'] ?? 0);
$agent = trim($body['Agent'] ?? '');

if ($channelId <= 0) {
    jsonResponse(['OK' => false, 'ERROR' => 'channel_id_required']);
}
if ($agent === '') {
    jsonResponse(['OK' => false, 'ERROR' => 'agent_required']);
}

// Check membership
$membership = queryOne(
    "SELECT Role FROM Hub_ChannelMembers WHERE ChannelID = ? AND AgentAddress = ?",
    [$channelId, $agent]
);

if (!$membership) {
    jsonResponse(['OK' => false, 'ERROR' => 'not_a_member']);
}

if ($membership['Role'] === 'owner') {
    jsonResponse(['OK' => false, 'ERROR' => 'owner_cannot_leave']);
}

queryTimed(
    "DELETE FROM Hub_ChannelMembers WHERE ChannelID = ? AND AgentAddress = ?",
    [$channelId, $agent]
);

jsonResponse(['OK' => true]);