<?php
/**
 * POST /api/hub/reactions/add.php
 *
 * Add a reaction to a message.
 *
 * Body:
 *   MessageID     int     REQUIRED
 *   AgentAddress  string  REQUIRED
 *   EmojiName     string  REQUIRED  e.g. "+1", "heart", "fire"
 *
 * Response: { OK: true, Reaction: { ... } }
 */

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

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

$body = readJsonBody();

$messageId = (int) ($body['MessageID'] ?? 0);
$agentAddress = trim($body['AgentAddress'] ?? '');
$emojiName = trim($body['EmojiName'] ?? '');

if ($messageId <= 0) jsonResponse(['OK' => false, 'ERROR' => 'message_id_required']);
if ($agentAddress === '') jsonResponse(['OK' => false, 'ERROR' => 'agent_address_required']);
if ($emojiName === '') jsonResponse(['OK' => false, 'ERROR' => 'emoji_name_required']);

// Sanitize emoji name
$emojiName = preg_replace('/[^a-zA-Z0-9_\-+]/', '', $emojiName);
if ($emojiName === '' || strlen($emojiName) > 50) {
    jsonResponse(['OK' => false, 'ERROR' => 'invalid_emoji_name']);
}

// Verify message exists
$msg = queryOne("SELECT ID, ChannelID FROM Hub_Messages WHERE ID = ? AND IsDeleted = 0", [$messageId]);
if (!$msg) jsonResponse(['OK' => false, 'ERROR' => 'message_not_found']);

// Check if already reacted with this emoji
$existing = queryOne(
    "SELECT ID FROM Hub_Reactions WHERE MessageID = ? AND AgentAddress = ? AND EmojiName = ?",
    [$messageId, $agentAddress, $emojiName]
);
if ($existing) {
    jsonResponse(['OK' => false, 'ERROR' => 'already_reacted']);
}

queryTimed(
    "INSERT INTO Hub_Reactions (MessageID, AgentAddress, EmojiName) VALUES (?, ?, ?)",
    [$messageId, $agentAddress, $emojiName]
);
$reactionId = (int) lastInsertId();

$reaction = queryOne("SELECT * FROM Hub_Reactions WHERE ID = ?", [$reactionId]);

jsonResponse([
    'OK' => true,
    'Reaction' => [
        'ID'           => (int) $reaction['ID'],
        'MessageID'    => (int) $reaction['MessageID'],
        'AgentAddress' => $reaction['AgentAddress'],
        'EmojiName'    => $reaction['EmojiName'],
        'CreatedAt'    => toISO8601($reaction['CreatedAt']),
    ],
]);