#!/usr/bin/env php
<?php


// 节点 ID
$node_id = '{{NODE_ID}}';

// Nginx 单个站点的配置文件路径
$nginx_conf_path = '/path/to/api.laecloud.com.conf';


/** 自动生成的配置文件，如有变动，按照需求编辑。 **/
$redis_info = [
    'host' => '{{REDIS_HOST}}',
    'port' => '{{REDIS_PORT}}',
    'password' => '{{REDIS_PASSWORD}}',
    'prefix' => '{{REDIS_PREFIX}}',

];


/**  好了，不要再编辑了。配置到此为止了。 **/
$nginx_conf = '';
$nginx_file_md5 = '';

$prefix = $redis_info['prefix'];

// 检查是否存在配置文件
if (!file_exists($nginx_conf_path)) {
    echo 'nginx.conf not found';
    exit;
} else {
    $nginx_conf = file_get_contents($nginx_conf_path);
    $nginx_file_md5 = md5_file($nginx_conf_path);
}

// 检查redis_info是否正确
foreach ($redis_info as $key => $value) {
    if (empty($value)) {
        echo "redis_info[$key] is empty";
        exit;
    }
}

$redis = new Redis();

try {
    $redis->connect($redis_info['host'], $redis_info['port']);
    $redis->auth($redis_info['password']);

    // set db 0
    $redis->select(0);
} catch (RedisException $e) {
    echo 'Connection to Redis failed: ' . $e->getMessage();
}

try {
    if ($redis->ping('')) {
        output('redis is ok');
    }
} catch (RedisException $e) {
    output('redis is error');
}

// 检验环境
// 检测 Nginx 是否存在 which nginx
$nginx_path = trim(shell_exec('which nginx'));
if (empty($nginx_path)) {
    echo 'nginx not found';

    redis_publish('edge.error', [
        'message' => '此节点上并没有安装 Nginx ，但是 Edge 被启动了，现在已经退出。',
    ]);

    exit;
}

redis_publish('edge.launched');

$last_run_at = time() - 100;

$ip = '';

// 获取本机 IP ifconfig.me
$ip = trim(shell_exec('curl -s ifconfig.me'));

$run_count = 0;

// 逻辑部分
while (true) {
    if ($run_count >= 10000) {
        $run_count = 0;

        // 重新获取 IP
        $ip = trim(shell_exec('curl -s ifconfig.me'));
    }

    redis_hset('nodes', $node_id, [
        'type' => 'edge',
        'id' => 'edge-' . $node_id,
        'ip' => $ip,
        // utc +8 timestamp
        'last_heartbeat' => time(),
    ]);

    // 上次运行时间需要满 60s，才继续，否则 continue
    if (time() - $last_run_at < 60) {
        sleep(1);

        continue;
    }

    // 重新载入 nginx.conf
    if (!file_exists($nginx_conf_path)) {
        echo 'nginx.conf not found';

        redis_publish('edge.error', [
            'message' => 'Nginx 配置文件在启动后被删除，Edge 进程退出。',
        ]);

        exit;
    } else {
        $nginx_conf = file_get_contents($nginx_conf_path);
        $nginx_file_md5 = md5_file($nginx_conf_path);
    }

    // 检查 laecloud_database_cluster:nodes 是否存在
    try {
        if (!$redis->exists($prefix . 'cluster:nodes')) {
            output('cluster:nodes not found');
        }
    } catch (RedisException $e) {
        output('redis is error');
    }

    $nodes = redis_hgetAll('nodes');
    if (!$nodes) {
        output('nodes is empty');

        continue;
    }

    foreach ($nodes as $node) {
        // if node last_heartbeat(utc+8 timestamp) is over 10s, skip
        if (time() - $node['last_heartbeat'] > 10) {
            // 删除节点
            redis_hdel('nodes', $node['id']);
        }
    }

    $conf = '';

    foreach ($nodes as $node) {
        // only allow node type master, slave
        if (!in_array($node['type'], ['master', 'slave'])) {
            continue;
        }

        output('node_type: ' . $node['type']);
        output('node_id: ' . $node['id']);
        output('================================================================');

        $temp_conf = "#node {$node['type']}:{$node['id']}\n";
        $temp_conf .= "server {$node['ip']}";

        if (isset($node['weight'])) {
            if ($node['weight'] !== '0') {
                $temp_conf .= " weight={$node['weight']} ";
            }
        } else {
            $temp_conf .= ' weight=1 ';
        }

        if ($node['type'] == 'master') {
            if (count($nodes) <= 2) {
                $temp_conf .= ' backup ';
            }
        }

        $temp_conf .= ' max_fails=1 fail_timeout=10s ';

        $temp_conf .= ";\n";

        echo $temp_conf . PHP_EOL;

        output('================================================================');

        $conf .= $temp_conf . PHP_EOL;
    }

    output('!!!!!!!!!!!!!!!!!');
    echo $conf;
    output('!!!!!!!!!!!!!!!!!');

    $add_header = <<<EOF
add_header 'Cluster-Ready-Node-Id' 'edge-$node_id';
add_header 'Powered-by' 'Cluster Ready!';
EOF;

    // 放入配置文件，以 ##########CLUSTERREADY######### 开始，以 ##########END_CLUSTERREADY######### 结束
    $nginx_conf = preg_replace('/##########CLUSTERREADY#########.*##########END_CLUSTERREADY#########/s', '##########CLUSTERREADY#########' . PHP_EOL . $conf . '##########END_CLUSTERREADY#########', $nginx_conf);
    $nginx_conf = preg_replace('/##########CLUSTERREADY_PROXY#########.*##########END_CLUSTERREADY_PROXY#########/s', '##########CLUSTERREADY_PROXY#########' . PHP_EOL . $add_header . PHP_EOL . '##########END_CLUSTERREADY_PROXY#########', $nginx_conf);

    if (md5($nginx_conf) != $nginx_file_md5) {
        file_put_contents($nginx_conf_path, $nginx_conf);
        output('nginx.conf is changed, reload nginx');

        // reload nginx
        exec('nginx -s reload');

        output('nginx is reloaded.');

        // 收尾
        redis_publish('edge.deployed');
    }

    $last_run_at = time();

    $run_count++;
}
function output($context): void
{
    $time_string = date('Y-m-d H:i:s');
    echo $time_string . ': ' . $context . PHP_EOL;
}

function redis_get($key, $default = null)
{
    global $redis, $prefix;

    try {
        $value = $redis->get($prefix . 'cluster:' . $key);
    } catch (RedisException $e) {
        exit('redis get error: ' . $e->getMessage());
    }

    if (empty($value)) {
        return $default;
    }

    return $value;
}

function redis_hget($key, $hash_key, $default = null)
{
    global $redis, $prefix;

    try {
        $value = $redis->hget($prefix . 'cluster:' . $key, $hash_key);
    } catch (RedisException $e) {
        exit('redis get error: ' . $e->getMessage());
    }

    if (empty($value)) {
        return $default;
    }

    return $value;
}

function redis_hgetAll($key)
{
    global $redis, $prefix;

    try {
        $value = $redis->hGetAll($prefix . 'cluster:' . $key);
    } catch (RedisException $e) {
        exit('redis get error: ' . $e->getMessage());
    }

    // json_decode all
    foreach ($value as $k => $v) {
        $value[$k] = json_decode($v, true);
    }

    return $value;
}

function redis_hset($key, $hash_key, $value)
{
    global $redis, $prefix;

    try {
        $redis->hset($prefix . 'cluster:' . $key, $hash_key, json_encode($value));
    } catch (RedisException $e) {
        echo 'redis get error: ' . $e->getMessage();
    }
}

function redis_hdel($key, $hash_key): void
{
    global $redis, $prefix;

    try {
        $redis->hdel($prefix . 'cluster:' . $key, $hash_key);
    } catch (RedisException $e) {
        echo 'redis get error: ' . $e->getMessage();
    }
}

function redis_publish($event, $message = []): void
{
    global $redis, $prefix, $node_id;

    $data = [
        'event' => $event,
        'node' => [
            'type' => 'edge',
            'id' => $node_id,
        ],
        'data' => $message,
    ];

    $data = json_encode($data);

    try {
        $redis->publish($prefix . 'cluster_ready', $data);
    } catch (RedisException $e) {
        echo 'redis publish error: ' . $e->getMessage();
    }
}