import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * 代付 Demo。编译：javac -encoding UTF-8 *.java
 * 运行：java Demo balance|submit|query <OrderNo>
 */
public class Demo {
    static final String BASE_URL = env("BASE_URL", "https://example.com").replaceAll("/$", "");
    static final String ACCESS_KEY = env("ACCESS_KEY", "your_access_key");
    static final String SECRET_KEY = env("SECRET_KEY", "your_secret_key");
    static final String PAY_CHANNEL_ID = env("PAY_CHANNEL_ID", "821");

    public static void main(String[] args) throws Exception {
        if (args.length < 1) {
            System.out.println("usage: java Demo balance|submit|query <OrderNo>");
            return;
        }
        String cmd = args[0];
        if ("balance".equals(cmd)) {
            Map<String, Object> body = new LinkedHashMap<>();
            body.put("Timestamp", System.currentTimeMillis() / 1000);
            body.put("AccessKey", ACCESS_KEY);
            System.out.println(post("/api/apiv1/open/withdrawal/querybalance", body));
        } else if ("submit".equals(cmd)) {
            String orderNo = "DEMO" + new java.text.SimpleDateFormat("yyyyMMddHHmmss").format(new java.util.Date()) + String.format("%04d", new java.util.Random().nextInt(10000));
            Map<String, Object> body = new LinkedHashMap<>();
            body.put("Timestamp", System.currentTimeMillis() / 1000);
            body.put("AccessKey", ACCESS_KEY);
            body.put("PayChannelId", PAY_CHANNEL_ID);
            body.put("OrderNo", orderNo);
            body.put("Amount", "100.01");
            body.put("CallbackUrl", "https://xxxxx.com/xxxx/callback");
            body.put("Ext", "-");
            body.put("Payee", "张三");
            body.put("PayeeNo", "6235753100001261596");
            body.put("PayeeAddress", "招商银行");
            System.out.println(post("/api/apiv1/open/withdrawal/submit", body));
        } else if ("query".equals(cmd)) {
            if (args.length < 2) {
                System.out.println("usage: java Demo query <OrderNo>");
                return;
            }
            Map<String, Object> body = new LinkedHashMap<>();
            body.put("Timestamp", System.currentTimeMillis() / 1000);
            body.put("AccessKey", ACCESS_KEY);
            body.put("OrderNo", args[1]);
            System.out.println(post("/api/apiv1/open/withdrawal/queryorder", body));
        } else {
            System.out.println("unknown command: " + cmd);
        }
    }

    static String post(String path, Map<String, Object> body) throws Exception {
        body.put("Sign", SignUtil.buildSign(body, SECRET_KEY));
        String json = toJson(body);
        HttpURLConnection conn = (HttpURLConnection) new URL(BASE_URL + path).openConnection();
        conn.setRequestMethod("POST");
        conn.setConnectTimeout(15000);
        conn.setReadTimeout(30000);
        conn.setDoOutput(true);
        conn.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
        try (OutputStream os = conn.getOutputStream()) {
            os.write(json.getBytes(StandardCharsets.UTF_8));
        }
        try (InputStream in = conn.getResponseCode() >= 400 ? conn.getErrorStream() : conn.getInputStream()) {
            return new String(in.readAllBytes(), StandardCharsets.UTF_8);
        }
    }

    static String env(String k, String def) {
        String v = System.getenv(k);
        return v == null || v.isEmpty() ? def : v;
    }

    /** 极简 JSON（仅本 Demo 字段类型） */
    static String toJson(Map<String, Object> map) {
        StringBuilder sb = new StringBuilder("{");
        boolean first = true;
        for (Map.Entry<String, Object> e : map.entrySet()) {
            if (!first) sb.append(',');
            first = false;
            sb.append('"').append(e.getKey()).append('"').append(':');
            Object v = e.getValue();
            if (v instanceof Number) {
                sb.append(v);
            } else {
                sb.append('"').append(String.valueOf(v).replace("\\", "\\\\").replace("\"", "\\\"")).append('"');
            }
        }
        return sb.append('}').toString();
    }
}