package com.zzwtec.wechat.sdk.kit;

import com.jfinal.kit.StrKit;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.net.ssl.*;
import javax.servlet.http.HttpServletRequest;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.Map;

public class HttpKit {
    private static final Logger logger = LoggerFactory.getLogger(HttpKit.class);
    private HttpKit() {}

    /**
     * https 域名校验
     */
    private static class TrustAnyHostnameVerifier implements HostnameVerifier {
        @Override
        public boolean verify(String hostname, SSLSession session) {
            return true;
        }
    }

    /**
     * https 证书管理
     */
    private static class TrustAnyTrustManager implements X509TrustManager {
        @Override
        public X509Certificate[] getAcceptedIssuers() {
            return null;
        }
        @Override
        public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
        }
        @Override
        public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
        }
    }

    private static final String GET  = "GET";
    private static final String POST = "POST";
    private static String CHARSET = "UTF-8";

    private static final SSLSocketFactory sslSocketFactory = initSSLSocketFactory();
    private static final TrustAnyHostnameVerifier trustAnyHostnameVerifier = new HttpKit.TrustAnyHostnameVerifier();

    private static SSLSocketFactory initSSLSocketFactory() {
        try {
            TrustManager[] tm = {new HttpKit.TrustAnyTrustManager() };
            SSLContext sslContext = SSLContext.getInstance("TLS");	// ("TLS", "SunJSSE");
            sslContext.init(null, tm, new java.security.SecureRandom());
            return sslContext.getSocketFactory();
        }
        catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static void setCharSet(String charSet) {
        if (StrKit.isBlank(charSet)) {
            throw new IllegalArgumentException("charSet can not be blank.");
        }
        HttpKit.CHARSET = charSet;
    }

    private static HttpURLConnection getHttpConnection(String url, String method, Map<String, String> headers) throws IOException, NoSuchAlgorithmException, NoSuchProviderException, KeyManagementException {
        URL _url = new URL(url);
        HttpURLConnection conn = (HttpURLConnection)_url.openConnection();
        if (conn instanceof HttpsURLConnection) {
            ((HttpsURLConnection)conn).setSSLSocketFactory(sslSocketFactory);
            ((HttpsURLConnection)conn).setHostnameVerifier(trustAnyHostnameVerifier);
        }

        conn.setRequestMethod(method);
        conn.setDoOutput(true);
        conn.setDoInput(true);

        conn.setConnectTimeout(19000);
        conn.setReadTimeout(19000);

        conn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
        conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.146 Safari/537.36");

        if (headers != null && !headers.isEmpty()) {
            for (Map.Entry<String, String> entry : headers.entrySet()) {
                conn.setRequestProperty(entry.getKey(), entry.getValue());
            }
        }

        return conn;
    }

    /**
     * Send GET request
     */
    public static String get(String url, Map<String, String> queryParas, Map<String, String> headers) {
        HttpURLConnection conn = null;
        try {
            conn = getHttpConnection(buildUrlWithQueryString(url, queryParas), GET, headers);
            conn.connect();
            return readResponseString(conn);
        }
        catch (Exception e) {
            throw new RuntimeException(e);
        }
        finally {
            if (conn != null) {
                conn.disconnect();
            }
        }
    }

    public static String get(String url, Map<String, String> queryParas) {
        return get(url, queryParas, null);
    }

    public static String get(String url) {
        return get(url, null, null);
    }

    /**
     * Send POST request
     */
    public static String post(String url, Map<String, String> queryParas, String data, Map<String, String> headers) {
        HttpURLConnection conn = null;
        try {
            conn = getHttpConnection(buildUrlWithQueryString(url, queryParas), POST, headers);
            conn.connect();

            if (data != null) {
                OutputStream out = conn.getOutputStream();
                out.write(data.getBytes(CHARSET));
                out.flush();
                out.close();
            }

            return readResponseString(conn);
        }
        catch (Exception e) {
            throw new RuntimeException(e);
        }
        finally {
            if (conn != null) {
                conn.disconnect();
            }
        }
    }

    public static String post(String url, Map<String, String> queryParas, String data) {
        return post(url, queryParas, data, null);
    }

    public static String post(String url, String data, Map<String, String> headers) {
        return post(url, null, data, headers);
    }

    public static String post(String url, String data) {
        return post(url, null, data, null);
    }

    private static String readResponseString(HttpURLConnection conn) {
        BufferedReader reader = null;
        try {
            StringBuilder ret;
            reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), CHARSET));
            String line = reader.readLine();
            if (line != null) {
                ret = new StringBuilder();
                ret.append(line);
            } else {
                return "";
            }

            while ((line = reader.readLine()) != null) {
                ret.append('\n').append(line);
            }
            return ret.toString();
        }
        catch (Exception e) {
            throw new RuntimeException(e);
        }
        finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    logger.error(e.getMessage(), e);
                }
            }
        }
    }

    /**
     * Build queryString of the value
     */
    private static String buildUrlWithQueryString(String url, Map<String, String> queryParas) {
        if (queryParas == null || queryParas.isEmpty()) {
            return url;
        }

        StringBuilder sb = new StringBuilder(url);
        boolean isFirst;
        if (url.indexOf('?') == -1) {
            isFirst = true;
            sb.append('?');
        }
        else {
            isFirst = false;
        }

        for (Map.Entry<String, String> entry : queryParas.entrySet()) {
            if (isFirst) {
                isFirst = false;
            } else {
                sb.append('&');
            }

            String key = entry.getKey();
            String value = entry.getValue();
            if (StrKit.notBlank(value)) {
                try {value = URLEncoder.encode(value, CHARSET);} catch (UnsupportedEncodingException e) {throw new RuntimeException(e);}
            }
            sb.append(key).append('=').append(value);
        }
        return sb.toString();
    }

    public static String readData(HttpServletRequest request) {
        BufferedReader br = null;
        try {
            StringBuilder ret;
            br = request.getReader();

            String line = br.readLine();
            if (line != null) {
                ret = new StringBuilder();
                ret.append(line);
            } else {
                return "";
            }

            while ((line = br.readLine()) != null) {
                ret.append('\n').append(line);
            }

            return ret.toString();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        finally {
            if (br != null) {
                try {br.close();} catch (IOException e) {logger.error(e.getMessage(), e);}
            }
        }
    }

    @Deprecated
    public static String readIncommingRequestData(HttpServletRequest request) {
        return readData(request);
    }
}
