package com.hdl.sdk.connect.cloud.interceptor;

import android.net.Uri;
import android.text.TextUtils;

import androidx.annotation.NonNull;

import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.reflect.TypeToken;
import com.hdl.sdk.connect.HDLLink;
import com.hdl.sdk.connect.cloud.GsonUtils;
import com.hdl.sdk.connect.cloud.MD5Utils;

import java.io.IOException;
import java.net.URLDecoder;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import okhttp3.FormBody;
import okhttp3.Headers;
import okhttp3.Interceptor;
import okhttp3.MediaType;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import okio.Buffer;

/**
 * Created by Tong on 2021/11/4.
 * 加密并自动补充参数,appKey、timestamp
 * 只支持表单、json
 * 最终json方式提交
 */
public class EncryptInterceptor implements Interceptor {


    @NonNull
    @Override
    public Response intercept(@NonNull Chain chain) throws IOException {
        Request request = chain.request();
        Headers headers = request.headers();
        if (!isIgnoreSignHeader(headers)) {
            return chain.proceed(encrypt(request));
        }

        return chain.proceed(request);
    }


    /**
     * 添加sign字段
     */
    private Request encrypt(Request request) {
        final String timestamp = String.valueOf(System.currentTimeMillis());
        final String appKey = HDLLink.getInstance().getAppKey();
        final String appSecret = HDLLink.getInstance().getAppSecret();
        final JsonObject json = getBodyJson(request);
        if (json != null) {
            json.addProperty("appKey", appKey);
            json.addProperty("timestamp", timestamp);
            json.addProperty("sign", getSign(json, appSecret));
            final RequestBody requestBody = RequestBody.create(json.toString(), MediaType.parse("application/json;charset=UTF-8"));
            return request.newBuilder().post(requestBody)
                    .build();
        }
        return request;
    }

    /**
     * 需要按字母排序
     *
     * @param json 所有字段使用urlParameter拼接，除了appSecret
     */
    private String getSign(JsonObject json, String appSecret) {
        String builder = jsonToUrlParameter(json) +
                appSecret;
        return MD5Utils.encodeMD5(builder);
    }


    /**
     * 是否忽略自定义的加密头
     */
    private boolean isIgnoreSignHeader(Headers headers) {
        String signHeader = headers.get(SmartHeader.IGNORE_SIGN_HEADER);
        return !TextUtils.isEmpty(signHeader);
    }

    private JsonObject getBodyJson(Request request) {
        RequestBody body = request.body();
        if (body instanceof FormBody) {
            JsonObject object = new JsonObject();
            FormBody formBody = (FormBody) body;
            for (int i = 0; i < formBody.size(); i++) {
                object.addProperty(formBody.name(i), formBody.value(i));
            }
            return object;
        } else {
            //json格式
            try {
                String bodyString = getBodyString(request);
                if (!TextUtils.isEmpty(bodyString)) {
                    final JsonElement parseString = JsonParser.parseString(bodyString);
                    return parseString.getAsJsonObject();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }

        }
        return null;
    }

    private String getBodyString(Request request) {
        try {
            RequestBody body = request.body();
            if (body != null) {
                Buffer buffer = new Buffer();
                body.writeTo(buffer);
                Charset charset = Charset.forName("UTF-8");
                MediaType contentType = body.contentType();
                charset = contentType.charset(charset);
                return buffer.readString(charset);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "";
    }





    private String jsonToUrlParameter(JsonObject object) {
        final Map<String, String> map = GsonUtils.getGson().fromJson(object, new TypeToken<Map<String, String>>() {
        }.getType());
        final Uri.Builder builder = new Uri.Builder();
        List<String> list = new ArrayList<>(map.keySet());
        Collections.sort(list);
        for (String key : list) {
            String value = map.get(key);
            if (valueNeedSign(value)) {
                builder.appendQueryParameter(key, value);
            }
        }
        return builder.build().getQuery();
    }


    /**
     * 判断当前值是否需要参与签名，保持跟云端一致
     * 空字符串不参与
     * 数组,集合不参与
     *
     * @return ture 需要加密
     */
    private static boolean valueNeedSign(String valueStr) {
        try {
            if (TextUtils.isEmpty(valueStr)) return false;
            final char[] strChar = URLDecoder.decode(valueStr, "utf-8")
                    .substring(0, 1).toCharArray();
            final char firstChar = strChar[0];
            return firstChar != '{' && firstChar != '[';
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }
}