package com.amazon.SellingPartnerAPIAA;

import com.google.gson.Gson;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.squareup.okhttp.MediaType;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.RequestBody;
import com.squareup.okhttp.Response;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.Setter;

import java.io.IOException;

class LWAClient {
    private static final String ACCESS_TOKEN_KEY = "access_token";
    private static final MediaType JSON_MEDIA_TYPE = MediaType.parse("application/json; charset=utf-8");

    @Getter
    private String endpoint;

    @Setter(AccessLevel.PACKAGE)
    private OkHttpClient okHttpClient;

    LWAClient(String endpoint) {
        okHttpClient = new OkHttpClient();
        this.endpoint = endpoint;
    }

    String getAccessToken(LWAAccessTokenRequestMeta lwaAccessTokenRequestMeta) {
        RequestBody requestBody = RequestBody.create(JSON_MEDIA_TYPE,
                new Gson().toJson(lwaAccessTokenRequestMeta));
        Request accessTokenRequest = new Request.Builder()
                .url(endpoint)
                .post(requestBody)
                .build();

        String accessToken;
        try {
            Response response = okHttpClient.newCall(accessTokenRequest).execute();
            if (!response.isSuccessful()) {
                throw new IOException("Unsuccessful LWA token exchange");
            }

            JsonObject responseJson = new JsonParser()
                    .parse(response.body().string())
                    .getAsJsonObject();

            accessToken = responseJson.get(ACCESS_TOKEN_KEY).getAsString();
        } catch (Exception e) {
            throw new RuntimeException("Error getting LWA Access Token", e);
        }

        return accessToken;
    }
}