// Copyright (c) Microsoft Corporation.
// All rights reserved.
//
// This code is licensed under the MIT License.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files(the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions :
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package com.microsoft.aad.adal4j;

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLSocketFactory;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.Proxy;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Collections;
import java.util.Map;

import com.nimbusds.oauth2.sdk.ParseException;
import com.nimbusds.oauth2.sdk.http.CommonContentTypes;
import com.nimbusds.oauth2.sdk.http.HTTPRequest;
import com.nimbusds.oauth2.sdk.http.HTTPResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

class AdalOAuthRequest extends HTTPRequest {

    private final Map<String, String> extraHeaderParams;
    private final Logger log = LoggerFactory.getLogger(AdalOAuthRequest.class);

    private final Proxy proxy;
    private final SSLSocketFactory sslSocketFactory;

    
Params:
method – 
url – /**
     * 
     * @param method
     * @param url
     */
    AdalOAuthRequest(final Method method, final URL url,
            final Map<String, String> extraHeaderParams, final Proxy proxy,
            final SSLSocketFactory sslSocketFactory) {
        super(method, url);
        this.extraHeaderParams = extraHeaderParams;
        this.proxy = proxy;
        this.sslSocketFactory = sslSocketFactory;
    }

    Map<String, String> getReadOnlyExtraHeaderParameters() {
        return Collections.unmodifiableMap(this.extraHeaderParams);
    }

    /**
     * 
     */
    @Override
    public HTTPResponse send() throws IOException {

        final HttpsURLConnection conn = HttpHelper.openConnection(this.getURL(),
                this.proxy, this.sslSocketFactory);
        this.configureHeaderAndExecuteOAuthCall(conn);
        final String out = this.processAndReadResponse(conn);
        HttpHelper.verifyReturnedCorrelationId(log, conn,
                this.extraHeaderParams
                        .get(ClientDataHttpHeaders.CORRELATION_ID_HEADER_NAME));
        return createResponse(conn, out);
    }

    HTTPResponse createResponse(final HttpURLConnection conn, final String out)
            throws IOException {
        final HTTPResponse response = new HTTPResponse(conn.getResponseCode());
        final String location = conn.getHeaderField("Location");
        if (!StringHelper.isBlank(location)) {
            try {
                response.setLocation(new URI(location));
            } catch (URISyntaxException e) {
                throw new IOException("Invalid location URI " + location, e);
            }
        }

        try {
            response.setContentType(conn.getContentType());
        }
        catch (final ParseException e) {
            throw new IOException("Couldn't parse Content-Type header: "
                    + e.getMessage(), e);
        }

        response.setCacheControl(conn.getHeaderField("Cache-Control"));
        response.setPragma(conn.getHeaderField("Pragma"));
        response.setWWWAuthenticate(conn.getHeaderField("WWW-Authenticate"));
        if (!StringHelper.isBlank(out)) {
            response.setContent(out);
        }
        return response;
    }

    void configureHeaderAndExecuteOAuthCall(final HttpsURLConnection conn)
            throws IOException {

        if (this.getAuthorization() != null) {
            conn.setRequestProperty("Authorization", this.getAuthorization());
        }

        Map<String, String> params = new java.util.HashMap<>();
        if (this.extraHeaderParams != null && !this.extraHeaderParams.isEmpty()) {
            for (java.util.Map.Entry<String, String> entry : this.extraHeaderParams
                    .entrySet()) {
                if (entry.getValue() == null || entry.getValue().isEmpty()) {
                    continue;
                }
                params.put(entry.getKey(), entry.getValue());
            }
        }

        HttpHelper.configureAdditionalHeaders(conn, params);
        conn.setDoOutput(true);
        conn.setRequestProperty("Content-Type",
                CommonContentTypes.APPLICATION_URLENCODED.toString());

        if (this.getQuery() != null) {
            try(final OutputStreamWriter writer = new OutputStreamWriter(
                        conn.getOutputStream())) {
                writer.write(getQuery());
                writer.flush();
            }
        }
    }

    String processAndReadResponse(final HttpURLConnection conn)
            throws IOException {
        Reader inReader = null;
        final int responseCode = conn.getResponseCode();
        if (responseCode == 200) {
            inReader = new InputStreamReader(conn.getInputStream());
        }
        else {
            InputStream stream = conn.getErrorStream();
            if (stream == null && responseCode == 404) {
                stream = conn.getInputStream();
            }

            if (stream == null) {
                stream = conn.getInputStream();
            }

            inReader = new InputStreamReader(stream);
        }
        final BufferedReader reader = new BufferedReader(inReader);
        final char[] buffer = new char[256];
        final StringBuilder out = new StringBuilder();
        try {
            for (;;) {
                final int rsz = reader.read(buffer, 0, buffer.length);
                if (rsz < 0) {
                    break;
                }
                out.append(buffer, 0, rsz);
            }
        }
        finally {
            reader.close();
        }
        return out.toString();
    }
}