LibJF/libjf-web-v1/src/main/java/io/gitlab/jfronny/libjf/web/impl/util/HttpRequestImpl.java

/*
 * This file is part of BlueMap, licensed under the MIT License (MIT).
 *
 * Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
 * Copyright (c) contributors
 *
 * 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 io.gitlab.jfronny.libjf.web.impl.util;

import io.gitlab.jfronny.libjf.web.api.v1.*;
import io.gitlab.jfronny.libjf.web.impl.variant.hosted.HttpConnection;

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.*;
import java.util.Map.Entry;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class HttpRequestImpl implements HttpRequest {
	private static final Pattern REQUEST_PATTERN = Pattern.compile("^(\\w+) (\\S+) (.+)$");

	private final String method;
	private final String address;
	private final String version;
	private final Map<String, Set<String>> header;
	private final Map<String, Set<String>> headerLC;
	private byte[] data;

	private String path = null;
	private Map<String, String> queryParameters = null;
	private String queryString = null;

	public HttpRequestImpl(String method, String address, String version, Map<String, Set<String>> header) {
		this.method = method;
		this.address = address;
		this.version = version;
		this.header = header;
		this.headerLC = new HashMap<>();

		for (Entry<String, Set<String>> e : header.entrySet()){
			Set<String> values = new HashSet<>();
			for (String v : e.getValue()){
				values.add(v.toLowerCase());
			}

			headerLC.put(e.getKey().toLowerCase(), values);
		}

		this.data = new byte[0];
	}

    @Override
	public String getMethod() {
		return method;
	}

    @Override
	public String getAddress(){
		return address;
	}

    @Override
	public String getVersion() {
		return version;
	}

    @Override
	public Map<String, Set<String>> getHeader() {
		return header;
	}

    @Override
	public Map<String, Set<String>> getLowercaseHeader() {
		return headerLC;
	}

    @Override
	public Set<String> getHeader(String key){
		Set<String> headerValues = header.get(key);
		if (headerValues == null) return Collections.emptySet();
		return headerValues;
	}

    @Override
	public Set<String> getLowercaseHeader(String key){
		Set<String> headerValues = headerLC.get(key.toLowerCase());
		if (headerValues == null) return Collections.emptySet();
		return headerValues;
	}

    @Override
	public String getPath() {
		if (path == null) parseAddress();
		return path;
	}

    @Override
	public Map<String, String> getQuery() {
		if (queryParameters == null) parseAddress();
		return Collections.unmodifiableMap(queryParameters);
	}

    @Override
    public String getQueryString() {
		if (queryString == null) parseAddress();
		return queryString;
	}

	private void parseAddress() {
		String adress = this.address;
		if (adress.isEmpty()) adress = "/";
		String[] addressParts = adress.split("\\?", 2);
		String path = addressParts[0];
		this.queryString = addressParts.length > 1 ? addressParts[1] : "";

		Map<String, String> queryParams = new HashMap<>();
		for (String queryParam : this.queryString.split("&")){
			if (queryParam.isEmpty()) continue;
			String[] kv = queryParam.split("=", 2);
			String key = kv[0];
			String value = kv.length > 1 ? kv[1] : "";
			queryParams.put(key, value);
		}

		this.path = path;
		this.queryParameters = queryParams;
	}

    @Override
	public InputStream getData(){
		return new ByteArrayInputStream(data);
	}

	public static HttpRequestImpl read(InputStream in) throws IOException {
		BufferedReader reader = new BufferedReader(new InputStreamReader(in, StandardCharsets.UTF_8));
        HttpRequestImpl request = fromHeaders(extractHeaders(reader));
        readData(in, request, reader);
        return request;
    }

    private static void readData(InputStream in, HttpRequestImpl request, BufferedReader reader) throws IOException {
        if (request.getLowercaseHeader("Transfer-Encoding").contains("chunked")) {
			try {
				ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
				while (dataStream.size() < 1000000) {
					String hexSize = reader.readLine();
					int chunkSize = Integer.parseInt(hexSize, 16);
					if (chunkSize <= 0) break;
					byte[] data = new byte[chunkSize];
					in.read(data);
					dataStream.write(data);
				}

				if (dataStream.size() >= 1000000) {
					throw new HttpConnection.InvalidRequestException();
				}

				request.data = dataStream.toByteArray();
            } catch (NumberFormatException ex) {
            }
		} else {
			Set<String> clSet = request.getLowercaseHeader("Content-Length");
            if (clSet.isEmpty()) return;
            try {
                int cl = Integer.parseInt(clSet.iterator().next());
                byte[] data = new byte[cl];
                in.read(data);
                request.data = data;
            } catch (NumberFormatException ex) {
            }
        }
    }

    private static List<String> extractHeaders(BufferedReader reader) throws IOException {
        List<String> headers = new ArrayList<>(20);
        while (headers.size() < 1000) {
            String headerLine = readLine(reader);
            if (headerLine.isEmpty()) break;
            headers.add(headerLine);
        }
        return headers;
    }

    private static HttpRequestImpl fromHeaders(List<String> headers) throws HttpConnection.InvalidRequestException {
        if (headers.isEmpty()) throw new HttpConnection.InvalidRequestException();

        Matcher m = REQUEST_PATTERN.matcher(headers.remove(0));
        if (!m.find()) throw new HttpConnection.InvalidRequestException();

        String method = m.group(1);
        if (method == null) throw new HttpConnection.InvalidRequestException();

        String adress = m.group(2);
        if (adress == null) throw new HttpConnection.InvalidRequestException();

        String version = m.group(3);
        if (version == null) throw new HttpConnection.InvalidRequestException();

        return new HttpRequestImpl(method, adress, version, parseExtraHeaders(headers));
    }

    private static Map<String, Set<String>> parseExtraHeaders(List<String> header) {
        Map<String, Set<String>> headerMap = new HashMap<>();
        for (String line : header) {
            if (line.trim().isEmpty()) continue;

            String[] kv = line.split(":", 2);
            if (kv.length < 2) continue;

            Set<String> values = new HashSet<>();
            if (kv[0].trim().equalsIgnoreCase("If-Modified-Since")) {
                values.add(kv[1].trim());
            } else {
                for (String v : kv[1].split(",")) {
                    values.add(v.trim());
                }
            }

            headerMap.put(kv[0].trim(), values);
        }
        return headerMap;
    }

    private static String readLine(BufferedReader in) throws IOException {
		String line = in.readLine();
		if (line == null) {
			throw new HttpConnection.ConnectionClosedException();
		}
		return line;
	}
}