/*
 * Copyright 2024-2025 Revetware LLC.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.soklet.servlet.javax;

import com.soklet.Request;
import com.soklet.Utilities;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.concurrent.NotThreadSafe;
import javax.servlet.AsyncContext;
import javax.servlet.DispatcherType;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpUpgradeHandler;
import javax.servlet.http.Part;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.InetAddress;
import java.net.URI;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.StandardCharsets;
import java.nio.charset.UnsupportedCharsetException;
import java.security.Principal;
import java.time.Instant;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.time.format.SignStyle;
import java.time.temporal.ChronoField;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Optional;
import java.util.Set;
import java.util.TreeMap;
import java.util.UUID;

import static java.lang.String.format;
import static java.util.Locale.ROOT;
import static java.util.Locale.US;
import static java.util.Locale.getDefault;
import static java.util.Objects.requireNonNull;

/**
 * Soklet integration implementation of {@link HttpServletRequest}.
 *
 * @author <a href="https://www.revetkn.com">Mark Allen</a>
 */
@NotThreadSafe
public final class SokletHttpServletRequest implements HttpServletRequest {
        @Nonnull
        private static final Charset DEFAULT_CHARSET;
        @Nonnull
        private static final DateTimeFormatter RFC_1123_PARSER;
        @Nonnull
        private static final DateTimeFormatter RFC_1036_PARSER;
        @Nonnull
        private static final DateTimeFormatter ASCTIME_PARSER;

        static {
                DEFAULT_CHARSET = StandardCharsets.ISO_8859_1; // Per Servlet spec
                RFC_1123_PARSER = DateTimeFormatter.RFC_1123_DATE_TIME;
                // RFC 1036: spaces between day/month/year + 2-digit year reduced to 19xx baseline.
                RFC_1036_PARSER = new DateTimeFormatterBuilder()
                                .parseCaseInsensitive()
                                .appendPattern("EEE, dd MMM ")
                                .appendValueReduced(ChronoField.YEAR, 2, 2, 1900) // 94 -> 1994
                                .appendPattern(" HH:mm:ss zzz")
                                .toFormatter(US)
                                .withZone(ZoneOffset.UTC);

                // asctime: "EEE MMM  d HH:mm:ss yyyy" — allow 1 or 2 spaces before day, no zone in text → default GMT.
                ASCTIME_PARSER = new DateTimeFormatterBuilder()
                                .parseCaseInsensitive()
                                .appendPattern("EEE MMM")
                                .appendLiteral(' ')
                                .optionalStart().appendLiteral(' ').optionalEnd() // tolerate double space before single-digit day
                                .appendValue(ChronoField.DAY_OF_MONTH, 1, 2, SignStyle.NOT_NEGATIVE)
                                .appendPattern(" HH:mm:ss yyyy")
                                .toFormatter(US)
                                .withZone(ZoneOffset.UTC);
        }

        @Nonnull
        private final Request request;
        @Nullable
        private final String host;
        @Nullable
        private final Integer port;
        @Nonnull
        private final ServletContext servletContext;
        @Nullable
        private HttpSession httpSession;
        @Nonnull
        private final Map<String, Object> attributes;
        @Nonnull
        private final List<Cookie> cookies;
        @Nullable
        private Charset charset;
        @Nullable
        private String contentType;

        @Nonnull
        public static Builder withRequest(@Nonnull Request request) {
                return new Builder(request);
        }

        private SokletHttpServletRequest(@Nonnull Builder builder) {
                requireNonNull(builder);
                requireNonNull(builder.request);

                this.request = builder.request;
                this.attributes = new HashMap<>();
                this.cookies = parseCookies(request);
                this.charset = parseCharacterEncoding(request).orElse(null);
                this.contentType = parseContentType(request).orElse(null);
                this.host = builder.host;
                this.port = builder.port;
                this.servletContext = builder.servletContext == null ? SokletServletContext.withDefaults() : builder.servletContext;
                this.httpSession = builder.httpSession;
        }

        @Nonnull
        protected Request getRequest() {
                return this.request;
        }

        @Nonnull
        protected Map<String, Object> getAttributes() {
                return this.attributes;
        }

        @Nonnull
        protected List<Cookie> parseCookies(@Nonnull Request request) {
                requireNonNull(request);

                Map<String, Set<String>> cookies = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
                cookies.putAll(request.getCookies());

                List<Cookie> convertedCookies = new ArrayList<>(cookies.size());

                for (Entry<String, Set<String>> entry : cookies.entrySet()) {
                        String name = entry.getKey();
                        Set<String> values = entry.getValue();

                        // Should never occur...
                        if (name == null)
                                continue;

                        for (String value : values)
                                convertedCookies.add(new Cookie(name, value));
                }

                return convertedCookies;
        }

        @Nonnull
        protected Optional<Charset> parseCharacterEncoding(@Nonnull Request request) {
                requireNonNull(request);
                return Utilities.extractCharsetFromHeaders(request.getHeaders());
        }

        @Nonnull
        protected Optional<String> parseContentType(@Nonnull Request request) {
                requireNonNull(request);
                return Utilities.extractContentTypeFromHeaders(request.getHeaders());
        }

        @Nonnull
        protected Optional<HttpSession> getHttpSession() {
                return Optional.ofNullable(this.httpSession);
        }

        protected void setHttpSession(@Nullable HttpSession httpSession) {
                this.httpSession = httpSession;
        }

        @Nonnull
        protected Optional<Charset> getCharset() {
                return Optional.ofNullable(this.charset);
        }

        protected void setCharset(@Nullable Charset charset) {
                this.charset = charset;
        }

        @Nonnull
        protected Optional<String> getHost() {
                return Optional.ofNullable(this.host);
        }

        @Nonnull
        protected Optional<Integer> getPort() {
                return Optional.ofNullable(this.port);
        }

        /**
         * Builder used to construct instances of {@link SokletHttpServletRequest}.
         * <p>
         * This class is intended for use by a single thread.
         *
         * @author <a href="https://www.revetkn.com">Mark Allen</a>
         */
        @NotThreadSafe
        public static class Builder {
                @Nonnull
                private Request request;
                @Nullable
                private Integer port;
                @Nullable
                private String host;
                @Nullable
                private ServletContext servletContext;
                @Nullable
                private HttpSession httpSession;

                @Nonnull
                private Builder(@Nonnull Request request) {
                        requireNonNull(request);
                        this.request = request;
                }

                @Nonnull
                public Builder request(@Nonnull Request request) {
                        requireNonNull(request);
                        this.request = request;
                        return this;
                }

                @Nonnull
                public Builder host(@Nullable String host) {
                        this.host = host;
                        return this;
                }

                @Nonnull
                public Builder port(@Nullable Integer port) {
                        this.port = port;
                        return this;
                }

                @Nonnull
                public Builder servletContext(@Nullable ServletContext servletContext) {
                        this.servletContext = servletContext;
                        return this;
                }

                @Nonnull
                public Builder httpSession(@Nullable HttpSession httpSession) {
                        this.httpSession = httpSession;
                        return this;
                }

                @Nonnull
                public SokletHttpServletRequest build() {
                        return new SokletHttpServletRequest(this);
                }
        }

        // Implementation of HttpServletRequest methods below:

        // Helpful reference at https://stackoverflow.com/a/21046620 by Victor Stafusa - BozoNaCadeia
        //
        // Method              URL-Decoded Result
        // ----------------------------------------------------
        // getContextPath()        no      /app
        // getLocalAddr()                  127.0.0.1
        // getLocalName()                  30thh.loc
        // getLocalPort()                  8480
        // getMethod()                     GET
        // getPathInfo()           yes     /a?+b
        // getProtocol()                   HTTP/1.1
        // getQueryString()        no      p+1=c+d&p+2=e+f
        // getRequestedSessionId() no      S%3F+ID
        // getRequestURI()         no      /app/test%3F/a%3F+b;jsessionid=S+ID
        // getRequestURL()         no      http://30thh.loc:8480/app/test%3F/a%3F+b;jsessionid=S+ID
        // getScheme()                     http
        // getServerName()                 30thh.loc
        // getServerPort()                 8480
        // getServletPath()        yes     /test?
        // getParameterNames()     yes     [p 2, p 1]
        // getParameter("p 1")     yes     c d

        @Override
        @Nullable
        public String getAuthType() {
                // This is legal according to spec
                return null;
        }

        @Override
        @Nonnull
        public Cookie[] getCookies() {
                return this.cookies.toArray(new Cookie[0]);
        }

        @Override
        public long getDateHeader(@Nullable String name) {
                if (name == null)
                        return -1;

                String value = getHeader(name);

                if (value == null)
                        return -1;

                // Try HTTP-date formats (RFC 1123 → RFC 1036 → asctime)
                for (DateTimeFormatter fmt : List.of(RFC_1123_PARSER, RFC_1036_PARSER, ASCTIME_PARSER)) {
                        try {
                                return Instant.from(fmt.parse(value)).toEpochMilli();
                        } catch (Exception ignored) {
                                // try next
                        }
                }

                // Fallback: epoch millis
                try {
                        return Long.parseLong(value);
                } catch (NumberFormatException e) {
                        throw new IllegalArgumentException(
                                        String.format("Header with name '%s' and value '%s' cannot be converted to a date", name, value),
                                        e
                        );
                }
        }

        @Override
        @Nullable
        public String getHeader(@Nullable String name) {
                if (name == null)
                        return null;

                return getRequest().getHeader(name).orElse(null);
        }

        @Override
        @Nonnull
        public Enumeration<String> getHeaders(@Nullable String name) {
                if (name == null)
                        return Collections.emptyEnumeration();

                Set<String> values = request.getHeaders().get(name);
                return values == null ? Collections.emptyEnumeration() : Collections.enumeration(values);
        }

        @Override
        @Nonnull
        public Enumeration<String> getHeaderNames() {
                return Collections.enumeration(getRequest().getHeaders().keySet());
        }

        @Override
        public int getIntHeader(@Nullable String name) {
                if (name == null)
                        return -1;

                String value = getHeader(name);

                if (value == null)
                        return -1;

                // Throws NumberFormatException if parsing fails, per spec
                return Integer.valueOf(value, 10);
        }

        @Override
        @Nonnull
        public String getMethod() {
                return getRequest().getHttpMethod().name();
        }

        @Override
        @Nullable
        public String getPathInfo() {
                return getRequest().getPath();
        }

        @Override
        @Nullable
        public String getPathTranslated() {
                return getRequest().getPath();
        }

        @Override
        @Nonnull
        public String getContextPath() {
                return "";
        }

        @Override
        @Nullable
        public String getQueryString() {
                try {
                        URI uri = new URI(request.getUri());
                        return uri.getQuery();
                } catch (Exception ignored) {
                        return null;
                }
        }

        @Override
        @Nullable
        public String getRemoteUser() {
                // This is legal according to spec
                return null;
        }

        @Override
        public boolean isUserInRole(@Nullable String role) {
                // This is legal according to spec
                return false;
        }

        @Override
        @Nullable
        public Principal getUserPrincipal() {
                // This is legal according to spec
                return null;
        }

        @Override
        @Nullable
        public String getRequestedSessionId() {
                // This is legal according to spec
                return null;
        }

        @Override
        @Nonnull
        public String getRequestURI() {
                return getRequest().getPath();
        }

        @Override
        @Nonnull
        public StringBuffer getRequestURL() {
                // Try forwarded/synthesized absolute prefix first
                String clientUrlPrefix = Utilities.extractClientUrlPrefixFromHeaders(getRequest().getHeaders()).orElse(null);

                if (clientUrlPrefix != null)
                        return new StringBuffer(format("%s%s", clientUrlPrefix, getRequest().getPath()));

                // Fall back to builder-provided host/port when available
                String scheme = getScheme(); // Soklet returns "http" by design
                String host = getServerName();
                int port = getServerPort(); // may throw if not initialized by builder
                boolean defaultPort = ("https".equalsIgnoreCase(scheme) && port == 443) || ("http".equalsIgnoreCase(scheme) && port == 80);
                String authority = defaultPort ? host : format("%s:%d", host, port);
                return new StringBuffer(format("%s://%s%s", scheme, authority, getRequest().getPath()));
        }

        @Override
        @Nonnull
        public String getServletPath() {
                // This is legal according to spec
                return "";
        }

        @Override
        @Nullable
        public HttpSession getSession(boolean create) {
                HttpSession currentHttpSession = getHttpSession().orElse(null);

                if (create && currentHttpSession == null) {
                        currentHttpSession = SokletHttpSession.withServletContext(getServletContext());
                        setHttpSession(currentHttpSession);
                }

                return currentHttpSession;
        }

        @Override
        @Nonnull
        public HttpSession getSession() {
                HttpSession currentHttpSession = getHttpSession().orElse(null);

                if (currentHttpSession == null) {
                        currentHttpSession = SokletHttpSession.withServletContext(getServletContext());
                        setHttpSession(currentHttpSession);
                }

                return currentHttpSession;
        }

        @Override
        @Nonnull
        public String changeSessionId() {
                HttpSession currentHttpSession = getHttpSession().orElse(null);

                if (currentHttpSession == null)
                        throw new IllegalStateException("No session is present");

                if (!(currentHttpSession instanceof SokletHttpSession))
                        throw new IllegalStateException(format("Cannot change session IDs. Session must be of type %s; instead it is of type %s",
                                        SokletHttpSession.class.getSimpleName(), currentHttpSession.getClass().getSimpleName()));

                UUID newSessionId = UUID.randomUUID();
                ((SokletHttpSession) currentHttpSession).setSessionId(newSessionId);
                return String.valueOf(newSessionId);
        }

        @Override
        public boolean isRequestedSessionIdValid() {
                // This is legal according to spec
                return false;
        }

        @Override
        public boolean isRequestedSessionIdFromCookie() {
                // This is legal according to spec
                return false;
        }

        @Override
        public boolean isRequestedSessionIdFromURL() {
                // This is legal according to spec
                return false;
        }

        @Override
        @Deprecated
        public boolean isRequestedSessionIdFromUrl() {
                // This is legal according to spec
                return false;
        }

        @Override
        public boolean authenticate(@Nonnull HttpServletResponse httpServletResponse) throws IOException, ServletException {
                requireNonNull(httpServletResponse);
                // TODO: perhaps revisit this in the future
                throw new ServletException("Authentication is not supported");
        }

        @Override
        public void login(@Nullable String username,
                                                                                @Nullable String password) throws ServletException {
                // This is legal according to spec
                throw new ServletException("Authentication login is not supported");
        }

        @Override
        public void logout() throws ServletException {
                // This is legal according to spec
                throw new ServletException("Authentication logout is not supported");
        }

        @Override
        @Nonnull
        public Collection<Part> getParts() throws IOException, ServletException {
                // Legal if the request body is larger than maxRequestSize, or any Part in the request is larger than maxFileSize,
                // or there is no @MultipartConfig or multipart-config in deployment descriptors
                throw new IllegalStateException("Servlet multipart configuration is not supported");
        }

        @Override
        @Nullable
        public Part getPart(@Nullable String name) throws IOException, ServletException {
                // Legal if the request body is larger than maxRequestSize, or any Part in the request is larger than maxFileSize,
                // or there is no @MultipartConfig or multipart-config in deployment descriptors
                throw new IllegalStateException("Servlet multipart configuration is not supported");
        }

        @Override
        @Nonnull
        public <T extends HttpUpgradeHandler> T upgrade(@Nullable Class<T> handlerClass) throws IOException, ServletException {
                // Legal if the given handlerClass fails to be instantiated
                throw new ServletException("HTTP upgrade is not supported");
        }

        @Override
        @Nullable
        public Object getAttribute(@Nullable String name) {
                if (name == null)
                        return null;

                return getAttributes().get(name);
        }

        @Override
        @Nonnull
        public Enumeration<String> getAttributeNames() {
                return Collections.enumeration(getAttributes().keySet());
        }

        @Override
        @Nonnull
        public String getCharacterEncoding() {
                Charset charset = getCharset().orElse(null);
                return charset == null ? null : charset.name();
        }

        @Override
        public void setCharacterEncoding(@Nullable String env) throws UnsupportedEncodingException {
                // Note that spec says: "This method must be called prior to reading request parameters or
                // reading input using getReader(). Otherwise, it has no effect."
                // ...but we don't need to care about this because Soklet requests are byte arrays of finite size, not streams
                if (env == null) {
                        setCharset(null);
                } else {
                        try {
                                setCharset(Charset.forName(env));
                        } catch (IllegalCharsetNameException | UnsupportedCharsetException e) {
                                throw new UnsupportedEncodingException(format("Not sure how to handle character encoding '%s'", env));
                        }
                }
        }

        @Override
        public int getContentLength() {
                byte[] body = request.getBody().orElse(null);
                return body == null ? 0 : body.length;
        }

        @Override
        public long getContentLengthLong() {
                byte[] body = request.getBody().orElse(null);
                return body == null ? 0 : body.length;
        }

        @Override
        @Nullable
        public String getContentType() {
                return this.contentType;
        }

        @Override
        @Nonnull
        public ServletInputStream getInputStream() throws IOException {
                byte[] body = getRequest().getBody().orElse(new byte[]{});
                return SokletServletInputStream.withInputStream(new ByteArrayInputStream(body));
        }

        @Override
        @Nullable
        public String getParameter(@Nullable String name) {
                String value = null;

                // First, check query parameters.
                if (getRequest().getQueryParameters().keySet().contains(name)) {
                        // If there is a query parameter with the given name, return it
                        value = getRequest().getQueryParameter(name).orElse(null);
                } else if (getRequest().getFormParameters().keySet().contains(name)) {
                        // Otherwise, check form parameters in request body
                        value = getRequest().getFormParameter(name).orElse(null);
                }

                return value;
        }

        @Override
        @Nonnull
        public Enumeration<String> getParameterNames() {
                Set<String> queryParameterNames = getRequest().getQueryParameters().keySet();
                Set<String> formParameterNames = getRequest().getFormParameters().keySet();

                Set<String> parameterNames = new HashSet<>(queryParameterNames.size() + formParameterNames.size());
                parameterNames.addAll(queryParameterNames);
                parameterNames.addAll(formParameterNames);

                return Collections.enumeration(parameterNames);
        }

        @Override
        @Nullable
        public String[] getParameterValues(@Nullable String name) {
                if (name == null)
                        return null;

                List<String> parameterValues = new ArrayList<>();

                Set<String> queryValues = getRequest().getQueryParameters().get(name);

                if (queryValues != null)
                        parameterValues.addAll(queryValues);

                Set<String> formValues = getRequest().getFormParameters().get(name);

                if (formValues != null)
                        parameterValues.addAll(formValues);

                return parameterValues.isEmpty() ? null : parameterValues.toArray(new String[0]);
        }

        @Override
        @Nonnull
        public Map<String, String[]> getParameterMap() {
                Map<String, Set<String>> parameterMap = new HashMap<>();

                // Mutable copy of entries
                for (Entry<String, Set<String>> entry : getRequest().getQueryParameters().entrySet())
                        parameterMap.put(entry.getKey(), new HashSet<>(entry.getValue()));

                // Add form parameters to entries
                for (Entry<String, Set<String>> entry : getRequest().getFormParameters().entrySet()) {
                        Set<String> existingEntries = parameterMap.get(entry.getKey());

                        if (existingEntries != null)
                                existingEntries.addAll(entry.getValue());
                        else
                                parameterMap.put(entry.getKey(), entry.getValue());
                }

                Map<String, String[]> finalParameterMap = new HashMap<>();

                for (Entry<String, Set<String>> entry : parameterMap.entrySet())
                        finalParameterMap.put(entry.getKey(), entry.getValue().toArray(new String[0]));

                return Collections.unmodifiableMap(finalParameterMap);
        }

        @Override
        @Nonnull
        public String getProtocol() {
                return "HTTP/1.1";
        }

        @Override
        @Nonnull
        public String getScheme() {
                // Honor common reverse-proxy header; fall back to http
                String proto = getRequest().getHeader("X-Forwarded-Proto").orElse(null);

                if (proto != null) {
                        proto = proto.trim().toLowerCase(ROOT);
                        if (proto.equals("https") || proto.equals("http"))
                                return proto;
                }

                return "http";
        }

        @Override
        @Nonnull
        public String getServerName() {
                // Path only (no query parameters) preceded by remote protocol, host, and port (if available)
                // e.g. https://www.soklet.com/test/abc
                String clientUrlPrefix = Utilities.extractClientUrlPrefixFromHeaders(getRequest().getHeaders()).orElse(null);

                if (clientUrlPrefix == null)
                        return getLocalName();

                clientUrlPrefix = clientUrlPrefix.toLowerCase(ROOT);

                // Remove protocol prefix
                if (clientUrlPrefix.startsWith("https://"))
                        clientUrlPrefix = clientUrlPrefix.replace("https://", "");
                else if (clientUrlPrefix.startsWith("http://"))
                        clientUrlPrefix = clientUrlPrefix.replace("http://", "");

                // Remove "/" and anything after it
                int indexOfFirstSlash = clientUrlPrefix.indexOf("/");

                if (indexOfFirstSlash != -1)
                        clientUrlPrefix = clientUrlPrefix.substring(0, indexOfFirstSlash);

                // Remove ":" and anything after it (port)
                int indexOfColon = clientUrlPrefix.indexOf(":");

                if (indexOfColon != -1)
                        clientUrlPrefix = clientUrlPrefix.substring(0, indexOfColon);

                return clientUrlPrefix;
        }

        @Override
        public int getServerPort() {
                // Path only (no query parameters) preceded by remote protocol, host, and port (if available)
                // e.g. https://www.soklet.com/test/abc
                String clientUrlPrefix = Utilities.extractClientUrlPrefixFromHeaders(getRequest().getHeaders()).orElse(null);

                if (clientUrlPrefix == null)
                        return getLocalPort();

                clientUrlPrefix = clientUrlPrefix.toLowerCase(ROOT);

                boolean https = false;

                // Remove protocol prefix
                if (clientUrlPrefix.startsWith("https://")) {
                        clientUrlPrefix = clientUrlPrefix.replace("https://", "");
                        https = true;
                } else if (clientUrlPrefix.startsWith("http://")) {
                        clientUrlPrefix = clientUrlPrefix.replace("http://", "");
                }

                // Remove "/" and anything after it
                int indexOfFirstSlash = clientUrlPrefix.indexOf("/");

                if (indexOfFirstSlash != -1)
                        clientUrlPrefix = clientUrlPrefix.substring(0, indexOfFirstSlash);

                String[] hostAndPortComponents = clientUrlPrefix.split(":");

                // No explicit port?  Look at protocol for guidance
                if (hostAndPortComponents.length == 1)
                        return https ? 443 : 80;

                try {
                        return Integer.parseInt(hostAndPortComponents[1], 10);
                } catch (Exception ignored) {
                        return getLocalPort();
                }
        }

        @Override
        @Nonnull
        public BufferedReader getReader() throws IOException {
                Charset charset = getCharset().orElse(DEFAULT_CHARSET);
                InputStream inputStream = new ByteArrayInputStream(getRequest().getBody().orElse(new byte[0]));
                return new BufferedReader(new InputStreamReader(inputStream, charset));
        }

        @Override
        @Nullable
        public String getRemoteAddr() {
                String xForwardedForHeader = getRequest().getHeader("X-Forwarded-For").orElse(null);

                if (xForwardedForHeader == null)
                        return null;

                // Example value: 203.0.113.195,2001:db8:85a3:8d3:1319:8a2e:370:7348,198.51.100.178
                String[] components = xForwardedForHeader.split(",");

                if (components.length == 0 || components[0] == null)
                        return null;

                String value = components[0].trim();
                return value.length() > 0 ? value : "127.0.0.1";
        }

        @Override
        @Nullable
        public String getRemoteHost() {
                // This is X-Forwarded-For and is generally what we want (if present)
                String remoteAddr = getRemoteAddr();

                if (remoteAddr != null)
                        return remoteAddr;

                // Path only (no query parameters) preceded by remote protocol, host, and port (if available)
                // e.g. https://www.soklet.com/test/abc
                String clientUrlPrefix = Utilities.extractClientUrlPrefixFromHeaders(getRequest().getHeaders()).orElse(null);

                if (clientUrlPrefix != null) {
                        clientUrlPrefix = clientUrlPrefix.toLowerCase(ROOT);

                        // Remove protocol prefix
                        if (clientUrlPrefix.startsWith("https://"))
                                clientUrlPrefix = clientUrlPrefix.replace("https://", "");
                        else if (clientUrlPrefix.startsWith("http://"))
                                clientUrlPrefix = clientUrlPrefix.replace("http://", "");

                        // Remove "/" and anything after it
                        int indexOfFirstSlash = clientUrlPrefix.indexOf("/");

                        if (indexOfFirstSlash != -1)
                                clientUrlPrefix = clientUrlPrefix.substring(0, indexOfFirstSlash);

                        String[] hostAndPortComponents = clientUrlPrefix.split(":");

                        String host = null;

                        if (hostAndPortComponents != null && hostAndPortComponents.length > 0 && hostAndPortComponents[0] != null)
                                host = hostAndPortComponents[0].trim();

                        if (host != null && host.length() > 0)
                                return host;
                }

                // "If the engine cannot or chooses not to resolve the hostname (to improve performance),
                // this method returns the dotted-string form of the IP address."
                return getRemoteAddr();
        }

        @Override
        public void setAttribute(@Nullable String name,
                                                                                                         @Nullable Object o) {
                if (name == null)
                        return;

                if (o == null)
                        removeAttribute(name);
                else
                        getAttributes().put(name, o);
        }

        @Override
        public void removeAttribute(@Nullable String name) {
                if (name == null)
                        return;

                getAttributes().remove(name);
        }

        @Override
        @Nonnull
        public Locale getLocale() {
                List<Locale> locales = getRequest().getLocales();
                return locales.size() == 0 ? getDefault() : locales.get(0);
        }

        @Override
        @Nonnull
        public Enumeration<Locale> getLocales() {
                List<Locale> locales = getRequest().getLocales();
                return Collections.enumeration(locales.size() == 0 ? List.of(getDefault()) : locales);
        }

        @Override
        public boolean isSecure() {
                return getScheme().equals("https");
        }

        @Override
        @Nullable
        public RequestDispatcher getRequestDispatcher(@Nullable String path) {
                // "This method returns null if the servlet container cannot return a RequestDispatcher."
                return null;
        }

        @Override
        @Deprecated
        @Nullable
        public String getRealPath(String path) {
                // "As of Version 2.1 of the Java Servlet API, use ServletContext.getRealPath(java.lang.String) instead."
                return getServletContext().getRealPath(path);
        }

        @Override
        public int getRemotePort() {
                // Not reliably knowable without a socket; return 0 to indicate "unknown"
                return 0;
        }

        @Override
        @Nonnull
        public String getLocalName() {
                if (getHost().isPresent())
                        return getHost().get();

                try {
                        String hostName = InetAddress.getLocalHost().getHostName();

                        if (hostName != null) {
                                hostName = hostName.trim();

                                if (hostName.length() > 0)
                                        return hostName;
                        }
                } catch (Exception e) {
                        // Ignored
                }

                return "localhost";
        }

        @Override
        @Nonnull
        public String getLocalAddr() {
                try {
                        String hostAddress = InetAddress.getLocalHost().getHostAddress();

                        if (hostAddress != null) {
                                hostAddress = hostAddress.trim();

                                if (hostAddress.length() > 0)
                                        return hostAddress;
                        }
                } catch (Exception e) {
                        // Ignored
                }

                return "127.0.0.1";
        }

        @Override
        public int getLocalPort() {
                return getPort().orElseThrow(() -> new IllegalStateException(format("%s must be initialized with a port in order to call this method",
                                getClass().getSimpleName())));
        }

        @Override
        @Nonnull
        public ServletContext getServletContext() {
                return this.servletContext;
        }

        @Override
        @Nonnull
        public AsyncContext startAsync() throws IllegalStateException {
                throw new IllegalStateException("Soklet does not support async servlet operations");
        }

        @Override
        @Nonnull
        public AsyncContext startAsync(@Nonnull ServletRequest servletRequest,
                                                                                                                                 @Nonnull ServletResponse servletResponse) throws IllegalStateException {
                requireNonNull(servletResponse);
                requireNonNull(servletResponse);

                throw new IllegalStateException("Soklet does not support async servlet operations");
        }

        @Override
        public boolean isAsyncStarted() {
                return false;
        }

        @Override
        public boolean isAsyncSupported() {
                return false;
        }

        @Override
        @Nonnull
        public AsyncContext getAsyncContext() {
                throw new IllegalStateException("Soklet does not support async servlet operations");
        }

        @Override
        @Nonnull
        public DispatcherType getDispatcherType() {
                // Currently Soklet does not support RequestDispatcher, so this is safe to hardcode
                return DispatcherType.REQUEST;
        }
}