package io.quarkus.resteasy.runtime.standalone;

import java.io.IOException;
import java.io.OutputStream;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionStage;

import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.NewCookie;
import javax.ws.rs.ext.RuntimeDelegate;

import org.jboss.resteasy.specimpl.MultivaluedMapImpl;
import org.jboss.resteasy.spi.HttpResponse;
import org.jboss.resteasy.spi.ResteasyProviderFactory;

import io.netty.buffer.ByteBuf;
import io.vertx.core.http.HttpHeaders;
import io.vertx.core.http.HttpMethod;
import io.vertx.core.http.HttpServerRequest;
import io.vertx.core.http.HttpServerResponse;

public class VertxHttpResponse implements HttpResponse {
    private int status = 200;
    private OutputStream os;
    private MultivaluedMap<String, Object> outputHeaders;
    final HttpServerRequest request;
    final HttpServerResponse response;
    private boolean committed;
    private boolean finished;
    private ResteasyProviderFactory providerFactory;
    private final HttpMethod method;
    private final VertxOutput output;

    public VertxHttpResponse(HttpServerRequest request, ResteasyProviderFactory providerFactory,
            final HttpMethod method, BufferAllocator allocator, VertxOutput output) {
        outputHeaders = new MultivaluedMapImpl<String, Object>();
        this.method = method;
        os = (method == null || !method.equals(HttpMethod.HEAD)) ? new VertxOutputStream(this, allocator)
                : null;
        this.request = request;
        this.response = request.response();
        this.providerFactory = providerFactory;
        this.output = output;
    }

    @Override
    public void setOutputStream(OutputStream os) {
        this.os = os;
    }

    @Override
    public int getStatus() {
        return status;
    }

    @Override
    public void setStatus(int status) {
        this.status = status;
    }

    @Override
    public MultivaluedMap<String, Object> getOutputHeaders() {
        return outputHeaders;
    }

    @Override
    public OutputStream getOutputStream() throws IOException {
        return os;
    }

    @Override
    public void addNewCookie(NewCookie cookie) {
        outputHeaders.add(javax.ws.rs.core.HttpHeaders.SET_COOKIE, cookie);
    }

    void checkException() throws IOException {
        // todo from old code, do we still need it?
    }

    @Override
    public void sendError(int status) throws IOException {
        checkException();
        sendError(status, null);
    }

    @Override
    public void sendError(int status, String message) throws IOException {
        checkException();
        if (committed) {
            throw new IllegalStateException();
        }
        response.setStatusCode(status);
        if (message != null) {
            response.end(message);
        } else {
            response.end();
        }
        committed = true;
    }

    @Override
    public boolean isCommitted() {
        return committed;
    }

    @Override
    public void reset() {
        if (committed) {
            throw new IllegalStateException("Response already committed");
        }
        outputHeaders.clear();
    }

    @SuppressWarnings({ "rawtypes", "unchecked" })
    public static void transformHeaders(VertxHttpResponse vertxResponse, HttpServerResponse response,
            ResteasyProviderFactory factory) {
        for (Map.Entry<String, List<Object>> entry : vertxResponse.getOutputHeaders().entrySet()) {
            String key = entry.getKey();
            for (Object value : entry.getValue()) {
                RuntimeDelegate.HeaderDelegate delegate = factory.getHeaderDelegate(value.getClass());
                if (delegate != null) {
                    response.headers().add(key, delegate.toString(value));
                } else {
                    response.headers().add(key, value.toString());
                }
            }
        }
    }

    public void finish() throws IOException {
        checkException();
        if (finished || response.ended())
            return;
        try {
            if (os != null) {
                os.close(); // this will end() vertx response
            } else {
                committed = true;
                response.setStatusCode(getStatus());
                transformHeaders(this, response, providerFactory);
                response.headersEndHandler(h -> {
                    response.headers().remove(HttpHeaders.CONTENT_LENGTH);
                    response.headers().set(HttpHeaders.CONNECTION, HttpHeaders.KEEP_ALIVE);
                });
                response.end();
            }
        } finally {
            finished = true;
        }
    }

    @Override
    public void flushBuffer() throws IOException {
        checkException();
        if (os != null) {
            os.flush();
        }
    }

    public void writeBlocking(ByteBuf buffer, boolean finished) throws IOException {
        checkException();
        prepareWrite(buffer, finished);
        output.write(buffer, finished);
    }

    public CompletionStage<Void> writeNonBlocking(ByteBuf buffer, boolean finished) {
        try {
            prepareWrite(buffer, finished);
        } catch (IOException e) {
            CompletableFuture<Void> ret = new CompletableFuture<>();
            ret.completeExceptionally(e);
            return ret;
        }
        return output.writeNonBlocking(buffer, finished);
    }

    private void prepareWrite(ByteBuf buffer, boolean finished) throws IOException {
        if (!isCommitted()) {
            committed = true;
            response.setStatusCode(getStatus());
            if (finished) {
                if (buffer == null) {
                    getOutputHeaders().putSingle(javax.ws.rs.core.HttpHeaders.CONTENT_LENGTH, "0");
                } else {
                    getOutputHeaders().putSingle(javax.ws.rs.core.HttpHeaders.CONTENT_LENGTH, "" + buffer.readableBytes());
                }

            } else {
                response.setChunked(true);
            }
            transformHeaders(this, response, providerFactory);
        }
        if (finished)
            this.finished = true;
    }

}
