/**

* Jooby https://jooby.io

* Apache License Version 2.0 https://jooby.io/LICENSE.txt

* Copyright 2014 Edgar Espina

*/

package io.jooby;

import javax.annotation.Nonnull;

/**

* Catch and encode application errors.

*

* @author edgar

* @since 2.0.0

*/

public interface ErrorHandler {

/**

* Produces an error response using the given exception and status code.

*

* @param ctx Web context.

* @param cause Application error.

* @param code Status code.

*/

@Nonnull void apply(@Nonnull Context ctx, @Nonnull Throwable cause,

@Nonnull StatusCode code);

/**

* Chain this error handler with next and produces a new error handler.

*

* @param next Next error handler.

* @return A new error handler.

*/

@Nonnull default ErrorHandler then(@Nonnull ErrorHandler next) {

return (ctx, cause, statusCode) -> {

apply(ctx, cause, statusCode);

if (!ctx.isResponseStarted()) {

next.apply(ctx, cause, statusCode);

}

};

}

/**

* Build a line error message that describe the current web context and the status code.

*

* <pre>GET /path Status-Code Status-Reason</pre>

*

* @param ctx Web context.

* @param statusCode Status code.

* @return Single line message.

*/

static @Nonnull String errorMessage(@Nonnull Context ctx, @Nonnull StatusCode statusCode) {

return new StringBuilder()

.append(ctx.getMethod())

.append(" ")

.append(ctx.getRequestPath())

.append(" ")

.append(statusCode.value())

.append(" ")

.append(statusCode.reason())

.toString();

}

/**

* Creates a default error handler.

* @return Default error handler.

*/

static @Nonnull DefaultErrorHandler create() {

return new DefaultErrorHandler();

}

}