package dev.getchat.sdk;

import java.time.Duration;

import java.util.Objects;

import org.jspecify.annotations.Nullable;

/**

* Request-reliability settings. Set instance-wide on {@link GetChatClient}, and

* overridable per call via {@link RequestControl}.

*

* <p>Bounds are validated on construction so a typo fails fast rather than

* quietly hammering the backend. Durations must be non-negative;

* {@link Duration#ZERO} is the documented way to disable the per-attempt

* timeout (and to skip the backoff wait).

*/

public final class RequestOptions {

/** Per-attempt timeout, stored as milliseconds; 0 disables it. */

private final long timeout;

/** Retry attempts after the first failure; 0 disables retrying. */

private final int retries;

/** Base backoff delay in milliseconds (exponential with jitter). */

private final long retryDelay;

public static final long DEFAULT_TIMEOUT_MS = 30_000L;

public static final int DEFAULT_RETRIES = 2;

public static final long DEFAULT_RETRY_DELAY_MS = 200L;

/** Same cap as the node SDK, so a {@code retries: 10000} typo is rejected. */

public static final int MAX_RETRIES = 10;

private RequestOptions(long timeout, int retries, long retryDelay) {

this.timeout = validateNonNegative(timeout, "timeout");

this.retryDelay = validateNonNegative(retryDelay, "retryDelay");

if (retries < 0 || retries > MAX_RETRIES) {

throw new GetChatException("retries must be between 0 and " + MAX_RETRIES + ", got " + retries);

}

this.retries = retries;

}

private static long validateNonNegative(long value, String name) {

if (value < 0) {

throw new GetChatException(name + " must be >= 0, got " + value);

}

return value;

}

public static RequestOptions defaults() {

return builder().build();

}

public static Builder builder() {

return new Builder();

}

/** Per-attempt timeout; {@link Duration#ZERO} means no per-attempt deadline. */

public Duration timeout() {

return Duration.ofMillis(timeout);

}

public int retries() {

return retries;

}

/** Base backoff delay (exponential with jitter); {@link Duration#ZERO} skips the wait. */

public Duration retryDelay() {

return Duration.ofMillis(retryDelay);

}

/**

* Base backoff delay in milliseconds, for the internal retry machinery which

* works in millis. Package-private: the public surface speaks {@link Duration}.

*/

long retryDelayMillis() {

return retryDelay;

}

/** Equal to another {@code RequestOptions} with the same timeout, retries and delay. */

@Override

public boolean equals(@Nullable Object o) {

return this == o

|| (o instanceof RequestOptions other

&& timeout == other.timeout

&& retries == other.retries

&& retryDelay == other.retryDelay);

}

@Override

public int hashCode() {

return Objects.hash(timeout, retries, retryDelay);

}

@Override

public String toString() {

return "RequestOptions{timeout=" + timeout + ", retries=" + retries + ", retryDelay=" + retryDelay + "}";

}

/** Builder for {@link RequestOptions}. */

public static final class Builder {

private long timeout = DEFAULT_TIMEOUT_MS;

private int retries = DEFAULT_RETRIES;

private long retryDelay = DEFAULT_RETRY_DELAY_MS;

private Builder() {}

/**

* Per-attempt timeout. {@link Duration#ZERO} disables the deadline.

*

* @throws NullPointerException if {@code timeout} is null — it is a

* required, non-null setting (this package is {@code @NullMarked})

*/

public Builder timeout(Duration timeout) {

this.timeout =

Objects.requireNonNull(timeout, "timeout is required").toMillis();

return this;

}

public Builder retries(int retries) {

this.retries = retries;

return this;

}

/**

* Base backoff delay. {@link Duration#ZERO} skips the wait between retries.

*

* @throws NullPointerException if {@code retryDelay} is null — it is a

* required, non-null setting (this package is {@code @NullMarked})

*/

public Builder retryDelay(Duration retryDelay) {

this.retryDelay =

Objects.requireNonNull(retryDelay, "retryDelay is required").toMillis();

return this;

}

public RequestOptions build() {

return new RequestOptions(timeout, retries, retryDelay);

}

}

}