package shared

import (
	"context"
	"errors"
	"fmt"

	"galaxy/authsession/internal/domain/devicesession"
	"galaxy/authsession/internal/domain/gatewayprojection"
	"galaxy/authsession/internal/ports"
	"galaxy/authsession/internal/telemetry"
)

// PublishProjectionSnapshot publishes snapshot through publisher with a small
// bounded retry loop suitable for request-path consistency repair.
func PublishProjectionSnapshot(ctx context.Context, publisher ports.GatewaySessionProjectionPublisher, snapshot gatewayprojection.Snapshot) error {
	return PublishProjectionSnapshotWithTelemetry(ctx, publisher, snapshot, nil, "")
}

// PublishProjectionSnapshotWithTelemetry publishes snapshot through publisher
// with the bounded request-path retry policy and optional publish-failure
// telemetry.
func PublishProjectionSnapshotWithTelemetry(
	ctx context.Context,
	publisher ports.GatewaySessionProjectionPublisher,
	snapshot gatewayprojection.Snapshot,
	telemetryRuntime *telemetry.Runtime,
	operation string,
) error {
	if publisher == nil {
		return InternalError(errors.New("projection publisher must not be nil"))
	}
	if ctx == nil {
		return ServiceUnavailable(errors.New("projection publish context must not be nil"))
	}
	if err := snapshot.Validate(); err != nil {
		return InternalError(fmt.Errorf("publish projection snapshot: %w", err))
	}

	var lastErr error
	for attempt := 0; attempt < MaxProjectionPublishAttempts; attempt++ {
		if err := ctx.Err(); err != nil {
			return ServiceUnavailable(err)
		}

		if err := publisher.PublishSession(ctx, snapshot); err == nil {
			return nil
		} else {
			lastErr = err
		}
	}

	telemetryRuntime.RecordProjectionPublishFailure(ctx, operation)
	return ServiceUnavailable(
		fmt.Errorf(
			"publish projection snapshot %q after %d attempts: %w",
			snapshot.DeviceSessionID,
			MaxProjectionPublishAttempts,
			lastErr,
		),
	)
}

// PublishSessionProjection converts record into the gateway-facing snapshot and
// publishes it with the bounded request-path retry policy.
func PublishSessionProjection(ctx context.Context, publisher ports.GatewaySessionProjectionPublisher, record devicesession.Session) error {
	return PublishSessionProjectionWithTelemetry(ctx, publisher, record, nil, "")
}

// PublishSessionProjectionWithTelemetry converts record into the
// gateway-facing snapshot and publishes it with the bounded request-path retry
// policy and optional publish-failure telemetry.
func PublishSessionProjectionWithTelemetry(
	ctx context.Context,
	publisher ports.GatewaySessionProjectionPublisher,
	record devicesession.Session,
	telemetryRuntime *telemetry.Runtime,
	operation string,
) error {
	snapshot, err := ToGatewayProjectionSnapshot(record)
	if err != nil {
		return InternalError(err)
	}

	return PublishProjectionSnapshotWithTelemetry(ctx, publisher, snapshot, telemetryRuntime, operation)
}