package transcribe

import (
	"context"
	"time"

	"git.d-ma.be/mathias/tapir/internal/domain"
)

// WithTimeout gives every call to b its own deadline. A wedged engine does not answer at
// all (iguana after a Metal OOM, infra#273), and with only the job's deadline it used up
// the whole job before a fallback could run -- and Chain then refuses the fallback because
// the job context has expired. With its own deadline the call fails while the job is still
// alive, which is exactly when the fallback, or the other engine, can take over.
//
// A zero or negative d returns b unchanged. The wrapper is invisible: Name is b's.
func WithTimeout(b Backend, d time.Duration) Backend {
	if d <= 0 {
		return b
	}
	return timeoutBackend{Backend: b, d: d}
}

type timeoutBackend struct {
	Backend
	d time.Duration
}

func (t timeoutBackend) Transcribe(ctx context.Context, wavPath string) (domain.Transcription, error) {
	ctx, cancel := context.WithTimeout(ctx, t.d)
	defer cancel()
	return t.Backend.Transcribe(ctx, wavPath)
}