package videogen

import "context"

// VideoUpscaleRequest asks a super-resolution backend (per-frame Real-ESRGAN
// style) to enlarge a clip. Zero values mean "backend default" (ADR-0025).
type VideoUpscaleRequest struct {
	// Video is the encoded clip to upscale. Required. Carried as bytes
	// (never a URL).
	Video []byte

	// MIME is the video MIME type (e.g. "video/mp4"); "" = let the backend
	// sniff it.
	MIME string

	// Filename is the multipart filename hint some backends key their format
	// detection on; "" derives one from MIME ("video.mp4") or falls back to
	// "video".
	Filename string

	// Scale is the enlargement factor (2 or 4 on the reference backend);
	// 0 = backend default.
	Scale int
}

// VideoUpscaleOption mutates a VideoUpscaleRequest before it is sent.
type VideoUpscaleOption func(*VideoUpscaleRequest)

// WithVideoUpscaleScale sets the enlargement factor.
func WithVideoUpscaleScale(s int) VideoUpscaleOption {
	return func(r *VideoUpscaleRequest) { r.Scale = s }
}

// Apply returns a copy of the request with all options applied.
func (r VideoUpscaleRequest) Apply(opts ...VideoUpscaleOption) VideoUpscaleRequest {
	for _, opt := range opts {
		opt(&r)
	}
	return r
}

// VideoUpscaler enlarges video clips frame by frame — the moving-picture
// sibling of imagegen.Upscaler.
type VideoUpscaler interface {
	// UpscaleVideo returns the enlarged clip. Upscaling is slow (per-frame
	// inference); bound the call with a context deadline.
	UpscaleVideo(ctx context.Context, req VideoUpscaleRequest, opts ...VideoUpscaleOption) (*Result, error)
}

// VideoUpscalerModelOption configures a VideoUpscaler at construction time.
// Reserved for future per-model settings.
type VideoUpscalerModelOption func(*VideoUpscalerModelConfig)

// VideoUpscalerModelConfig carries per-model construction settings.
type VideoUpscalerModelConfig struct{}

// ApplyVideoUpscalerModelOptions folds options into a config.
func ApplyVideoUpscalerModelOptions(opts []VideoUpscalerModelOption) VideoUpscalerModelConfig {
	var cfg VideoUpscalerModelConfig
	for _, opt := range opts {
		opt(&cfg)
	}
	return cfg
}

// VideoUpscaleProvider mints VideoUpscalers bound to one backend.
type VideoUpscaleProvider interface {
	// Name is the registry identifier for the provider.
	Name() string

	// VideoUpscalerModel returns a VideoUpscaler bound to the given id
	// (passed through to the backend verbatim; no catalog validation).
	VideoUpscalerModel(id string, opts ...VideoUpscalerModelOption) (VideoUpscaler, error)
}