// enhance.go implements audio.SpeechEnhancementProvider against a
// DeepFilterNet shim (audioutils) reached through llama-swap's /upstream
// passthrough (ADR-0024):
//
//	POST /upstream/<id>/v1/enhance   multipart file -> WAV
package llamaswap

import (
	"context"
	"fmt"
	"net/http"

	"gitea.stevedudenhoeffer.com/steve/majordomo/audio"
	"gitea.stevedudenhoeffer.com/steve/majordomo/llm"
)

// SpeechEnhancerModel implements audio.SpeechEnhancementProvider. The id
// selects which upstream llama-swap loads.
func (p *Provider) SpeechEnhancerModel(id string, opts ...audio.SpeechEnhancerModelOption) (audio.SpeechEnhancer, error) {
	if err := p.requireBaseURL(); err != nil {
		return nil, err
	}
	_ = audio.ApplySpeechEnhancerModelOptions(opts)
	return &speechEnhancerModel{p: p, id: id}, nil
}

type speechEnhancerModel struct {
	p  *Provider
	id string
}

// Enhance implements audio.SpeechEnhancer. The endpoint always answers WAV.
func (m *speechEnhancerModel) Enhance(ctx context.Context, req audio.EnhancementRequest, opts ...audio.EnhancementOption) (*audio.SpeechResult, error) {
	req = req.Apply(opts...)
	if len(req.Audio) == 0 {
		return nil, fmt.Errorf("%w: speech enhancement requires audio bytes", llm.ErrUnsupported)
	}
	path, err := upstreamPath(m.id, "/v1/enhance")
	if err != nil {
		return nil, err
	}
	body, contentType, err := buildMultipart("build enhance form",
		filePart{field: "file", filename: transcriptionFilename(req.Filename, req.MIME), data: req.Audio},
		nil)
	if err != nil {
		return nil, err
	}
	raw, respType, err := m.p.doRaw(ctx, http.MethodPost, path, m.id, contentType, body, maxAudioResponseBytes)
	if err != nil {
		return nil, err
	}
	if len(raw) == 0 {
		return nil, &llm.APIError{Provider: m.p.name, Model: m.id, Message: "enhance response contained no audio"}
	}
	mimeType := audioResultMIME(respType, raw)
	if mimeType == "" {
		return nil, &llm.APIError{Provider: m.p.name, Model: m.id,
			Message: fmt.Sprintf("enhance response is not audio (Content-Type %q): %s", respType, truncateForError(raw))}
	}
	return &audio.SpeechResult{Audio: raw, MIME: mimeType}, nil
}