package bridge

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"
)

// EngineEmbeddings reads templates from the local engine's API.
type EngineEmbeddings struct {
	Base     string
	User     string
	Password string
	Client   *http.Client
}

func NewEngineEmbeddings(base, user, password string) *EngineEmbeddings {
	return &EngineEmbeddings{
		Base: strings.TrimRight(base, "/"), User: user, Password: password,
		Client: &http.Client{Timeout: 10 * time.Second},
	}
}

func (e *EngineEmbeddings) Embedding(ctx context.Context, id int64) ([]float32, string, error) {
	url := fmt.Sprintf("%s/api/identities/%d/embedding", e.Base, id)
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
	if err != nil {
		return nil, "", err
	}
	if e.User != "" {
		req.SetBasicAuth(e.User, e.Password)
	}
	resp, err := e.Client.Do(req)
	if err != nil {
		return nil, "", err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return nil, "", fmt.Errorf("engine returned %s", resp.Status)
	}
	var body struct {
		Model     string    `json:"model"`
		Embedding []float32 `json:"embedding"`
	}
	if err := json.NewDecoder(io.LimitReader(resp.Body, 1<<20)).Decode(&body); err != nil {
		return nil, "", err
	}
	if len(body.Embedding) == 0 {
		return nil, "", fmt.Errorf("engine returned an empty embedding")
	}
	return body.Embedding, body.Model, nil
}