package llamaswap

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

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

// Health reports whether the llama-swap instance is reachable (GET
// {base}/health, which answers "OK" without touching any model). A nil error
// means the proxy itself is up — it says nothing about how long a subsequent
// request will take (a cold model swap can still block for minutes). Bound
// the probe with a short context deadline; the client has no timeout by
// design.
//
// Failure taxonomy matches the rest of the package: transport failures wrap
// the raw net error; a reachable-but-unhealthy status comes back as
// *llm.APIError, so callers can errors.As-distinguish the two.
func (p *Provider) Health(ctx context.Context) error {
	if err := p.requireBaseURL(); err != nil {
		return err
	}
	req, err := p.newRequest(ctx, http.MethodGet, "/health", "", nil)
	if err != nil {
		return err
	}
	resp, err := p.client.Do(req)
	if err != nil {
		return fmt.Errorf("llama-swap: health probe: %w", err)
	}
	defer resp.Body.Close()
	_, _ = io.Copy(io.Discard, io.LimitReader(resp.Body, 1<<10))
	if resp.StatusCode/100 != 2 {
		return &llm.APIError{
			Provider: p.name,
			Status:   resp.StatusCode,
			Message:  "health endpoint returned a non-2xx status",
		}
	}
	return nil
}