package cdn

import (
	"context"
	"fmt"
	"strings"
)

// Provider implements third-party CDN distribution via RTMP/SRT forward.
type Provider struct {
	rtmpURL string
	name    string
}

// NewProvider creates a CDN provider. rtmpURL is the base RTMP URL, e.g. rtmp://cdn.example.com/live
func NewProvider(rtmpURL, name string) *Provider {
	if name == "" {
		name = "CDN"
	}
	return &Provider{rtmpURL: rtmpURL, name: name}
}

func (p *Provider) Kind() string      { return "cdn" }
func (p *Provider) Name() string      { return p.name }
func (p *Provider) Configured() bool  { return strings.TrimSpace(p.rtmpURL) != "" }
func (p *Provider) RTMPURL() string   { return p.rtmpURL }

// Forward returns the RTMP push URL for the given stream.
// In the current implementation this is a stub that just composes the URL and returns ready status.
// Future: actually trigger SRS forward API or external pusher.
func (p *Provider) Forward(ctx context.Context, room, stream string) (*ForwardResult, error) {
	if !p.Configured() {
		return nil, fmt.Errorf("cdn not configured: CDN_RTMP_URL empty")
	}
	base := strings.TrimRight(p.rtmpURL, "/")
	url := base + "/" + stream
	return &ForwardResult{Kind: "cdn", URL: url, Status: "ready"}, nil
}

// ForwardResult mirrors sfu.ForwardResult to avoid import cycle
type ForwardResult struct {
	Kind   string
	URL    string
	Status string
}