package edge

import (
	"context"
	"encoding/pem"
	"fmt"
	"io"
	"net"
	"os"
	"path/filepath"
	"testing"

	"github.com/carlosframework/platform/internal/release"
)

const dbfBackhaulHost = "console.backhaul.test"

// TestDBForwardBackhaulPairHelper is not a test of its own: the root
// package's TestDBForwardThroughTheBackhaulHop builds this package's test
// binary and runs this as a helper process. It stands up two real edges
// over one bucket, as TestBackhaulE2EAcrossTwoEdges does: annie, home of
// console.backhaul.test, routed to DBF_BACKHAUL_UPSTREAM (the real console
// the parent serves), and betty, which serves no host and so backhauls every
// request for it to annie. It writes the test CA to DBF_BACKHAUL_DIR/ca.pem,
// prints betty's TLS address on a line starting "DBF-BACKHAUL ", and serves
// until its stdin closes.
func TestDBForwardBackhaulPairHelper(t *testing.T) {
	if os.Getenv("DBF_BACKHAUL_HELPER") != "1" {
		t.Skip("a helper process for the root package's TestDBForwardThroughTheBackhaulHop")
	}
	upstream, dir := os.Getenv("DBF_BACKHAUL_UPSTREAM"), os.Getenv("DBF_BACKHAUL_DIR")
	e2eQuietLogs(t)
	bucket := t.TempDir()
	seed := release.NewDirStore(bucket)
	if err := MintMeshKey(context.Background(), seed); err != nil {
		t.Fatal(err)
	}
	ca := newE2ECA(t)
	ca.publish(t, seed, dbfBackhaulHost)
	home := newBackhaulEdge(t, bucket, "annie", ca, nil, map[string]string{dbfBackhaulHost: upstream})
	sender := newBackhaulEdge(t, bucket, "betty", ca, nil, nil)
	eip, port, err := net.SplitHostPort(home.tlsAddr)
	if err != nil {
		t.Fatal(err)
	}
	oldPort, oldCAs := backhaulPort, backhaulRootCAs
	backhaulPort, backhaulRootCAs = port, ca.pool
	t.Cleanup(func() { backhaulPort, backhaulRootCAs = oldPort, oldCAs })
	putJSON(t, seed, "control/edges/annie.json", fmt.Sprintf(`{"v":1,"box":"annie","eip":%q,"hosts":{%q:{"role":"home"}}}`, eip, dbfBackhaulHost))
	bEIP, _, err := net.SplitHostPort(sender.tlsAddr)
	if err != nil {
		t.Fatal(err)
	}
	putJSON(t, seed, "control/edges/betty.json", fmt.Sprintf(`{"v":1,"box":"betty","eip":%q,"hosts":{}}`, bEIP))
	for _, be := range []*backhaulEdge{home, sender} {
		if err := be.mirror.Refresh(context.Background()); err != nil {
			t.Fatal(err)
		}
		refreshHomeMap(t, be.homes)
	}
	caPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: ca.root.Raw})
	if err := os.WriteFile(filepath.Join(dir, "ca.pem"), caPEM, 0o600); err != nil {
		t.Fatal(err)
	}
	fmt.Println("DBF-BACKHAUL " + sender.tlsAddr)
	io.Copy(io.Discard, os.Stdin)
}