//go:build unix

package host

import (
	"errors"
	"io"
	"os"
	"os/exec"
	"os/user"
	"path/filepath"
	"strconv"
	"testing"

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

func TestRegistryChildHelper(t *testing.T) {
	for i, arg := range os.Args {
		if arg == "--registry-test-child" {
			if err := RunRegistryChild(os.Args[i+1:]); err != nil {
				os.Exit(1)
			}
			os.Exit(0)
		}
	}
}

func TestRegistryChildDropsCredentials(t *testing.T) {
	if os.Geteuid() != 0 {
		t.Skip("requires root to set the child uid/gid and clear supplementary groups")
	}
	t.Setenv("CARLOS_HOST_CLAIM", "true")
	service, err := user.Lookup(serviceUser)
	if err != nil {
		t.Skip("requires the carlos service account")
	}
	uid, err := strconv.Atoi(service.Uid)
	if err != nil || uid <= 0 {
		t.Skip("requires a nonzero service uid")
	}
	gid, err := strconv.Atoi(service.Gid)
	if err != nil {
		t.Fatal(err)
	}
	dir, err := os.MkdirTemp(os.TempDir(), "registry-child-")
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { os.RemoveAll(dir) })
	if err := os.Chmod(dir, 0755); err != nil {
		t.Fatal(err)
	}
	executable, err := os.Executable()
	if err != nil {
		t.Fatal(err)
	}
	source, err := os.Open(executable)
	if err != nil {
		t.Fatal(err)
	}
	defer source.Close()
	bin := filepath.Join(dir, "test-worker")
	dest, err := os.OpenFile(bin, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0755)
	if err != nil {
		t.Fatal(err)
	}
	_, err = io.Copy(dest, source)
	closeErr := dest.Close()
	if err != nil {
		t.Fatal(err)
	}
	if closeErr != nil {
		t.Fatal(closeErr)
	}
	data := filepath.Join(dir, "data")
	if err := os.Mkdir(data, 0700); err != nil {
		t.Fatal(err)
	}
	if err := os.Chown(data, uid, gid); err != nil {
		t.Fatal(err)
	}
	path := filepath.Join(data, "registry.db")
	legacy, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0644)
	if err != nil {
		t.Fatal(err)
	}
	if err := legacy.Close(); err != nil {
		t.Fatal(err)
	}
	changed, err := ownRegistryFile(path, uid, gid)
	if err != nil || !changed {
		t.Fatalf("repair root-owned registry: changed=%v, err=%v", changed, err)
	}
	cmd := exec.Command(bin, "-test.run=^TestRegistryChildHelper$", "--", "--registry-test-child", path, service.Uid, service.Gid)
	r, err := startRegistryChild(cmd, path, uid, gid)
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { r.Close() })
	if err := r.Upsert(registry.Route{Host: "dropped", Kind: "instance"}); err != nil {
		r.Close()
		t.Fatal(err)
	}
	owner := registry.ClaimOwnership{ClaimIncarnation: "inc", ClaimStamp: 1, ClaimOwner: "owner", ClaimRowID: "row"}
	row, err := r.Get("dropped")
	if err != nil {
		t.Fatal(err)
	}
	if err := r.AdoptClaimRoute(t.Context(), *row, owner); err != nil {
		t.Fatal(err)
	}
	timer := registry.Timer{Host: "dropped", Name: "tick", Kind: "cron", Spec: "* * * * *"}
	if err := r.UpsertTimer(timer); err != nil {
		t.Fatal(err)
	}
	saved, err := r.GetTimer("dropped", "tick")
	if err != nil || saved == nil || saved.Registration == "" || saved.ClaimOwner != owner.ClaimOwner {
		t.Fatalf("worker lost claim mode: %+v, %v", saved, err)
	}
	timer.ClaimOwnership = owner
	timer.ClaimOwner = "other"
	if err := r.UpsertTimer(timer); !errors.Is(err, registry.ErrClaimOwnership) {
		t.Fatalf("worker accepted conflicting claim: %v", err)
	}
	for _, name := range []string{path, path + "-wal", path + "-shm"} {
		info, err := os.Stat(name)
		if err != nil {
			t.Fatal(err)
		}
		gotUID, gotGID, ok := fileOwner(info)
		if !ok || gotUID != uid || gotGID != gid {
			t.Fatalf("%s owner = %d:%d, want %d:%d", name, gotUID, gotGID, uid, gid)
		}
	}
	if err := r.Close(); err != nil {
		t.Fatal(err)
	}

}

func TestRegistryChildRefusesRootCredentials(t *testing.T) {
	if _, err := openRegistryChild(filepath.Join(t.TempDir(), "registry.db"), 0, 0); err == nil {
		t.Fatal("root worker accepted")
	}
}

func TestRegistryChildCommandEnvironment(t *testing.T) {
	t.Setenv("CARLOS_HOST_CLAIM", "true")
	t.Setenv("AWS_SECRET_ACCESS_KEY", "must-not-reach-worker")
	cmd := exec.Command(filepath.Join(t.TempDir(), "missing-executable"))
	if _, err := startRegistryChild(cmd, "unused", 65534, 65534); err == nil {
		t.Fatal("missing worker started")
	}
	if len(cmd.Env) != 1 || cmd.Env[0] != "CARLOS_HOST_CLAIM=true" {
		t.Fatalf("worker environment = %q", cmd.Env)
	}
	if cmd.Dir != "/" || cmd.SysProcAttr != nil {
		t.Fatalf("unsafe worker command: %+v", cmd)
	}
}