package host

import (
	"context"
	"fmt"
	"os"
	"strings"
	"testing"

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

func TestPlan14OperatorUnitPredecessorStop(t *testing.T) {
	for _, attack := range []string{"none", "invocation", "cgroup", "inode", "dropin", "fragment", "missing property", "child remains", "lost stop"} {
		t.Run(attack, func(t *testing.T) {
			b, in, _ := plan14UnitBindingFixture(t, "console.service", "", "")
			binding, err := b.establish(t.Context(), in.Host)
			if err != nil {
				t.Fatal(err)
			}
			invocation, group, state := "original", "/system.slice/console.service", "active"
			id := rootstate.FileIdentity{Device: 1, Inode: 2}
			populated, stops := true, 0
			k := claimPredecessorKernel{group: func(string) (rootstate.FileIdentity, bool, error) { return id, populated, nil }}
			k.ctl = func(_ context.Context, args ...string) (string, error) {
				if args[0] == "stop" {
					stops++
					state = "inactive"
					if attack != "child remains" {
						populated = false
					}
					if attack == "lost stop" {
						return "", os.ErrInvalid
					}
					return "", nil
				}
				out := fmt.Sprintf("ActiveState=%s\nInvocationID=%s\nControlGroup=%s\nFragmentPath=/etc/systemd/system/console.service\nDropInPaths=", state, invocation, group)
				switch attack {
				case "dropin":
					out += "/etc/systemd/system/console.service.d/override.conf"
				case "fragment":
					out = strings.ReplaceAll(out, "/etc/systemd/system", "/run/systemd/system")
				case "missing property":
					out = strings.ReplaceAll(out, "\nDropInPaths=", "")
				}
				return out, nil
			}
			p, err := k.capture(t.Context(), binding)
			if attack == "dropin" || attack == "fragment" || attack == "missing property" {
				if err == nil || stops != 0 {
					t.Fatal("bad definition accepted", err)
				}
				return
			}
			if err != nil {
				t.Fatal(err)
			}
			switch attack {
			case "invocation":
				invocation = "successor"
			case "cgroup":
				group = "/system.slice/sibling.service"
			case "inode":
				id.Inode++
			}
			ctx, cancel := context.WithCancel(t.Context())
			if attack == "child remains" {
				original := k.ctl
				k.ctl = func(ctx context.Context, args ...string) (string, error) {
					out, e := original(ctx, args...)
					if args[0] == "stop" {
						cancel()
					}
					return out, e
				}
			}
			defer cancel()
			err = k.stop(ctx, p)
			if attack == "none" {
				if err != nil || stops != 1 {
					t.Fatal(err, stops)
				}
				if err = k.stop(t.Context(), p); err != nil || stops != 1 {
					t.Fatal("stop replay", err, stops)
				}
			} else if err == nil {
				t.Fatal("unsafe stop accepted")
			}
			if (attack == "invocation" || attack == "cgroup" || attack == "inode") && stops != 0 {
				t.Fatal("stopped successor")
			}
			if attack == "lost stop" {
				if err = k.stop(t.Context(), p); err != nil || stops != 1 {
					t.Fatal("lost stop replay", err, stops)
				}
			}
		})
	}
}

func TestPlan14PredecessorDeviceAcrossBoot(t *testing.T) {
	p := claimUnitPredecessor{Unit: "console.service", Invocation: "before", Group: "system.slice/console.service", GroupIdentity: rootstate.FileIdentity{Device: 1, Inode: 2}, Boot: "boot-before"}
	state := "inactive"
	calls := 0
	k := claimPredecessorKernel{
		boot: func() (string, error) { return "boot-after", nil },
		group: func(string) (rootstate.FileIdentity, bool, error) {
			return rootstate.FileIdentity{Device: 8, Inode: 9}, state == "active", nil
		},
		ctl: func(_ context.Context, args ...string) (string, error) {
			if args[0] != "show" {
				calls++
				return "", nil
			}
			return "ActiveState=" + state + "\nInvocationID=\nControlGroup=\nFragmentPath=/etc/systemd/system/console.service\nDropInPaths=\n", nil
		},
	}
	if err := k.stop(t.Context(), p); err != nil {
		t.Fatal("old boot empty group refused", err)
	}
	state = "active"
	if err := k.stop(t.Context(), p); err == nil {
		t.Fatal("old boot authorized stopping new population")
	}
	if calls != 0 {
		t.Fatal("systemctl stop crossed a boot")
	}
}