//go:build linux && rootrunner

package host

import (
	"context"
	"crypto/ed25519"
	"crypto/sha256"
	"errors"
	"io"
	"io/fs"
	"net"
	"net/http"
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"testing"
	"time"

	"github.com/carlosframework/platform/internal/controlsock"
	"github.com/carlosframework/platform/internal/domains"
	"github.com/carlosframework/platform/internal/hostbox"
	"github.com/carlosframework/platform/internal/hostclaim"
	execlease "github.com/carlosframework/platform/internal/hostexec"
	"github.com/carlosframework/platform/internal/hostguard"
	"github.com/carlosframework/platform/internal/provision"
	"github.com/carlosframework/platform/internal/release"
)

func lifecycleActiveSibling(t *testing.T) {
	t.Helper()
	s, err := openClaimRootAuthority()
	lifecycleCheck(t, "sibling authority", err)
	defer s.Close()
	views, err := hostguard.NewRootAuthority(s).GenerationInstallations(t.Context())
	lifecycleCheck(t, "sibling installations", err)
	for _, view := range views {
		if view.Host != lifecycleSibling {
			continue
		}
		if view.Installation.Stamp == 0 || view.Barrier != nil {
			t.Fatal("sibling is not active")
		}
		for _, old := range view.Retired {
			if old.Incarnation == view.Installation.Incarnation && old.Stamp == view.Installation.Stamp {
				t.Fatal("sibling retired")
			}
		}
		transport := &http.Transport{DialContext: func(ctx context.Context, _, _ string) (net.Conn, error) {
			return (&net.Dialer{}).DialContext(ctx, "unix", "/run/carlos/instances/"+lifecycleSibling+"/app.sock")
		}}
		defer transport.CloseIdleConnections()
		response, err := (&http.Client{Transport: transport, Timeout: time.Second}).Get("http://sibling/")
		lifecycleCheck(t, "active sibling response", err)
		defer response.Body.Close()
		raw, err := io.ReadAll(response.Body)
		lifecycleCheck(t, "active sibling body", err)
		if response.StatusCode != http.StatusOK || string(raw) != "lifecycle tenant" {
			t.Fatal("sibling stopped serving", response.StatusCode, string(raw))
		}
		return
	}
	t.Fatal("missing production sibling installation")
}

func lifecycleRetainedBytes(t *testing.T) map[string][32]byte {
	t.Helper()
	out := map[string][32]byte{}
	for _, root := range []string{"/var/lib/carlos-claims", "/data/.parked"} {
		lifecycleCheck(t, "retained evidence", filepath.WalkDir(root, func(path string, e fs.DirEntry, err error) error {
			if err != nil {
				return err
			}
			if !e.Type().IsRegular() || strings.HasSuffix(path, ".lock") {
				return nil
			}
			raw, err := os.ReadFile(path)
			if err != nil {
				return err
			}
			if strings.HasPrefix(path, "/data/.parked/") || strings.Contains(string(raw), lifecycleHost) {
				out[path] = sha256.Sum256(raw)
			}
			return nil
		}))
	}
	return out
}

func lifecycleReinstall(t *testing.T, store release.Store, key ed25519.PrivateKey, actor hostbox.Actor, pointer release.SystemPointer) {
	t.Helper()
	lifecycleActiveSibling(t)
	removed, err := domains.DetachClaim(t.Context(), store, lifecycleHost, "bab", "lifecycle")
	lifecycleCheck(t, "release deleted instance domain", err)
	if !removed {
		t.Fatal("deleted instance domain was not released")
	}
	before := lifecycleRetainedBytes(t)
	lifecycleCreate(t, store, key, actor, pointer, provision.Record{Schema: 1, Host: lifecycleHost, Account: "bab", App: "reinstall", Channel: "stable", CreatedAt: time.Now().UTC()})
	lifecycleCheck(t, "request reinstall", os.WriteFile("/run/carlos/lifecycle-reinstall", []byte("ready"), 0644))
	deadline := time.Now().Add(time.Minute)
	for {
		if _, err := os.Stat("/run/carlos/lifecycle-reinstall-refused"); err == nil {
			break
		}
		if time.Now().After(deadline) {
			t.Fatal("reinstall refusal timeout")
		}
		time.Sleep(20 * time.Millisecond)
	}
	if !reflect.DeepEqual(before, lifecycleRetainedBytes(t)) {
		t.Fatal("reinstall changed retained evidence")
	}
	lifecycleActiveSibling(t)
}

func lifecycleAgentReinstall(t *testing.T, ctx context.Context, store release.Store) {
	t.Helper()
	deadline := time.Now().Add(2 * time.Minute)
	refused := false
	for time.Now().Before(deadline) {
		if _, err := os.Stat("/run/carlos/lifecycle-finish"); err == nil {
			return
		}
		if _, err := os.Stat("/run/carlos/lifecycle-reinstall"); err == nil && !refused {
			obs, err := hostclaim.Read(ctx, store, lifecycleHost)
			lifecycleCheck(t, "reinstall claim", err)
			q := executionExpectation(obs.Claim)
			q.ID, q.Operation = "reinstall", "executionView"
			_, err = rootExecutionClient(controlsock.Path)(ctx, q)
			want := lifecycleHost + ": hostname was retired on this box; reinstalling it is not yet supported"
			if err == nil || errors.Is(err, execlease.ErrLost) || err.Error() != want {
				t.Fatalf("reinstall refusal: %v", err)
			}
			lifecycleCheck(t, "reinstall refused", os.WriteFile("/run/carlos/lifecycle-reinstall-refused", []byte("ready"), 0644))
			refused = true
		}
		time.Sleep(20 * time.Millisecond)
	}
	t.Fatal("lifecycle verification timeout")
}