package companion

import (
	"errors"
	"reflect"
	"strings"
	"sync"
	"testing"
	"time"

	"longheng.io/server/internal/modules/dnf/repository"
)

// Synthetic fixtures test policies only, not any real DNF job/skill ABI.
func fixture(t *testing.T) (repository.CompanionSourceState, Selection, Profile) {
	t.Helper()
	data := repository.CompanionSourceState{
		Owner:  repository.CharacterRecord{CharacterID: "1", AccountID: "account-test"},
		Source: repository.CharacterRecord{CharacterID: "2", AccountID: "account-test", Name: "Fixture", Job: "0", Level: 40, Stats: map[string]int64{"grow_type": 1}},
		Equipment: repository.EquipmentRecord{CharacterID: "2", Entries: map[string]repository.EquipmentEntry{
			"weapon": {SlotIndex: 12, ItemID: 10000, RawEntry: []byte{1, 2}, Extra: map[string]string{"test": "unchanged"}},
		}},
		Skill: repository.SkillRecord{CharacterID: "2", Skills: map[int64]repository.SkillState{
			10: {Level: 3, Enabled: true}, 20: {Level: 7, Enabled: true}, 30: {Level: 4, Enabled: false},
		}, Cooldowns: map[int64]time.Time{10: time.Unix(100, 0)}}, HasEquipment: true, HasSkill: true,
	}
	s := Selection{AccountID: "account-test", OwnerCharacterID: "1", SourceCharacterID: "2", OnlineStateKnown: true,
		ClientSHA256: strings.Repeat("a", 64), PVFSHA256: strings.Repeat("b", 64)}
	p := Profile{ID: "synthetic-policy-test-only", Version: 1, EvidenceID: "unit-test-not-native-evidence",
		ClientSHA256: s.ClientSHA256, PVFSHA256: s.PVFSHA256, Job: 0, GrowType: 1,
		BasicAttackVerified: true, SkillLevelLimits: map[int64]int{10: 5}}
	return data, s, p
}
func prepared(t *testing.T) Snapshot {
	t.Helper()
	data, s, p := fixture(t)
	snapshot, err := Prepare(data, s, p, time.Unix(1000, 0))
	if err != nil {
		t.Fatal(err)
	}
	return snapshot
}
func runKey() RunKey {
	return RunKey{Instance: "test-instance", SessionGeneration: 1, OwnerCharacterID: "1", LifecycleToken: 2, SpawnSequence: 1, Nonce: strings.Repeat("c", 64)}
}

func TestCompanionProductionProfilesFailClosed(t *testing.T) {
	if len(VerifiedProfiles()) != 0 {
		t.Fatal("unverified native profile advertised")
	}
	data, s, p := fixture(t)
	p.BasicAttackVerified = false
	if _, err := Prepare(data, s, p, time.Unix(1000, 0)); !errors.Is(err, ErrProfile) {
		t.Fatal(err)
	}
}
func TestCompanionConfigRevisionAndDisable(t *testing.T) {
	c := DefaultConfig()
	if _, err := NextConfig(c, 1, true, "2", "1", nil); !errors.Is(err, ErrRevision) {
		t.Fatal(err)
	}
	if _, err := NextConfig(c, 0, true, "1", "1", nil); !errors.Is(err, ErrSelf) {
		t.Fatal(err)
	}
	if _, err := NextConfig(c, 0, true, "2", "1", ErrProfile); !errors.Is(err, ErrProfile) {
		t.Fatal(err)
	}
	next, err := NextConfig(c, 0, false, "2", "1", ErrProfile)
	if err != nil || next.Enabled || next.Revision != 1 || c.Revision != 0 {
		t.Fatalf("%+v %v", next, err)
	}
	c.Revision = ^uint64(0)
	if _, err := NextConfig(c, c.Revision, false, "", "1", nil); !errors.Is(err, ErrRevision) {
		t.Fatal(err)
	}
}
func TestCompanionInvalidCharacterIDs(t *testing.T) {
	for _, id := range []string{"0", "01", " 2", "65536", "-1", "2.0", ""} {
		t.Run(id, func(t *testing.T) {
			if validCharacterID(id) {
				t.Fatal("accepted invalid ID")
			}
		})
	}
}
func TestCompanionSelectionRejections(t *testing.T) {
	tests := []struct {
		name string
		edit func(*repository.CompanionSourceState, *Selection, *Profile)
		want error
	}{
		{"self", func(d *repository.CompanionSourceState, s *Selection, p *Profile) { s.SourceCharacterID = "1" }, ErrSelf},
		{"other-account", func(d *repository.CompanionSourceState, s *Selection, p *Profile) { d.Source.AccountID = "another" }, ErrAccount},
		{"deleted", func(d *repository.CompanionSourceState, s *Selection, p *Profile) { d.Source.Stats["delete_flag"] = 1 }, ErrSource},
		{"online", func(d *repository.CompanionSourceState, s *Selection, p *Profile) { s.SourceOnline = true }, ErrOnline},
		{"online-unknown", func(d *repository.CompanionSourceState, s *Selection, p *Profile) { s.OnlineStateKnown = false }, ErrOnlineUnknown},
		{"client-version", func(d *repository.CompanionSourceState, s *Selection, p *Profile) {
			s.ClientSHA256 = strings.Repeat("d", 64)
		}, ErrAssets},
		{"job", func(d *repository.CompanionSourceState, s *Selection, p *Profile) { d.Source.Job = "3" }, ErrProfile},
		{"missing-grow", func(d *repository.CompanionSourceState, s *Selection, p *Profile) {
			delete(d.Source.Stats, "grow_type")
		}, ErrProfile},
		{"missing-skills", func(d *repository.CompanionSourceState, s *Selection, p *Profile) { d.HasSkill = false }, ErrSnapshot},
		{"cross-equipment", func(d *repository.CompanionSourceState, s *Selection, p *Profile) { d.Equipment.CharacterID = "3" }, ErrSnapshot},
		{"duplicate-slot", func(d *repository.CompanionSourceState, s *Selection, p *Profile) {
			d.Equipment.Entries["duplicate"] = d.Equipment.Entries["weapon"]
		}, ErrSnapshot},
	}
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			data, s, p := fixture(t)
			tc.edit(&data, &s, &p)
			if _, err := Prepare(data, s, p, time.Unix(1000, 0)); !errors.Is(err, tc.want) {
				t.Fatalf("got %v want %v", err, tc.want)
			}
		})
	}
}
func TestCompanionSnapshotDetachedAndStable(t *testing.T) {
	data, s, p := fixture(t)
	a, err := Prepare(data, s, p, time.Unix(1000, 0))
	if err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(a.Skills, []SkillSpec{{ID: 10, Level: 3}}) {
		t.Fatal(a.Skills)
	}
	b, err := Prepare(data, s, p, time.Unix(1000, 0))
	if err != nil || a.Fingerprint() != b.Fingerprint() {
		t.Fatal("unstable fingerprint")
	}
	a.Equipment[0].ItemID = 123
	a.Skills[0].Level = 1
	if data.Equipment.Entries["weapon"].ItemID != 10000 || data.Skill.Skills[10].Level != 3 {
		t.Fatal("source mutation")
	}
	data.Source.Name = "changed"
	data.Skill.Skills[10] = repository.SkillState{Level: 5, Enabled: true}
	if b.Name != "Fixture" || b.Skills[0].Level != 3 {
		t.Fatal("snapshot mutation")
	}
}
func TestCompanionEmptySnapshotClonePreservesFingerprint(t *testing.T) {
	data, s, p := fixture(t)
	data.Equipment.Entries = map[string]repository.EquipmentEntry{}
	data.Skill.Skills = nil
	a, err := Prepare(data, s, p, time.Unix(1000, 0))
	if err != nil {
		t.Fatal(err)
	}
	if a.Fingerprint() != a.Clone().Fingerprint() {
		t.Fatal("empty-list clone changed content hash")
	}
}
func TestCompanionExpiredEquipmentExcluded(t *testing.T) {
	data, s, p := fixture(t)
	gear := data.Equipment.Entries["weapon"]
	gear.ExpireAt = time.Unix(999, 0)
	data.Equipment.Entries["weapon"] = gear
	a, err := Prepare(data, s, p, time.Unix(1000, 0))
	if err != nil || len(a.Equipment) != 0 {
		t.Fatalf("%+v %v", a, err)
	}
}

func TestCompanionLifecycleFullRun(t *testing.T) {
	key := runKey()
	source := prepared(t)
	i, err := NewInstance(key, source, 3, 1)
	if err != nil {
		t.Fatal(err)
	}
	source.Name = "external change"
	event := func(seq uint64, kind string, room uint64) Event {
		return Event{Run: key, Sequence: seq, Kind: kind, RoomGeneration: room, ObjectKey: 24, ObjectGeneration: 7}
	}
	apply := func(e Event) {
		t.Helper()
		if err := i.Apply(e, map[uint16]bool{1: true, 400: true}); err != nil {
			t.Fatal(e.Kind, err)
		}
	}
	apply(event(1, "room_ready", 1))
	apply(event(2, "native_created", 1))
	if i.Owns(key, 24, 7) {
		t.Fatal("owner allowed before binding")
	}
	if err := i.Apply(event(3, "activate", 1), nil); !errors.Is(err, ErrTransition) {
		t.Fatal(err)
	}
	apply(event(3, "owner_bound", 1))
	apply(event(4, "activate", 1))
	apply(event(4, "activate", 1))
	if !i.Owns(key, 24, 7) || i.Owns(key, 24, 8) {
		t.Fatal("owner generation validation")
	}
	apply(event(5, "room_leaving", 1))
	apply(event(6, "room_ready", 2))
	if i.Status().ObjectKey != 24 || i.Snapshot().Name != "Fixture" || i.Status().ConfigRevision != 3 {
		t.Fatal("cross-room instance replaced")
	}
	apply(event(7, "dead", 2))
	if err := i.Apply(event(8, "activate", 2), nil); !errors.Is(err, ErrTransition) {
		t.Fatal("dead actor revived", err)
	}
	if !i.Owns(key, 24, 7) {
		t.Fatal("in-flight ownership lost prematurely")
	}
	apply(event(8, "retire", 2))
	apply(event(9, "disposed", 2))
	if i.Owns(key, 24, 7) {
		t.Fatal("disposed owner retained")
	}
	if err := i.Apply(event(10, "room_ready", 3), nil); err == nil {
		t.Fatal("disposed run resurrected")
	}
}
func TestCompanionLifecycleRejectsStaleAndCollision(t *testing.T) {
	key := runKey()
	i, err := NewInstance(key, prepared(t), 1, 1)
	if err != nil {
		t.Fatal(err)
	}
	stale := key
	stale.LifecycleToken++
	if err := i.Apply(Event{Run: stale, Sequence: 1, Kind: "room_ready", RoomGeneration: 1}, nil); !errors.Is(err, ErrStaleRun) {
		t.Fatal(err)
	}
	if err := i.Apply(Event{Run: key, Sequence: 1, Kind: "room_ready", RoomGeneration: 1}, nil); err != nil {
		t.Fatal(err)
	}
	for _, n := range []uint16{0, 1, 400, 65535} {
		e := Event{Run: key, Sequence: 2, Kind: "native_created", RoomGeneration: 1, ObjectKey: n, ObjectGeneration: 1}
		if err := i.Apply(e, map[uint16]bool{400: true}); !errors.Is(err, ErrCollision) {
			t.Fatalf("key %d: %v", n, err)
		}
	}
	if i.Status().LastSequence != 1 {
		t.Fatal("rejected event advanced ledger")
	}
	if err := i.Apply(Event{Run: key, Sequence: 1, Kind: "skip"}, nil); !errors.Is(err, ErrTransition) {
		t.Fatal("sequence reused")
	}
	e := Event{Run: key, Sequence: 2, Kind: "native_created", RoomGeneration: 1, ObjectKey: 24, ObjectGeneration: 1}
	if err := i.Apply(e, nil); !errors.Is(err, ErrCollision) {
		t.Fatal("missing collision evidence accepted")
	}
}
func TestCompanionLifecycleConcurrentDuplicates(t *testing.T) {
	key := runKey()
	i, err := NewInstance(key, prepared(t), 1, 1)
	if err != nil {
		t.Fatal(err)
	}
	e := Event{Run: key, Sequence: 1, Kind: "room_ready", RoomGeneration: 1}
	var wg sync.WaitGroup
	for n := 0; n < 32; n++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if err := i.Apply(e, nil); err != nil {
				t.Error(err)
			}
			_ = i.Snapshot()
			_ = i.Status()
		}()
	}
	wg.Wait()
	if i.Status().LastSequence != 1 || i.Status().Phase != Ready {
		t.Fatal(i.Status())
	}
	clone := i.Snapshot()
	clone.Equipment[0].ItemID = 12
	if i.Snapshot().Equipment[0].ItemID == 12 {
		t.Fatal("status query mutated run")
	}
}