package identityruntime

import (
	"context"
	"errors"
	"testing"

	"github.com/easyai/easyai-ai-gateway/apps/api/internal/identity"
)

type runtimeRepositoryFake struct {
	revisions      map[string]identity.Revision
	active         identity.Revision
	activateCalled bool
}

func (f *runtimeRepositoryFake) IdentityConfigurationRevision(_ context.Context, id string) (identity.Revision, error) {
	revision, ok := f.revisions[id]
	if !ok {
		return identity.Revision{}, identity.ErrRevisionNotFound
	}
	return revision, nil
}
func (f *runtimeRepositoryFake) ActiveIdentityConfigurationRevision(context.Context) (identity.Revision, error) {
	if f.active.ID == "" {
		return identity.Revision{}, identity.ErrRevisionNotFound
	}
	return f.active, nil
}
func (f *runtimeRepositoryFake) MarkIdentityRevisionValidated(_ context.Context, id string, expected int64, _, _ string) (identity.Revision, error) {
	revision := f.revisions[id]
	if revision.Version != expected {
		return identity.Revision{}, identity.ErrRevisionConflict
	}
	revision.State, revision.Version = identity.RevisionValidated, revision.Version+1
	f.revisions[id] = revision
	return revision, nil
}
func (f *runtimeRepositoryFake) MarkIdentityRevisionFailed(_ context.Context, id string, expected int64, category, _, _ string) (identity.Revision, error) {
	revision := f.revisions[id]
	if revision.Version != expected {
		return identity.Revision{}, identity.ErrRevisionConflict
	}
	revision.State, revision.Version, revision.LastErrorCategory = identity.RevisionFailed, revision.Version+1, category
	f.revisions[id] = revision
	return revision, nil
}
func (f *runtimeRepositoryFake) ActivateIdentityRevision(_ context.Context, id string, expected int64, traceID, auditID string) (identity.Revision, bool, error) {
	f.activateCalled = true
	revision := f.revisions[id]
	if revision.Version != expected || revision.State != identity.RevisionValidated {
		return identity.Revision{}, false, identity.ErrRevisionConflict
	}
	if f.active.ID != "" {
		old := f.active
		old.State = identity.RevisionSuperseded
		f.revisions[old.ID] = old
	}
	revision.State, revision.Version, revision.LastTraceID, revision.LastAuditID = identity.RevisionActive, revision.Version+1, traceID, auditID
	f.active, f.revisions[id] = revision, revision
	return revision, true, nil
}
func (f *runtimeRepositoryFake) DisableActiveIdentityRevision(_ context.Context, expected int64, traceID, auditID string) (identity.Revision, error) {
	if f.active.Version != expected {
		return identity.Revision{}, identity.ErrRevisionConflict
	}
	disabled := f.active
	disabled.State, disabled.Version, disabled.LastTraceID, disabled.LastAuditID = identity.RevisionSuperseded, disabled.Version+1, traceID, auditID
	f.revisions[disabled.ID] = disabled
	f.active = identity.Revision{}
	return disabled, nil
}

type runtimeBuilderFake struct {
	err      error
	builtIDs []string
}

func (f *runtimeBuilderFake) Build(_ context.Context, revision identity.Revision) (*Runtime, error) {
	f.builtIDs = append(f.builtIDs, revision.ID)
	if f.err != nil {
		return nil, f.err
	}
	return &Runtime{Revision: revision}, nil
}

func TestValidationFailureKeepsCurrentRuntimeAndDoesNotActivate(t *testing.T) {
	active := identity.Revision{ID: "active", State: identity.RevisionActive, Version: 4}
	draft := identity.Revision{ID: "draft", State: identity.RevisionDraft, Version: 1}
	repository := &runtimeRepositoryFake{revisions: map[string]identity.Revision{"active": active, "draft": draft}, active: active}
	builder := &runtimeBuilderFake{err: errors.New("discovery failed")}
	manager := NewManager(repository, builder)
	manager.current.Store(&Runtime{Revision: active})

	if _, err := manager.Validate(context.Background(), draft.ID, draft.Version, "trace", "audit"); err == nil {
		t.Fatal("validation failure was ignored")
	}
	if manager.Current().Revision.ID != active.ID || repository.activateCalled {
		t.Fatal("validation failure changed current runtime or activated the draft")
	}
	if repository.revisions[draft.ID].State != identity.RevisionFailed {
		t.Fatal("failed draft was not marked failed")
	}
}

func TestActivationSwapsRuntimeOnlyAfterRepositoryActivation(t *testing.T) {
	active := identity.Revision{ID: "old", State: identity.RevisionActive, Version: 2}
	candidate := identity.Revision{ID: "new", State: identity.RevisionValidated, Version: 3}
	repository := &runtimeRepositoryFake{revisions: map[string]identity.Revision{"old": active, "new": candidate}, active: active}
	manager := NewManager(repository, &runtimeBuilderFake{})
	manager.current.Store(&Runtime{Revision: active})

	activated, err := manager.Activate(context.Background(), candidate.ID, candidate.Version, "trace", "audit")
	if err != nil {
		t.Fatal(err)
	}
	if !repository.activateCalled || activated.State != identity.RevisionActive || manager.Current().Revision.ID != candidate.ID {
		t.Fatalf("activation order failed: activated=%#v current=%#v", activated, manager.Current())
	}
}

func TestRollbackValidatesAndAtomicallyReplacesActiveRuntime(t *testing.T) {
	active := identity.Revision{ID: "current", State: identity.RevisionActive, Version: 5}
	previous := identity.Revision{ID: "previous", State: identity.RevisionSuperseded, Version: 3}
	repository := &runtimeRepositoryFake{
		revisions: map[string]identity.Revision{"current": active, "previous": previous}, active: active,
	}
	manager := NewManager(repository, &runtimeBuilderFake{})
	manager.current.Store(&Runtime{Revision: active})

	rolledBack, err := manager.Rollback(context.Background(), previous.ID, previous.Version, "trace", "audit")
	if err != nil {
		t.Fatal(err)
	}
	if rolledBack.State != identity.RevisionActive || manager.Current().Revision.ID != previous.ID || repository.active.ID != previous.ID {
		t.Fatalf("rollback did not replace active runtime: revision=%#v current=%#v", rolledBack, manager.Current())
	}
}