package entities

import (
	"context"
	"errors"
	"sort"
	"testing"

	hav1 "gitea.nik4nao.com/nik/home-services/gen/ha/v1"
	"google.golang.org/grpc"
)

type fakeEntityServiceClient struct {
	listStatesFunc func(ctx context.Context, in *hav1.ListStatesRequest) (*hav1.ListStatesResponse, error)
}

func (f *fakeEntityServiceClient) GetState(ctx context.Context, in *hav1.GetStateRequest, _ ...grpc.CallOption) (*hav1.GetStateResponse, error) {
	return &hav1.GetStateResponse{}, nil
}

func (f *fakeEntityServiceClient) ListStates(ctx context.Context, in *hav1.ListStatesRequest, _ ...grpc.CallOption) (*hav1.ListStatesResponse, error) {
	if f.listStatesFunc == nil {
		return &hav1.ListStatesResponse{}, nil
	}
	return f.listStatesFunc(ctx, in)
}

func TestClientFetchAll(t *testing.T) {
	t.Run("fetches per domain and extracts friendly_name", func(t *testing.T) {
		fake := &fakeEntityServiceClient{
			listStatesFunc: func(ctx context.Context, in *hav1.ListStatesRequest) (*hav1.ListStatesResponse, error) {
				switch in.GetDomain() {
				case "light":
					return &hav1.ListStatesResponse{States: []*hav1.EntityState{
						{EntityId: "light.living_room", Attributes: map[string]string{"friendly_name": "Living Room Lamp"}},
					}}, nil
				case "switch":
					return &hav1.ListStatesResponse{States: []*hav1.EntityState{
						{EntityId: "switch.fan", Attributes: map[string]string{"friendly_name": "Fan"}},
					}}, nil
				case "climate":
					return &hav1.ListStatesResponse{States: []*hav1.EntityState{
						{EntityId: "climate.air_conditioner", Attributes: map[string]string{}},
					}}, nil
				}
				t.Fatalf("unexpected domain %q", in.GetDomain())
				return nil, nil
			},
		}
		c := NewClient(fake, []string{"light", "switch", "climate"})

		got, err := c.FetchAll(context.Background())
		if err != nil {
			t.Fatalf("FetchAll() error = %v", err)
		}
		sort.Slice(got, func(i, j int) bool { return got[i].EntityID < got[j].EntityID })

		want := []struct {
			entityID, friendlyName, domain string
		}{
			{"climate.air_conditioner", "climate.air_conditioner", "climate"}, // no friendly_name attr -> falls back to entity_id
			{"light.living_room", "Living Room Lamp", "light"},
			{"switch.fan", "Fan", "switch"},
		}
		if len(got) != len(want) {
			t.Fatalf("len(got) = %d, want %d (got=%#v)", len(got), len(want), got)
		}
		for i, w := range want {
			if got[i].EntityID != w.entityID || got[i].FriendlyName != w.friendlyName || got[i].Domain != w.domain {
				t.Fatalf("got[%d] = %#v, want {%s %s %s}", i, got[i], w.entityID, w.friendlyName, w.domain)
			}
		}
	})

	t.Run("one domain failing fails the whole fetch", func(t *testing.T) {
		wantErr := errors.New("boom")
		fake := &fakeEntityServiceClient{
			listStatesFunc: func(ctx context.Context, in *hav1.ListStatesRequest) (*hav1.ListStatesResponse, error) {
				if in.GetDomain() == "switch" {
					return nil, wantErr
				}
				return &hav1.ListStatesResponse{}, nil
			},
		}
		c := NewClient(fake, []string{"light", "switch", "climate"})

		got, err := c.FetchAll(context.Background())
		if err == nil {
			t.Fatal("FetchAll() error = nil, want error")
		}
		if !errors.Is(err, wantErr) {
			t.Fatalf("FetchAll() error = %v, want it to wrap %v", err, wantErr)
		}
		if got != nil {
			t.Fatalf("FetchAll() entities = %#v, want nil on partial failure", got)
		}
	})

	t.Run("empty domain list returns empty result", func(t *testing.T) {
		c := NewClient(&fakeEntityServiceClient{}, nil)
		got, err := c.FetchAll(context.Background())
		if err != nil {
			t.Fatalf("FetchAll() error = %v", err)
		}
		if len(got) != 0 {
			t.Fatalf("FetchAll() = %#v, want empty", got)
		}
	})
}