package directive

import (
	"context"
	"errors"
	"io"
	"log/slog"
	"testing"

	"gitea.nik4nao.com/nik/home-services/alexa-bridge/internal/alexa"
	"gitea.nik4nao.com/nik/home-services/alexa-bridge/internal/core/domain"
)

func discardLogger() *slog.Logger {
	return slog.New(slog.NewTextHandler(io.Discard, nil))
}

type fakeResolver struct {
	entities map[string]domain.Entity
}

func (f *fakeResolver) Resolve(friendlyName string) (domain.Entity, bool) {
	e, ok := f.entities[friendlyName]
	return e, ok
}

type fakeController struct {
	executeFunc func(ctx context.Context, entityID, action string, params map[string]any) error
	gotEntityID string
	gotAction   string
	gotParams   map[string]any
}

func (f *fakeController) ExecuteAction(ctx context.Context, entityID, action string, params map[string]any) error {
	f.gotEntityID = entityID
	f.gotAction = action
	f.gotParams = params
	if f.executeFunc == nil {
		return nil
	}
	return f.executeFunc(ctx, entityID, action, params)
}

func intentRequest(intentName string, slots map[string]alexa.Slot) alexa.Request {
	return alexa.Request{
		Version: "1.0",
		Request: alexa.RequestBody{
			Type: "IntentRequest",
			Intent: &alexa.Intent{
				Name:  intentName,
				Slots: slots,
			},
		},
	}
}

func TestRouterDispatchLaunchAndSessionEnded(t *testing.T) {
	r := NewRouter(&fakeResolver{}, &fakeController{}, discardLogger())

	t.Run("LaunchRequest keeps the session open", func(t *testing.T) {
		resp, err := r.Dispatch(context.Background(), alexa.Request{Request: alexa.RequestBody{Type: "LaunchRequest"}})
		if err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if resp.Response.ShouldEndSession {
			t.Fatal("LaunchRequest should not end the session")
		}
	})

	t.Run("SessionEndedRequest returns an empty response", func(t *testing.T) {
		resp, err := r.Dispatch(context.Background(), alexa.Request{Request: alexa.RequestBody{Type: "SessionEndedRequest"}})
		if err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if resp.Version != "1.0" {
			t.Fatalf("Version = %q, want %q", resp.Version, "1.0")
		}
	})

	t.Run("unrecognized request type does not error", func(t *testing.T) {
		resp, err := r.Dispatch(context.Background(), alexa.Request{Request: alexa.RequestBody{Type: "SomethingElse"}})
		if err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if resp.Response.OutputSpeech == nil {
			t.Fatal("expected a spoken fallback response")
		}
	})
}

func TestRouterDispatchBuiltinIntents(t *testing.T) {
	r := NewRouter(&fakeResolver{}, &fakeController{}, discardLogger())

	tests := []string{"AMAZON.HelpIntent", "AMAZON.StopIntent", "AMAZON.CancelIntent"}
	for _, name := range tests {
		t.Run(name, func(t *testing.T) {
			resp, err := r.Dispatch(context.Background(), intentRequest(name, nil))
			if err != nil {
				t.Fatalf("Dispatch() error = %v", err)
			}
			if resp.Response.OutputSpeech == nil || resp.Response.OutputSpeech.Text == "" {
				t.Fatal("expected spoken output")
			}
		})
	}

	t.Run("unrecognized intent", func(t *testing.T) {
		resp, err := r.Dispatch(context.Background(), intentRequest("NoSuchIntent", nil))
		if err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if resp.Response.OutputSpeech == nil {
			t.Fatal("expected a spoken fallback response")
		}
	})
}

func TestRouterDispatchDeviceActions(t *testing.T) {
	entity := domain.Entity{EntityID: "light.living_room", FriendlyName: "Living Room Lamp", Domain: "light"}
	resolver := &fakeResolver{entities: map[string]domain.Entity{"living room lamp": entity}}

	t.Run("TurnOnIntent resolves device and executes turn_on with no params", func(t *testing.T) {
		ctrl := &fakeController{}
		r := NewRouter(resolver, ctrl, discardLogger())

		req := intentRequest("TurnOnIntent", map[string]alexa.Slot{"Device": {Name: "Device", Value: "living room lamp"}})
		resp, err := r.Dispatch(context.Background(), req)
		if err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if ctrl.gotEntityID != "light.living_room" || ctrl.gotAction != "turn_on" {
			t.Fatalf("ExecuteAction called with (%q, %q), want (light.living_room, turn_on)", ctrl.gotEntityID, ctrl.gotAction)
		}
		if ctrl.gotParams != nil {
			t.Fatalf("params = %#v, want nil", ctrl.gotParams)
		}
		if !resp.Response.ShouldEndSession {
			t.Fatal("a completed action should end the session")
		}
	})

	t.Run("SetBrightnessIntent forwards the Brightness slot as brightness_pct", func(t *testing.T) {
		ctrl := &fakeController{}
		r := NewRouter(resolver, ctrl, discardLogger())

		req := intentRequest("SetBrightnessIntent", map[string]alexa.Slot{
			"Device":     {Name: "Device", Value: "living room lamp"},
			"Brightness": {Name: "Brightness", Value: "50"},
		})
		if _, err := r.Dispatch(context.Background(), req); err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if ctrl.gotAction != "set_brightness" || ctrl.gotParams["brightness_pct"] != "50" {
			t.Fatalf("action/params = %q/%#v, want set_brightness/{brightness_pct:50}", ctrl.gotAction, ctrl.gotParams)
		}
	})

	t.Run("SetTemperatureIntent forwards the Temperature slot as target_temperature", func(t *testing.T) {
		climateEntity := domain.Entity{EntityID: "climate.air_conditioner", FriendlyName: "Air Conditioner", Domain: "climate"}
		climateResolver := &fakeResolver{entities: map[string]domain.Entity{"air conditioner": climateEntity}}
		ctrl := &fakeController{}
		r := NewRouter(climateResolver, ctrl, discardLogger())

		req := intentRequest("SetTemperatureIntent", map[string]alexa.Slot{
			"Device":      {Name: "Device", Value: "air conditioner"},
			"Temperature": {Name: "Temperature", Value: "23.5"},
		})
		if _, err := r.Dispatch(context.Background(), req); err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if ctrl.gotEntityID != "climate.air_conditioner" || ctrl.gotAction != "set_temperature" {
			t.Fatalf("entity/action = %q/%q, want climate.air_conditioner/set_temperature", ctrl.gotEntityID, ctrl.gotAction)
		}
		if ctrl.gotParams["target_temperature"] != "23.5" {
			t.Fatalf("params = %#v, want target_temperature=23.5", ctrl.gotParams)
		}
	})

	t.Run("SetColorIntent forwards Red/Green/Blue slots as an rgb_color map", func(t *testing.T) {
		ctrl := &fakeController{}
		r := NewRouter(resolver, ctrl, discardLogger())

		req := intentRequest("SetColorIntent", map[string]alexa.Slot{
			"Device": {Name: "Device", Value: "living room lamp"},
			"Red":    {Name: "Red", Value: "255"},
			"Green":  {Name: "Green", Value: "0"},
			"Blue":   {Name: "Blue", Value: "0"},
		})
		if _, err := r.Dispatch(context.Background(), req); err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		rgb, ok := ctrl.gotParams["rgb_color"].(map[string]any)
		if !ok || rgb["r"] != "255" {
			t.Fatalf("rgb_color = %#v, want map with r=255", ctrl.gotParams["rgb_color"])
		}
	})

	t.Run("missing Device slot does not call the controller", func(t *testing.T) {
		ctrl := &fakeController{}
		r := NewRouter(resolver, ctrl, discardLogger())

		req := intentRequest("TurnOnIntent", nil)
		resp, err := r.Dispatch(context.Background(), req)
		if err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if ctrl.gotAction != "" {
			t.Fatal("controller should not be called without a Device slot")
		}
		if resp.Response.OutputSpeech == nil {
			t.Fatal("expected a spoken response explaining the missing device")
		}
	})

	t.Run("unresolvable device does not call the controller", func(t *testing.T) {
		ctrl := &fakeController{}
		r := NewRouter(resolver, ctrl, discardLogger())

		req := intentRequest("TurnOnIntent", map[string]alexa.Slot{"Device": {Name: "Device", Value: "nonexistent"}})
		resp, err := r.Dispatch(context.Background(), req)
		if err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if ctrl.gotAction != "" {
			t.Fatal("controller should not be called for an unresolvable device")
		}
		if resp.Response.OutputSpeech == nil {
			t.Fatal("expected a spoken response explaining the device wasn't found")
		}
	})

	t.Run("missing required action slot does not call the controller", func(t *testing.T) {
		ctrl := &fakeController{}
		r := NewRouter(resolver, ctrl, discardLogger())

		req := intentRequest("SetBrightnessIntent", map[string]alexa.Slot{"Device": {Name: "Device", Value: "living room lamp"}})
		resp, err := r.Dispatch(context.Background(), req)
		if err != nil {
			t.Fatalf("Dispatch() error = %v", err)
		}
		if ctrl.gotAction != "" {
			t.Fatal("controller should not be called when a required param slot is missing")
		}
		if resp.Response.OutputSpeech == nil {
			t.Fatal("expected a spoken response explaining the request wasn't understood")
		}
	})

	t.Run("controller error is turned into a spoken failure, not a Dispatch error", func(t *testing.T) {
		ctrl := &fakeController{executeFunc: func(ctx context.Context, entityID, action string, params map[string]any) error {
			return errors.New("ha-gateway unreachable")
		}}
		r := NewRouter(resolver, ctrl, discardLogger())

		req := intentRequest("TurnOnIntent", map[string]alexa.Slot{"Device": {Name: "Device", Value: "living room lamp"}})
		resp, err := r.Dispatch(context.Background(), req)
		if err != nil {
			t.Fatalf("Dispatch() error = %v, want nil (errors should be spoken, not propagated)", err)
		}
		if resp.Response.OutputSpeech == nil {
			t.Fatal("expected a spoken failure response")
		}
	})
}