package server

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

	devicecontrol "git.cactoz.su/cacto/home_automatization/proto/device_control"
)

type fakeShadow struct {
	err     error
	patches []map[string]any
}

func (f *fakeShadow) PatchDesiredState(_ context.Context, _ string, patch map[string]any) error {
	if f.err != nil {
		return f.err
	}
	f.patches = append(f.patches, patch)
	return nil
}

type fakeMQTT struct {
	err     error
	topic   string
	payload []byte
}

func (f *fakeMQTT) Publish(topic string, _ byte, _ bool, payload []byte) error {
	if f.err != nil {
		return f.err
	}
	f.topic = topic
	f.payload = payload
	return nil
}

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

func TestTurnOn_Success(t *testing.T) {
	sh := &fakeShadow{}
	mq := &fakeMQTT{}
	s := New(sh, mq, discardLogger())

	res, err := s.TurnOn(context.Background(), &devicecontrol.TurnOnRequest{DeviceId: "d1"})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if !res.Success {
		t.Fatalf("expected success, got error %q", res.Error)
	}
	if len(sh.patches) != 1 || sh.patches[0]["power"] != "on" {
		t.Fatalf("got desired patches %+v, want [{power: on}]", sh.patches)
	}
	if mq.topic != "devices/d1/commands" {
		t.Fatalf("got topic %q, want devices/d1/commands", mq.topic)
	}
	var payload map[string]any
	if err := json.Unmarshal(mq.payload, &payload); err != nil {
		t.Fatalf("unmarshal published payload: %v", err)
	}
	if payload["action"] != "turn_on" {
		t.Fatalf("got payload %+v, want action=turn_on", payload)
	}
}

func TestSetLevel_Success(t *testing.T) {
	sh := &fakeShadow{}
	mq := &fakeMQTT{}
	s := New(sh, mq, discardLogger())

	res, err := s.SetLevel(context.Background(), &devicecontrol.SetLevelRequest{DeviceId: "d1", Level: 42.5})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if !res.Success {
		t.Fatalf("expected success, got error %q", res.Error)
	}
	if sh.patches[0]["level"] != 42.5 {
		t.Fatalf("got desired patch %+v, want level=42.5", sh.patches[0])
	}
}

func TestDispatch_MissingDeviceID(t *testing.T) {
	s := New(&fakeShadow{}, &fakeMQTT{}, discardLogger())

	res, err := s.TurnOff(context.Background(), &devicecontrol.TurnOffRequest{DeviceId: ""})
	if err != nil {
		t.Fatalf("unexpected transport error: %v", err)
	}
	if res.Success {
		t.Fatal("expected failure for missing device_id")
	}
}

func TestDispatch_ShadowFailure(t *testing.T) {
	s := New(&fakeShadow{err: errors.New("redis down")}, &fakeMQTT{}, discardLogger())

	res, err := s.TurnOn(context.Background(), &devicecontrol.TurnOnRequest{DeviceId: "d1"})
	if err != nil {
		t.Fatalf("unexpected transport error: %v", err)
	}
	if res.Success {
		t.Fatal("expected failure when shadow patch errors")
	}
}

func TestDispatch_PublishFailure(t *testing.T) {
	s := New(&fakeShadow{}, &fakeMQTT{err: errors.New("broker unreachable")}, discardLogger())

	res, err := s.TurnOn(context.Background(), &devicecontrol.TurnOnRequest{DeviceId: "d1"})
	if err != nil {
		t.Fatalf("unexpected transport error: %v", err)
	}
	if res.Success {
		t.Fatal("expected failure when mqtt publish errors")
	}
}