package app

import (
	"context"
	"strings"
	"sync"

	"gitea.nik4nao.com/nik/home-services/ha-gateway/internal/core/domain"
	"gitea.nik4nao.com/nik/home-services/ha-gateway/internal/core/ports/driven"
)

type LightApp struct {
	ha    driven.HAClient
	mu    sync.RWMutex
	cache []domain.Light
}

// NewLightApp constructs the light application service.
func NewLightApp(ha driven.HAClient) *LightApp {
	return &LightApp{ha: ha}
}

// Refresh repopulates the light cache from the full Home Assistant state list.
func (a *LightApp) Refresh(ctx context.Context) error {
	all, err := a.ha.ListStates(ctx)
	if err != nil {
		return err
	}

	var lights []domain.Light
	for _, s := range all {
		if !strings.HasPrefix(s.EntityID, "light.") {
			continue
		}
		lights = append(lights, haStateToLight(s))
	}

	a.mu.Lock()
	a.cache = lights
	a.mu.Unlock()
	return nil
}

// ListLights returns cached light discovery data, refreshing lazily on first use.
func (a *LightApp) ListLights(ctx context.Context) ([]domain.Light, error) {
	a.mu.RLock()
	c := a.cache
	a.mu.RUnlock()
	if c == nil {
		if err := a.Refresh(ctx); err != nil {
			return nil, err
		}
		a.mu.RLock()
		c = a.cache
		a.mu.RUnlock()
	}
	return c, nil
}

// TurnOn maps application parameters into a Home Assistant light.turn_on call.
func (a *LightApp) TurnOn(ctx context.Context, p domain.TurnOnParams) (*domain.EntityState, error) {
	payload := map[string]any{"entity_id": string(p.EntityID)}
	if p.BrightnessPct != nil {
		payload["brightness_pct"] = *p.BrightnessPct
	}
	if p.ColorTempKelvin != nil {
		payload["color_temp_kelvin"] = *p.ColorTempKelvin
	}
	if p.RGBColor != nil {
		payload["rgb_color"] = []uint8{p.RGBColor.R, p.RGBColor.G, p.RGBColor.B}
	}
	if p.Transition != nil {
		payload["transition"] = *p.Transition
	}
	return a.callService(ctx, "light", "turn_on", payload)
}

// TurnOff maps application parameters into a Home Assistant light.turn_off call.
func (a *LightApp) TurnOff(ctx context.Context, p domain.TurnOffParams) (*domain.EntityState, error) {
	payload := map[string]any{"entity_id": string(p.EntityID)}
	if p.Transition != nil {
		payload["transition"] = *p.Transition
	}
	return a.callService(ctx, "light", "turn_off", payload)
}

// Toggle maps directly to Home Assistant light.toggle.
func (a *LightApp) Toggle(ctx context.Context, id domain.EntityID) (*domain.EntityState, error) {
	payload := map[string]any{"entity_id": string(id)}
	return a.callService(ctx, "light", "toggle", payload)
}

// callService falls back to GetState because Home Assistant may succeed without
// returning a full entity state list for the service call response.
func (a *LightApp) callService(ctx context.Context, svcDomain, service string, payload map[string]any) (*domain.EntityState, error) {
	states, err := a.ha.CallService(ctx, svcDomain, service, payload)
	if err != nil {
		return nil, err
	}
	entityID, _ := payload["entity_id"].(string)
	for _, s := range states {
		if s.EntityID == entityID {
			return haStateToDomain(s), nil
		}
	}
	// HA may return an empty list on success; fall back to GetState.
	s, err := a.ha.GetState(ctx, entityID)
	if err != nil {
		return nil, err
	}
	return haStateToDomain(s), nil
}

// haStateToLight extracts the subset of attributes needed for discovery clients.
func haStateToLight(s *driven.HAState) domain.Light {
	l := domain.Light{
		EntityID: domain.EntityID(s.EntityID),
		State:    s.State,
	}

	if v, ok := s.Attributes["friendly_name"].(string); ok {
		l.FriendlyName = v
	}
	if v, ok := s.Attributes["is_hue_group"].(bool); ok {
		l.IsHueGroup = v
	}
	if v, ok := s.Attributes["min_color_temp_kelvin"].(float64); ok {
		l.MinColorTempKelvin = uint32(v)
	}
	if v, ok := s.Attributes["max_color_temp_kelvin"].(float64); ok {
		l.MaxColorTempKelvin = uint32(v)
	}
	if modes, ok := s.Attributes["supported_color_modes"].([]any); ok {
		for _, m := range modes {
			if ms, ok := m.(string); ok {
				l.SupportedColorModes = append(l.SupportedColorModes, domain.ColorMode(ms))
			}
		}
	}
	if effects, ok := s.Attributes["effect_list"].([]any); ok {
		for _, e := range effects {
			if es, ok := e.(string); ok {
				l.EffectList = append(l.EffectList, es)
			}
		}
	}

	return l
}