package haclient

import (
	"fmt"
	"strconv"

	hav1 "gitea.nik4nao.com/nik/home-services/gen/ha/v1"
)

// optUint32 returns nil when key is absent. A present-but-unparsable value is
// treated as absent rather than failing the whole action — brightness/
// color-temp/transition are optional TurnOn/TurnOff fields, so a bad value
// there shouldn't block the rest of the request.
func optUint32(params map[string]any, key string) *uint32 {
	v, ok := params[key]
	if !ok {
		return nil
	}
	n, err := toUint32(v)
	if err != nil {
		return nil
	}
	return &n
}

func reqUint32(params map[string]any, key string) (uint32, error) {
	v, ok := params[key]
	if !ok {
		return 0, fmt.Errorf("missing required param %q", key)
	}
	return toUint32(v)
}

func reqFloat64(params map[string]any, key string) (float64, error) {
	v, ok := params[key]
	if !ok {
		return 0, fmt.Errorf("missing required param %q", key)
	}
	return toFloat64(v)
}

func reqString(params map[string]any, key string) (string, error) {
	v, ok := params[key]
	if !ok {
		return "", fmt.Errorf("missing required param %q", key)
	}
	s, ok := v.(string)
	if !ok {
		return "", fmt.Errorf("param %q = %v (%T), want string", key, v, v)
	}
	return s, nil
}

// optRGB mirrors optUint32's absent-or-unparsable-means-nil contract.
func optRGB(params map[string]any, key string) *hav1.RGBColor {
	rgb, err := parseRGB(params, key)
	if err != nil {
		return nil
	}
	return rgb
}

func reqRGB(params map[string]any, key string) (*hav1.RGBColor, error) {
	rgb, err := parseRGB(params, key)
	if err != nil {
		return nil, err
	}
	if rgb == nil {
		return nil, fmt.Errorf("missing required param %q", key)
	}
	return rgb, nil
}

func parseRGB(params map[string]any, key string) (*hav1.RGBColor, error) {
	v, ok := params[key]
	if !ok {
		return nil, nil
	}
	m, ok := v.(map[string]any)
	if !ok {
		return nil, fmt.Errorf("param %q = %v (%T), want map with r/g/b", key, v, v)
	}
	r, err := toUint32(m["r"])
	if err != nil {
		return nil, fmt.Errorf("param %q.r: %w", key, err)
	}
	g, err := toUint32(m["g"])
	if err != nil {
		return nil, fmt.Errorf("param %q.g: %w", key, err)
	}
	b, err := toUint32(m["b"])
	if err != nil {
		return nil, fmt.Errorf("param %q.b: %w", key, err)
	}
	return &hav1.RGBColor{R: r, G: g, B: b}, nil
}

// toUint32/toFloat64 primarily parse strings, since params values arriving
// from Alexa slots (via internal/directive) are always strings — even
// AMAZON.NUMBER slots decode to their literal spoken-number string, e.g.
// "80". The float64/int fallback exists only so tests (or a hypothetical
// future non-Alexa caller) can pass typed values directly; it isn't
// exercised on the real Alexa -> directive -> haclient path.
func toUint32(v any) (uint32, error) {
	switch t := v.(type) {
	case string:
		n, err := strconv.ParseUint(t, 10, 32)
		if err != nil {
			return 0, fmt.Errorf("parse uint32 %q: %w", t, err)
		}
		return uint32(n), nil
	case float64:
		return uint32(t), nil
	case int:
		return uint32(t), nil
	case uint32:
		return t, nil
	default:
		return 0, fmt.Errorf("value %v (%T) is not a uint32-compatible type", v, v)
	}
}

func toFloat64(v any) (float64, error) {
	switch t := v.(type) {
	case string:
		n, err := strconv.ParseFloat(t, 64)
		if err != nil {
			return 0, fmt.Errorf("parse float64 %q: %w", t, err)
		}
		return n, nil
	case float64:
		return t, nil
	case int:
		return float64(t), nil
	default:
		return 0, fmt.Errorf("value %v (%T) is not a float64-compatible type", v, v)
	}
}