package config

import (
	"fmt"

	"gopkg.in/yaml.v3"
)

// UnmarshalYAML accepts either a scalar ("#7D56F4") applied to both
// appearances, or a mapping ({light: "#...", dark: "#..."}).
func (c *Color) UnmarshalYAML(n *yaml.Node) error {
	switch n.Kind {
	case yaml.ScalarNode:
		var s string
		if err := n.Decode(&s); err != nil {
			return err
		}
		c.Light, c.Dark = s, s
		return nil
	case yaml.MappingNode:
		var pair struct {
			Light string `yaml:"light"`
			Dark  string `yaml:"dark"`
		}
		if err := n.Decode(&pair); err != nil {
			return err
		}
		c.Light, c.Dark = pair.Light, pair.Dark
		return nil
	default:
		return fmt.Errorf("color must be a string or a {light, dark} mapping, got %v", n.Kind)
	}
}

func (c Color) MarshalYAML() (interface{}, error) {
	if c.Light == c.Dark {
		return c.Light, nil
	}
	return map[string]string{"light": c.Light, "dark": c.Dark}, nil
}