package config

import (
	"errors"
	"os"
	"time"

	"gopkg.in/yaml.v3"
)

// Config holds the application configuration
type Config struct {
	Yandex  YandexConfig  `yaml:"yandex"`
	Artists []Artist      `yaml:"artists"`
	Storage StorageConfig `yaml:"storage"`
	Monitor MonitorConfig `yaml:"monitor"`
	Debug   bool          `yaml:"debug"`
}

// YandexConfig holds Yandex Music API credentials
type YandexConfig struct {
	Token    string `yaml:"token"`
	Username string `yaml:"username"`
	Password string `yaml:"password"`
}

// Artist represents an artist to monitor
type Artist struct {
	ID int `yaml:"id"`
}

// StorageConfig holds storage settings
type StorageConfig struct {
	Path     string `yaml:"path"`
	Organize bool   `yaml:"organize"`
}

// MonitorConfig holds monitor settings
type MonitorConfig struct {
	Interval string `yaml:"interval"`
}

// Load loads configuration from a YAML file
func Load(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}

	var cfg Config
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, err
	}

	if err := cfg.Validate(); err != nil {
		return nil, err
	}

	return &cfg, nil
}

// Validate validates the configuration
func (c *Config) Validate() error {
	if len(c.Artists) == 0 {
		return errors.New("at least one artist must be configured")
	}

	for _, a := range c.Artists {
		if a.ID <= 0 {
			return errors.New("artist ID must be positive")
		}
	}

	if c.Storage.Path == "" {
		return errors.New("storage path is required")
	}

	if c.Yandex.Token == "" && (c.Yandex.Username == "" || c.Yandex.Password == "") {
		return errors.New("either yandex.token or yandex.username/password must be provided")
	}

	if _, err := time.ParseDuration(c.Monitor.Interval); err != nil {
		return errors.New("monitor.interval must be a valid duration (e.g., 24h, 1h, 7d)")
	}

	return nil
}

// GetMonitorInterval returns the parsed monitor interval
func (c *Config) GetMonitorInterval() (time.Duration, error) {
	return time.ParseDuration(c.Monitor.Interval)
}