package service

import (
	"fmt"
	"os"
	"time"

	"git.server.ky/slackcoder/mirror/internal"
	"github.com/BurntSushi/toml"
)

type Duration struct {
	time.Duration
}

func (s Duration) MarshalText() ([]byte, error) {
	return []byte(s.Duration.String()), nil
}

func (s *Duration) UnmarshalText(text []byte) error {
	v, err := time.ParseDuration(string(text))
	if err != nil {
		return err
	}
	*s = Duration{v}

	return nil
}

// Global parameters
type GlobalConfig struct {
	MaxInterval Duration `toml:"max-interval"`
	MinInterval Duration `toml:"min-interval"`
}

type Config struct {
	*GlobalConfig `toml:"global"`
	Mirrors       []*Mirror `toml:"mirrors,omitempty"`
}

func (c *Config) String() string {
	return internal.MustTOML(c)
}

var DefaultConfig = Config{
	GlobalConfig: &GlobalConfig{
		MaxInterval: Duration{24 * time.Hour},
		MinInterval: Duration{time.Hour},
	},
}

func (c *Config) Apply(src Config) {
	if c.MaxInterval.Duration == 0 && src.MaxInterval.Duration != 0 {
		c.MaxInterval = src.MaxInterval
	}
	if c.MinInterval.Duration == 0 && src.MinInterval.Duration != 0 {
		c.MinInterval = src.MinInterval
	}
	if len(c.Mirrors) == 0 {
		c.Mirrors = src.Mirrors
	}
}

// ApplyFileConfig loads the configuration described by the given yaml file.
func ApplyFileConfig(cfg *Config, filePath string) error {
	var ret Config

	f, err := os.Open(filePath)
	if os.IsNotExist(err) {
		return nil
	} else if err != nil {
		return err
	}
	defer f.Close()

	_, err = toml.NewDecoder(f).Decode(&ret)
	if err != nil {
		return fmt.Errorf("loading configuration file: %w", err)
	}

	cfg.Apply(ret)

	return nil
}