package config

import (
	"io"
	"io/ioutil"

	"github.com/caarlos0/env/v6"
	"github.com/pkg/errors"

	"gopkg.in/yaml.v2"
)

type Config struct {
	HTTP HTTPConfig `yaml:"http"`
	Data DataConfig `ymal:"data"`
}

type HTTPConfig struct {
	Address string `yaml:"address" env:"GUESSTIMATE_HTTP_ADDRESS"`
}

type DataConfig struct {
	Path string `yaml:"path" env:"GUESSTIMATE_DATA_PATH"`
}

// NewFromFile retrieves the configuration from the given file
func NewFromFile(filepath string) (*Config, error) {
	config := NewDefault()

	data, err := ioutil.ReadFile(filepath)
	if err != nil {
		return nil, errors.Wrapf(err, "could not read file '%s'", filepath)
	}

	if err := yaml.Unmarshal(data, config); err != nil {
		return nil, errors.Wrapf(err, "could not unmarshal configuration")
	}

	return config, nil
}

func WithEnvironment(conf *Config) error {
	if err := env.Parse(conf); err != nil {
		return err
	}

	return nil
}

func NewDumpDefault() *Config {
	config := NewDefault()
	return config
}

func NewDefault() *Config {
	return &Config{
		HTTP: HTTPConfig{
			Address: ":8081",
		},
		Data: DataConfig{
			Path: "guesstimate.db",
		},
	}
}

func Dump(config *Config, w io.Writer) error {
	data, err := yaml.Marshal(config)
	if err != nil {
		return errors.Wrap(err, "could not dump config")
	}

	if _, err := w.Write(data); err != nil {
		return err
	}

	return nil
}