package fetch

import (
	"io/ioutil"
	"net/http"
)

type Savable interface {
	Namespace() string
	Key() string
	Value() []byte
}

type Fetch struct {
	process func([]byte) ([]Savable, error)
	save    func(string, string, []byte) error
	client  *http.Client
}

func New(process func([]byte) ([]Savable, error), save func(string, string, []byte) error) (*Fetch, error) {
	return &Fetch{
		save:    save,
		process: process,
		client:  &http.Client{},
	}, nil
}

func (fetcher *Fetch) FetchProcessSave(url string) error {
	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return err
	}
	resp, err := fetcher.client.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	b, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return err
	}
	items, err := fetcher.process(b)
	if err != nil {
		return err
	}
	for i := range items {
		err := fetcher.save(items[i].Namespace(), items[i].Key(), items[i].Value())
		if err != nil {
			return err
		}
	}
	return nil
}