package nomad

import (
	"crypto/sha256"
	"fmt"
	"io/ioutil"
	"net/http"

	"github.com/anaskhan96/soup"
)

// Source provides data for the various parsing functions.
type Source interface {
	Fetch() (string, error)
	FetchBytes() ([]byte, error)
	ID() string
	String() string
}

// URLSource fetches data from an HTTP resource.
type URLSource struct {
	url string
}

func (u URLSource) FetchBytes() ([]byte, error) {
	resp, err := http.Get(u.url)
	if err != nil {
		return nil, err
	}

	defer resp.Body.Close()
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	return body, err
}

func (u URLSource) Fetch() (string, error) {
	body, err := u.FetchBytes()
	if err != nil {
		return "", err
	}

	return string(body), nil
}

func (u URLSource) ID() string {
	return u.url
}

func (u URLSource) String() string {
	return u.url
}

func NewURLSource(url string) URLSource {
	return URLSource{url: url}
}

type StringSource struct {
	s string
}

func (s StringSource) Fetch() (string, error) {
	return s.String(), nil
}

func (s StringSource) FetchBytes() ([]byte, error) {
	return []byte(s.s), nil
}

func NewStringSource(s string) *StringSource {
	return &StringSource{s: s}
}

func (s StringSource) ID() string {
	h := sha256.Sum256([]byte(s.s))
	return fmt.Sprintf("%s", h[:])
}

func (s StringSource) String() string {
	return s.s
}

// SoupSource uses the soup package to fetch data.
type SoupSource struct {
	url string
}

func (s SoupSource) Fetch() (string, error) {
	return soup.Get(s.url)
}

func (s SoupSource) FetchBytes() ([]byte, error) {
	body, err := s.Fetch()
	if err != nil {
		return nil, err
	}

	return []byte(body), nil
}

func (s SoupSource) ID() string {
	return s.url
}

func (s SoupSource) String() string {
	return s.url
}

func NewSoupSource(url string) SoupSource {
	return SoupSource{url: url}
}