package skate

import (
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"strings"

	"github.com/sethgrid/pester"
)

const cdxApi = "http://web.archive.org/cdx/search/cdx"

// CDX line, might add more fields later.
type CDX struct {
	Surt        string
	Date        string
	Link        string
	ContentType string
	StatusCode  string
	Checksum    string
	Size        string
}

// LookupCDX asks CDX API. Result will be like:
// net,ijmse)/uploadfile/2016/1214/20161214052559646.pdf 20170516210333
// http://www.ijmse.net:80/uploadfile/2016/1214/20161214052559646.pdf
// application/pdf 200 PBPHE2OILTB43TAOUO33GBWLE2SS4LQX 2079755
//
// Also returns the raw response body.
func LookupCDX(link string) (result []CDX, b []byte, err error) {
	link = prependSchema(link)
	cdxlink := fmt.Sprintf("%s?url=%s", cdxApi, link)
	log.Printf("[lookup] %s", cdxlink)
	req, err := http.NewRequest("GET", cdxlink, nil)
	if err != nil {
		return nil, b, err
	}
	resp, err := pester.Do(req)
	if err != nil {
		return nil, b, err
	}
	defer resp.Body.Close()
	b, err = ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, b, err
	}
	result, err = ParseCDX(b)
	return result, b, err
}

func ParseCDX(b []byte) (result []CDX, err error) {
	for _, line := range strings.Split(string(b), "\n") {
		var fields = strings.Fields(line)
		if len(fields) == 0 {
			continue
		}
		if len(fields) < 7 {
			log.Printf("short line: %s", line)
			continue
		}
		cdx := CDX{
			Surt:        fields[0],
			Date:        fields[1],
			Link:        fields[2],
			ContentType: fields[3],
			StatusCode:  fields[4],
			Checksum:    fields[5],
			Size:        fields[6],
		}
		result = append(result, cdx)
	}
	return result, nil
}

func prependSchema(s string) string {
	if strings.HasPrefix(s, "http") {
		return s
	}
	return fmt.Sprintf("http://%s", s)
}