From cec830ea500b50e9d38b0d6193b22cd10f577370 Mon Sep 17 00:00:00 2001
From: Martin Czygan <martin.czygan@gmail.com>
Date: Thu, 20 May 2021 11:39:50 +0200
Subject: add slim cdx wrapper

---
 skate/cdx.go | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 skate/cdx.go

diff --git a/skate/cdx.go b/skate/cdx.go
new file mode 100644
index 0000000..c618c97
--- /dev/null
+++ b/skate/cdx.go
@@ -0,0 +1,74 @@
+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
+func LookupCDX(link string) (result []CDX, 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, err
+	}
+	resp, err := pester.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	b, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	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)
+		}
+		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)
+}
-- 
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