From 4756ffad637adedd897ffb17cd4fac84e9571f9e Mon Sep 17 00:00:00 2001
From: Alexander Avery <alex.avery@beetbox.io>
Date: Mon, 19 May 2025 18:27:18 -0400
Subject: [PATCH] first commit for odl

---
 go.mod            |   3 ++
 odl.go            | 102 ++++++++++++++++++++++++++++++++++++++++++++++
 odl_test.go       |  62 ++++++++++++++++++++++++++++
 testdata/somefile |   1 +
 4 files changed, 168 insertions(+)
 create mode 100644 go.mod
 create mode 100644 odl.go
 create mode 100644 odl_test.go
 create mode 100644 testdata/somefile

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..246bcbe
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module gitea.beetbox.io/Alex/odl
+
+go 1.18
diff --git a/odl.go b/odl.go
new file mode 100644
index 0000000..9f77d10
--- /dev/null
+++ b/odl.go
@@ -0,0 +1,102 @@
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strconv"
+)
+
+func main() {
+	flag.Parse()
+
+	var err error
+	f := os.Stdin
+	filename := flag.Arg(0)
+
+	if filename != "-" && filename != "" {
+		f, err = os.Open(filename)
+		if err != nil {
+			log.Fatalf("failed to open file %s: %v", filename, err)
+		}
+	}
+
+	Download(Read(".", f))
+}
+
+type request struct {
+	w   io.Writer
+	url string
+}
+
+func Download(c <-chan request) {
+	dl := func(w io.Writer, url string) error {
+		response, err := http.Get(url)
+		if err != nil {
+			return fmt.Errorf("downloading file %s: %v", url, err)
+		}
+		defer response.Body.Close()
+
+		if response.StatusCode != http.StatusOK {
+			return fmt.Errorf("unexpected status code for %s: %d", url, response.StatusCode)
+		}
+
+		_, err = io.Copy(w, response.Body)
+		return err
+	}
+
+	for r := range c {
+		if err := dl(r.w, r.url); err != nil {
+			log.Println(err)
+		}
+	}
+}
+
+func Read(root string, r io.Reader) <-chan request {
+	scanner := bufio.NewScanner(r)
+
+	var n int
+	var name string
+	c := make(chan request)
+
+	create := func(name, uri string, n int) (io.Writer, error) {
+		var f io.Writer
+
+		u, err := url.Parse(uri)
+		if err != nil {
+			return f, fmt.Errorf("parsing url %s: %v", uri, err)
+		}
+
+		filename := filepath.Join(root, name+strconv.Itoa(n)+filepath.Ext(u.Path))
+		return os.Create(filename)
+	}
+
+	go func() {
+
+		for scanner.Scan() {
+			txt := scanner.Text()
+
+			if name == "" || txt == "" {
+				name = txt
+				n = 0
+				continue
+			}
+
+			f, err := create(name, txt, n)
+			if err != nil {
+				log.Println(err)
+				continue
+			}
+			c <- request{w: f, url: txt}
+			n++
+		}
+		close(c)
+	}()
+	return c
+}
diff --git a/odl_test.go b/odl_test.go
new file mode 100644
index 0000000..dbe5934
--- /dev/null
+++ b/odl_test.go
@@ -0,0 +1,62 @@
+package main
+
+import (
+	"bytes"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"os"
+	"testing/fstest"
+)
+
+var fs = http.FileServer(http.Dir("./testdata"))
+
+var srv = httptest.NewServer(fs)
+
+func TestDownload(t *testing.T) {
+	var (
+		b bytes.Buffer
+		c = make(chan request)
+	)
+
+	url := srv.URL + "/somefile"
+	t.Logf("file URL: %s", url)
+
+	go func() { c <- request{&b, url}; close(c) }()
+	Download(c)
+
+	want := "somefile inner data"
+	if got := b.String(); got != want {
+		t.Errorf("file buffer received unexpected value\nGot:\n%s\nWant:\n%s", got, want)
+	}
+}
+
+func TestRead(t *testing.T) {
+	input := `boston
+http://localhost/someboston
+http://localhost/anotherboston.mp4
+http://localhost/finalboston.jpg
+
+orlando
+http://localhost/someorlando.jpg
+`
+	dir := t.TempDir()
+	t.Logf("root directory: %s", dir)
+
+	c := Read(dir, strings.NewReader(input))
+	for range c {
+	} // drain the channel
+
+	err := fstest.TestFS(
+		os.DirFS(dir),
+		"boston0",
+		"boston1.mp4",
+		"boston2.jpg",
+		"orlando0.jpg",
+	)
+	
+	if err != nil {
+		t.Fatal(err)
+	}
+}
diff --git a/testdata/somefile b/testdata/somefile
new file mode 100644
index 0000000..39e5b17
--- /dev/null
+++ b/testdata/somefile
@@ -0,0 +1 @@
+somefile inner data
\ No newline at end of file