From 687ac2a1bcff576ee7cf9095eef0045601b480c5 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

---
 LICENSE           |  10 +++++
 go.mod            |   3 ++
 odl.go            | 102 ++++++++++++++++++++++++++++++++++++++++++++++
 odl_test.go       |  62 ++++++++++++++++++++++++++++
 testdata/somefile |   1 +
 5 files changed, 178 insertions(+)
 create mode 100644 LICENSE
 create mode 100644 go.mod
 create mode 100644 odl.go
 create mode 100644 odl_test.go
 create mode 100644 testdata/somefile

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..80407c5
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,10 @@
+Copyright 2025, Alexander Avery
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
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