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Markdown to Hugo converter
package main
import (
"bytes"
"errors"
"flag"
"fmt"
"io/ioutil"
"log"
"os"
"path/filepath"
"regexp"
"strconv"
"strings"
"time"
"github.com/BurntSushi/toml"
)
type header struct {
Author string `toml:"author"`
Comments bool `toml:"comments"`
Date time.Time `toml:"date"`
Title string `toml:"title"`
Slug string `toml:"slug"`
Tags []string `toml:"tags"`
URL string `toml:"url"`
// if true, the content will not be rendered
Draft bool `toml:"draft"`
// user_defined
FeaturedImage string `toml:"featured_image"`
Description string `toml:"description"`
}
type extraction struct {
imagePath string
oldPath string
newPath string
index int
caption string
}
func main() {
if err := realMain(); err != nil {
log.Fatalln(err)
}
}
func realMain() error {
var (
flagDir = flag.String("dir", "", "Directory to parse. By default it looks into the current dir")
flagFile = flag.String("file", "index.md", "File to parse inside the directory.")
)
flag.Parse()
if *flagDir == "" {
return errors.New("-dir needs to be specified")
}
srcDir := *flagDir
dstDir, err := os.Getwd()
if err != nil {
return err
}
files, err := ioutil.ReadDir(srcDir)
if err != nil {
return err
}
re := regexp.MustCompile(`!\[(.*?)\]\((.*?)\)`)
// search for index file in the dir
fileName := ""
for _, f := range files {
if f.Name() != *flagFile {
continue
}
fileName = filepath.Join(srcDir, f.Name())
}
if fileName == "" {
return fmt.Errorf("couldn't find markdown file to parse: %q", *flagFile)
}
out, err := ioutil.ReadFile(fileName)
if err != nil {
return err
}
content := strings.Split(string(out), "\n")
extracted := []extraction{}
// extract and validate data
title := ""
count := 0
for i, line := range content {
// get the tile and convert it to foo_bar to be used for image renames
if title == "" && strings.HasPrefix(line, "# ") {
title = strings.TrimSpace(strings.TrimPrefix(line, "#"))
}
if i == 0 {
if title == "" {
return fmt.Errorf("can't continue without a title. Have this on the first line: %q", line)
} else {
// remove the title as hugo creates it's own
content[i] = ""
}
}
splitted := re.FindStringSubmatch(line)
if len(splitted) == 0 {
continue
}
if len(splitted) != 3 {
return fmt.Errorf("regex should return three matches, have: %+v", splitted)
}
count++
caption := splitted[1]
image := splitted[2]
if image == "" {
return fmt.Errorf("an image tag without an url detected: %q", line)
}
oldPath := filepath.Join(srcDir, image)
ext := filepath.Ext(image)
if ext == "" {
return fmt.Errorf("found image without an extension: %q", line)
}
newImage := fmt.Sprintf("%s-%s%s", join(title, "-"), strconv.Itoa(count), ext)
newPath := filepath.Join(dstDir, "static", "images", newImage)
extracted = append(extracted, extraction{
index: i,
imagePath: filepath.Join("/images", newImage),
oldPath: oldPath,
newPath: newPath,
caption: caption,
})
}
now := time.Now().UTC()
slug := join(title, "-")
newName := fmt.Sprintf("%d-%d-%d-%s.markdown", now.Year(), now.Month(), now.Day(), slug)
newFile := filepath.Join(dstDir, "content", "posts", "arslan.io", newName)
// decode the front matter if it's exists already
hdr := header{}
output, err := ioutil.ReadFile(newFile)
if err == nil {
splitted := strings.Split(string(output), "+++\n")
if _, err := toml.Decode(splitted[1], &hdr); err != nil {
return err
}
} else {
hdr = header{
Author: "Fatih Arslan",
Comments: true,
Date: now,
Title: title,
Slug: slug,
Draft: false,
FeaturedImage: extracted[0].imagePath,
URL: fmt.Sprintf("/%d/%d/%d/%s/",
now.Year(), now.Month(), now.Day(), slug),
}
}
buf := new(bytes.Buffer)
if err := toml.NewEncoder(buf).Encode(hdr); err != nil {
log.Fatal(err)
}
frontMatter := "+++\n" + buf.String() + "+++\n"
fmt.Println("Front Matter generated in TOML:")
fmt.Println(frontMatter)
fmt.Printf("Found %d images to be renamed and converted to shortcode\n", len(extracted))
for _, ex := range extracted {
finalLine := fmt.Sprintf(`{{< figure src="%s" >}}`, ex.imagePath)
if ex.caption != "" {
finalLine = fmt.Sprintf(`{{< figure src="%s" caption="%s" >}}`,
ex.imagePath, ex.caption)
}
if err := os.Rename(ex.oldPath, ex.newPath); err != nil {
return err
}
content[ex.index] = finalLine
}
final := frontMatter + strings.Join(content, "\n")
err = ioutil.WriteFile(fileName, []byte(final), 0644)
if err != nil {
return err
}
if err := os.Rename(fileName, newFile); err != nil {
return err
}
fmt.Println("Done!")
return nil
}
func join(path, sep string) string {
splitted := strings.Split(path, " ")
for i, s := range splitted {
splitted[i] = strings.ToLower(s)
}
return strings.Join(splitted, sep)
}
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