gonotes/internal/notes/notes.go

// Notes implements a data structure for reasoning about and rendering
// markdown notes
package notes

import (
	"bytes"
	"encoding/base64"
	"fmt"
	"html/template"
	"log"
	"os"
	"path/filepath"

	"forgejo.gwairfelin.com/max/gonotes/internal/conf"
	"github.com/yuin/goldmark"
	"github.com/yuin/goldmark/extension"
)

// Note is the central data structure.  It can be Saved, Rendered and Loaded
// using the Save, Render and LoadNote functions.
type Note struct {
	Title        string
	BodyRendered template.HTML
	Body         []byte
}

func fmtPath(path string) string {
	return fmt.Sprintf("%s.%s", path, conf.Conf.Extension)
}

// Save a note to a path derived from the title
func (n *Note) Save() error {
	filename := filepath.Join(conf.Conf.NotesDir, fmtPath(n.EncodedTitle()))
	return os.WriteFile(filename, n.Body, 0600)
}

// Render the markdown content of the note to HTML
func (n *Note) Render() {
	var buf bytes.Buffer
	md := goldmark.New(
		goldmark.WithExtensions(
			extension.TaskList,
		),
	)
	err := md.Convert(n.Body, &buf)
	if err != nil {
		log.Fatal(err)
	}

	n.BodyRendered = template.HTML(buf.String())
}

// Load a note from the disk. The path is derived from the title
func LoadNote(encodedTitle string) (*Note, error) {
	filename := filepath.Join(conf.Conf.NotesDir, fmtPath(encodedTitle))
	body, err := os.ReadFile(filename)
	if err != nil {
		return nil, err
	}
	title := DecodeTitle(encodedTitle)
	return &Note{Title: title, Body: body}, nil
}

func DeleteNote(title string) error {
	filename := filepath.Join(conf.Conf.NotesDir, fmtPath(title))
	return os.Remove(filename)
}

func (n *Note) EncodedTitle() string {
	return base64.StdEncoding.EncodeToString([]byte(n.Title))
}

func DecodeTitle(encodedTitle string) string {
	title, err := base64.StdEncoding.DecodeString(encodedTitle)
	if err != nil {
		log.Printf("Couldn't decode base64 string '%s': %s", encodedTitle, err)
	}

	return string(title)
}