add parser for blog articles

Signed-off-by: Tobias Erbshäußer <tobias@tesoft.dev>
2026-05-24 09:22:16 +02:00
parent 5147b61c9d
commit 333211d4d0
5 changed files with 427 additions and 0 deletions
@@ -0,0 +1,151 @@
+package main
+
+import (
+	"archive/tar"
+	"backend/md"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type ArticleStatus = int
+
+const (
+	ArticleStatusDraft ArticleStatus = iota
+	ArticleStatusPublished
+	ArticleStatusOffline
+)
+
+type ArticleProperties struct {
+	Id               int64         `json:"id"`
+	Title            string        `json:"title"`
+	Status           ArticleStatus `json:"status"`
+	Tags             []string      `json:"tags"`
+	ReleaseDate      time.Time     `json:"date"`
+	ModificationDate *time.Time    `json:"mod-date"`
+}
+
+type Article struct {
+	ArticleProperties
+	Content string
+	Files   []ArticleFile
+}
+
+type ArticleFile struct {
+	Id   int
+	Data []byte
+}
+
+func ParseArticle(reader io.Reader, filePrefix string) (*Article, error) {
+	tarFiles := make(map[string][]byte)
+	tarReader := tar.NewReader(reader)
+	for {
+		header, err := tarReader.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+
+		content, err := io.ReadAll(tarReader)
+		if err != nil {
+			return nil, err
+		}
+		tarFiles[header.Name] = content
+	}
+
+	readmeBytes, found := tarFiles["README.md"]
+	if !found {
+		return nil, errors.New("README.md not found")
+	}
+
+	usedFiles := make(map[string]ArticleFile)
+	nextFileId := 0
+
+	pc, html, err := md.Parse(func(path string) (string, error) {
+		content, ok := tarFiles[strings.TrimPrefix(path, "./")]
+		if !ok {
+			return "", errors.New("file '" + path + "' not found")
+		}
+
+		usedFiles[path] = ArticleFile{nextFileId, content}
+		nextFileId++
+
+		return filePrefix + strconv.Itoa(nextFileId), nil
+	}, readmeBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	title, err := md.GetProperty(pc, "title")
+	if err != nil {
+		if errors.Is(err, md.PropertyNotFoundError) {
+			return nil, errors.New("title property not found")
+		}
+
+		return nil, err
+	}
+
+	tagsStr, err := md.GetProperty(pc, "tags")
+	if err != nil && !errors.Is(err, md.PropertyNotFoundError) {
+		return nil, err
+	}
+
+	tags := make([]string, 0)
+	if strings.TrimSpace(tagsStr) != "" {
+		for _, tagStr := range strings.Split(tagsStr, ",") {
+			tags = append(tags, strings.TrimSpace(tagStr))
+		}
+	}
+
+	dateStr, err := md.GetProperty(pc, "date")
+	if err != nil {
+		if errors.Is(err, md.PropertyNotFoundError) {
+			return nil, errors.New("date property not found")
+		}
+
+		return nil, err
+	}
+	releaseDate, err := time.Parse(time.DateOnly, dateStr)
+	if err != nil {
+		return nil, fmt.Errorf("invalid date property '%s': %v", dateStr, err)
+	}
+
+	var modificationDate *time.Time
+	dateStr, err = md.GetProperty(pc, "mod-date")
+	if err == nil {
+		tmp, err := time.Parse(time.DateOnly, dateStr)
+		if err != nil {
+			return nil, fmt.Errorf("invalid mod-date property '%s': %v", dateStr, err)
+		}
+
+		modificationDate = &tmp
+	} else if !errors.Is(err, md.PropertyNotFoundError) {
+		return nil, err
+	}
+
+	files := make([]ArticleFile, 0, len(usedFiles))
+	for _, file := range usedFiles {
+		files = append(files, file)
+	}
+
+	return &Article{
+		ArticleProperties{
+			-1,
+			title,
+			ArticleStatusDraft,
+			tags,
+			releaseDate,
+			modificationDate,
+		},
+		string(html),
+		files,
+	}, nil
+}