refactor: move things to packages

internal/changelog/changelog.go

@@ -0,0 +1,54 @@
+package changelog
+
+import (
+	"bytes"
+	_ "embed"
+	"html/template"
+	"log"
+
+	"github.com/apricote/releaser-pleaser/internal/commitparser"
+)
+
+var (
+	changelogTemplate *template.Template
+)
+
+//go:embed changelog.md.tpl
+var rawChangelogTemplate string
+
+func init() {
+	var err error
+	changelogTemplate, err = template.New("changelog").Parse(rawChangelogTemplate)
+	if err != nil {
+		log.Fatalf("failed to parse changelog template: %v", err)
+	}
+}
+
+func NewChangelogEntry(commits []commitparser.AnalyzedCommit, version, link, prefix, suffix string) (string, error) {
+	features := make([]commitparser.AnalyzedCommit, 0)
+	fixes := make([]commitparser.AnalyzedCommit, 0)
+
+	for _, commit := range commits {
+		switch commit.Type {
+		case "feat":
+			features = append(features, commit)
+		case "fix":
+			fixes = append(fixes, commit)
+		}
+	}
+
+	var changelog bytes.Buffer
+	err := changelogTemplate.Execute(&changelog, map[string]any{
+		"Features":    features,
+		"Fixes":       fixes,
+		"Version":     version,
+		"VersionLink": link,
+		"Prefix":      prefix,
+		"Suffix":      suffix,
+	})
+	if err != nil {
+		return "", err
+	}
+
+	return changelog.String(), nil
+}