implemented basic templating and default settings

internal/build/build_page.go

@@ -0,0 +1,112 @@
+package build
+
+import (
+	"bytes"
+	"fmt"
+	"html/template"
+	"path/filepath"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+type PageData struct {
+	Title      string
+	Icon       string
+	Stylesheet string
+	Header     string
+	Content    template.HTML
+	NextPost   string
+	PrevPost   string
+	Footer     string
+}
+
+type Metadata map[string]interface{}
+
+func processWithYaml(f []byte) (Metadata, []byte, error) {
+	// Check if the file has valid metadata
+	if !bytes.HasPrefix(f, []byte("---\n")) {
+		// No valid yaml, so return the entire content
+		return nil, f, nil
+	}
+	// Separate YAML from rest of document
+	split := strings.SplitN(string(f), "---\n", 3)
+	if len(split) < 3 {
+		return nil, nil, fmt.Errorf("Invalid frontmatter format.")
+	}
+	var meta Metadata
+	// Parse YAML
+	if err := yaml.Unmarshal([]byte(split[1]), &meta); err != nil {
+		return nil, nil, err
+	}
+	return meta, []byte(split[2]), nil
+}
+
+// this function converts a file path to its title form
+func pathToTitle(path string) string {
+	stripped := ChangeExtension(filepath.Base(path), "")
+	replaced := strings.NewReplacer("-", " ", "_", " ", `\ `, " ").Replace(stripped)
+	return strings.ToTitle(replaced)
+}
+
+func buildPageData(m Metadata, path string) *PageData {
+	p := &PageData{}
+	if title, ok := m["title"].(string); ok {
+		p.Title = title
+	} else {
+		p.Title = pathToTitle(path)
+	}
+	if icon, ok := m["icon"].(string); ok {
+		p.Icon = icon
+	} else {
+		p.Icon = DefaultIcon
+	}
+	if style, ok := m["style"].(string); ok {
+		p.Stylesheet = style
+	} else {
+		p.Stylesheet = DefaultStylesheet
+	}
+	if header, ok := m["header"].(string); ok {
+		p.Header = header
+	} else {
+		p.Header = DefaultHeader
+	}
+	if footer, ok := m["footer"].(string); ok {
+		p.Footer = footer
+	} else {
+		p.Footer = DefaultFooter
+	}
+	return p
+}
+
+func ConvertFile(in string, out string) error {
+	mdPre, err := ReadFile(in)
+	if err != nil {
+		return err
+	}
+	metadata, md, err := processWithYaml(mdPre)
+	if err != nil {
+		return err
+	}
+	pd := buildPageData(metadata, in)
+
+	// build according to template here
+	html, err := MdToHTML(md)
+	if err != nil {
+		return err
+	}
+	pd.Content = template.HTML(html)
+
+	tmpl, err := template.New("webpage").Parse(DefaultTemplate)
+	if err != nil {
+		return err
+	}
+
+	var output bytes.Buffer
+	if err := tmpl.Execute(&output, pd); err != nil {
+		return err
+	}
+
+	err = WriteFile(output.Bytes(), out)
+	return err
+}