seperate styles logic

Signed-off-by: Naman Sood <mail@nsood.in>

style.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strings"
+
+	"github.com/wellington/go-libsass"
+)
+
+func newStylesMap() (map[string]string, error) {
+	folder, err := os.ReadDir("styles/")
+	if err != nil {
+		return nil, fmt.Errorf("Could not load styles directory: %s", err)
+	}
+
+	styles := make(map[string]string)
+	for _, s := range folder {
+		contents, filename, err := loadStylesheet(s.Name())
+		if err != nil {
+			return nil, fmt.Errorf("could not generate styles for %s: %v", s.Name(), err)
+		}
+		styles[filename] = contents
+		log.Printf("Loaded stylesheet %s", filename)
+	}
+
+	return styles, nil
+}
+
+func newStylesListener(updateMap func(func(map[string]string))) *listener {
+	ln := &listener{
+		folder: "styles/",
+		update: func(file string) error {
+			contents, filename, err := loadStylesheet(file)
+			if err != nil {
+				return err
+			}
+			updateMap(func(styles map[string]string) {
+				styles[filename] = contents
+			})
+			return nil
+		},
+		clean: func(file string) error {
+			updateMap(func(styles map[string]string) {
+				delete(styles, file+".css")
+			})
+			return nil
+		},
+	}
+	return ln
+}
+
+func loadStylesheet(filename string) (string, string, error) {
+	if strings.HasSuffix(filename, ".scss") {
+		return loadSCSS(filename)
+	}
+	return loadCSS(filename)
+}
+
+func loadSCSS(filename string) (string, string, error) {
+	in, err := os.Open("styles/" + filename)
+	if err != nil {
+		return "", "", fmt.Errorf("Could not open style infile %s: %w", filename, err)
+	}
+	var buf strings.Builder
+	comp, err := libsass.New(&buf, in)
+	if err != nil {
+		return "", "", fmt.Errorf("Could not start sass compiler for file %s: %w", filename, err)
+	}
+	if err = comp.Run(); err != nil {
+		return "", "", fmt.Errorf("Could not generate stylesheet %s: %w", filename, err)
+	}
+	return buf.String(), strings.TrimSuffix(filename, ".scss") + ".css", nil
+}
+
+func loadCSS(filename string) (string, string, error) {
+	in, err := os.Open("styles/" + filename)
+	if err != nil {
+		return "", "", fmt.Errorf("Could not open style infile %s: %w", filename, err)
+	}
+	var buf strings.Builder
+	_, err = io.Copy(&buf, in)
+	if err != nil {
+		return "", "", fmt.Errorf("Could not copy stylesheet %s: %s", filename, err)
+	}
+	return buf.String(), filename, nil
+}