feat(template): add Templating functionality and endpoint

pkg/svg/actions/download.go

@@ -0,0 +1,22 @@
+package actions
+
+import (
+	"bytes"
+	"log"
+
+	"tomatentum.net/svg-templater/pkg/format"
+	"tomatentum.net/svg-templater/pkg/svg"
+)
+
+func ProvideFile(r *TemplateParameters, conversion *format.ConversionParameters) (string, error) {
+	templatedSvgblob, err := Template(r)
+	if err != nil {
+		return "", err
+	}
+	log.Printf("Converting %s to format %s (w=%d,h=%d)", r.Id, conversion.Format, conversion.Width, conversion.Height)
+	result, err := format.ConvertByte(templatedSvgblob, *conversion)
+	if err != nil {
+		return "", err
+	}
+	return svg.Storage.CreatePublic(bytes.NewReader(result), conversion.Format)
+}

pkg/svg/actions/template.go

@@ -0,0 +1,66 @@
+package actions
+
+import (
+	"errors"
+	"io"
+	"log"
+	"maps"
+	"regexp"
+	"slices"
+
+	"github.com/hymkor/exregexp-go"
+	"tomatentum.net/svg-templater/internal/database"
+	"tomatentum.net/svg-templater/pkg/svg"
+)
+
+type TemplateParameters struct {
+	Id   string
+	Keys map[string]string
+}
+
+func Template(r *TemplateParameters) ([]byte, error) {
+	mapkeys := slices.Collect(maps.Keys(r.Keys))
+	ok, err := verifyTemplate(r.Id, mapkeys)
+	if err != nil {
+		return nil, err
+	}
+	if !ok {
+		return nil, errors.New("Template does not exist.")
+	}
+	log.Printf("Replacing keys of %s template\n", r.Id)
+
+	reader, err := svg.Storage.Get(r.Id)
+	if err != nil {
+		return nil, err
+	}
+	defer reader.Close()
+	svgblob, err := io.ReadAll(reader)
+	if err != nil {
+		return nil, err
+	}
+	replaceAll(&svgblob, r.Keys)
+	log.Printf("Finished replacing keys of %s template\n", r.Id)
+	return svgblob, nil
+}
+
+func replaceAll(svgblob *[]byte, keys map[string]string) {
+	regex := regexp.MustCompile(svg.KeyRegex)
+	*svgblob = []byte(exregexp.ReplaceAllStringSubmatchFunc(regex, string(*svgblob), func(s []string) string {
+		log.Printf("Replacing key %s with %s\n", s[1], keys[s[1]])
+		return keys[s[1]]
+	}))
+}
+
+func verifyTemplate(id string, keys []string) (bool, error) {
+	data, err := database.GetSpecificSVG(id)
+	if err != nil {
+		return false, err
+	}
+
+	for _, key := range data.TemplateKeys {
+		if !slices.Contains(keys, key) {
+			return false, nil
+		}
+	}
+	return true, nil
+}