From c1791c8d2b038f4f6abdf49c5585684da41aa12b Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 26 Feb 2023 22:09:07 +0530
Subject: [PATCH] Function to load theme code

---
 tools/themes/collection.go      | 51 +++++++++++++++++++++++----------
 tools/themes/collection_test.go | 18 ++++++++++++
 2 files changed, 54 insertions(+), 15 deletions(-)

diff --git a/tools/themes/collection.go b/tools/themes/collection.go
index 3eedf61f7..4dcd4eb0b 100644
--- a/tools/themes/collection.go
+++ b/tools/themes/collection.go
@@ -215,6 +215,23 @@ type Theme struct {
 	is_user_defined bool
 }
 
+func (self *Theme) Code() (string, error) {
+	if self.zip_reader != nil {
+		f, err := self.zip_reader.Open()
+		self.zip_reader = nil
+		if err != nil {
+			return "", err
+		}
+		defer f.Close()
+		data, err := io.ReadAll(f)
+		if err != nil {
+			return "", err
+		}
+		self.code = utils.UnsafeBytesToString(data)
+	}
+	return self.code, nil
+}
+
 type Themes struct {
 	name_map  map[string]*Theme
 	index_map []string
@@ -255,10 +272,10 @@ func (self *Themes) add_from_dir(dirpath string) error {
 	return nil
 }
 
-func (self *Themes) add_from_zip_file(zippath string) error {
+func (self *Themes) add_from_zip_file(zippath string) (io.Closer, error) {
 	r, err := zip.OpenReader(zippath)
 	if err != nil {
-		return err
+		return nil, err
 	}
 	name_map := make(map[string]*zip.File, len(r.File))
 	var themes []ThemeMetadata
@@ -269,21 +286,21 @@ func (self *Themes) add_from_zip_file(zippath string) error {
 			theme_dir = path.Dir(file.Name)
 			fr, err := file.Open()
 			if err != nil {
-				return fmt.Errorf("Error while opening %s from the ZIP file: %w", file.Name, err)
+				return nil, fmt.Errorf("Error while opening %s from the ZIP file: %w", file.Name, err)
 			}
 			defer fr.Close()
 			raw, err := io.ReadAll(fr)
 			if err != nil {
-				return fmt.Errorf("Error while reading %s from the ZIP file: %w", file.Name, err)
+				return nil, fmt.Errorf("Error while reading %s from the ZIP file: %w", file.Name, err)
 			}
 			err = json.Unmarshal(raw, &themes)
 			if err != nil {
-				return fmt.Errorf("Error while decoding %s: %w", file.Name, err)
+				return nil, fmt.Errorf("Error while decoding %s: %w", file.Name, err)
 			}
 		}
 	}
 	if theme_dir == "" {
-		return fmt.Errorf("No themes.json found in ZIP file")
+		return nil, fmt.Errorf("No themes.json found in ZIP file")
 	}
 	for _, theme := range themes {
 		key := path.Join(theme_dir, theme.Filepath)
@@ -293,25 +310,29 @@ func (self *Themes) add_from_zip_file(zippath string) error {
 			self.name_map[theme.Name] = &t
 		}
 	}
-	return nil
+	return r, nil
 }
 
-func LoadThemes(cache_age_in_days time.Duration, ignore_no_cache bool) (*Themes, error) {
-	zip_path, err := FetchCached(cache_age_in_days * time.Hour * 24)
-	ans := Themes{name_map: make(map[string]*Theme)}
+func (self *Themes) ThemeByName(name string) *Theme {
+	return self.name_map[name]
+}
+
+func LoadThemes(cache_age time.Duration, ignore_no_cache bool) (ans *Themes, closer io.Closer, err error) {
+	zip_path, err := FetchCached(cache_age)
+	ans = &Themes{name_map: make(map[string]*Theme)}
 	if err != nil {
 		if !errors.Is(err, ErrNoCacheFound) || ignore_no_cache {
-			return nil, err
+			return nil, nil, err
 		}
 	} else {
-		if err = ans.add_from_zip_file(zip_path); err != nil {
-			return nil, err
+		if closer, err = ans.add_from_zip_file(zip_path); err != nil {
+			return nil, nil, err
 		}
 	}
 	if err = ans.add_from_dir(filepath.Join(utils.ConfigDir(), "themes")); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 	ans.index_map = maps.Keys(ans.name_map)
 	ans.index_map = utils.StableSortWithKey(ans.index_map, strings.ToLower)
-	return &ans, nil
+	return ans, closer, nil
 }
diff --git a/tools/themes/collection_test.go b/tools/themes/collection_test.go
index 55f81cf49..db9f8e1de 100644
--- a/tools/themes/collection_test.go
+++ b/tools/themes/collection_test.go
@@ -136,4 +136,22 @@ func TestThemeCollections(t *testing.T) {
 	if after2.ModTime() != after.ModTime() {
 		t.Fatal("Cached zip file was incorrectly not re-downloaded")
 	}
+	coll := Themes{name_map: map[string]*Theme{}}
+	closer, err := coll.add_from_zip_file(filepath.Join(tdir, "test.zip"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer closer.Close()
+	if code, err := coll.ThemeByName("Empty").Code(); code != "empty" {
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Fatal("failed to load code for empty theme")
+	}
+	if code, err := coll.ThemeByName("Alabaster Dark").Code(); code != "alabaster" {
+		if err != nil {
+			t.Fatal(err)
+		}
+		t.Fatal("failed to load code for alabaster theme")
+	}
 }