diff --git a/blogo/plugin_foldingrenderer.go b/blogo/plugin_foldingrenderer.go new file mode 100644 index 0000000..5991ce8 --- /dev/null +++ b/blogo/plugin_foldingrenderer.go @@ -0,0 +1,146 @@ +// Copyright 2025-present Gustavo "Guz" L. de Mello +// Copyright 2025-present The Lored.dev Contributors +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package blogo + +import ( + "bytes" + "fmt" + "io" + "log/slog" +) + +const foldingRendererPluginName = "blogo-foldingrenderer-renderer" + +type foldingRenderer struct { + plugins []RendererPlugin + + panicOnInit bool + + log *slog.Logger +} + +type FoldingRendererOpts struct { + PanicOnInit bool + + Logger *slog.Logger +} + +type FoldingRenderer interface { + PluginWithPlugins + RendererPlugin +} + +func NewFoldingRenderer(opts ...FoldingRendererOpts) FoldingRenderer { + opt := FoldingRendererOpts{} + if len(opts) > 0 { + opt = opts[0] + } + + if opt.Logger == nil { + opt.Logger = slog.New(slog.NewTextHandler(io.Discard, &slog.HandlerOptions{})) + } + opt.Logger = opt.Logger.WithGroup(foldingRendererPluginName) + + return &foldingRenderer{ + plugins: []RendererPlugin{}, + + log: opt.Logger, + } +} + +func (p *foldingRenderer) Name() string { + return foldingRendererPluginName +} + +func (p *foldingRenderer) Use(plugin Plugin) { + log := p.log.With(slog.String("plugin", plugin.Name())) + + if plg, ok := plugin.(RendererPlugin); ok { + p.plugins = append(p.plugins, plg) + } else { + m := fmt.Sprintf("failed to add plugin %q, since it doesn't implement RendererPlugin", plugin.Name()) + log.Error(m) + if p.panicOnInit { + panic(fmt.Sprintf("%s: %s", multiRendererPluginName, m)) + } + } +} + +func (p *foldingRenderer) Render(src File, w io.Writer) error { + if len(p.plugins) == 0 { + _, err := io.Copy(w, src) + return err + } + + f, err := newFoldignFile(src) + if err != nil { + return err + } + + for _, r := range p.plugins { + err := r.Render(f, f) + if err != nil { + return err + } + + if err := f.Fold(); err != nil { + return err + } + } + + _, err = io.Copy(w, f) + return err +} + +type foldingFile struct { + File + read *bytes.Buffer + writer *bytes.Buffer +} + +func newFoldignFile(f File) (*foldingFile, error) { + var r, w bytes.Buffer + + if _, err := io.Copy(&r, f); err != nil { + return nil, err + } + if err := f.Close(); err != nil { + return nil, err + } + + return &foldingFile{File: f, read: &r, writer: &w}, nil +} + +func (f *foldingFile) Close() error { + return nil +} + +func (f *foldingFile) Read(p []byte) (int, error) { + return f.read.Read(p) +} + +func (f *foldingFile) Write(p []byte) (int, error) { + return f.writer.Write(p) +} + +func (f *foldingFile) Fold() error { + f.read.Reset() + if _, err := io.Copy(f.writer, f.read); err != nil { + return err + } + f.writer.Reset() + return nil +}