Files
x/blogo/plugins/multirenderer.go

161 lines
3.7 KiB
Go

// 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 plugins
import (
"bytes"
"errors"
"fmt"
"io"
"io/fs"
"log/slog"
"forge.capytal.company/loreddev/x/blogo/plugin"
)
var ErrRendererNotSupportedFile = errors.New("this file is not supported by renderer")
const multiRendererName = "blogo-multirenderer-renderer"
type MultiRenderer interface {
plugin.Renderer
plugin.WithPlugins
}
type multiRenderer struct {
renderers []plugin.Renderer
skipOnError bool
panicOnInit bool
log *slog.Logger
}
type MultiRendererOpts struct {
NotSkipOnError bool
NotPanicOnInit bool
Logger *slog.Logger
}
func NewMultiRenderer(opts ...MultiRendererOpts) MultiRenderer {
opt := MultiRendererOpts{}
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(multiRendererName)
return &multiRenderer{
renderers: []plugin.Renderer{},
skipOnError: !opt.NotSkipOnError,
panicOnInit: !opt.NotPanicOnInit,
log: opt.Logger,
}
}
func (r *multiRenderer) Name() string {
return multiRendererName
}
func (r *multiRenderer) Use(p plugin.Plugin) {
log := r.log.With(slog.String("plugin", p.Name()))
if pr, ok := p.(plugin.Renderer); ok {
log.Debug("Added renderer plugin")
r.renderers = append(r.renderers, pr)
} else {
m := fmt.Sprintf("failed to add plugin %q, since it doesn't implement plugin.Renderer", p.Name())
log.Error(m)
if r.panicOnInit {
panic(fmt.Sprintf("%s: %s", r.Name(), m))
}
}
}
func (r *multiRenderer) Render(src fs.File, w io.Writer) error {
mf := newMultiRendererFile(src)
for _, pr := range r.renderers {
log := r.log.With(slog.String("plugin", pr.Name()))
log.Debug("Trying to render with plugin")
err := pr.Render(src, w)
if err == nil {
break
}
if !r.skipOnError && !errors.Is(err, ErrRendererNotSupportedFile) {
log.Error("Failed to render using plugin", slog.String("error", err.Error()))
return errors.Join(fmt.Errorf("failed to render using plugin %q", pr.Name()), err)
}
log.Debug("Unable to render using plugin", slog.String("error", err.Error()))
log.Debug("Resetting file for next read")
if err := mf.Reset(); err != nil {
log.Error("Failed to reset file read offset", slog.String("error", err.Error()))
return errors.Join(fmt.Errorf("failed to reset file read offset"), err)
}
}
return nil
}
type multiRendererFile struct {
fs.File
buf *bytes.Buffer
reader io.Reader
}
func newMultiRendererFile(f fs.File) *multiRendererFile {
if _, ok := f.(io.Seeker); ok {
return &multiRendererFile{
File: f,
reader: f,
}
}
var buf bytes.Buffer
return &multiRendererFile{
File: f,
reader: io.TeeReader(f, &buf),
buf: &buf,
}
}
func (f *multiRendererFile) Read(p []byte) (int, error) {
return f.reader.Read(p)
}
func (f *multiRendererFile) Reset() error {
if s, ok := f.File.(io.Seeker); ok {
_, err := s.Seek(0, io.SeekStart)
return err
}
var buf bytes.Buffer
r := io.MultiReader(f.buf, f.File)
f.reader = io.TeeReader(r, &buf)
f.buf = &buf
return nil
}