move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/cmd/gotdgen/main.go

@@ -0,0 +1,108 @@
+// Binary gotdgen generates go source code from TL schema.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"go/format"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/gotd/tl"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/gen"
+)
+
+type formattedSource struct {
+	Format bool
+	Root   string
+}
+
+func (t formattedSource) WriteFile(name string, content []byte) error {
+	out := content
+	if t.Format {
+		buf, err := format.Source(content)
+		if err != nil {
+			return err
+		}
+		out = buf
+	}
+	return os.WriteFile(filepath.Join(t.Root, name), out, 0600)
+}
+
+func main() {
+	schemaPath := flag.String("schema", "", "Path to .tl file")
+	targetDir := flag.String("target", "td", "Path to target dir")
+	packageName := flag.String("package", "td", "Target package name")
+	performFormat := flag.Bool("format", true, "Perform code formatting")
+	clean := flag.Bool("clean", false, "Clean generated files before generation")
+
+	genOpts := gen.GeneratorOptions{}
+	genOpts.RegisterFlags(flag.CommandLine)
+
+	flag.Parse()
+	if *schemaPath == "" {
+		panic("no schema provided")
+	}
+	f, err := os.Open(*schemaPath)
+	if err != nil {
+		panic(err)
+	}
+	defer func() { _ = f.Close() }()
+
+	schema, err := tl.Parse(f)
+	if err != nil {
+		panic(err)
+	}
+	files, err := os.ReadDir(*targetDir)
+	if err != nil && !os.IsNotExist(err) {
+		panic(err)
+	}
+	if os.IsNotExist(err) {
+		if err := os.Mkdir(*targetDir, 0750); err != nil {
+			panic(err)
+		}
+	}
+	if *clean {
+		for _, f := range files {
+			if f.IsDir() {
+				continue
+			}
+			name := f.Name()
+			if !strings.HasSuffix(name, "_gen.go") {
+				continue
+			}
+			if !strings.HasPrefix(name, "tl_") {
+				continue
+			}
+			if err := os.Remove(filepath.Join(*targetDir, name)); err != nil {
+				panic(err)
+			}
+		}
+	}
+
+	start := time.Now()
+	fs := formattedSource{
+		Root:   *targetDir,
+		Format: *performFormat,
+	}
+	g, err := gen.NewGenerator(schema, genOpts)
+	if err != nil {
+		panic(fmt.Sprintf("%+v", err))
+	}
+	collectInfoTime := time.Since(start)
+
+	start = time.Now()
+	if err := g.WriteSource(fs, *packageName, gen.Template()); err != nil {
+		panic(fmt.Sprintf("%+v", err))
+	}
+	writeTime := time.Since(start)
+
+	fmt.Printf("Generation %s complete, collect time: %s, write time: %s\n",
+		*packageName,
+		collectInfoTime,
+		writeTime,
+	)
+}