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/telegram/message/internal/mkrun/generator.go

@@ -0,0 +1,15 @@
+package mkrun
+
+import "flag"
+
+// Generator represents generator script.
+type Generator interface {
+	// Name is generator name.
+	Name() string
+	// Flags sets generator flags.
+	Flags(set *flag.FlagSet)
+	// Template returns generation template.
+	Template() string
+	// Data returns associated generation data.
+	Data() (interface{}, error)
+}

pkg/gotd/telegram/message/internal/mkrun/mkrun.go

@@ -0,0 +1,115 @@
+// Package mkrun contains some helpers for generation scripts.
+package mkrun
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"go/format"
+	"io"
+	"os"
+	"strings"
+	"text/template"
+	"time"
+	"unicode"
+	"unicode/utf8"
+
+	"github.com/go-faster/errors"
+	"go.uber.org/multierr"
+)
+
+// Config is generation config.
+type Config struct {
+	PackageName string
+	Data        interface{}
+}
+
+func generate(w io.Writer, pkgName string, g Generator) error {
+	start := time.Now()
+	data, err := g.Data()
+	if err != nil {
+		return err
+	}
+	collectInfoTime := time.Since(start)
+
+	start = time.Now()
+	buf := bytes.Buffer{}
+	t, err := template.New("gen").Funcs(template.FuncMap{
+		"trimPrefix": strings.TrimPrefix,
+		"trimSuffix": strings.TrimSuffix,
+		"lowerFirst": func(s string) string {
+			r, size := utf8.DecodeRuneInString(s)
+			if r == utf8.RuneError || unicode.IsLower(r) {
+				return s
+			}
+			return string(unicode.ToLower(r)) + s[size:]
+		},
+	}).Parse(g.Template())
+	if err != nil {
+		return errors.Errorf("parse: %w", err)
+	}
+
+	if err := t.Execute(&buf, Config{
+		PackageName: pkgName,
+		Data:        data,
+	}); err != nil {
+		return errors.Errorf("execute: %w", err)
+	}
+
+	formatted, err := format.Source(buf.Bytes())
+	if err != nil {
+		_, _ = os.Stderr.Write(buf.Bytes())
+		return errors.Errorf("format: %w", err)
+	}
+
+	if _, err := w.Write(formatted); err != nil {
+		return errors.Errorf("write: %w", err)
+	}
+	writeTime := time.Since(start)
+
+	fmt.Printf("Generation %s complete, collect time: %s, write time: %s\n",
+		g.Name(),
+		collectInfoTime,
+		writeTime,
+	)
+
+	return nil
+}
+
+func run(g Generator) (rErr error) {
+	set := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+	var (
+		o       = set.String("output", "", "output file")
+		pkgName = set.String("package", os.Getenv("GOPACKAGE"), "package name")
+	)
+	g.Flags(set)
+	if err := set.Parse(os.Args[1:]); err != nil {
+		return errors.Wrap(err, "parse")
+	}
+
+	if *pkgName == "" {
+		if *o != "" {
+			return errors.New("package name is empty")
+		}
+		*pkgName = "pkg"
+	}
+
+	var w io.Writer = os.Stdout
+	if path := *o; path != "" {
+		f, err := os.Create(path) // #nosec G304
+		if err != nil {
+			return err
+		}
+		defer multierr.AppendInvoke(&rErr, multierr.Close(f))
+		w = f
+	}
+
+	return generate(w, *pkgName, g)
+}
+
+// Main is generation main function.
+func Main(g Generator) {
+	if err := run(g); err != nil {
+		panic(err)
+	}
+}