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/query/internal/itergen/special.go

@@ -0,0 +1,90 @@
+package main
+
+import (
+	"go/types"
+	"sort"
+	"strings"
+
+	"github.com/go-faster/errors"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/telegram/query/internal/genutil"
+)
+
+func (c *collector) unpackClass(
+	field Param,
+	typeName, trimPrefix string,
+) ([]SpecialCaseChain, error) {
+	var r []SpecialCaseChain
+	if field.Type == "tg."+typeName {
+		impls, err := c.ifaces.Implementations(typeName)
+		if err != nil {
+			return nil, errors.Wrapf(err, "find %q constructors", typeName)
+		}
+		for _, impl := range impls {
+			s, ok := impl.Underlying().(*types.Struct)
+			if !ok {
+				continue
+			}
+
+			cse := SpecialCaseChain{
+				ConstructorName: strings.TrimPrefix(impl.Obj().Name(), trimPrefix),
+				ConstructorType: genutil.PrintType(impl),
+				Field:           field,
+			}
+
+			if strings.Contains(cse.ConstructorName, "Empty") {
+				continue
+			}
+
+			for i := 0; i < s.NumFields(); i++ {
+				field := s.Field(i)
+				if field.Name() == "Flags" {
+					continue
+				}
+
+				cse.Args = append(cse.Args, varToParam(field))
+			}
+
+			cse.Args = sortParams(cse.Args)
+			r = append(r, cse)
+		}
+	}
+
+	return r, nil
+}
+
+func (c *collector) unpackClasses(
+	field Param,
+	classes ...[2]string,
+) ([]SpecialCaseChain, error) {
+	var r []SpecialCaseChain
+	for _, class := range classes {
+		cases, err := c.unpackClass(field, class[0], class[1])
+		if err != nil {
+			return nil, errors.Wrapf(err, "unpack %q", class[0])
+		}
+		r = append(r, cases...)
+	}
+
+	return r, nil
+}
+
+func (c *collector) collectSpecial(m Method) ([]SpecialCaseChain, error) {
+	var r []SpecialCaseChain
+	for _, field := range m.AdditionalParams {
+		cases, err := c.unpackClasses(field, [][2]string{
+			{"MessagesFilterClass", "InputMessagesFilter"},
+			{"ChannelParticipantsFilterClass", "ChannelParticipants"},
+		}...)
+		if err != nil {
+			return nil, err
+		}
+
+		r = append(r, cases...)
+	}
+
+	sort.SliceStable(r, func(i, j int) bool {
+		return r[i].ConstructorName < r[j].ConstructorName
+	})
+	return r, nil
+}