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/tgerr/error.go

@@ -0,0 +1,152 @@
+// Package tgerr implements helpers for error handling.
+package tgerr
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/go-faster/errors"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/ascii"
+)
+
+// Error represents RPC error returned as result to request.
+type Error struct {
+	Code     int    // 420
+	Message  string // FLOOD_WAIT_3
+	Type     string // FLOOD_WAIT
+	Argument int    // 3
+}
+
+// New creates new *Error from code and message, extracting argument
+// and type.
+func New(code int, msg string) *Error {
+	e := &Error{
+		Code:    code,
+		Message: msg,
+	}
+	e.extractArgument()
+	return e
+}
+
+// IsType reports whether error has type t.
+func (e *Error) IsType(t string) bool {
+	if e == nil {
+		return false
+	}
+	return e.Type == t
+}
+
+// IsCode reports whether error Code is equal to code.
+func (e *Error) IsCode(code int) bool {
+	if e == nil {
+		return false
+	}
+	return e.Code == code
+}
+
+// IsOneOf returns true if error type is in tt.
+func (e *Error) IsOneOf(tt ...string) bool {
+	if e == nil {
+		return false
+	}
+	for _, t := range tt {
+		if e.IsType(t) {
+			return true
+		}
+	}
+	return false
+}
+
+// IsCodeOneOf returns true if error code is one of codes.
+func (e *Error) IsCodeOneOf(codes ...int) bool {
+	if e == nil {
+		return false
+	}
+	for _, code := range codes {
+		if e.IsCode(code) {
+			return true
+		}
+	}
+	return false
+}
+
+// extractArgument extracts Type and Argument from Message.
+func (e *Error) extractArgument() {
+	if e.Message == "" {
+		return
+	}
+
+	// Defaulting Type to Message.
+	e.Type = e.Message
+
+	// Splitting by underscore.
+	parts := strings.Split(e.Message, "_")
+	if len(parts) < 2 {
+		return
+	}
+
+	var nonDigit []string
+Parts:
+	for _, part := range parts {
+		for _, r := range part {
+			if ascii.IsDigit(r) {
+				continue
+			}
+
+			// Found non-digit part, skipping.
+			nonDigit = append(nonDigit, part)
+			continue Parts
+		}
+
+		// Found digit-only part, using as argument.
+		argument, err := strconv.Atoi(part)
+		if err != nil {
+			// Should be unreachable.
+			return
+		}
+		e.Argument = argument
+	}
+
+	e.Type = strings.Join(nonDigit, "_")
+}
+
+func (e *Error) Error() string {
+	if e.Type != e.Message {
+		return fmt.Sprintf("rpc error code %d: %s (%d)", e.Code, e.Type, e.Argument)
+	}
+	return fmt.Sprintf("rpc error code %d: %s", e.Code, e.Message)
+}
+
+// AsType returns *Error from err if rpc error type is t.
+func AsType(err error, t string) (rpcErr *Error, ok bool) {
+	if errors.As(err, &rpcErr) && rpcErr.Type == t {
+		return rpcErr, true
+	}
+	return nil, false
+}
+
+// As extracts *Error from err if possible.
+func As(err error) (rpcErr *Error, ok bool) {
+	if errors.As(err, &rpcErr) {
+		return rpcErr, true
+	}
+	return nil, false
+}
+
+// Is returns true if err type is t.
+func Is(err error, tt ...string) bool {
+	if rpcErr, ok := As(err); ok {
+		return rpcErr.IsOneOf(tt...)
+	}
+	return false
+}
+
+// IsCode returns true of error code is as provided.
+func IsCode(err error, code ...int) bool {
+	if rpcErr, ok := As(err); ok {
+		return rpcErr.IsCodeOneOf(code...)
+	}
+	return false
+}