aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/python/mypy-protobuf/mypy_protobuf/main.py
blob: 6e825d828019239090f60a74131f3a05a7eb87de (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
#!/usr/bin/env python
"""Protoc Plugin to generate mypy stubs. Loosely based on @zbarsky's go implementation"""
import os

import sys
from collections import defaultdict
from contextlib import contextmanager
from functools import wraps
from typing import (
    Any,
    Callable,
    Dict,
    Iterable,
    Iterator,
    List,
    Optional,
    Set,
    Sequence,
    Tuple,
)

import google.protobuf.descriptor_pb2 as d
from google.protobuf.compiler import plugin_pb2 as plugin_pb2
from google.protobuf.internal.containers import RepeatedCompositeFieldContainer
from google.protobuf.internal.well_known_types import WKTBASES
from . import extensions_pb2

__version__ = "3.2.0"

# SourceCodeLocation is defined by `message Location` here
# https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/descriptor.proto
SourceCodeLocation = List[int]

# So phabricator doesn't think mypy_protobuf.py is generated
GENERATED = "@ge" + "nerated"
HEADER = f"""\"\"\"
{GENERATED} by mypy-protobuf.  Do not edit manually!
isort:skip_file
\"\"\"
"""

# See https://github.com/dropbox/mypy-protobuf/issues/73 for details
PYTHON_RESERVED = {
    "False",
    "None",
    "True",
    "and",
    "as",
    "async",
    "await",
    "assert",
    "break",
    "class",
    "continue",
    "def",
    "del",
    "elif",
    "else",
    "except",
    "finally",
    "for",
    "from",
    "global",
    "if",
    "import",
    "in",
    "is",
    "lambda",
    "nonlocal",
    "not",
    "or",
    "pass",
    "raise",
    "return",
    "try",
    "while",
    "with",
    "yield",
}

PROTO_ENUM_RESERVED = {
    "Name",
    "Value",
    "keys",
    "values",
    "items",
}


def _mangle_global_identifier(name: str) -> str:
    """
    Module level identifiers are mangled and aliased so that they can be disambiguated
    from fields/enum variants with the same name within the file.

    Eg:
    Enum variant `Name` or message field `Name` might conflict with a top level
    message or enum named `Name`, so mangle it with a global___ prefix for
    internal references. Note that this doesn't affect inner enums/messages
    because they get fuly qualified when referenced within a file"""
    return f"global___{name}"


class Descriptors(object):
    def __init__(self, request: plugin_pb2.CodeGeneratorRequest) -> None:
        files = {f.name: f for f in request.proto_file}
        to_generate = {n: files[n] for n in request.file_to_generate}
        self.files: Dict[str, d.FileDescriptorProto] = files
        self.to_generate: Dict[str, d.FileDescriptorProto] = to_generate
        self.messages: Dict[str, d.DescriptorProto] = {}
        self.message_to_fd: Dict[str, d.FileDescriptorProto] = {}

        def _add_enums(
            enums: "RepeatedCompositeFieldContainer[d.EnumDescriptorProto]",
            prefix: str,
            _fd: d.FileDescriptorProto,
        ) -> None:
            for enum in enums:
                self.message_to_fd[prefix + enum.name] = _fd
                self.message_to_fd[prefix + enum.name + ".ValueType"] = _fd

        def _add_messages(
            messages: "RepeatedCompositeFieldContainer[d.DescriptorProto]",
            prefix: str,
            _fd: d.FileDescriptorProto,
        ) -> None:
            for message in messages:
                self.messages[prefix + message.name] = message
                self.message_to_fd[prefix + message.name] = _fd
                sub_prefix = prefix + message.name + "."
                _add_messages(message.nested_type, sub_prefix, _fd)
                _add_enums(message.enum_type, sub_prefix, _fd)

        for fd in request.proto_file:
            start_prefix = "." + fd.package + "." if fd.package else "."
            _add_messages(fd.message_type, start_prefix, fd)
            _add_enums(fd.enum_type, start_prefix, fd)


class PkgWriter(object):
    """Writes a single pyi file"""

    def __init__(
        self,
        fd: d.FileDescriptorProto,
        descriptors: Descriptors,
        readable_stubs: bool,
        relax_strict_optional_primitives: bool,
        grpc: bool,
    ) -> None:
        self.fd = fd
        self.descriptors = descriptors
        self.readable_stubs = readable_stubs
        self.relax_strict_optional_primitives = relax_strict_optional_primitives
        self.grpc = grpc
        self.lines: List[str] = []
        self.indent = ""

        # Set of {x}, where {x} corresponds to to `import {x}`
        self.imports: Set[str] = set()
        # dictionary of x->(y,z) for `from {x} import {y} as {z}`
        # if {z} is None, then it shortens to `from {x} import {y}`
        self.from_imports: Dict[str, Set[Tuple[str, Optional[str]]]] = defaultdict(set)

        # Comments
        self.source_code_info_by_scl = {
            tuple(location.path): location for location in fd.source_code_info.location
        }

    def _import(self, path: str, name: str) -> str:
        """Imports a stdlib path and returns a handle to it
        eg. self._import("typing", "Optional") -> "Optional"
        """
        imp = path.replace("/", ".")
        if self.readable_stubs:
            self.from_imports[imp].add((name, None))
            return name
        else:
            self.imports.add(imp)
            return imp + "." + name

    def _import_message(self, name: str) -> str:
        """Import a referenced message and return a handle"""
        message_fd = self.descriptors.message_to_fd[name]
        assert message_fd.name.endswith(".proto")

        # Strip off package name
        if message_fd.package:
            assert name.startswith("." + message_fd.package + ".")
            name = name[len("." + message_fd.package + ".") :]
        else:
            assert name.startswith(".")
            name = name[1:]

        # Use prepended "_r_" to disambiguate message names that alias python reserved keywords
        split = name.split(".")
        for i, part in enumerate(split):
            if part in PYTHON_RESERVED:
                split[i] = "_r_" + part
        name = ".".join(split)

        # Message defined in this file. Note: GRPC stubs in same .proto are generated into separate files
        if not self.grpc and message_fd.name == self.fd.name:
            return name if self.readable_stubs else _mangle_global_identifier(name)

        # Not in file. Must import
        # Python generated code ignores proto packages, so the only relevant factor is
        # whether it is in the file or not.
        import_name = self._import(
            message_fd.name[:-6].replace("-", "_") + "_pb2", split[0]
        )

        remains = ".".join(split[1:])
        if not remains:
            return import_name

        # remains could either be a direct import of a nested enum or message
        # from another package.
        return import_name + "." + remains

    def _builtin(self, name: str) -> str:
        return self._import("builtins", name)

    @contextmanager
    def _indent(self) -> Iterator[None]:
        self.indent = self.indent + "    "
        yield
        self.indent = self.indent[:-4]

    def _write_line(self, line: str, *args: Any) -> None:
        if args:
            line = line.format(*args)
        if line == "":
            self.lines.append(line)
        else:
            self.lines.append(self.indent + line)

    def _break_text(self, text_block: str) -> List[str]:
        if text_block == "":
            return []
        return [
            l[1:] if l.startswith(" ") else l for l in text_block.rstrip().split("\n")
        ]

    def _has_comments(self, scl: SourceCodeLocation) -> bool:
        sci_loc = self.source_code_info_by_scl.get(tuple(scl))
        return sci_loc is not None and bool(
            sci_loc.leading_detached_comments
            or sci_loc.leading_comments
            or sci_loc.trailing_comments
        )

    def _write_comments(self, scl: SourceCodeLocation) -> bool:
        """Return true if any comments were written"""
        if not self._has_comments(scl):
            return False

        sci_loc = self.source_code_info_by_scl.get(tuple(scl))
        assert sci_loc is not None

        lines = []
        for leading_detached_comment in sci_loc.leading_detached_comments:
            lines.extend(self._break_text(leading_detached_comment))
            lines.append("")
        if sci_loc.leading_comments is not None:
            lines.extend(self._break_text(sci_loc.leading_comments))
        # Trailing comments also go in the header - to make sure it gets into the docstring
        if sci_loc.trailing_comments is not None:
            lines.extend(self._break_text(sci_loc.trailing_comments))

        lines = [
            # Escape triple-quotes that would otherwise end the docstring early.
            line.replace("\\", "\\\\").replace('"""', r"\"\"\"")
            for line in lines
        ]
        if len(lines) == 1:
            line = lines[0]
            if line.endswith(('"', "\\")):
                # Docstrings are terminated with triple-quotes, so if the documentation itself ends in a quote,
                # insert some whitespace to separate it from the closing quotes.
                # This is not necessary with multiline comments
                # because in that case we always insert a newline before the trailing triple-quotes.
                line = line + " "
            self._write_line(f'"""{line}"""')
        else:
            for i, line in enumerate(lines):
                if i == 0:
                    self._write_line(f'"""{line}')
                else:
                    self._write_line(f"{line}")
            self._write_line('"""')

        return True

    def write_enum_values(
        self,
        values: Iterable[Tuple[int, d.EnumValueDescriptorProto]],
        value_type: str,
        scl_prefix: SourceCodeLocation,
    ) -> None:
        for i, val in values:
            if val.name in PYTHON_RESERVED:
                continue

            scl = scl_prefix + [i]
            self._write_line(
                f"{val.name}: {value_type}  # {val.number}",
            )
            if self._write_comments(scl):
                self._write_line("")  # Extra newline to separate

    def write_module_attributes(self) -> None:
        l = self._write_line
        fd_type = self._import("google.protobuf.descriptor", "FileDescriptor")
        l(f"DESCRIPTOR: {fd_type}")
        l("")

    def write_enums(
        self,
        enums: Iterable[d.EnumDescriptorProto],
        prefix: str,
        scl_prefix: SourceCodeLocation,
    ) -> None:
        l = self._write_line
        for i, enum in enumerate(enums):
            class_name = (
                enum.name if enum.name not in PYTHON_RESERVED else "_r_" + enum.name
            )
            value_type_fq = prefix + class_name + ".ValueType"
            enum_helper_class = "_" + enum.name
            value_type_helper_fq = prefix + enum_helper_class + ".ValueType"
            etw_helper_class = "_" + enum.name + "EnumTypeWrapper"
            scl = scl_prefix + [i]

            l(f"class {enum_helper_class}:")
            with self._indent():
                l(
                    "ValueType = {}('ValueType', {})",
                    self._import("typing", "NewType"),
                    self._builtin("int"),
                )
                # Alias to the classic shorter definition "V"
                l("V: {} = ValueType", self._import("typing_extensions", "TypeAlias"))
            l(
                "class {}({}[{}], {}):",
                etw_helper_class,
                self._import(
                    "google.protobuf.internal.enum_type_wrapper", "_EnumTypeWrapper"
                ),
                value_type_helper_fq,
                self._builtin("type"),
            )
            with self._indent():
                ed = self._import("google.protobuf.descriptor", "EnumDescriptor")
                l(f"DESCRIPTOR: {ed}")
                self.write_enum_values(
                    [
                        (i, v)
                        for i, v in enumerate(enum.value)
                        if v.name not in PROTO_ENUM_RESERVED
                    ],
                    value_type_helper_fq,
                    scl + [d.EnumDescriptorProto.VALUE_FIELD_NUMBER],
                )
            l(f"class {class_name}({enum_helper_class}, metaclass={etw_helper_class}):")
            with self._indent():
                self._write_comments(scl)
                l("pass")
            l("")

            self.write_enum_values(
                enumerate(enum.value),
                value_type_fq,
                scl + [d.EnumDescriptorProto.VALUE_FIELD_NUMBER],
            )
            if prefix == "" and not self.readable_stubs:
                l(f"{_mangle_global_identifier(class_name)} = {class_name}")
                l("")
            l("")

    def write_messages(
        self,
        messages: Iterable[d.DescriptorProto],
        prefix: str,
        scl_prefix: SourceCodeLocation,
    ) -> None:
        l = self._write_line

        for i, desc in enumerate(messages):
            qualified_name = prefix + desc.name

            # Reproduce some hardcoded logic from the protobuf implementation - where
            # some specific "well_known_types" generated protos to have additional
            # base classes
            addl_base = ""
            if self.fd.package + "." + desc.name in WKTBASES:
                # chop off the .proto - and import the well known type
                # eg `from google.protobuf.duration import Duration`
                well_known_type = WKTBASES[self.fd.package + "." + desc.name]
                addl_base = ", " + self._import(
                    "google.protobuf.internal.well_known_types",
                    well_known_type.__name__,
                )

            class_name = (
                desc.name if desc.name not in PYTHON_RESERVED else "_r_" + desc.name
            )
            message_class = self._import("google.protobuf.message", "Message")
            l(f"class {class_name}({message_class}{addl_base}):")
            with self._indent():
                scl = scl_prefix + [i]
                self._write_comments(scl)

                desc_type = self._import("google.protobuf.descriptor", "Descriptor")
                l(f"DESCRIPTOR: {desc_type}")

                # Nested enums/messages
                self.write_enums(
                    desc.enum_type,
                    qualified_name + ".",
                    scl + [d.DescriptorProto.ENUM_TYPE_FIELD_NUMBER],
                )
                self.write_messages(
                    desc.nested_type,
                    qualified_name + ".",
                    scl + [d.DescriptorProto.NESTED_TYPE_FIELD_NUMBER],
                )

                # integer constants  for field numbers
                for f in desc.field:
                    l(f"{f.name.upper()}_FIELD_NUMBER: {self._builtin('int')}")

                for idx, field in enumerate(desc.field):
                    if field.name in PYTHON_RESERVED:
                        continue
                    field_type = self.python_type(field)

                    if (
                        is_scalar(field)
                        and field.label != d.FieldDescriptorProto.LABEL_REPEATED
                    ):
                        # Scalar non repeated fields are r/w
                        l(f"{field.name}: {field_type}")
                        if self._write_comments(
                            scl + [d.DescriptorProto.FIELD_FIELD_NUMBER, idx]
                        ):
                            l("")
                    else:
                        # r/o Getters for non-scalar fields and scalar-repeated fields
                        scl_field = scl + [d.DescriptorProto.FIELD_FIELD_NUMBER, idx]
                        l("@property")
                        body = " ..." if not self._has_comments(scl_field) else ""
                        l(f"def {field.name}(self) -> {field_type}:{body}")
                        if self._has_comments(scl_field):
                            with self._indent():
                                self._write_comments(scl_field)
                                l("pass")

                self.write_extensions(
                    desc.extension, scl + [d.DescriptorProto.EXTENSION_FIELD_NUMBER]
                )

                # Constructor
                if any(f.name == "self" for f in desc.field):
                    l("# pyright: reportSelfClsParameterName=false")
                    l(f"def __init__(self_,")
                else:
                    l(f"def __init__(self,")
                with self._indent():
                    constructor_fields = [
                        f for f in desc.field if f.name not in PYTHON_RESERVED
                    ]
                    if len(constructor_fields) > 0:
                        # Only positional args allowed
                        # See https://github.com/dropbox/mypy-protobuf/issues/71
                        l("*,")
                    for field in constructor_fields:
                        field_type = self.python_type(field, generic_container=True)
                        if (
                            self.fd.syntax == "proto3"
                            and is_scalar(field)
                            and field.label != d.FieldDescriptorProto.LABEL_REPEATED
                            and not self.relax_strict_optional_primitives
                            and not field.proto3_optional
                        ):
                            l(f"{field.name}: {field_type} = ...,")
                        else:
                            opt = self._import("typing", "Optional")
                            l(f"{field.name}: {opt}[{field_type}] = ...,")
                    l(") -> None: ...")

                self.write_stringly_typed_fields(desc)

            if prefix == "" and not self.readable_stubs:
                l(f"{_mangle_global_identifier(class_name)} = {class_name}")
            l("")

    def write_stringly_typed_fields(self, desc: d.DescriptorProto) -> None:
        """Type the stringly-typed methods as a Union[Literal, Literal ...]"""
        l = self._write_line
        # HasField, ClearField, WhichOneof accepts both bytes/str
        # HasField only supports singular. ClearField supports repeated as well
        # In proto3, HasField only supports message fields and optional fields
        # HasField always supports oneof fields
        hf_fields = [
            f.name
            for f in desc.field
            if f.HasField("oneof_index")
            or (
                f.label != d.FieldDescriptorProto.LABEL_REPEATED
                and (
                    self.fd.syntax != "proto3"
                    or f.type == d.FieldDescriptorProto.TYPE_MESSAGE
                    or f.proto3_optional
                )
            )
        ]
        cf_fields = [f.name for f in desc.field]
        wo_fields = {
            oneof.name: [
                f.name
                for f in desc.field
                if f.HasField("oneof_index") and f.oneof_index == idx
            ]
            for idx, oneof in enumerate(desc.oneof_decl)
        }

        hf_fields.extend(wo_fields.keys())
        cf_fields.extend(wo_fields.keys())

        hf_fields_text = ",".join(sorted(f'"{name}",b"{name}"' for name in hf_fields))
        cf_fields_text = ",".join(sorted(f'"{name}",b"{name}"' for name in cf_fields))

        if not hf_fields and not cf_fields and not wo_fields:
            return

        if hf_fields:
            l(
                "def HasField(self, field_name: {}[{}]) -> {}: ...",
                self._import("typing_extensions", "Literal"),
                hf_fields_text,
                self._builtin("bool"),
            )
        if cf_fields:
            l(
                "def ClearField(self, field_name: {}[{}]) -> None: ...",
                self._import("typing_extensions", "Literal"),
                cf_fields_text,
            )

        for wo_field, members in sorted(wo_fields.items()):
            if len(wo_fields) > 1:
                l("@{}", self._import("typing", "overload"))
            l(
                "def WhichOneof(self, oneof_group: {}[{}]) -> {}[{}[{}]]: ...",
                self._import("typing_extensions", "Literal"),
                # Accepts both str and bytes
                f'"{wo_field}",b"{wo_field}"',
                self._import("typing", "Optional"),
                self._import("typing_extensions", "Literal"),
                # Returns `str`
                ",".join(f'"{m}"' for m in members),
            )

    def write_extensions(
        self,
        extensions: Sequence[d.FieldDescriptorProto],
        scl_prefix: SourceCodeLocation,
    ) -> None:
        l = self._write_line

        for ext in extensions:
            l(f"{ext.name.upper()}_FIELD_NUMBER: {self._builtin('int')}")

        for i, ext in enumerate(extensions):
            scl = scl_prefix + [i]

            l(
                "{}: {}[{}, {}]",
                ext.name,
                self._import(
                    "google.protobuf.internal.extension_dict",
                    "_ExtensionFieldDescriptor",
                ),
                self._import_message(ext.extendee),
                self.python_type(ext),
            )
            self._write_comments(scl)
            l("")

    def write_methods(
        self,
        service: d.ServiceDescriptorProto,
        class_name: str,
        is_abstract: bool,
        scl_prefix: SourceCodeLocation,
    ) -> None:
        l = self._write_line
        l(
            "DESCRIPTOR: {}",
            self._import("google.protobuf.descriptor", "ServiceDescriptor"),
        )
        methods = [
            (i, m)
            for i, m in enumerate(service.method)
            if m.name not in PYTHON_RESERVED
        ]
        if not methods:
            l("pass")
        for i, method in methods:
            if is_abstract:
                l("@{}", self._import("abc", "abstractmethod"))
            l(f"def {method.name}(")
            with self._indent():
                l(f"inst: {class_name},")
                l(
                    "rpc_controller: {},",
                    self._import("google.protobuf.service", "RpcController"),
                )
                l("request: {},", self._import_message(method.input_type))
                l(
                    "callback: {}[{}[[{}], None]]{},",
                    self._import("typing", "Optional"),
                    self._import("typing", "Callable"),
                    self._import_message(method.output_type),
                    "" if is_abstract else " = None",
                )

            scl_method = scl_prefix + [d.ServiceDescriptorProto.METHOD_FIELD_NUMBER, i]
            l(
                ") -> {}[{}]:{}",
                self._import("concurrent.futures", "Future"),
                self._import_message(method.output_type),
                " ..." if not self._has_comments(scl_method) else "",
            )
            if self._has_comments(scl_method):
                with self._indent():
                    self._write_comments(scl_method)
                    l("pass")

    def write_services(
        self,
        services: Iterable[d.ServiceDescriptorProto],
        scl_prefix: SourceCodeLocation,
    ) -> None:
        l = self._write_line
        for i, service in enumerate(services):
            scl = scl_prefix + [i]
            class_name = (
                service.name
                if service.name not in PYTHON_RESERVED
                else "_r_" + service.name
            )
            # The service definition interface
            l(
                "class {}({}, metaclass={}):",
                class_name,
                self._import("google.protobuf.service", "Service"),
                self._import("abc", "ABCMeta"),
            )
            with self._indent():
                self._write_comments(scl)
                self.write_methods(
                    service, class_name, is_abstract=True, scl_prefix=scl
                )

            # The stub client
            stub_class_name = service.name + "_Stub"
            l("class {}({}):", stub_class_name, class_name)
            with self._indent():
                self._write_comments(scl)
                l(
                    "def __init__(self, rpc_channel: {}) -> None: ...",
                    self._import("google.protobuf.service", "RpcChannel"),
                )
                self.write_methods(
                    service, stub_class_name, is_abstract=False, scl_prefix=scl
                )

    def _import_casttype(self, casttype: str) -> str:
        split = casttype.split(".")
        assert (
            len(split) == 2
        ), "mypy_protobuf.[casttype,keytype,valuetype] is expected to be of format path/to/file.TypeInFile"
        pkg = split[0].replace("/", ".")
        return self._import(pkg, split[1])

    def _map_key_value_types(
        self,
        map_field: d.FieldDescriptorProto,
        key_field: d.FieldDescriptorProto,
        value_field: d.FieldDescriptorProto,
    ) -> Tuple[str, str]:
        key_casttype = map_field.options.Extensions[extensions_pb2.keytype]
        ktype = (
            self._import_casttype(key_casttype)
            if key_casttype
            else self.python_type(key_field)
        )
        value_casttype = map_field.options.Extensions[extensions_pb2.valuetype]
        vtype = (
            self._import_casttype(value_casttype)
            if value_casttype
            else self.python_type(value_field)
        )
        return ktype, vtype

    def _callable_type(self, method: d.MethodDescriptorProto) -> str:
        if method.client_streaming:
            if method.server_streaming:
                return self._import("grpc", "StreamStreamMultiCallable")
            else:
                return self._import("grpc", "StreamUnaryMultiCallable")
        else:
            if method.server_streaming:
                return self._import("grpc", "UnaryStreamMultiCallable")
            else:
                return self._import("grpc", "UnaryUnaryMultiCallable")

    def _input_type(
        self, method: d.MethodDescriptorProto, use_stream_iterator: bool = True
    ) -> str:
        result = self._import_message(method.input_type)
        if use_stream_iterator and method.client_streaming:
            result = f"{self._import('typing', 'Iterator')}[{result}]"
        return result

    def _output_type(
        self, method: d.MethodDescriptorProto, use_stream_iterator: bool = True
    ) -> str:
        result = self._import_message(method.output_type)
        if use_stream_iterator and method.server_streaming:
            result = f"{self._import('typing', 'Iterator')}[{result}]"
        return result

    def write_grpc_methods(
        self, service: d.ServiceDescriptorProto, scl_prefix: SourceCodeLocation
    ) -> None:
        l = self._write_line
        methods = [
            (i, m)
            for i, m in enumerate(service.method)
            if m.name not in PYTHON_RESERVED
        ]
        if not methods:
            l("pass")
            l("")
        for i, method in methods:
            scl = scl_prefix + [d.ServiceDescriptorProto.METHOD_FIELD_NUMBER, i]

            l("@{}", self._import("abc", "abstractmethod"))
            l("def {}(self,", method.name)
            with self._indent():
                input_name = (
                    "request_iterator" if method.client_streaming else "request"
                )
                input_type = self._input_type(method)
                l(f"{input_name}: {input_type},")
                l("context: {},", self._import("grpc", "ServicerContext"))
            l(
                ") -> {}:{}",
                self._output_type(method),
                " ..." if not self._has_comments(scl) else "",
            ),
            if self._has_comments(scl):
                with self._indent():
                    self._write_comments(scl)
                    l("pass")
            l("")

    def write_grpc_stub_methods(
        self, service: d.ServiceDescriptorProto, scl_prefix: SourceCodeLocation
    ) -> None:
        l = self._write_line
        methods = [
            (i, m)
            for i, m in enumerate(service.method)
            if m.name not in PYTHON_RESERVED
        ]
        if not methods:
            l("pass")
            l("")
        for i, method in methods:
            scl = scl_prefix + [d.ServiceDescriptorProto.METHOD_FIELD_NUMBER, i]

            l("{}: {}[", method.name, self._callable_type(method))
            with self._indent():
                l("{},", self._input_type(method, False))
                l("{}]", self._output_type(method, False))
            self._write_comments(scl)
            l("")

    def write_grpc_services(
        self,
        services: Iterable[d.ServiceDescriptorProto],
        scl_prefix: SourceCodeLocation,
    ) -> None:
        l = self._write_line
        for i, service in enumerate(services):
            if service.name in PYTHON_RESERVED:
                continue

            scl = scl_prefix + [i]

            # The stub client
            l(f"class {service.name}Stub:")
            with self._indent():
                self._write_comments(scl)
                l(
                    "def __init__(self, channel: {}) -> None: ...",
                    self._import("grpc", "Channel"),
                )
                self.write_grpc_stub_methods(service, scl)
            l("")

            # The service definition interface
            l(
                "class {}Servicer(metaclass={}):",
                service.name,
                self._import("abc", "ABCMeta"),
            )
            with self._indent():
                self._write_comments(scl)
                self.write_grpc_methods(service, scl)
            l("")
            l(
                "def add_{}Servicer_to_server(servicer: {}Servicer, server: {}) -> None: ...",
                service.name,
                service.name,
                self._import("grpc", "Server"),
            )
            l("")

    def python_type(
        self, field: d.FieldDescriptorProto, generic_container: bool = False
    ) -> str:
        """
        generic_container
          if set, type the field with generic interfaces. Eg.
          - Iterable[int] rather than RepeatedScalarFieldContainer[int]
          - Mapping[k, v] rather than MessageMap[k, v]
          Can be useful for input types (eg constructor)
        """
        casttype = field.options.Extensions[extensions_pb2.casttype]
        if casttype:
            return self._import_casttype(casttype)

        mapping: Dict[d.FieldDescriptorProto.Type.V, Callable[[], str]] = {
            d.FieldDescriptorProto.TYPE_DOUBLE: lambda: self._builtin("float"),
            d.FieldDescriptorProto.TYPE_FLOAT: lambda: self._builtin("float"),
            d.FieldDescriptorProto.TYPE_INT64: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_UINT64: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_FIXED64: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_SFIXED64: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_SINT64: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_INT32: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_UINT32: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_FIXED32: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_SFIXED32: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_SINT32: lambda: self._builtin("int"),
            d.FieldDescriptorProto.TYPE_BOOL: lambda: self._builtin("bool"),
            d.FieldDescriptorProto.TYPE_STRING: lambda: self._import("typing", "Text"),
            d.FieldDescriptorProto.TYPE_BYTES: lambda: self._builtin("bytes"),
            d.FieldDescriptorProto.TYPE_ENUM: lambda: self._import_message(
                field.type_name + ".ValueType"
            ),
            d.FieldDescriptorProto.TYPE_MESSAGE: lambda: self._import_message(
                field.type_name
            ),
            d.FieldDescriptorProto.TYPE_GROUP: lambda: self._import_message(
                field.type_name
            ),
        }

        assert field.type in mapping, "Unrecognized type: " + repr(field.type)
        field_type = mapping[field.type]()

        # For non-repeated fields, we're done!
        if field.label != d.FieldDescriptorProto.LABEL_REPEATED:
            return field_type

        # Scalar repeated fields go in RepeatedScalarFieldContainer
        if is_scalar(field):
            container = (
                self._import("typing", "Iterable")
                if generic_container
                else self._import(
                    "google.protobuf.internal.containers",
                    "RepeatedScalarFieldContainer",
                )
            )
            return f"{container}[{field_type}]"

        # non-scalar repeated map fields go in ScalarMap/MessageMap
        msg = self.descriptors.messages[field.type_name]
        if msg.options.map_entry:
            # map generates a special Entry wrapper message
            if generic_container:
                container = self._import("typing", "Mapping")
            elif is_scalar(msg.field[1]):
                container = self._import(
                    "google.protobuf.internal.containers", "ScalarMap"
                )
            else:
                container = self._import(
                    "google.protobuf.internal.containers", "MessageMap"
                )
            ktype, vtype = self._map_key_value_types(field, msg.field[0], msg.field[1])
            return f"{container}[{ktype}, {vtype}]"

        # non-scalar repetated fields go in RepeatedCompositeFieldContainer
        container = (
            self._import("typing", "Iterable")
            if generic_container
            else self._import(
                "google.protobuf.internal.containers",
                "RepeatedCompositeFieldContainer",
            )
        )
        return f"{container}[{field_type}]"

    def write(self) -> str:
        for reexport_idx in self.fd.public_dependency:
            reexport_file = self.fd.dependency[reexport_idx]
            reexport_fd = self.descriptors.files[reexport_file]
            reexport_imp = (
                reexport_file[:-6].replace("-", "_").replace("/", ".") + "_pb2"
            )
            names = (
                [m.name for m in reexport_fd.message_type]
                + [m.name for m in reexport_fd.enum_type]
                + [v.name for m in reexport_fd.enum_type for v in m.value]
                + [m.name for m in reexport_fd.extension]
            )
            if reexport_fd.options.py_generic_services:
                names.extend(m.name for m in reexport_fd.service)

            if names:
                # n,n to force a reexport (from x import y as y)
                self.from_imports[reexport_imp].update((n, n) for n in names)

        import_lines = []
        for pkg in sorted(self.imports):
            import_lines.append(f"import {pkg}")

        for pkg, items in sorted(self.from_imports.items()):
            import_lines.append(f"from {pkg} import (")
            for (name, reexport_name) in sorted(items):
                if reexport_name is None:
                    import_lines.append(f"    {name},")
                else:
                    import_lines.append(f"    {name} as {reexport_name},")
            import_lines.append(")\n")
        import_lines.append("")

        return "\n".join(import_lines + self.lines)


def is_scalar(fd: d.FieldDescriptorProto) -> bool:
    return not (
        fd.type == d.FieldDescriptorProto.TYPE_MESSAGE
        or fd.type == d.FieldDescriptorProto.TYPE_GROUP
    )


def generate_mypy_stubs(
    descriptors: Descriptors,
    response: plugin_pb2.CodeGeneratorResponse,
    quiet: bool,
    readable_stubs: bool,
    relax_strict_optional_primitives: bool,
) -> None:
    for name, fd in descriptors.to_generate.items():
        pkg_writer = PkgWriter(
            fd,
            descriptors,
            readable_stubs,
            relax_strict_optional_primitives,
            grpc=False,
        )

        pkg_writer.write_module_attributes()
        pkg_writer.write_enums(
            fd.enum_type, "", [d.FileDescriptorProto.ENUM_TYPE_FIELD_NUMBER]
        )
        pkg_writer.write_messages(
            fd.message_type, "", [d.FileDescriptorProto.MESSAGE_TYPE_FIELD_NUMBER]
        )
        pkg_writer.write_extensions(
            fd.extension, [d.FileDescriptorProto.EXTENSION_FIELD_NUMBER]
        )
        if fd.options.py_generic_services:
            pkg_writer.write_services(
                fd.service, [d.FileDescriptorProto.SERVICE_FIELD_NUMBER]
            )

        assert name == fd.name
        assert fd.name.endswith(".proto")
        output = response.file.add()
        output.name = fd.name[:-6].replace("-", "_").replace(".", "/") + "_pb2.pyi"
        output.content = HEADER + pkg_writer.write()


def generate_mypy_grpc_stubs(
    descriptors: Descriptors,
    response: plugin_pb2.CodeGeneratorResponse,
    quiet: bool,
    readable_stubs: bool,
    relax_strict_optional_primitives: bool,
) -> None:
    for name, fd in descriptors.to_generate.items():
        pkg_writer = PkgWriter(
            fd,
            descriptors,
            readable_stubs,
            relax_strict_optional_primitives,
            grpc=True,
        )
        pkg_writer.write_grpc_services(
            fd.service, [d.FileDescriptorProto.SERVICE_FIELD_NUMBER]
        )

        assert name == fd.name
        assert fd.name.endswith(".proto")
        output = response.file.add()
        output.name = fd.name[:-6].replace("-", "_").replace(".", "/") + "_pb2_grpc.pyi"
        output.content = HEADER + pkg_writer.write()


@contextmanager
def code_generation() -> Iterator[
    Tuple[plugin_pb2.CodeGeneratorRequest, plugin_pb2.CodeGeneratorResponse],
]:
    if len(sys.argv) > 1 and sys.argv[1] in ("-V", "--version"):
        print("mypy-protobuf " + __version__)
        sys.exit(0)

    # Read request message from stdin
    data = sys.stdin.buffer.read()

    # Parse request
    request = plugin_pb2.CodeGeneratorRequest()
    request.ParseFromString(data)

    # Create response
    response = plugin_pb2.CodeGeneratorResponse()

    # Declare support for optional proto3 fields
    response.supported_features |= (
        plugin_pb2.CodeGeneratorResponse.FEATURE_PROTO3_OPTIONAL
    )

    yield request, response

    # Serialise response message
    output = response.SerializeToString()

    # Write to stdout
    sys.stdout.buffer.write(output)


def main() -> None:
    # Generate mypy
    with code_generation() as (request, response):
        generate_mypy_stubs(
            Descriptors(request),
            response,
            "quiet" in request.parameter,
            "readable_stubs" in request.parameter,
            "relax_strict_optional_primitives" in request.parameter,
        )


def grpc() -> None:
    # Generate grpc mypy
    with code_generation() as (request, response):
        generate_mypy_grpc_stubs(
            Descriptors(request),
            response,
            "quiet" in request.parameter,
            "readable_stubs" in request.parameter,
            "relax_strict_optional_primitives" in request.parameter,
        )


if __name__ == "__main__":
    main()