mago-analyzer 1.47.1

A PHP static analyzer that can detect type errors in PHP code, and provide suggestions for fixing them.
Documentation
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
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
use std::collections::BTreeMap;

use mago_codex::assertion::Assertion;
use mago_codex::identifier::function_like::FunctionLikeIdentifier;
use mago_codex::identifier::method::MethodIdentifier;
use mago_codex::metadata::CodebaseMetadata;
use mago_codex::metadata::attribute::AttributeMetadata;
use mago_codex::metadata::class_like::ClassLikeMetadata;
use mago_codex::metadata::class_like::TemplateTypes;
use mago_codex::metadata::class_like_constant::ClassLikeConstantMetadata;
use mago_codex::metadata::constant::ConstantMetadata;
use mago_codex::metadata::enum_case::EnumCaseMetadata;
use mago_codex::metadata::function_like::FunctionLikeKind;
use mago_codex::metadata::function_like::FunctionLikeMetadata;
use mago_codex::metadata::parameter::FunctionLikeParameterMetadata;
use mago_codex::metadata::property::PropertyMetadata;
use mago_codex::metadata::property_hook::PropertyHookMetadata;
use mago_codex::metadata::ttype::TypeMetadata;
use mago_codex::metadata::version_constraint::VersionConstraint;
use mago_codex::symbol::SymbolKind;
use mago_codex::ttype::atomic::TAtomic;
use mago_codex::ttype::atomic::array::key::ArrayKey;
use mago_codex::ttype::template::variance::Variance;
use mago_codex::ttype::union::TUnion;
use mago_codex::visibility::Visibility;
use mago_extension::PayloadReader;
use mago_extension::PayloadWriter;
use mago_span::Span;
use mago_word::Word;
use mago_word::ascii_lowercase_word;
use mago_word::word;

use crate::external::ExternalAnalysisSession;
use crate::external::error::ExternalAnalyzerError;
use crate::external::error::protocol;
use crate::external::protocol::decode_function_like_identifier;
use crate::external::protocol::encode_function_like_identifier;
use crate::external::protocol::encode_generic_parent;
use crate::external::protocol::encode_union_snapshot;

pub(super) const CODEBASE_QUERY_REQUEST: u16 = 4;
pub(super) const CODEBASE_QUERY_RESPONSE: u16 = 0x8004;

const GET_CLASS_LIKES: u8 = 1;
const GET_FUNCTIONS: u8 = 2;
const GET_METHODS: u8 = 3;
const GET_CONSTANTS: u8 = 4;
const GET_PROPERTIES: u8 = 5;
const GET_CLASS_CONSTANTS: u8 = 6;
const GET_ENUM_CASES: u8 = 7;
const LIST_CLASS_LIKES: u8 = 8;
const LIST_FUNCTIONS: u8 = 9;
const LIST_CONSTANTS: u8 = 10;
const GET_DECLARING_METHODS: u8 = 11;
const GET_DECLARING_PROPERTIES: u8 = 12;
const CHECK_EXISTENCE: u8 = 13;
const CHECK_MEMBER_EXISTENCE: u8 = 14;
const GET_CLASS_LIKE_RELATIONS: u8 = 15;
const GET_MAGIC_PROPERTIES: u8 = 16;
const GET_DECLARING_MAGIC_PROPERTIES: u8 = 17;
const GET_FUNCTION_LIKES: u8 = 18;
const FIND_METHODS: u8 = 19;

const ANY_CLASS_LIKE: u8 = 0;
const CLASS: u8 = 1;
const INTERFACE: u8 = 2;
const TRAIT: u8 = 3;
const ENUM: u8 = 4;

const MAXIMUM_QUERIES: usize = 0x0001_0000;
const MAXIMUM_METHOD_PROJECTIONS: usize = 0x000F_4240;

const METHOD_SEARCH_ANY_CLASS: u8 = 0;
const METHOD_SEARCH_EXACT_CLASS: u8 = 1;
const METHOD_SEARCH_DESCENDANTS: u8 = 2;

const METHOD_FIELDS_NAMES: u32 = 1;
const METHOD_FIELDS_LOCATIONS: u32 = 1 << 1;
const METHOD_FIELDS_PARAMETERS: u32 = 1 << 2;
const METHOD_FIELDS_RETURN_TYPES: u32 = 1 << 3;
const METHOD_FIELDS_TEMPLATES: u32 = 1 << 4;
const METHOD_FIELDS_ATTRIBUTES: u32 = 1 << 5;
const METHOD_FIELDS_THROWN_TYPES: u32 = 1 << 6;
const METHOD_FIELDS_ASSERTIONS: u32 = 1 << 7;
const METHOD_FIELDS_GLOBALS: u32 = 1 << 8;
const METHOD_FIELDS_DOCBLOCK: u32 = 1 << 9;
const METHOD_FIELDS_FLAGS: u32 = 1 << 10;
const METHOD_FIELDS_AVAILABLE_VERSIONS: u32 = 1 << 11;
const METHOD_FIELDS_METHOD_DETAILS: u32 = 1 << 12;
const METHOD_FIELDS_WHERE_CONSTRAINTS: u32 = 1 << 13;
const METHOD_FIELDS_ALL: u32 = (1 << 14) - 1;

const EXISTS_CLASS: u8 = 1;
const EXISTS_INTERFACE: u8 = 2;
const EXISTS_TRAIT: u8 = 3;
const EXISTS_ENUM: u8 = 4;
const EXISTS_CLASS_LIKE: u8 = 5;
const EXISTS_NAMESPACE: u8 = 6;
const EXISTS_FUNCTION: u8 = 7;
const EXISTS_CONSTANT: u8 = 8;
const EXISTS_CLASS_OR_TRAIT: u8 = 9;
const EXISTS_CLASS_OR_INTERFACE: u8 = 10;

const EXISTS_METHOD: u8 = 1;
const EXISTS_PROPERTY: u8 = 2;
const EXISTS_CLASS_CONSTANT: u8 = 3;
const EXISTS_ENUM_CASE: u8 = 4;
const EXISTS_MAGIC_PROPERTY: u8 = 5;

const DIRECT_DESCENDANTS: u8 = 1;
const ALL_DESCENDANTS: u8 = 2;
const ALL_ANCESTORS: u8 = 3;

pub(super) fn handle_query(
    reader: &mut PayloadReader<'_>,
    codebase: &CodebaseMetadata,
    session: &ExternalAnalysisSession,
    writer: &mut PayloadWriter,
) -> Result<(), ExternalAnalyzerError> {
    let generation = reader.read_u64("codebase generation")?;
    if generation != session.generation() {
        return Err(protocol(format!(
            "metadata query targets generation {generation}, but the active generation is {}",
            session.generation()
        )));
    }

    writer.write_u64(generation);
    let operation = reader.read_u8("codebase query operation")?;
    writer.write_u8(operation);
    match operation {
        GET_CLASS_LIKES => query_class_likes(reader, writer, codebase, session),
        GET_FUNCTIONS => query_names(reader, writer, |name, writer| {
            write_optional(writer, codebase.get_function(name), |writer, metadata| {
                write_function_like(writer, FunctionLikeIdentifier::Function(metadata.original_name), metadata, session)
            })
        }),
        GET_METHODS => query_members(reader, writer, |class, member, writer| {
            write_optional(writer, codebase.get_method(class, member), |writer, metadata| {
                write_function_like(writer, method_identifier(codebase, class, member, metadata), metadata, session)
            })
        }),
        GET_CONSTANTS => query_names(reader, writer, |name, writer| {
            write_optional(writer, codebase.get_constant(name), |writer, metadata| {
                write_constant(writer, metadata, session)
            })
        }),
        GET_PROPERTIES => query_members(reader, writer, |class, member, writer| {
            write_optional(writer, codebase.get_property(class, member), |writer, metadata| {
                write_property(writer, metadata, session)
            })
        }),
        GET_CLASS_CONSTANTS => query_members(reader, writer, |class, member, writer| {
            write_optional(writer, codebase.get_class_constant(class, member), |writer, metadata| {
                write_class_constant(writer, metadata, session)
            })
        }),
        GET_ENUM_CASES => query_members(reader, writer, |class, member, writer| {
            write_optional(writer, codebase.get_enum_case(class, member), |writer, metadata| {
                write_enum_case(writer, metadata, session)
            })
        }),
        LIST_CLASS_LIKES => list_class_likes(reader, writer, codebase),
        LIST_FUNCTIONS => list_functions(reader, writer, codebase),
        LIST_CONSTANTS => list_constants(reader, writer, codebase),
        GET_DECLARING_METHODS => query_members(reader, writer, |class, member, writer| {
            write_optional(writer, codebase.get_declaring_method(class, member), |writer, metadata| {
                write_function_like(writer, method_identifier(codebase, class, member, metadata), metadata, session)
            })
        }),
        GET_DECLARING_PROPERTIES => query_members(reader, writer, |class, member, writer| {
            write_optional(writer, codebase.get_declaring_property(class, member), |writer, metadata| {
                write_property(writer, metadata, session)
            })
        }),
        CHECK_EXISTENCE => check_existence(reader, writer, codebase),
        CHECK_MEMBER_EXISTENCE => check_member_existence(reader, writer, codebase),
        GET_CLASS_LIKE_RELATIONS => get_class_like_relations(reader, writer, codebase),
        GET_MAGIC_PROPERTIES => query_members(reader, writer, |class, member, writer| {
            write_optional(writer, codebase.get_magic_property(class, member), |writer, metadata| {
                write_property(writer, metadata, session)
            })
        }),
        GET_DECLARING_MAGIC_PROPERTIES => query_members(reader, writer, |class, member, writer| {
            write_optional(writer, codebase.get_declaring_magic_property(class, member), |writer, metadata| {
                write_property(writer, metadata, session)
            })
        }),
        GET_FUNCTION_LIKES => query_function_likes(reader, writer, codebase, session),
        FIND_METHODS => find_methods(reader, writer, codebase, session),
        unknown => Err(protocol(format!("unknown codebase query operation {unknown}"))),
    }
}

#[allow(clippy::too_many_lines)]
fn find_methods(
    reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    codebase: &CodebaseMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    let started = tracing::enabled!(tracing::Level::TRACE).then(std::time::Instant::now);
    let class_filter = reader.read_u8("method search class filter")?;
    let class = match class_filter {
        METHOD_SEARCH_ANY_CLASS => None,
        METHOD_SEARCH_EXACT_CLASS | METHOD_SEARCH_DESCENDANTS => {
            let class = reader.read_bytes("method search class")?;
            if class.is_empty() {
                return Err(protocol("method search class cannot be empty"));
            }

            Some(ascii_lowercase_word(class))
        }
        unknown => return Err(protocol(format!("unknown method search class filter {unknown}"))),
    };

    let pattern = reader.read_bytes("method search name pattern")?;
    if pattern.is_empty() {
        return Err(protocol("method search name pattern cannot be empty"));
    }
    let prefix = pattern.ends_with(b"*");
    let pattern = if prefix { &pattern[..pattern.len() - 1] } else { pattern };
    if pattern.contains(&b'*') {
        return Err(protocol("method search wildcards are only allowed at the end"));
    }
    let pattern = ascii_lowercase_word(pattern);
    let declared_only = reader.read_bool("method search declared-only filter")?;

    let attribute_count = reader.read_count("method search attribute filters", MAXIMUM_QUERIES)?;
    let mut attributes = Vec::with_capacity(attribute_count);
    for _ in 0..attribute_count {
        let attribute = reader.read_bytes("method search attribute")?;
        if attribute.is_empty() {
            return Err(protocol("method search attribute cannot be empty"));
        }
        attributes.push(ascii_lowercase_word(attribute));
    }

    let fields = reader.read_u32("method projection fields")?;
    if fields & !METHOD_FIELDS_ALL != 0 {
        return Err(protocol(format!("method projection contains unknown fields {fields:#x}")));
    }
    writer.write_u32(fields);

    let mut scanned_classes = 0usize;
    let mut scanned_methods = 0usize;
    let mut matches = Vec::new();
    let mut collect = |class_like: &ClassLikeMetadata| {
        scanned_classes += 1;
        for (method_name, declaring) in &class_like.declaring_method_ids {
            scanned_methods += 1;
            let matches_name =
                if prefix { method_name.as_bytes().starts_with(pattern.as_bytes()) } else { *method_name == pattern };
            if !matches_name || (declared_only && declaring.get_class_name() != class_like.name) {
                continue;
            }

            let Some(metadata) = codebase.get_method_by_id(declaring) else {
                continue;
            };
            if !attributes.is_empty()
                && !metadata.attributes.iter().any(|attribute| {
                    attributes
                        .iter()
                        .any(|requested| attribute.name.as_bytes().eq_ignore_ascii_case(requested.as_bytes()))
                })
            {
                continue;
            }

            matches.push((class_like.name, *method_name, *declaring));
        }
    };

    match (class_filter, class) {
        (METHOD_SEARCH_EXACT_CLASS, Some(class)) => {
            if let Some(class_like) = codebase.class_likes.get(&class) {
                collect(class_like);
            }
        }
        (METHOD_SEARCH_DESCENDANTS, Some(class)) => {
            for class_like in codebase.class_likes.values() {
                if class_like.name != class && codebase.is_instance_of(class_like.name.as_bytes(), class.as_bytes()) {
                    collect(class_like);
                }
            }
        }
        (METHOD_SEARCH_ANY_CLASS, None) => {
            for class_like in codebase.class_likes.values() {
                collect(class_like);
            }
        }
        _ => unreachable!(),
    }

    if matches.len() > MAXIMUM_METHOD_PROJECTIONS {
        return Err(protocol(format!(
            "method search returned {} results, exceeding the limit of {MAXIMUM_METHOD_PROJECTIONS}",
            matches.len()
        )));
    }
    matches.sort_unstable_by(|(left_class, left_method, _), (right_class, right_method, _)| {
        left_class
            .as_bytes()
            .cmp(right_class.as_bytes())
            .then_with(|| left_method.as_bytes().cmp(right_method.as_bytes()))
    });

    writer.write_u32(matches.len() as u32);
    for (class_name, method_name, declaring) in &matches {
        let class_like = codebase
            .class_likes
            .get(class_name)
            .ok_or_else(|| protocol("method projection references a missing class-like"))?;
        let metadata = codebase
            .get_method_by_id(declaring)
            .ok_or_else(|| protocol("method projection references missing method metadata"))?;
        write_method_projection(writer, class_like, *method_name, metadata, fields, codebase, session)?;
    }

    if let Some(started) = started {
        tracing::trace!(
            class_filter,
            fields,
            declared_only,
            attribute_filters = attributes.len(),
            scanned_classes,
            scanned_methods,
            matched_methods = matches.len(),
            elapsed_us = started.elapsed().as_micros(),
            "completed projected method metadata query"
        );
    }

    Ok(())
}

fn write_method_projection(
    writer: &mut PayloadWriter,
    class_like: &ClassLikeMetadata,
    method_name: Word,
    metadata: &FunctionLikeMetadata,
    fields: u32,
    codebase: &CodebaseMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_bytes(class_like.original_name.as_bytes())?;
    writer.write_bytes(metadata.original_name.as_bytes())?;
    encode_function_like_identifier(
        writer,
        method_identifier(codebase, class_like.name.as_bytes(), method_name.as_bytes(), metadata),
    )?;

    if fields & METHOD_FIELDS_NAMES != 0 {
        writer.write_bytes(metadata.name.as_bytes())?;
        writer.write_bytes(metadata.original_name.as_bytes())?;
    }
    if fields & METHOD_FIELDS_LOCATIONS != 0 {
        write_location(writer, metadata.span, session)?;
        write_optional_location(writer, metadata.name_span, session)?;
    }
    if fields & METHOD_FIELDS_PARAMETERS != 0 {
        writer.write_u32(metadata.parameters.len() as u32);
        for parameter in &metadata.parameters {
            write_parameter(writer, parameter, session)?;
        }
    }
    if fields & METHOD_FIELDS_RETURN_TYPES != 0 {
        write_optional_type_metadata(writer, metadata.return_type_declaration_metadata.as_ref(), session)?;
        write_optional_type_metadata(writer, metadata.return_type_metadata.as_ref(), session)?;
    }
    if fields & METHOD_FIELDS_TEMPLATES != 0 {
        write_templates(writer, &metadata.template_types, None, None)?;
    }
    if fields & METHOD_FIELDS_ATTRIBUTES != 0 {
        write_attributes(writer, &metadata.attributes, session)?;
    }
    if fields & METHOD_FIELDS_THROWN_TYPES != 0 {
        writer.write_u32(metadata.thrown_types.len() as u32);
        for thrown in &metadata.thrown_types {
            write_type_metadata(writer, thrown, session)?;
        }
    }
    if fields & METHOD_FIELDS_ASSERTIONS != 0 {
        write_assertions(writer, &metadata.assertions)?;
        write_assertions(writer, &metadata.if_true_assertions)?;
        write_assertions(writer, &metadata.if_false_assertions)?;
        writer.write_bool(metadata.assertions_inferred);
    }
    if fields & METHOD_FIELDS_GLOBALS != 0 {
        write_words(writer, metadata.globals_accessed.iter().copied())?;
    }
    if fields & METHOD_FIELDS_DOCBLOCK != 0 {
        writer.write_bool(metadata.has_docblock);
    }
    if fields & METHOD_FIELDS_FLAGS != 0 {
        writer.write_u64(metadata.flags.bits());
    }
    if fields & METHOD_FIELDS_AVAILABLE_VERSIONS != 0 {
        write_version_constraint(writer, &metadata.version_constraint);
    }

    let method = metadata.method_metadata.as_ref();
    if fields & METHOD_FIELDS_METHOD_DETAILS != 0 {
        let method = method.ok_or_else(|| protocol("method projection targets non-method metadata"))?;
        write_visibility(writer, method.visibility);
        writer.write_bool(method.is_final);
        writer.write_bool(method.is_abstract);
        writer.write_bool(method.is_static);
        writer.write_bool(method.is_constructor);
    }
    if fields & METHOD_FIELDS_WHERE_CONSTRAINTS != 0 {
        let mut constraints =
            method.map(|method| method.where_constraints.iter().collect::<Vec<_>>()).unwrap_or_default();
        constraints.sort_unstable_by(|(left, _), (right, _)| left.as_bytes().cmp(right.as_bytes()));
        writer.write_u32(constraints.len() as u32);
        for (name, constraint) in constraints {
            writer.write_bytes(name.as_bytes())?;
            write_type_metadata(writer, constraint, session)?;
        }
    }

    Ok(())
}

fn query_function_likes(
    reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    codebase: &CodebaseMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    let count = reader.read_count("function-like metadata queries", MAXIMUM_QUERIES)?;
    writer.write_u32(count as u32);
    for _ in 0..count {
        let identifier = decode_function_like_identifier(reader)?;
        write_optional(writer, codebase.get_function_like(&identifier), |writer, metadata| {
            write_function_like(
                writer,
                canonical_function_like_identifier(codebase, identifier, metadata),
                metadata,
                session,
            )
        })?;
    }
    Ok(())
}

fn get_class_like_relations(
    reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    codebase: &CodebaseMetadata,
) -> Result<(), ExternalAnalyzerError> {
    let relation = reader.read_u8("class-like relation")?;
    if !(DIRECT_DESCENDANTS..=ALL_ANCESTORS).contains(&relation) {
        return Err(protocol(format!("unknown class-like relation {relation}")));
    }

    writer.write_u8(relation);
    query_names(reader, writer, |name, writer| {
        match relation {
            DIRECT_DESCENDANTS => {
                let descendants = codebase
                    .get_class_like(name)
                    .and_then(|metadata| codebase.direct_classlike_descendants.get(&metadata.name));
                write_words(writer, descendants.into_iter().flatten().copied())?;
            }
            ALL_DESCENDANTS => write_words(writer, codebase.get_class_descendants(name))?,
            ALL_ANCESTORS => write_words(writer, codebase.get_class_ancestors(name))?,
            _ => unreachable!(),
        }

        Ok(())
    })
}

fn check_member_existence(
    reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    codebase: &CodebaseMetadata,
) -> Result<(), ExternalAnalyzerError> {
    let predicate = reader.read_u8("member existence predicate")?;
    if !(EXISTS_METHOD..=EXISTS_MAGIC_PROPERTY).contains(&predicate) {
        return Err(protocol(format!("unknown member existence predicate {predicate}")));
    }

    writer.write_u8(predicate);
    query_members(reader, writer, |class, member, writer| {
        writer.write_bool(match predicate {
            EXISTS_METHOD => codebase.method_exists(class, member),
            EXISTS_PROPERTY => codebase.property_exists(class, member),
            EXISTS_CLASS_CONSTANT => codebase.class_constant_exists(class, member),
            EXISTS_ENUM_CASE => codebase.get_enum_case(class, member).is_some(),
            EXISTS_MAGIC_PROPERTY => codebase.magic_property_exists(class, member),
            _ => unreachable!(),
        });

        Ok(())
    })
}

fn check_existence(
    reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    codebase: &CodebaseMetadata,
) -> Result<(), ExternalAnalyzerError> {
    let predicate = reader.read_u8("existence predicate")?;
    if !(EXISTS_CLASS..=EXISTS_CLASS_OR_INTERFACE).contains(&predicate) {
        return Err(protocol(format!("unknown existence predicate {predicate}")));
    }

    writer.write_u8(predicate);
    query_names(reader, writer, |name, writer| {
        writer.write_bool(match predicate {
            EXISTS_CLASS => codebase.class_exists(name),
            EXISTS_INTERFACE => codebase.interface_exists(name),
            EXISTS_TRAIT => codebase.trait_exists(name),
            EXISTS_ENUM => codebase.enum_exists(name),
            EXISTS_CLASS_LIKE => codebase.class_like_exists(name),
            EXISTS_NAMESPACE => codebase.namespace_exists(name),
            EXISTS_FUNCTION => codebase.function_exists(name),
            EXISTS_CONSTANT => codebase.constant_exists(name),
            EXISTS_CLASS_OR_TRAIT => codebase.class_or_trait_exists(name),
            EXISTS_CLASS_OR_INTERFACE => codebase.class_or_interface_exists(name),
            _ => unreachable!(),
        });

        Ok(())
    })
}

fn list_class_likes(
    reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    codebase: &CodebaseMetadata,
) -> Result<(), ExternalAnalyzerError> {
    let filter = reader.read_u8("class-like kind filter")?;
    if filter > ENUM {
        return Err(protocol(format!("unknown class-like kind filter {filter}")));
    }

    writer.write_u8(filter);
    write_words(
        writer,
        codebase
            .class_likes
            .values()
            .filter(|metadata| class_like_matches(metadata.kind, filter))
            .map(|metadata| metadata.original_name),
    )
}

fn list_functions(
    _reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    codebase: &CodebaseMetadata,
) -> Result<(), ExternalAnalyzerError> {
    write_words(
        writer,
        codebase
            .function_likes
            .iter()
            .filter(|((scope, _), metadata)| scope.is_empty() && metadata.kind == FunctionLikeKind::Function)
            .map(|(_, metadata)| metadata.original_name),
    )
}

fn list_constants(
    _reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    codebase: &CodebaseMetadata,
) -> Result<(), ExternalAnalyzerError> {
    write_words(writer, codebase.constants.values().map(|metadata| metadata.name))
}

fn query_class_likes(
    reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    codebase: &CodebaseMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    let filter = reader.read_u8("class-like kind filter")?;
    if filter > ENUM {
        return Err(protocol(format!("unknown class-like kind filter {filter}")));
    }

    writer.write_u8(filter);
    query_names(reader, writer, |name, writer| {
        let metadata = match filter {
            ANY_CLASS_LIKE => codebase.get_class_like(name),
            CLASS => codebase.get_class(name),
            INTERFACE => codebase.get_interface(name),
            TRAIT => codebase.get_trait(name),
            ENUM => codebase.get_enum(name),
            _ => unreachable!(),
        };

        write_optional(writer, metadata, |writer, metadata| write_class_like(writer, metadata, session))
    })
}

fn query_names<F>(
    reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    mut query: F,
) -> Result<(), ExternalAnalyzerError>
where
    F: FnMut(&[u8], &mut PayloadWriter) -> Result<(), ExternalAnalyzerError>,
{
    let count = reader.read_count("metadata query names", MAXIMUM_QUERIES)?;
    writer.write_u32(count as u32);
    for _ in 0..count {
        query(reader.read_bytes("metadata query name")?, writer)?;
    }

    Ok(())
}

fn query_members<F>(
    reader: &mut PayloadReader<'_>,
    writer: &mut PayloadWriter,
    mut query: F,
) -> Result<(), ExternalAnalyzerError>
where
    F: FnMut(&[u8], &[u8], &mut PayloadWriter) -> Result<(), ExternalAnalyzerError>,
{
    let count = reader.read_count("metadata query members", MAXIMUM_QUERIES)?;
    writer.write_u32(count as u32);
    for _ in 0..count {
        let class = reader.read_bytes("metadata query class")?;
        let member = reader.read_bytes("metadata query member")?;
        query(class, member, writer)?;
    }

    Ok(())
}

fn write_optional<T, F>(writer: &mut PayloadWriter, value: Option<&T>, encode: F) -> Result<(), ExternalAnalyzerError>
where
    F: FnOnce(&mut PayloadWriter, &T) -> Result<(), ExternalAnalyzerError>,
{
    writer.write_bool(value.is_some());
    if let Some(value) = value {
        encode(writer, value)?;
    }

    Ok(())
}

pub(super) fn write_class_like(
    writer: &mut PayloadWriter,
    metadata: &ClassLikeMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_bytes(metadata.name.as_bytes())?;
    writer.write_bytes(metadata.original_name.as_bytes())?;
    writer.write_u8(symbol_kind(metadata.kind));
    write_location(writer, metadata.span, session)?;
    write_optional_location(writer, metadata.name_span, session)?;
    writer.write_u64(metadata.flags.bits());
    write_optional_word(writer, metadata.direct_parent_class)?;
    write_words(writer, metadata.direct_parent_interfaces.iter().copied())?;
    write_words(writer, metadata.all_parent_interfaces.iter().copied())?;
    write_words(writer, metadata.all_parent_classes.iter().copied())?;
    write_words(writer, metadata.require_extends.iter().copied())?;
    write_words(writer, metadata.require_implements.iter().copied())?;
    write_words(writer, metadata.used_traits.iter().copied())?;
    write_words(writer, metadata.incomplete_hierarchy_dependencies())?;
    write_words(writer, metadata.methods.iter().copied())?;
    write_words(writer, metadata.pseudo_methods.iter().copied())?;
    write_words(writer, metadata.static_pseudo_methods.iter().copied())?;
    write_words(writer, metadata.properties.keys().copied())?;
    write_words(writer, metadata.magic_properties.keys().copied())?;
    write_words(writer, metadata.constants.keys().copied())?;
    write_words(writer, metadata.enum_cases.keys().copied())?;
    write_optional_words(writer, metadata.child_class_likes.as_ref().map(|words| words.iter().copied()))?;
    write_optional_words(writer, metadata.permitted_inheritors.as_ref().map(|words| words.iter().copied()))?;
    write_templates(
        writer,
        &metadata.template_types,
        Some(&metadata.template_variance),
        Some(&metadata.template_readonly),
    )?;
    write_attributes(writer, &metadata.attributes, session)?;
    write_type_aliases(writer, &metadata.type_aliases, session)?;
    write_mixins(writer, &metadata.mixins)?;
    write_optional_atomic(writer, metadata.enum_type.as_ref())?;
    write_optional_bool(writer, metadata.has_sealed_methods);
    write_optional_bool(writer, metadata.has_sealed_properties);
    write_version_constraint(writer, &metadata.version_constraint);
    Ok(())
}

fn write_function_like(
    writer: &mut PayloadWriter,
    identifier: FunctionLikeIdentifier,
    metadata: &FunctionLikeMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    encode_function_like_identifier(writer, identifier)?;
    writer.write_u8(match metadata.kind {
        FunctionLikeKind::Function => 1,
        FunctionLikeKind::Method => 2,
        FunctionLikeKind::Closure => 3,
        FunctionLikeKind::ArrowFunction => 4,
    });

    writer.write_bytes(metadata.name.as_bytes())?;
    writer.write_bytes(metadata.original_name.as_bytes())?;
    write_location(writer, metadata.span, session)?;
    write_optional_location(writer, metadata.name_span, session)?;
    writer.write_u32(metadata.parameters.len() as u32);
    for parameter in &metadata.parameters {
        write_parameter(writer, parameter, session)?;
    }

    write_optional_type_metadata(writer, metadata.return_type_declaration_metadata.as_ref(), session)?;
    write_optional_type_metadata(writer, metadata.return_type_metadata.as_ref(), session)?;
    write_templates(writer, &metadata.template_types, None, None)?;
    write_attributes(writer, &metadata.attributes, session)?;
    writer.write_u32(metadata.thrown_types.len() as u32);
    for thrown in &metadata.thrown_types {
        write_type_metadata(writer, thrown, session)?;
    }

    write_words(writer, metadata.globals_accessed.iter().copied())?;
    write_assertions(writer, &metadata.assertions)?;
    write_assertions(writer, &metadata.if_true_assertions)?;
    write_assertions(writer, &metadata.if_false_assertions)?;
    writer.write_bool(metadata.assertions_inferred);
    writer.write_bool(metadata.has_docblock);
    writer.write_u64(metadata.flags.bits());
    write_version_constraint(writer, &metadata.version_constraint);
    writer.write_bool(metadata.method_metadata.is_some());
    if let Some(method) = &metadata.method_metadata {
        write_visibility(writer, method.visibility);
        writer.write_bool(method.is_final);
        writer.write_bool(method.is_abstract);
        writer.write_bool(method.is_static);
        writer.write_bool(method.is_constructor);
        let mut constraints: Vec<_> = method.where_constraints.iter().collect();
        constraints.sort_unstable_by(|(left, _), (right, _)| left.as_bytes().cmp(right.as_bytes()));
        writer.write_u32(constraints.len() as u32);
        for (name, constraint) in constraints {
            writer.write_bytes(name.as_bytes())?;
            write_type_metadata(writer, constraint, session)?;
        }
    }

    Ok(())
}

fn canonical_function_like_identifier(
    codebase: &CodebaseMetadata,
    identifier: FunctionLikeIdentifier,
    metadata: &FunctionLikeMetadata,
) -> FunctionLikeIdentifier {
    match identifier {
        FunctionLikeIdentifier::Function(_) => FunctionLikeIdentifier::Function(metadata.original_name),
        FunctionLikeIdentifier::Method(class, method) => {
            method_identifier(codebase, class.as_bytes(), method.as_bytes(), metadata)
        }
        FunctionLikeIdentifier::Closure(_) => FunctionLikeIdentifier::Closure(metadata.name),
    }
}

fn method_identifier(
    codebase: &CodebaseMetadata,
    class: &[u8],
    method: &[u8],
    metadata: &FunctionLikeMetadata,
) -> FunctionLikeIdentifier {
    let declaring = codebase.get_declaring_method_identifier(&MethodIdentifier::new(word(class), word(method)));
    let class = codebase
        .get_class_like(declaring.get_class_name().as_bytes())
        .map_or(declaring.get_class_name(), |metadata| metadata.original_name);

    FunctionLikeIdentifier::Method(class, metadata.original_name)
}

fn write_assertions(
    writer: &mut PayloadWriter,
    assertions: &BTreeMap<Word, Vec<Assertion>>,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_u32(assertions.len() as u32);
    for (variable, values) in assertions {
        writer.write_bytes(variable.as_bytes())?;
        writer.write_u32(values.len() as u32);
        for assertion in values {
            write_assertion(writer, assertion)?;
        }
    }
    Ok(())
}

#[allow(clippy::too_many_lines)]
fn write_assertion(writer: &mut PayloadWriter, assertion: &Assertion) -> Result<(), ExternalAnalyzerError> {
    let kind = match assertion {
        Assertion::Any => 1,
        Assertion::IsType(_) => 2,
        Assertion::IsNotType(_) => 3,
        Assertion::Falsy => 4,
        Assertion::Truthy => 5,
        Assertion::IsIdentical(_) => 6,
        Assertion::IsNotIdentical(_) => 7,
        Assertion::IsEqual(_) => 8,
        Assertion::IsNotEqual(_) => 9,
        Assertion::IsEqualIsset => 10,
        Assertion::IsIsset => 11,
        Assertion::IsNotIsset => 12,
        Assertion::HasStringArrayAccess => 13,
        Assertion::HasIntOrStringArrayAccess => 14,
        Assertion::ArrayKeyExists => 15,
        Assertion::ArrayKeyDoesNotExist => 16,
        Assertion::InArray(_) => 17,
        Assertion::NotInArray(_) => 18,
        Assertion::HasArrayKey(_) => 19,
        Assertion::DoesNotHaveArrayKey(_) => 20,
        Assertion::HasNonnullEntryForKey(_) => 21,
        Assertion::DoesNotHaveNonnullEntryForKey(_) => 22,
        Assertion::Empty => 23,
        Assertion::NonEmpty => 24,
        Assertion::NonEmptyCountable(_) => 25,
        Assertion::EmptyCountable => 26,
        Assertion::HasExactCount(_) => 27,
        Assertion::HasAtLeastCount(_) => 28,
        Assertion::DoesNotHaveExactCount(_) => 29,
        Assertion::DoesNotHasAtLeastCount(_) => 30,
        Assertion::IsLessThan(_) => 31,
        Assertion::IsLessThanOrEqual(_) => 32,
        Assertion::IsGreaterThan(_) => 33,
        Assertion::IsGreaterThanOrEqual(_) => 34,
        Assertion::IsLessThanFromBound(_) => 35,
        Assertion::IsLessThanOrEqualFromBound(_) => 36,
        Assertion::IsGreaterThanFromBound(_) => 37,
        Assertion::IsGreaterThanOrEqualFromBound(_) => 38,
        Assertion::IsLessThanVariable(_) => 39,
        Assertion::IsLessThanOrEqualVariable(_) => 40,
        Assertion::IsGreaterThanVariable(_) => 41,
        Assertion::IsGreaterThanOrEqualVariable(_) => 42,
        Assertion::Countable => 43,
        Assertion::NotCountable(_) => 44,
    };
    writer.write_u8(kind);

    match assertion {
        Assertion::IsType(atomic)
        | Assertion::IsNotType(atomic)
        | Assertion::IsIdentical(atomic)
        | Assertion::IsNotIdentical(atomic)
        | Assertion::IsEqual(atomic)
        | Assertion::IsNotEqual(atomic) => write_atomic(writer, atomic)?,
        Assertion::InArray(union) | Assertion::NotInArray(union) => write_union(writer, union)?,
        Assertion::HasArrayKey(key)
        | Assertion::DoesNotHaveArrayKey(key)
        | Assertion::HasNonnullEntryForKey(key)
        | Assertion::DoesNotHaveNonnullEntryForKey(key) => write_array_key(writer, key)?,
        Assertion::NonEmptyCountable(negatable) | Assertion::NotCountable(negatable) => {
            writer.write_bool(*negatable);
        }
        Assertion::HasExactCount(value)
        | Assertion::HasAtLeastCount(value)
        | Assertion::DoesNotHaveExactCount(value)
        | Assertion::DoesNotHasAtLeastCount(value) => writer.write_u64(*value as u64),
        Assertion::IsLessThan(value)
        | Assertion::IsLessThanOrEqual(value)
        | Assertion::IsGreaterThan(value)
        | Assertion::IsGreaterThanOrEqual(value)
        | Assertion::IsLessThanFromBound(value)
        | Assertion::IsLessThanOrEqualFromBound(value)
        | Assertion::IsGreaterThanFromBound(value)
        | Assertion::IsGreaterThanOrEqualFromBound(value) => writer.write_u64(*value as u64),
        Assertion::IsLessThanVariable(variable)
        | Assertion::IsLessThanOrEqualVariable(variable)
        | Assertion::IsGreaterThanVariable(variable)
        | Assertion::IsGreaterThanOrEqualVariable(variable) => writer.write_bytes(variable.as_bytes())?,
        _ => {}
    }

    Ok(())
}

fn write_atomic(writer: &mut PayloadWriter, atomic: &TAtomic) -> Result<(), ExternalAnalyzerError> {
    write_union(writer, &TUnion::from_atomic(atomic.clone()))
}

fn write_array_key(writer: &mut PayloadWriter, key: &ArrayKey) -> Result<(), ExternalAnalyzerError> {
    match key {
        ArrayKey::Integer(value) => {
            writer.write_u8(1);
            writer.write_u64(*value as u64);
        }
        ArrayKey::String(value) => {
            writer.write_u8(2);
            writer.write_bytes(value.as_bytes())?;
        }
        ArrayKey::ClassLikeConstant { class_like_name, constant_name } => {
            writer.write_u8(3);
            writer.write_bytes(class_like_name.as_bytes())?;
            writer.write_bytes(constant_name.as_bytes())?;
        }
    }
    Ok(())
}

fn write_parameter(
    writer: &mut PayloadWriter,
    metadata: &FunctionLikeParameterMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_bytes(metadata.name.0.as_bytes())?;
    write_location(writer, metadata.span, session)?;
    write_location(writer, metadata.name_span, session)?;
    write_optional_type_metadata(writer, metadata.type_declaration_metadata.as_ref(), session)?;
    write_optional_type_metadata(writer, metadata.type_metadata.as_ref(), session)?;
    write_optional_type_metadata(writer, metadata.out_type.as_ref(), session)?;
    write_optional_type_metadata(writer, metadata.closure_this_type.as_ref(), session)?;
    write_optional_type_metadata(writer, metadata.default_type.as_ref(), session)?;
    write_attributes(writer, &metadata.attributes, session)?;
    writer.write_u64(metadata.flags.bits());
    Ok(())
}

pub(super) fn write_property(
    writer: &mut PayloadWriter,
    metadata: &PropertyMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_bytes(metadata.name.0.as_bytes())?;
    write_optional_location(writer, metadata.span, session)?;
    write_optional_location(writer, metadata.name_span, session)?;
    write_visibility(writer, metadata.read_visibility);
    write_visibility(writer, metadata.write_visibility);
    write_optional_type_metadata(writer, metadata.type_declaration_metadata.as_ref(), session)?;
    write_optional_type_metadata(writer, metadata.type_metadata.as_ref(), session)?;
    write_optional_type_metadata(writer, metadata.write_type_metadata.as_ref(), session)?;
    write_optional_type_metadata(writer, metadata.default_type_metadata.as_ref(), session)?;
    write_attributes(writer, &metadata.attributes, session)?;
    writer.write_u64(metadata.flags.bits());
    write_property_hooks(writer, &metadata.hooks, session)?;
    write_version_constraint(writer, &metadata.version_constraint);
    Ok(())
}

fn write_property_hooks(
    writer: &mut PayloadWriter,
    hooks: &mago_word::WordMap<PropertyHookMetadata>,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    let mut hooks: Vec<_> = hooks.values().collect();
    hooks.sort_unstable_by(|left, right| left.name.as_bytes().cmp(right.name.as_bytes()));
    writer.write_u32(hooks.len() as u32);
    for hook in hooks {
        writer.write_bytes(hook.name.as_bytes())?;
        write_location(writer, hook.span, session)?;
        writer.write_u64(hook.flags.bits());
        writer.write_bool(hook.parameter.is_some());
        if let Some(parameter) = &hook.parameter {
            write_parameter(writer, parameter, session)?;
        }

        writer.write_bool(hook.returns_by_ref);
        writer.write_bool(hook.is_abstract);
        write_attributes(writer, &hook.attributes, session)?;
        write_optional_type_metadata(writer, hook.return_type_metadata.as_ref(), session)?;
        writer.write_bool(hook.has_docblock);
    }

    Ok(())
}

fn write_class_constant(
    writer: &mut PayloadWriter,
    metadata: &ClassLikeConstantMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_bytes(metadata.name.as_bytes())?;
    write_location(writer, metadata.span, session)?;
    write_visibility(writer, metadata.visibility);
    write_optional_type_metadata(writer, metadata.type_declaration.as_ref(), session)?;
    write_optional_type_metadata(writer, metadata.type_metadata.as_ref(), session)?;
    write_optional_atomic(writer, metadata.inferred_type.as_ref())?;
    write_attributes(writer, &metadata.attributes, session)?;
    writer.write_u64(metadata.flags.bits());
    write_version_constraint(writer, &metadata.version_constraint);
    Ok(())
}

fn write_enum_case(
    writer: &mut PayloadWriter,
    metadata: &EnumCaseMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_bytes(metadata.name.as_bytes())?;
    write_location(writer, metadata.span, session)?;
    write_location(writer, metadata.name_span, session)?;
    write_optional_atomic(writer, metadata.value_type.as_ref())?;
    write_attributes(writer, &metadata.attributes, session)?;
    writer.write_u64(metadata.flags.bits());
    write_version_constraint(writer, &metadata.version_constraint);
    Ok(())
}

fn write_constant(
    writer: &mut PayloadWriter,
    metadata: &ConstantMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_bytes(metadata.name.as_bytes())?;
    write_location(writer, metadata.span, session)?;
    write_optional_type_metadata(writer, metadata.type_metadata.as_ref(), session)?;
    write_optional_union(writer, metadata.inferred_type.as_ref())?;
    write_attributes(writer, &metadata.attributes, session)?;
    writer.write_u64(metadata.flags.bits());
    write_version_constraint(writer, &metadata.version_constraint);
    Ok(())
}

fn write_location(
    writer: &mut PayloadWriter,
    span: Span,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    let source = session.source_name(span.file_id);
    writer.write_bool(source.is_some());
    if let Some(source) = source {
        writer.write_bytes(source)?;
    }

    writer.write_u32(span.start.offset);
    writer.write_u32(span.end.offset);
    Ok(())
}

fn write_optional_location(
    writer: &mut PayloadWriter,
    span: Option<Span>,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    write_optional(writer, span.as_ref(), |writer, span| write_location(writer, *span, session))
}

fn write_type_metadata(
    writer: &mut PayloadWriter,
    metadata: &TypeMetadata,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    write_location(writer, metadata.span, session)?;
    write_union(writer, &metadata.type_union)?;
    writer.write_bool(metadata.from_docblock);
    writer.write_bool(metadata.inferred);
    Ok(())
}

fn write_optional_type_metadata(
    writer: &mut PayloadWriter,
    metadata: Option<&TypeMetadata>,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    write_optional(writer, metadata, |writer, metadata| write_type_metadata(writer, metadata, session))
}

fn write_union(writer: &mut PayloadWriter, union: &TUnion) -> Result<(), ExternalAnalyzerError> {
    let mut references = Vec::new();
    encode_union_snapshot(writer, union, &mut references, 0)
}

trait MixinType {
    fn type_union(&self) -> &TUnion;
}

impl MixinType for TUnion {
    #[inline]
    fn type_union(&self) -> &TUnion {
        self
    }
}

impl MixinType for TypeMetadata {
    #[inline]
    fn type_union(&self) -> &TUnion {
        &self.type_union
    }
}

fn write_mixins<T>(writer: &mut PayloadWriter, mixins: &[T]) -> Result<(), ExternalAnalyzerError>
where
    T: MixinType,
{
    writer.write_u32(mixins.len() as u32);
    for mixin in mixins {
        write_union(writer, mixin.type_union())?;
    }

    Ok(())
}

fn write_optional_union(writer: &mut PayloadWriter, union: Option<&TUnion>) -> Result<(), ExternalAnalyzerError> {
    write_optional(writer, union, write_union)
}

fn write_optional_atomic(writer: &mut PayloadWriter, atomic: Option<&TAtomic>) -> Result<(), ExternalAnalyzerError> {
    write_optional(writer, atomic, |writer, atomic| write_union(writer, &TUnion::from_atomic(atomic.clone())))
}

fn write_attributes(
    writer: &mut PayloadWriter,
    attributes: &[AttributeMetadata],
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_u32(attributes.len() as u32);
    for attribute in attributes {
        writer.write_bytes(attribute.name.as_bytes())?;
        write_location(writer, attribute.span, session)?;
        writer.write_u32(attribute.arguments.len() as u32);
        for argument in &attribute.arguments {
            write_optional_word(writer, argument.name)?;
            write_location(writer, argument.span, session)?;
            write_optional_location(writer, argument.name_span, session)?;
            write_optional_location(writer, argument.value_span, session)?;
            write_optional_union(writer, argument.value_type.as_ref())?;
        }
    }

    Ok(())
}

fn write_templates(
    writer: &mut PayloadWriter,
    templates: &TemplateTypes,
    variances: Option<&[Variance]>,
    readonly: Option<&mago_word::WordSet>,
) -> Result<(), ExternalAnalyzerError> {
    writer.write_u32(templates.len() as u32);
    for (index, (name, template)) in templates.iter().enumerate() {
        writer.write_bytes(name.as_bytes())?;
        encode_generic_parent(writer, template.defining_entity)?;
        write_union(writer, &template.constraint)?;
        write_optional_union(writer, template.default.as_ref())?;
        writer
            .write_u8(variance(variances.and_then(|values| values.get(index)).copied().unwrap_or(Variance::Invariant)));
        writer.write_bool(readonly.is_some_and(|names| names.contains(name)));
    }

    Ok(())
}

fn write_type_aliases(
    writer: &mut PayloadWriter,
    aliases: &mago_word::WordMap<TypeMetadata>,
    session: &ExternalAnalysisSession,
) -> Result<(), ExternalAnalyzerError> {
    let mut aliases: Vec<_> = aliases.iter().collect();
    aliases.sort_unstable_by(|(left, _), (right, _)| left.as_bytes().cmp(right.as_bytes()));
    writer.write_u32(aliases.len() as u32);
    for (name, metadata) in aliases {
        writer.write_bytes(name.as_bytes())?;
        write_type_metadata(writer, metadata, session)?;
    }

    Ok(())
}

fn write_words(writer: &mut PayloadWriter, words: impl IntoIterator<Item = Word>) -> Result<(), ExternalAnalyzerError> {
    let mut words: Vec<_> = words.into_iter().collect();
    words.sort_unstable_by(|left, right| left.as_bytes().cmp(right.as_bytes()));
    writer.write_u32(words.len() as u32);
    for word in words {
        writer.write_bytes(word.as_bytes())?;
    }

    Ok(())
}

fn write_optional_words<I>(writer: &mut PayloadWriter, words: Option<I>) -> Result<(), ExternalAnalyzerError>
where
    I: IntoIterator<Item = Word>,
{
    writer.write_bool(words.is_some());
    if let Some(words) = words {
        write_words(writer, words)?;
    }

    Ok(())
}

fn write_optional_word(writer: &mut PayloadWriter, word: Option<Word>) -> Result<(), ExternalAnalyzerError> {
    write_optional(writer, word.as_ref(), |writer, word| Ok(writer.write_bytes(word.as_bytes())?))
}

fn write_version_constraint(writer: &mut PayloadWriter, constraint: &VersionConstraint) {
    writer.write_u32(constraint.ranges.len() as u32);
    for range in &constraint.ranges {
        writer.write_bool(range.min.is_some());
        if let Some(minimum) = range.min {
            writer.write_u32(minimum.to_version_id());
        }

        writer.write_bool(range.max.is_some());
        if let Some(maximum) = range.max {
            writer.write_u32(maximum.to_version_id());
        }
    }
}

fn write_optional_bool(writer: &mut PayloadWriter, value: Option<bool>) {
    writer.write_u8(match value {
        None => 0,
        Some(false) => 1,
        Some(true) => 2,
    });
}

fn write_visibility(writer: &mut PayloadWriter, visibility: Visibility) {
    writer.write_u8(match visibility {
        Visibility::Public => 1,
        Visibility::Protected => 2,
        Visibility::Private => 3,
    });
}

fn symbol_kind(kind: SymbolKind) -> u8 {
    match kind {
        SymbolKind::Class => 1,
        SymbolKind::Enum => 2,
        SymbolKind::Trait => 3,
        SymbolKind::Interface => 4,
    }
}

fn class_like_matches(kind: SymbolKind, filter: u8) -> bool {
    match filter {
        ANY_CLASS_LIKE => true,
        CLASS => kind == SymbolKind::Class,
        INTERFACE => kind == SymbolKind::Interface,
        TRAIT => kind == SymbolKind::Trait,
        ENUM => kind == SymbolKind::Enum,
        _ => false,
    }
}

fn variance(value: Variance) -> u8 {
    match value {
        Variance::Invariant => 1,
        Variance::Covariant => 2,
        Variance::Contravariant => 3,
        Variance::Bivariant => 4,
    }
}

#[cfg(test)]
#[allow(clippy::expect_used)]
mod tests {
    use super::*;
    use crate::external::protocol;
    use crate::external::protocol::NestedRequestKind;

    fn session(generation: u64) -> ExternalAnalysisSession {
        ExternalAnalysisSession { generation, sources: foldhash::HashMap::default() }
    }

    #[test]
    fn batched_existence_query_round_trips_in_request_order() {
        let session = session(17);
        let codebase = CodebaseMetadata::new();
        let mut writer = protocol::message_writer(CODEBASE_QUERY_REQUEST);
        writer.write_u64(17);
        writer.write_u8(CHECK_EXISTENCE);
        writer.write_u8(EXISTS_CLASS_LIKE);
        writer.write_u32(2);
        writer.write_bytes(b"MissingA").expect("name should fit in a frame");
        writer.write_bytes(b"MissingB").expect("name should fit in a frame");

        let (kind, response) = protocol::handle_nested_request(&writer.finish(), &codebase, &session, |_| None)
            .expect("metadata query should succeed");
        assert_eq!(kind, NestedRequestKind::CodebaseQuery);

        let mut reader = protocol::message_reader(&response, CODEBASE_QUERY_RESPONSE)
            .expect("metadata response should have a valid header");
        assert_eq!(reader.read_u64("generation").expect("generation should decode"), 17);
        assert_eq!(reader.read_u8("operation").expect("operation should decode"), CHECK_EXISTENCE);
        assert_eq!(reader.read_u8("predicate").expect("predicate should decode"), EXISTS_CLASS_LIKE);
        assert_eq!(reader.read_u32("count").expect("count should decode"), 2);
        assert!(!reader.read_bool("first result").expect("first result should decode"));
        assert!(!reader.read_bool("second result").expect("second result should decode"));
        reader.finish().expect("metadata response should contain no trailing bytes");
    }

    #[test]
    fn stale_generation_is_rejected_before_query_dispatch() {
        let session = session(19);
        let codebase = CodebaseMetadata::new();
        let mut writer = protocol::message_writer(CODEBASE_QUERY_REQUEST);
        writer.write_u64(18);

        let error = protocol::handle_nested_request(&writer.finish(), &codebase, &session, |_| None)
            .expect_err("stale metadata queries must fail");
        assert!(error.to_string().contains("active generation is 19"));
    }

    #[test]
    fn projected_method_query_returns_an_empty_ordered_result() {
        let session = session(23);
        let codebase = CodebaseMetadata::new();
        let mut writer = protocol::message_writer(CODEBASE_QUERY_REQUEST);
        writer.write_u64(23);
        writer.write_u8(FIND_METHODS);
        writer.write_u8(METHOD_SEARCH_ANY_CLASS);
        writer.write_bytes(b"set*").expect("pattern should fit in a frame");
        writer.write_bool(false);
        writer.write_u32(0);
        writer.write_u32(METHOD_FIELDS_NAMES | METHOD_FIELDS_ATTRIBUTES);

        let (kind, response) = protocol::handle_nested_request(&writer.finish(), &codebase, &session, |_| None)
            .expect("projected method query should succeed");
        assert_eq!(kind, NestedRequestKind::CodebaseQuery);

        let mut reader = protocol::message_reader(&response, CODEBASE_QUERY_RESPONSE)
            .expect("metadata response should have a valid header");
        assert_eq!(reader.read_u64("generation").expect("generation should decode"), 23);
        assert_eq!(reader.read_u8("operation").expect("operation should decode"), FIND_METHODS);
        assert_eq!(
            reader.read_u32("projection fields").expect("projection fields should decode"),
            METHOD_FIELDS_NAMES | METHOD_FIELDS_ATTRIBUTES
        );
        assert_eq!(reader.read_u32("result count").expect("result count should decode"), 0);
        reader.finish().expect("metadata response should contain no trailing bytes");
    }

    #[test]
    fn projected_method_query_rejects_unknown_fields() {
        let session = session(29);
        let codebase = CodebaseMetadata::new();
        let mut writer = protocol::message_writer(CODEBASE_QUERY_REQUEST);
        writer.write_u64(29);
        writer.write_u8(FIND_METHODS);
        writer.write_u8(METHOD_SEARCH_ANY_CLASS);
        writer.write_bytes(b"*").expect("pattern should fit in a frame");
        writer.write_bool(false);
        writer.write_u32(0);
        writer.write_u32(1 << 31);

        let error = protocol::handle_nested_request(&writer.finish(), &codebase, &session, |_| None)
            .expect_err("unknown method projection fields must fail");
        assert!(error.to_string().contains("unknown fields"));
    }
}