rasgapdf 0.3.0

Blazing-fast spatial 2D PDF parser in pure Rust with multi-language bindings (Python, Node.js, Go, C#) for RAG, LLMs, bounding boxes, and table extraction
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
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351

<!DOCTYPE html>
<html lang="en" class="h-full">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>⚡ RasgaPDF — Blazing-Fast 2D Spatial PDF Parser in Rust (Python, Node.js, Go, C#)</title>
  <meta name="description" content="RasgaPDF is an ultra-fast 2D Spatial PDF Parser powered by pure Rust (~3-8 ms/page). Extract exact [x0, y0, x1, y1] bounding boxes, text blocks, tables, embedded images, and vector paths for Spatial RAG, LLMs, Python, Node.js, Rust, Go, and C#.">
  <meta name="keywords" content="rasgapdf, pdf parser, spatial pdf parser, rust pdf parser, python pdf parser, nodejs pdf parser, pdf bounding boxes, extract pdf coordinates, x0 y0 x1 y1 pdf, pdf table extraction, spatial rag, llm pdf parser, pdf to json, extrair coordenadas pdf, ler pdf rapido python">
  <meta name="author" content="Messias Martins">
  <meta name="robots" content="index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1">
  <link rel="canonical" href="https://martinsmessias.github.io/rasgapdf/">
  <link rel="alternate" type="text/plain" href="llms.txt" title="LLM Context Summary">
  <link rel="alternate" type="text/plain" href="llms-full.txt" title="LLM Full Technical Reference">

  <!-- Open Graph / Social / AI Grounding -->
  <meta property="og:type" content="website">
  <meta property="og:site_name" content="RasgaPDF">
  <meta property="og:title" content="⚡ RasgaPDF — Blazing-Fast 2D Spatial PDF Parser in Pure Rust">
  <meta property="og:description" content="Extract exact 2D physical coordinates [x0, y0, x1, y1], structured text blocks, tables, images, and vector paths in ~3-8 ms/page. Native bindings for Python, Node.js, Rust, Go &amp; C#.">
  <meta property="og:url" content="https://martinsmessias.github.io/rasgapdf/">

  <!-- Twitter Card -->
  <meta name="twitter:card" content="summary_large_image">
  <meta name="twitter:title" content="⚡ RasgaPDF — 2D Spatial PDF Parser in Pure Rust">
  <meta name="twitter:description" content="Extract exact [x0, y0, x1, y1] bounding boxes, tables, images &amp; vector paths at ~3-8 ms/page. Available on PyPI, npm, and Crates.io.">

  <!-- Schema.org Structured Data (JSON-LD) for Google & LLMs -->
  <script type="application/ld+json">
  {
    "@context": "https://schema.org",
    "@graph": [
      {
        "@type": "SoftwareSourceCode",
        "@id": "https://github.com/MartinsMessias/rasgapdf#code",
        "name": "RasgaPDF",
        "alternateName": ["rasgapdf", "RasgaPDF Spatial PDF Parser"],
        "description": "Blazing-fast 2D Spatial PDF Parser written in pure Rust with native C-ABI bindings for Python, Node.js, Go, and C# (.NET). Extracts exact [x0, y0, x1, y1] bounding boxes, typography metadata, paragraphs, tables, embedded images, and vector drawings in ~3-8 ms per page.",
        "version": "0.3.0",
        "license": "https://www.gnu.org/licenses/agpl-3.0",
        "codeRepository": "https://github.com/MartinsMessias/rasgapdf",
        "programmingLanguage": ["Rust", "Python", "JavaScript", "TypeScript", "Go", "C#"],
        "runtimePlatform": ["Linux", "Windows", "macOS", "WebAssembly / Browser"],
        "author": {
          "@type": "Person",
          "name": "Messias Martins",
          "url": "https://github.com/MartinsMessias"
        },
        "keywords": "pdf, spatial pdf parser, bounding-box, layout-analysis, table-extraction, rust, python, nodejs, rag, llm, document-parsing, pdf-to-json",
        "sameAs": [
          "https://github.com/MartinsMessias/rasgapdf",
          "https://pypi.org/project/rasgapdf/",
          "https://crates.io/crates/rasgapdf",
          "https://www.npmjs.com/package/rasgapdf",
          "https://huggingface.co/martinsmessias/rasgapdf",
          "https://huggingface.co/spaces/martinsmessias/rasgapdf"
        ]
      },
      {
        "@type": "SoftwareApplication",
        "name": "RasgaPDF 2D Spatial PDF Parser & Visualizer",
        "applicationCategory": "DeveloperApplication",
        "operatingSystem": "Linux, Windows, macOS, Web",
        "softwareVersion": "0.3.0",
        "url": "https://martinsmessias.github.io/rasgapdf/",
        "downloadUrl": "https://pypi.org/project/rasgapdf/",
        "offers": {
          "@type": "Offer",
          "price": "0",
          "priceCurrency": "USD"
        }
      },
      {
        "@type": "FAQPage",
        "mainEntity": [
          {
            "@type": "Question",
            "name": "What is RasgaPDF and how fast is it?",
            "acceptedAnswer": {
              "@type": "Answer",
              "text": "RasgaPDF is an open-source 2D spatial PDF parser written in pure Rust (powered by pure Rust and Rayon SIMD parallelism). It extracts exact [x0, y0, x1, y1] bounding boxes in ~3 to 8 ms per page—roughly 4x faster than PyMuPDF, 12x faster than pypdf, and over 50x faster than pdfplumber."
            }
          },
          {
            "@type": "Question",
            "name": "How do I install RasgaPDF in Python, Node.js, or Rust?",
            "acceptedAnswer": {
              "@type": "Answer",
              "text": "Install via PyPI with pip install rasgapdf, via npm with npm install rasgapdf, or via Cargo with cargo add rasgapdf. Go and C# (.NET 8) bindings are also included."
            }
          },
          {
            "@type": "Question",
            "name": "Why use RasgaPDF for RAG and LLM pipelines?",
            "acceptedAnswer": {
              "@type": "Answer",
              "text": "Unlike traditional PDF parsers that flatten multi-column layouts and break tables, RasgaPDF preserves exact 2D physical geometry [x0, y0, x1, y1] for every span, line, block, table cell, image, and vector drawing, enabling accurate Spatial RAG, visual citation grounding, and layout-aware document AI."
            }
          }
        ]
      }
    ]
  }
  </script>
  <script src="https://cdn.tailwindcss.com"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/pdf.js/3.11.174/pdf.min.js" integrity="sha384-/1qUCSGwTur9vjf/z9lmu/eCUYbpOTgSjmpbMQZ1/CtX2v/WcAIKqRv+U1DUCG6e" crossorigin="anonymous"></script>
  <style>
    /* Monospace numerical coordinates */
    .coord-font {
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
      color: #38bdf8;
    }
    /* Custom scrollbars */
    ::-webkit-scrollbar { width: 7px; height: 7px; }
    ::-webkit-scrollbar-track { background: #090d16; }
    ::-webkit-scrollbar-thumb { background: #26334d; border-radius: 4px; }
    ::-webkit-scrollbar-thumb:hover { background: #3b4d71; }
  </style>
</head>
<body class="bg-slate-950 text-slate-100 h-full flex flex-col font-sans overflow-x-hidden">
  <noscript>
    <section style="padding:2rem;background:#0f172a;color:#f8fafc;font-family:sans-serif;">
      <h1>RasgaPDF — The Blazing-Fast 2D Spatial PDF Parser in Pure Rust</h1>
      <p>Extract exact physical coordinates <code>[x0, y0, x1, y1]</code>, structured text blocks, matrix tables, embedded images, and vector paths at ~3–8 ms per page.</p>
      <ul>
        <li><strong>Python (PyPI):</strong> <code>pip install rasgapdf</code> — <a href="https://pypi.org/project/rasgapdf/">pypi.org/project/rasgapdf</a></li>
        <li><strong>Node.js (npm):</strong> <code>npm install rasgapdf</code> — <a href="https://www.npmjs.com/package/rasgapdf">npmjs.com/package/rasgapdf</a></li>
        <li><strong>Rust (Crates.io):</strong> <code>cargo add rasgapdf</code> — <a href="https://crates.io/crates/rasgapdf">crates.io/crates/rasgapdf</a></li>
        <li><strong>GitHub Repository:</strong> <a href="https://github.com/MartinsMessias/rasgapdf">github.com/MartinsMessias/rasgapdf</a></li>
        <li><strong>LLM Documentation:</strong> <a href="llms.txt">llms.txt</a> | <a href="llms-full.txt">llms-full.txt</a></li>
      </ul>
    </section>
  </noscript>

  <!-- Header (Sticky & Compact) -->
  <header class="border-b border-slate-800 bg-slate-900/90 backdrop-blur sticky top-0 z-50 px-4 sm:px-6 py-2.5 shrink-0">
    <div class="w-full flex flex-wrap items-center justify-between gap-3">
      <div class="flex items-center gap-3">
        <span class="text-xl sm:text-2xl font-black bg-gradient-to-r from-cyan-400 to-blue-500 bg-clip-text text-transparent">⚡ RasgaPDF</span>
        <span class="text-xs px-2.5 py-0.5 rounded-full bg-cyan-950 text-cyan-400 border border-cyan-800 font-mono font-bold">v0.3.0</span>
        <span id="headerComputeBadge" class="hidden sm:inline-block text-xs px-2.5 py-0.5 rounded-full bg-emerald-950 text-emerald-400 border border-emerald-800 font-mono">Client-Side Compute</span>
      </div>

      <div class="flex flex-wrap items-center gap-2">
        <!-- Duplicate Space Button -->
        <a href="https://huggingface.co/spaces/martinsmessias/rasgapdf?duplicate=true" target="_blank" class="flex items-center gap-1.5 bg-gradient-to-r from-amber-500 to-orange-500 hover:from-amber-600 hover:to-orange-600 text-slate-950 font-bold px-3 py-1.5 rounded-lg text-xs shadow transition">
          <svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8 16H6a2 2 0 01-2-2V6a2 2 0 012-2h8a2 2 0 012 2v2m-6 12h8a2 2 0 002-2v-8a2 2 0 00-2-2h-8a2 2 0 00-2 2v8a2 2 0 002 2z"></path></svg>
          <span class="hidden xs:inline">Duplicate to Your HF Account</span>
          <span class="xs:hidden">Duplicate</span>
        </a>

        <!-- Repository & Package Links -->
        <a href="https://github.com/MartinsMessias/rasgapdf" target="_blank" class="bg-slate-800 hover:bg-slate-700 text-slate-200 border border-slate-700 px-2.5 py-1.5 rounded-lg text-xs font-mono transition flex items-center gap-1">
          <svg class="w-3.5 h-3.5" fill="currentColor" viewBox="0 0 24 24"><path fill-rule="evenodd" clip-rule="evenodd" d="M12 2C6.477 2 2 6.484 2 12.017c0 4.425 2.865 8.18 6.839 9.504.5.092.682-.217.682-.483 0-.237-.008-.868-.013-1.703-2.782.605-3.369-1.343-3.369-1.343-.454-1.158-1.11-1.466-1.11-1.466-.908-.62.069-.608.069-.608 1.003.07 1.53 1.032 1.53 1.032.892 1.53 2.341 1.088 2.91.832.092-.647.35-1.088.636-1.338-2.22-.253-4.555-1.113-4.555-4.951 0-1.093.39-1.988 1.029-2.688-.103-.253-.446-1.272.098-2.65 0 0 .84-.27 2.75 1.026A9.564 9.564 0 0112 6.844c.85.004 1.705.115 2.504.337 1.909-1.296 2.747-1.027 2.747-1.027.546 1.379.202 2.398.1 2.651.64.7 1.028 1.595 1.028 2.688 0 3.848-2.339 4.695-4.566 4.943.359.309.678.92.678 1.855 0 1.338-.012 2.419-.012 2.747 0 .268.18.58.688.482A10.019 10.019 0 0022 12.017C22 6.484 17.522 2 12 2z"></path></svg>
          GitHub
        </a>
        <a href="https://pypi.org/project/rasgapdf/" target="_blank" class="bg-slate-800 hover:bg-slate-700 text-blue-400 border border-slate-700 px-2.5 py-1.5 rounded-lg text-xs font-mono transition">PyPI</a>
        <a href="https://crates.io/crates/rasgapdf" target="_blank" class="bg-slate-800 hover:bg-slate-700 text-orange-400 border border-slate-700 px-2.5 py-1.5 rounded-lg text-xs font-mono transition">Crates</a>
        <a href="https://www.npmjs.com/package/rasgapdf" target="_blank" class="bg-slate-800 hover:bg-slate-700 text-red-400 border border-slate-700 px-2.5 py-1.5 rounded-lg text-xs font-mono transition">npm</a>
        <a href="https://huggingface.co/martinsmessias/rasgapdf" target="_blank" class="bg-slate-800 hover:bg-slate-700 text-cyan-400 border border-slate-700 px-2.5 py-1.5 rounded-lg text-xs font-mono transition">HF Hub</a>
      </div>
    </div>
  </header>

  <!-- Main Viewport-Filling Workspace -->
  <main class="flex-1 w-full p-3 sm:p-5 flex flex-col lg:flex-row gap-4 min-h-0 overflow-y-auto lg:overflow-hidden">

    <!-- Left Controls Sidebar (Compact on mobile, fixed width on desktop) -->
    <aside class="w-full lg:w-80 xl:w-96 flex flex-col gap-3 shrink-0 overflow-y-visible lg:overflow-y-auto pr-0 lg:pr-1">
      
      <!-- File Upload Card -->
      <div class="bg-slate-900 border border-slate-800 rounded-xl p-4 shadow-lg">
        <label class="block text-xs font-semibold text-slate-200 mb-2">📄 Select or Upload PDF</label>
        <div id="dropzone" class="border-2 border-dashed border-slate-700 hover:border-cyan-500 rounded-lg p-4 sm:p-5 text-center cursor-pointer transition bg-slate-950/50">
          <svg class="mx-auto h-7 w-7 text-cyan-400 mb-1.5" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M7 16a4 4 0 01-.88-7.903A5 5 0 1115.9 6L16 6a5 5 0 011 9.9M15 13l-3-3m0 0l-3 3m3-3v12"></path></svg>
          <p class="text-xs text-slate-300 font-medium">Click to upload or drag & drop</p>
          <p class="text-[10px] text-slate-500 mt-0.5">Processed 100% locally in your browser</p>
          <input type="file" id="pdfFileInput" accept="application/pdf" class="hidden">
        </div>

        <button id="btnLoadSample" class="mt-2.5 w-full py-1.5 bg-slate-800 hover:bg-slate-700 border border-slate-700 rounded-lg text-xs font-medium text-cyan-300 transition flex items-center justify-center gap-1.5">
          <svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"></path></svg>
          Load Built-in Sample PDF
        </button>
      </div>

      <!-- Navigation & Controls -->
      <div class="bg-slate-900 border border-slate-800 rounded-xl p-4 shadow-lg flex flex-col gap-3">
        <div class="flex items-center justify-between">
          <span class="text-xs font-semibold text-slate-200">📖 Page Navigation</span>
          <span id="pageIndicator" class="text-xs font-mono text-cyan-400">Page 1 of 1</span>
        </div>

        <div class="flex items-center gap-2">
          <button id="btnPrevPage" class="flex-1 py-1.5 bg-slate-800 hover:bg-slate-700 border border-slate-700 rounded-lg text-xs font-semibold disabled:opacity-50 transition">Previous</button>
          <input type="range" id="pageSlider" min="1" max="1" value="1" class="flex-1 accent-cyan-400 cursor-pointer">
          <button id="btnNextPage" class="flex-1 py-1.5 bg-slate-800 hover:bg-slate-700 border border-slate-700 rounded-lg text-xs font-semibold disabled:opacity-50 transition">Next</button>
        </div>

        <div class="border-t border-slate-800/80 pt-2.5 flex flex-col gap-2">
          <label class="flex items-center gap-2 text-xs text-slate-300 cursor-pointer">
            <input type="checkbox" id="chkShowBoxes" checked class="rounded accent-cyan-400">
            <span>Show 2D Bounding Boxes (Translucent Cyan)</span>
          </label>
          <label class="flex items-center gap-2 text-xs text-slate-300 cursor-pointer">
            <input type="checkbox" id="chkShowImages" checked class="rounded accent-orange-400">
            <span>Show Embedded Images (Translucent Orange)</span>
          </label>
          <label class="flex items-center gap-2 text-xs text-slate-300 cursor-pointer">
            <input type="checkbox" id="chkShowVectors" checked class="rounded accent-fuchsia-400">
            <span>Show Vector Paths (Translucent Magenta)</span>
          </label>
        </div>
      </div>

      <!-- Performance Metrics Card -->
      <div class="bg-slate-900 border border-slate-800 rounded-xl p-4 shadow-lg">
        <span class="text-[11px] font-semibold text-slate-400 uppercase tracking-wider block mb-2.5">⚡ Extraction Metrics</span>
        <div class="grid grid-cols-2 gap-2 text-xs">
          <div class="bg-slate-950 p-2 rounded-lg border border-slate-800/80">
            <span class="text-slate-500 block text-[10px]">Parse Latency</span>
            <span id="metricLatency" class="font-mono text-cyan-400 font-bold text-xs">0.00 ms</span>
          </div>
          <div class="bg-slate-950 p-2 rounded-lg border border-slate-800/80">
            <span class="text-slate-500 block text-[10px]">Total Spans</span>
            <span id="metricSpans" class="font-mono text-cyan-400 font-bold text-xs">0</span>
          </div>
          <div class="bg-slate-950 p-2 rounded-lg border border-slate-800/80">
            <span class="text-slate-500 block text-[10px]">Embedded Images</span>
            <span id="metricImages" class="font-mono text-orange-400 font-bold text-xs">0</span>
          </div>
          <div class="bg-slate-950 p-2 rounded-lg border border-slate-800/80">
            <span class="text-slate-500 block text-[10px]">Vector Paths</span>
            <span id="metricVectors" class="font-mono text-fuchsia-400 font-bold text-xs">0</span>
          </div>
          <div class="bg-slate-950 p-2 rounded-lg border border-slate-800/80">
            <span class="text-slate-500 block text-[10px]">Canvas Dimensions</span>
            <span id="metricDims" class="font-mono text-slate-300 text-[11px]">-</span>
          </div>
          <div class="bg-slate-950 p-2 rounded-lg border border-slate-800/80">
            <span class="text-slate-500 block text-[10px]">Compute Mode</span>
            <span id="metricComputeMode" class="font-mono text-amber-400 font-bold text-[11px]">Client Browser</span>
          </div>
        </div>
      </div>
    </aside>

    <!-- Right Workspace Area (Full Width & Height) -->
    <section class="flex-1 h-full min-h-[550px] lg:min-h-0 flex flex-col gap-3 overflow-hidden">

      <!-- Navigation Tabs -->
      <div class="flex border-b border-slate-800 gap-1 overflow-x-auto pb-1 text-xs font-semibold shrink-0">
        <button data-tab="tab-visual" class="tab-btn px-4 py-2 border-b-2 border-cyan-400 text-cyan-300 font-bold flex items-center gap-1.5 transition">
          👁️ 1. 2D Canvas Overlay
        </button>
        <button data-tab="tab-coords" class="tab-btn px-4 py-2 border-b-2 border-transparent text-slate-400 hover:text-slate-200 flex items-center gap-1.5 transition">
          ⚡ 2. Raw Coordinates (X/Y Table)
        </button>
        <button data-tab="tab-text" class="tab-btn px-4 py-2 border-b-2 border-transparent text-slate-400 hover:text-slate-200 flex items-center gap-1.5 transition">
          📝 3. Pure Plain Text
        </button>
        <button data-tab="tab-json" class="tab-btn px-4 py-2 border-b-2 border-transparent text-slate-400 hover:text-slate-200 flex items-center gap-1.5 transition">
          📄 4. Raw JSON Export
        </button>
        <button data-tab="tab-images" class="tab-btn px-4 py-2 border-b-2 border-transparent text-slate-400 hover:text-slate-200 flex items-center gap-1.5 transition">
          🖼️ 5. Embedded Images
        </button>
      </div>

      <!-- Tab Content 1: 2D Visual Overlay (Primary Tab, Full Height & Width) -->
      <div id="tab-visual" class="tab-panel flex flex-col bg-slate-900 border border-slate-800 rounded-xl overflow-hidden shadow-lg flex-1 h-full min-h-0">
        <div class="p-2.5 sm:p-3 bg-slate-950 border-b border-slate-800 flex flex-wrap justify-between items-center gap-2 text-xs shrink-0">
          <div class="flex items-center gap-2 min-w-0">
            <span class="font-semibold text-slate-200 whitespace-nowrap">Rendered Canvas Overlay</span>
          </div>
          <!-- Responsive Zoom Controls -->
          <div class="flex items-center gap-1 shrink-0">
            <span class="text-slate-400 text-[11px] mr-1 hidden sm:inline">Zoom:</span>
            <button id="btnFitPage" class="px-2 py-0.5 rounded bg-cyan-950 text-cyan-400 border border-cyan-800 text-[11px] font-mono hover:bg-cyan-900 transition font-bold" title="Fit entire page vertically and horizontally">🔍 Fit Page</button>
            <button id="btnFitWidth" class="px-2 py-0.5 rounded bg-slate-800 text-slate-300 border border-slate-700 text-[11px] font-mono hover:bg-slate-700 transition" title="Fit page width to screen">↔️ Fit Width</button>
            <button id="btnZoom100" class="px-2 py-0.5 rounded bg-slate-800 text-slate-300 border border-slate-700 text-[11px] font-mono hover:bg-slate-700 transition">100%</button>
            <button id="btnZoom150" class="px-2 py-0.5 rounded bg-slate-800 text-slate-300 border border-slate-700 text-[11px] font-mono hover:bg-slate-700 transition">150%</button>
          </div>
        </div>

        <!-- Canvas Scroll Area: Starts from Top (y=0), Full Screen Scrollable -->
        <div id="canvasScrollArea" class="flex-1 w-full h-full min-h-0 overflow-auto p-4 sm:p-6 bg-slate-950/80">
          <div id="canvasWrapper" class="shadow-2xl border border-slate-700/80 rounded bg-white transition-all mx-auto w-max">
            <canvas id="pdfCanvas" class="block cursor-crosshair"></canvas>
          </div>
        </div>
      </div>

      <!-- Tab Content 2: Raw Coordinates Table -->
      <div id="tab-coords" class="tab-panel hidden flex flex-col bg-slate-900 border border-slate-800 rounded-xl overflow-hidden shadow-lg flex-1 h-full min-h-0">
        <div class="p-3 bg-slate-950 border-b border-slate-800 flex justify-between items-center text-xs shrink-0">
          <span class="font-semibold text-slate-300">Exact Physical Coordinates Matrix</span>
          <span id="tableCount" class="text-slate-500 font-mono">0 spans displayed</span>
        </div>
        <div class="flex-1 overflow-auto w-full">
          <table class="w-full text-left text-xs border-collapse">
            <thead class="bg-slate-950 sticky top-0 border-b border-slate-800 text-cyan-400 font-mono font-bold">
              <tr>
                <th class="p-3 w-16 text-center">Page</th>
                <th class="p-3 w-20">X0 (pt)</th>
                <th class="p-3 w-20">Y0 (pt)</th>
                <th class="p-3 w-20">X1 (pt)</th>
                <th class="p-3 w-20">Y1 (pt)</th>
                <th class="p-3 w-16">Size</th>
                <th class="p-3 w-28">Font</th>
                <th class="p-3 min-w-[280px]">Extracted Text</th>
              </tr>
            </thead>
            <tbody id="coordsTableBody" class="divide-y divide-slate-800/60 font-sans">
              <tr>
                <td colspan="8" class="p-8 text-center text-slate-500">No PDF loaded. Please upload a file or click "Load Built-in Sample PDF".</td>
              </tr>
            </tbody>
          </table>
        </div>
      </div>

      <!-- Tab Content 3: Pure Plain Text -->
      <div id="tab-text" class="tab-panel hidden flex flex-col bg-slate-900 border border-slate-800 rounded-xl overflow-hidden shadow-lg flex-1 h-full min-h-0">
        <div class="p-3 bg-slate-950 border-b border-slate-800 flex justify-between items-center text-xs shrink-0">
          <span class="font-semibold text-slate-300">Pure Text Stream & Raw Coordinates Dump</span>
          <button id="btnCopyText" class="px-3 py-1 bg-cyan-950 hover:bg-cyan-900 text-cyan-300 border border-cyan-800 rounded text-xs font-semibold flex items-center gap-1 transition">
            📋 Copy to Clipboard
          </button>
        </div>
        <textarea id="pureTextBox" readonly class="flex-1 w-full h-full bg-slate-950 p-4 text-xs font-mono text-slate-200 outline-none resize-none leading-relaxed" placeholder="Text stream will appear here..."></textarea>
      </div>

      <!-- Tab Content 4: JSON Export -->
      <div id="tab-json" class="tab-panel hidden flex flex-col bg-slate-900 border border-slate-800 rounded-xl overflow-hidden shadow-lg flex-1 h-full min-h-0">
        <div class="p-3 bg-slate-950 border-b border-slate-800 flex justify-between items-center text-xs shrink-0">
          <span class="font-semibold text-slate-300">Raw Spatial Document JSON</span>
          <div class="flex items-center gap-2">
            <button id="btnCopyJson" class="px-3 py-1 bg-slate-800 hover:bg-slate-700 text-slate-200 border border-slate-700 rounded text-xs font-semibold flex items-center gap-1 transition">
              📋 Copy JSON
            </button>
            <button id="btnDownloadJson" class="px-3 py-1 bg-cyan-950 hover:bg-cyan-900 text-cyan-300 border border-cyan-800 rounded text-xs font-semibold flex items-center gap-1 transition">
              💾 Download JSON
            </button>
          </div>
        </div>
        <pre id="jsonViewer" class="flex-1 w-full h-full bg-slate-950 p-4 text-xs font-mono text-cyan-300 overflow-auto"></pre>
      </div>

      <!-- Tab Content 5: Embedded Images -->
      <div id="tab-images" class="tab-panel hidden flex flex-col bg-slate-900 border border-slate-800 rounded-xl overflow-hidden shadow-lg flex-1 h-full min-h-0">
        <div class="p-3 bg-slate-950 border-b border-slate-800 flex flex-wrap justify-between items-center gap-2 text-xs shrink-0">
          <span class="font-semibold text-slate-300">Embedded Images (decoded client-side from the content stream)</span>
          <span id="imagesCount" class="text-slate-500 font-mono">0 images on page 1</span>
        </div>
        <div id="imagesGrid" class="flex-1 overflow-auto w-full p-3 grid grid-cols-1 sm:grid-cols-2 xl:grid-cols-3 gap-3 content-start">
          <div class="col-span-full p-8 text-center text-slate-500 text-xs">No PDF loaded. Please upload a file or click "Load Built-in Sample PDF".</div>
        </div>
      </div>

    </section>
  </main>

  <!-- Floating hover tooltip: follows the cursor over the overlay canvas -->
  <div id="hoverInfo" class="hidden fixed z-40 pointer-events-none font-mono text-[11px] leading-snug text-cyan-200 bg-slate-950/95 px-2.5 py-1.5 rounded border border-cyan-700 shadow-xl truncate max-w-[420px]"></div>

  <!-- File load error toast: without it a rejected PDF fails silently -->
  <div id="loadError" class="hidden fixed bottom-6 left-1/2 -translate-x-1/2 z-50 w-[92%] sm:w-auto sm:max-w-lg bg-rose-950/95 border border-rose-700 text-rose-100 rounded-xl px-4 py-3 shadow-2xl">
    <div class="flex items-start gap-3">
      <span class="text-base leading-none mt-0.5">⚠️</span>
      <div class="min-w-0 flex-1">
        <p id="loadErrorTitle" class="text-sm font-bold text-rose-200">Could not open this PDF</p>
        <p id="loadErrorMessage" class="text-xs text-rose-200/80 mt-1 break-words"></p>
      </div>
      <button id="loadErrorClose" class="shrink-0 text-rose-300/70 hover:text-white text-sm leading-none px-1" title="Dismiss">✕</button>
    </div>
  </div>

  <!-- Embedded image lightbox -->
  <div id="imageLightbox" class="fixed inset-0 z-50 bg-slate-950/90 items-center justify-center p-6" style="display: none;">
    <div class="bg-slate-900 border border-slate-700 rounded-xl shadow-2xl flex flex-col max-w-full max-h-full overflow-hidden">
      <div class="flex items-start justify-between gap-6 px-4 py-2.5 bg-slate-950 border-b border-slate-800">
        <div class="flex flex-col min-w-0">
          <span id="lightboxTitle" class="text-sm font-bold text-orange-400 font-mono truncate">-</span>
          <span id="lightboxMeta" class="text-[11px] text-slate-400 font-mono truncate">-</span>
        </div>
        <button id="lightboxClose" class="shrink-0 text-slate-400 hover:text-slate-100 text-base leading-none px-2 py-1 rounded hover:bg-slate-800 transition" title="Close (Esc)">✕</button>
      </div>
      <div class="overflow-auto bg-slate-950 flex items-center justify-center p-4">
        <canvas id="lightboxCanvas" class="shadow-lg"></canvas>
      </div>
      <div class="px-4 py-2 bg-slate-950 border-t border-slate-800 text-[11px] text-slate-400 font-mono flex items-center justify-between gap-4">
        <span id="lightboxSize">-</span>
        <span class="text-slate-600">Esc to close · scroll to pan</span>
      </div>
    </div>
  </div>

  <!-- Script logic with PDF.js client-side parser -->
  <script>
    pdfjsLib.GlobalWorkerOptions.workerSrc = 'https://cdnjs.cloudflare.com/ajax/libs/pdf.js/3.11.174/pdf.worker.min.js';

    let currentPdfDoc = null;
    let currentPageNum = 1;
    let extractedSpans = [];
    let extractedImages = [];
    let extractedDrawings = [];
    let currentRenderScale = 1.0;
    let activeZoomMode = 'fit-page'; // 'fit-page' | 'fit-width' | 'manual'
    let currentViewport = null;
    let cleanPdfBitmap = null;
    let hoveredSpan = null;
    let hoveredImage = null;
    let hoveredDrawing = null;

    // Document-wide extraction cache. Each entry mirrors the Rust JSON schema
    // (coordinates in PDF points, top-down) so the visualizer can rebuild any
    // page from it and export a `pages[]` document exactly like the native engine.
    let pageCache = [];
    let docModel = null;
    let docFileName = 'document.pdf';
    let docParseMs = 0;
    let docParseStart = 0;
    let parseGeneration = 0;

    // Elements
    const fileInput = document.getElementById('pdfFileInput');
    const dropzone = document.getElementById('dropzone');
    const btnLoadSample = document.getElementById('btnLoadSample');
    const pageSlider = document.getElementById('pageSlider');
    const pageIndicator = document.getElementById('pageIndicator');
    const btnPrevPage = document.getElementById('btnPrevPage');
    const btnNextPage = document.getElementById('btnNextPage');
    const chkShowBoxes = document.getElementById('chkShowBoxes');
    const chkShowImages = document.getElementById('chkShowImages');
    const chkShowVectors = document.getElementById('chkShowVectors');
    const coordsTableBody = document.getElementById('coordsTableBody');
    const tableCount = document.getElementById('tableCount');
    const pureTextBox = document.getElementById('pureTextBox');
    const btnCopyText = document.getElementById('btnCopyText');
    const btnDownloadJson = document.getElementById('btnDownloadJson');
    const btnCopyJson = document.getElementById('btnCopyJson');
    const jsonViewer = document.getElementById('jsonViewer');
    const imagesGrid = document.getElementById('imagesGrid');
    const imagesCount = document.getElementById('imagesCount');
    const imageLightbox = document.getElementById('imageLightbox');
    const lightboxCanvas = document.getElementById('lightboxCanvas');
    const lightboxTitle = document.getElementById('lightboxTitle');
    const lightboxMeta = document.getElementById('lightboxMeta');
    const lightboxSize = document.getElementById('lightboxSize');
    const lightboxClose = document.getElementById('lightboxClose');
    const metricLatency = document.getElementById('metricLatency');
    const metricSpans = document.getElementById('metricSpans');
    const metricImages = document.getElementById('metricImages');
    const metricVectors = document.getElementById('metricVectors');
    const metricComputeMode = document.getElementById('metricComputeMode');
    const headerComputeBadge = document.getElementById('headerComputeBadge');
    let currentRustDoc = null;
    const loadError = document.getElementById('loadError');
    const loadErrorTitle = document.getElementById('loadErrorTitle');
    const loadErrorMessage = document.getElementById('loadErrorMessage');
    const loadErrorClose = document.getElementById('loadErrorClose');
    const metricDims = document.getElementById('metricDims');
    const hoverInfo = document.getElementById('hoverInfo');
    const canvasScrollArea = document.getElementById('canvasScrollArea');

    const btnFitPage = document.getElementById('btnFitPage');
    const btnFitWidth = document.getElementById('btnFitWidth');
    const btnZoom100 = document.getElementById('btnZoom100');
    const btnZoom150 = document.getElementById('btnZoom150');

    const pdfCanvas = document.getElementById('pdfCanvas');
    const pdfCtx = pdfCanvas.getContext('2d');

    // Tabs logic
    document.querySelectorAll('.tab-btn').forEach(btn => {
      btn.addEventListener('click', () => {
        document.querySelectorAll('.tab-btn').forEach(b => {
          b.classList.remove('border-cyan-400', 'text-cyan-300', 'font-bold');
          b.classList.add('border-transparent', 'text-slate-400');
        });
        btn.classList.add('border-cyan-400', 'text-cyan-300', 'font-bold');
        btn.classList.remove('border-transparent', 'text-slate-400');

        document.querySelectorAll('.tab-panel').forEach(p => p.classList.add('hidden'));
        const targetPanel = document.getElementById(btn.dataset.tab);
        targetPanel.classList.remove('hidden');

        // If switching to visual tab, guarantee instant repaint
        if (btn.dataset.tab === 'tab-visual') {
          if (cleanPdfBitmap) {
            drawCanvas(null);
          } else if (currentPdfDoc) {
            renderCurrentPage();
          }
        }
      });
    });

    // Zoom Buttons Styling
    function updateZoomButtons() {
      [btnFitPage, btnFitWidth, btnZoom100, btnZoom150].forEach(b => {
        b.className = 'px-2 py-0.5 rounded bg-slate-800 text-slate-300 border border-slate-700 text-[11px] font-mono hover:bg-slate-700 transition';
      });

      if (activeZoomMode === 'fit-page') {
        btnFitPage.className = 'px-2 py-0.5 rounded bg-cyan-950 text-cyan-400 border border-cyan-800 text-[11px] font-mono hover:bg-cyan-900 transition font-bold';
      } else if (activeZoomMode === 'fit-width') {
        btnFitWidth.className = 'px-2 py-0.5 rounded bg-cyan-950 text-cyan-400 border border-cyan-800 text-[11px] font-mono hover:bg-cyan-900 transition font-bold';
      } else if (currentRenderScale === 1.0) {
        btnZoom100.className = 'px-2 py-0.5 rounded bg-cyan-950 text-cyan-400 border border-cyan-800 text-[11px] font-mono hover:bg-cyan-900 transition font-bold';
      } else if (currentRenderScale === 1.5) {
        btnZoom150.className = 'px-2 py-0.5 rounded bg-cyan-950 text-cyan-400 border border-cyan-800 text-[11px] font-mono hover:bg-cyan-900 transition font-bold';
      }
    }

    async function calculateAutoZoom(mode = activeZoomMode) {
      if (!currentPdfDoc) return 1.0;
      const page = await currentPdfDoc.getPage(currentPageNum);
      const vp1 = page.getViewport({ scale: 1.0 });

      // Available container space
      const availW = Math.max(canvasScrollArea.clientWidth - 52, 280);
      const availH = Math.max(canvasScrollArea.clientHeight - 52, 320);

      if (mode === 'fit-page') {
        // Fits both width and height cleanly without clipping
        const scaleW = availW / vp1.width;
        const scaleH = availH / vp1.height;
        return Math.min(scaleW, scaleH);
      } else if (mode === 'fit-width') {
        // Fits width of available area
        return availW / vp1.width;
      }
      return currentRenderScale;
    }

    btnFitPage.addEventListener('click', async () => {
      activeZoomMode = 'fit-page';
      currentRenderScale = await calculateAutoZoom('fit-page');
      updateZoomButtons();
      renderCurrentPage();
    });

    btnFitWidth.addEventListener('click', async () => {
      activeZoomMode = 'fit-width';
      currentRenderScale = await calculateAutoZoom('fit-width');
      updateZoomButtons();
      renderCurrentPage();
    });

    btnZoom100.addEventListener('click', () => {
      activeZoomMode = 'manual';
      currentRenderScale = 1.0;
      updateZoomButtons();
      renderCurrentPage();
    });

    btnZoom150.addEventListener('click', () => {
      activeZoomMode = 'manual';
      currentRenderScale = 1.5;
      updateZoomButtons();
      renderCurrentPage();
    });

    // Window Resize Observer for Responsive Fit
    let resizeTimer = null;
    window.addEventListener('resize', () => {
      clearTimeout(resizeTimer);
      resizeTimer = setTimeout(async () => {
        if (currentPdfDoc && (activeZoomMode === 'fit-page' || activeZoomMode === 'fit-width')) {
          currentRenderScale = await calculateAutoZoom(activeZoomMode);
          renderCurrentPage();
        }
      }, 200);
    });

    // File selection
    dropzone.addEventListener('click', () => fileInput.click());
    dropzone.addEventListener('dragover', (e) => { e.preventDefault(); dropzone.classList.add('border-cyan-400'); });
    dropzone.addEventListener('dragleave', () => dropzone.classList.remove('border-cyan-400'));
    dropzone.addEventListener('drop', (e) => {
      e.preventDefault();
      dropzone.classList.remove('border-cyan-400');
      if (e.dataTransfer.files.length > 0) loadPdfFile(e.dataTransfer.files[0]);
    });
    fileInput.addEventListener('change', (e) => {
      if (e.target.files.length > 0) loadPdfFile(e.target.files[0]);
    });

    btnLoadSample.addEventListener('click', async () => {
      try {
        const res = await fetch('sample.pdf');
        const blob = await res.blob();
        loadPdfFile(blob, 'sample.pdf');
      } catch (e) {
        alert('Could not load sample.pdf: ' + e);
      }
    });

    function showLoadError(err, fileName) {
      const name = (err && err.name) || '';
      const msg = (err && err.message) || String(err || 'Unknown error');

      let title = 'Could not open this PDF';
      let text = msg;

      if (name === 'PasswordException' || /password/i.test(msg)) {
        title = 'Password-protected PDF';
        text = 'This file is encrypted with a password. Remove the password (or export an unprotected copy) and try again.';
      } else if (/encryption|EBX_HANDLER|ADEPT|encrypted/i.test(msg)) {
        title = 'This PDF is DRM-protected';
        text = "It uses Adobe ADEPT / EBX_HANDLER encryption (typical of e-books). The content is locked by the store's key, so no PDF library can read it without removing the DRM. Try an unprotected copy.";
      } else if (name === 'InvalidPDFException' || /invalid pdf/i.test(msg)) {
        title = 'This file is not a valid PDF';
        text = 'The file looks corrupted or is not a PDF at all. Try re-exporting it.';
      }

      if (fileName) text = fileName + ' — ' + text;

      loadErrorTitle.textContent = title;
      loadErrorMessage.textContent = text;
      loadError.classList.remove('hidden');
      console.error('loadPdfFile failed:', err);
    }

    loadErrorClose.addEventListener('click', () => loadError.classList.add('hidden'));

    
    // Load WebAssembly Pure Rust Engine (rasgapdf.wasm)
    let wasmEngine = null;
    async function initWasmEngine() {
      try {
        const wasmRes = await fetch('rasgapdf.wasm');
        if (wasmRes.ok) {
          const wasmBytes = await wasmRes.arrayBuffer();
          const { instance } = await WebAssembly.instantiate(wasmBytes);
          wasmEngine = instance.exports;
          console.log('⚡ Pure Rust WebAssembly Engine initialized successfully!');
        }
      } catch (err) {
        console.warn('WASM engine unavailable, using browser fallback:', err);
      }
    }
    initWasmEngine();

    function parsePdfWithWasm(pdfUint8Array) {
      if (!wasmEngine) return null;
      const t0 = performance.now();
      const ptr = wasmEngine.wasm_alloc(pdfUint8Array.length);
      const mem = new Uint8Array(wasmEngine.memory.buffer);
      mem.set(pdfUint8Array, ptr);

      // Parse structured document (blocks and tables)
      const resPtr = wasmEngine.rasgapdf_parse_bytes(ptr, pdfUint8Array.length);
      const memOut = new Uint8Array(wasmEngine.memory.buffer);
      let end = resPtr;
      while (memOut[end] !== 0) end++;
      const jsonStr = new TextDecoder('utf-8').decode(memOut.subarray(resPtr, end));
      const structured = JSON.parse(jsonStr);

      // Parse raw spans for highlighting
      const rawPtr = wasmEngine.rasgapdf_parse_raw_bytes(ptr, pdfUint8Array.length);
      const memRaw = new Uint8Array(wasmEngine.memory.buffer);
      let endRaw = rawPtr;
      while (memRaw[endRaw] !== 0) endRaw++;
      const rawJsonStr = new TextDecoder('utf-8').decode(memRaw.subarray(rawPtr, endRaw));
      const raw = JSON.parse(rawJsonStr);

      const elapsed = (performance.now() - t0).toFixed(2);

      wasmEngine.rasgapdf_free_string(resPtr);
      wasmEngine.rasgapdf_free_string(rawPtr);
      wasmEngine.wasm_free(ptr, pdfUint8Array.length);

      return {
        structured: structured,
        raw: raw,
        parse_time_ms: elapsed,
        is_wasm: true
      };
    }


async function loadPdfFile(file, name = null) {
      const fileName = name || file.name || 'document.pdf';

      try {
        loadError.classList.add('hidden');

        const arrayBuffer = await file.arrayBuffer();
        // Uint8Array lets pdf.js copy the bytes instead of adopting a detached buffer.
        const loadingTask = pdfjsLib.getDocument({ data: new Uint8Array(arrayBuffer) });
        currentPdfDoc = await loadingTask.promise;

        // 1. Try local native server or pure Rust WebAssembly engine in browser
        currentRustDoc = null;
        try {
          const formData = new FormData();
          formData.append('file', file, fileName);
          const apiRes = await fetch('/api/parse', { method: 'POST', body: formData });
          if (apiRes.ok) {
            currentRustDoc = await apiRes.json();
            console.log('⚡ Parsed with Native Rust Server in', currentRustDoc.parse_time_ms, 'ms');
          }
        } catch (e) {
          // Server not available (e.g. GitHub Pages) - use pure Rust WASM!
          if (wasmEngine) {
            try {
              currentRustDoc = parsePdfWithWasm(new Uint8Array(arrayBuffer));
              console.log('⚡ Parsed with Pure Rust WebAssembly Engine in', currentRustDoc.parse_time_ms, 'ms');
            } catch (wErr) {
              console.warn('WASM parse error:', wErr);
            }
          }
        }

        pageSlider.max = currentPdfDoc.numPages;
        pageSlider.value = 1;
        currentPageNum = 1;
        docFileName = fileName;

        // Reset the document model for the new file.
        parseGeneration += 1;
        pageCache = new Array(currentPdfDoc.numPages);
        docModel = null;
        docParseMs = 0;

        // On mobile devices, default to fit-width; on desktop, default to fit-page
        if (window.innerWidth < 768) {
          activeZoomMode = 'fit-width';
        } else {
          activeZoomMode = 'fit-page';
        }

        // Parse page 1 first so the canvas shows up immediately; the remaining
        // pages keep being extracted in the background to complete the JSON.
        if (!currentRustDoc) {
          docParseStart = performance.now();
          await parsePageToCache(1, parseGeneration);
          docParseMs = performance.now() - docParseStart;
        }

        currentRenderScale = await calculateAutoZoom(activeZoomMode);
        updateZoomButtons();
        await renderCurrentPage();

        if (!currentRustDoc) {
          parseRemainingPages(parseGeneration);
        }
      } catch (e) {
        showLoadError(e, fileName);
      }
    }

    let renderInFlight = false;
    let renderQueued = false;

    async function renderCurrentPage() {
      if (!currentPdfDoc) return;

      // Serialize renders: pdf.js refuses two render() calls on the same canvas,
      // and zoom / resize / page-change events can fire while a page is still
      // painting. Without this the later call dies silently and leaves the
      // extracted arrays empty.
      if (renderInFlight) {
        renderQueued = true;
        return;
      }

      renderInFlight = true;
      try {
        do {
          renderQueued = false;
          await renderPageOnce();
        } while (renderQueued && currentPdfDoc);
      } finally {
        renderInFlight = false;
      }
    }

    async function renderPageOnce() {
      if (!currentPdfDoc) return;

      const t0 = performance.now();
      pageIndicator.textContent = `Page ${currentPageNum} of ${currentPdfDoc.numPages}`;
      pageSlider.value = currentPageNum;
      btnPrevPage.disabled = (currentPageNum <= 1);
      btnNextPage.disabled = (currentPageNum >= currentPdfDoc.numPages);

      const page = await currentPdfDoc.getPage(currentPageNum);
      const viewport = page.getViewport({ scale: currentRenderScale });
      currentViewport = viewport;

      pdfCanvas.width = viewport.width;
      pdfCanvas.height = viewport.height;

      metricDims.textContent = `${Math.round(viewport.width / currentRenderScale)}x${Math.round(viewport.height / currentRenderScale)} pt`;

      // 1. Render base PDF page directly onto canvas
      await page.render({ canvasContext: pdfCtx, viewport }).promise;

      // 2. Cache clean rasterized bitmap of PDF for zero-latency redrawing
      cleanPdfBitmap = await createImageBitmap(pdfCanvas);

      // If Native Rust Engine processed this document, use its 100% native Rust data!
      if (currentRustDoc && currentRustDoc.structured && currentRustDoc.structured.pages) {
        const pageData = currentRustDoc.structured.pages[currentPageNum - 1] || {};

        // 1. Spans from Rust
        const pageSpans = (currentRustDoc.raw && currentRustDoc.raw.spans
          ? currentRustDoc.raw.spans.filter(s => s.page === currentPageNum)
          : []);

        extractedSpans = pageSpans.map(s => {
          const vx0 = s.x0 * currentRenderScale;
          const vy0 = s.y0 * currentRenderScale;
          const vx1 = s.x1 * currentRenderScale;
          const vy1 = s.y1 * currentRenderScale;
          return {
            page: s.page,
            x0: s.x0,
            y0: s.y0,
            x1: s.x1,
            y1: s.y1,
            font_size: s.font_size,
            font_name: s.font_name || 'Helvetica',
            text: s.text,
            vx0,
            vy0,
            vw: Math.max(vx1 - vx0, 1.0),
            vh: Math.max(vy1 - vy0, 1.0)
          };
        });

        // 2. Images from Rust
        extractedImages = (pageData.images || []).map(im => {
          const b = im.bbox || { x0: 0, y0: 0, x1: 0, y1: 0, width: 0, height: 0 };
          const vx = b.x0 * currentRenderScale;
          const vy = b.y0 * currentRenderScale;
          const vw = b.width * currentRenderScale;
          const vh = b.height * currentRenderScale;
          let thumb = null;
          const uriKey = im.xref ? `xref_${im.xref}` : `${currentPageNum}_${im.image_id}`;
          const uri = currentRustDoc.image_data_uris
            ? (currentRustDoc.image_data_uris[uriKey] || currentRustDoc.image_data_uris[im.image_id] || currentRustDoc.image_data_uris[String(im.image_id)])
            : null;
          if (uri) {
            thumb = new Image();
            thumb.src = uri;
          } else if (b.width > 0 && b.height > 0) {
            thumb = cropFromPage({ vx, vy, vw, vh });
          }
          return {
            objId: im.name || '#' + im.image_id,
            px: { width: im.pixel_width, height: im.pixel_height },
            pt: { x0: b.x0, y0: b.y0, x1: b.x1, y1: b.y1 },
            paint: { vx, vy, vw, vh },
            count: 1,
            thumb: thumb,
            cropped: !uri,
            mime: im.mime_type,
            sha256: im.sha256
          };
        });

        // 3. Vector drawings from Rust
        extractedDrawings = (pageData.drawings || []).map(d => {
          const b = d.bbox || { x0: 0, y0: 0, x1: 0, y1: 0, width: 0, height: 0 };
          const vx = b.x0 * currentRenderScale;
          const vy = b.y0 * currentRenderScale;
          const vw = b.width * currentRenderScale;
          const vh = b.height * currentRenderScale;
          return {
            paint: { vx, vy, vw, vh },
            pt: { x0: b.x0, y0: b.y0, x1: b.x1, y1: b.y1 }
          };
        });

        // 4. Update metrics with real Rust values
        const rustLatency = (currentRustDoc.parse_time_ms !== undefined)
          ? Number(currentRustDoc.parse_time_ms).toFixed(2)
          : (performance.now() - t0).toFixed(2);
        metricLatency.textContent = `${rustLatency} ms`;
        metricSpans.textContent = extractedSpans.length;
        metricImages.textContent = extractedImages.length;
        metricVectors.textContent = extractedDrawings.length;
        const isWasm = currentRustDoc && currentRustDoc.is_wasm;
        const modeTitle = isWasm ? 'Pure Rust WebAssembly (WASM)' : 'Native Rust Engine (FFI)';
        if (metricComputeMode) {
          metricComputeMode.textContent = modeTitle;
          metricComputeMode.className = 'font-mono text-emerald-400 font-bold text-[11px]';
        }
        if (headerComputeBadge) {
          headerComputeBadge.textContent = isWasm ? '⚡ Rust WebAssembly Engine' : '⚡ Native Rust Engine';
          headerComputeBadge.className = 'hidden sm:inline-block text-xs px-2.5 py-0.5 rounded-full bg-emerald-950 text-emerald-300 border border-emerald-700 font-mono font-bold';
        }

        updateTable();
        updateTextDump();
        updateImageGallery();
        drawCanvas(null);
        updateJsonViewer();
        return;
      }

      // 3. Fallback: rebuild this page from the document-wide client-side model.
      //    The model is extracted once per page (in PDF points) and cached, so the
      //    canvas, the overlays and the JSON export always agree with each other.
      const entry = pageCache[currentPageNum - 1];

      if (!entry) {
        extractedSpans = [];
        extractedImages = [];
        extractedDrawings = [];
        metricLatency.textContent = `${(performance.now() - t0).toFixed(2)} ms`;
        metricSpans.textContent = 0;
        metricImages.textContent = 0;
        metricVectors.textContent = 0;
        updateTable();
        updateTextDump();
        updateImageGallery();
        drawCanvas(null);
        updateJsonViewer();
        return;
      }

      const scale = currentRenderScale;

      extractedSpans = entry.spans.map(s => ({
        page: s.page,
        x0: s.x0,
        y0: s.y0,
        x1: s.x1,
        y1: s.y1,
        font_size: s.font_size,
        font_name: s.font_name || 'Helvetica',
        text: s.text,
        vx0: s.x0 * scale,
        vy0: s.y0 * scale,
        vw: Math.max((s.x1 - s.x0) * scale, 1.0),
        vh: Math.max((s.y1 - s.y0) * scale, 1.0)
      }));

      // Image previews are resolved lazily from the pdf.js object store; the
      // model keeps only metadata, exactly like the Rust JSON.
      extractedImages = [];
      for (const im of entry.images) {
        const b = im.bbox || { x0: 0, y0: 0, x1: 0, y1: 0, width: 0, height: 0 };
        const vx = b.x0 * scale;
        const vy = b.y0 * scale;
        const vw = Math.max(b.width * scale, 1.0);
        const vh = Math.max(b.height * scale, 1.0);

        let thumb = null;
        const decoded = im.inline ? im.inline : await resolveImageData(page, im.objId);
        if (decoded) thumb = decodedImageToCanvas(decoded);
        if (!thumb && cleanPdfBitmap) thumb = cropFromPage({ vx, vy, vw, vh });

        extractedImages.push({
          objId: im.name,
          px: { width: im.pixel_width, height: im.pixel_height },
          pt: { x0: b.x0, y0: b.y0, x1: b.x1, y1: b.y1 },
          paint: { vx, vy, vw, vh },
          count: im.count,
          thumb,
          cropped: !decoded,
          mime: im.mime_type,
          sha256: im.sha256
        });
      }

      extractedDrawings = entry.drawings.map(d => {
        const b = d.bbox || { x0: 0, y0: 0, x1: 0, y1: 0, width: 0, height: 0 };
        const vx = b.x0 * scale;
        const vy = b.y0 * scale;
        return {
          type: d.drawing_type,
          fill: rgb01ToHex(d.fill_color),
          stroke: rgb01ToHex(d.stroke_color),
          // Degenerate paths (straight lines) get a 1px floor so the box stays
          // visible; `pt` keeps the true extent so it matches the Rust output.
          paint: { vx, vy, vw: Math.max(b.width * scale, 1.0), vh: Math.max(b.height * scale, 1.0) },
          pt: { x0: b.x0, y0: b.y0, x1: b.x1, y1: b.y1 }
        };
      });

      metricLatency.textContent = `${entry.parse_time_ms.toFixed(2)} ms`;
      metricSpans.textContent = extractedSpans.length;
      metricImages.textContent = extractedImages.length;
      metricVectors.textContent = extractedDrawings.length;
      if (metricComputeMode) {
        metricComputeMode.textContent = 'Client Browser (pdf.js)';
        metricComputeMode.className = 'font-mono text-amber-400 font-bold text-[11px]';
      }
      if (headerComputeBadge) {
        headerComputeBadge.textContent = 'Client-Side Compute';
        headerComputeBadge.className = 'hidden sm:inline-block text-xs px-2.5 py-0.5 rounded-full bg-cyan-950 text-cyan-300 border border-cyan-800 font-mono font-bold';
      }

      updateTable();
      updateTextDump();
      updateImageGallery();
      drawCanvas(null);
      updateJsonViewer();
    }

    // ---------------------------------------------------------------------------
    // Embedded image extraction (client-side, from the content stream)
    //
    // pdf.js paints EVERY image into the unit square [0,1]x[0,1] transformed by the
    // current CTM. In canvas.js: paintInlineImageXObject does
    //     ctx.scale(1 / width, -1 / height);
    //     drawImage(..., 0, -height, width, height);
    // which maps the image onto exactly (0,0)-(1,1) in the current CTM space.
    // paintImageXObjectRepeat uses [scaleX, 0, 0, scaleY, x, y] per position, and
    // paintSolidColorImageMask fills the same unit square — same rule for all.
    // So: replay save/restore/transform and take the unit square on image ops.
    // ---------------------------------------------------------------------------
    const MAT_IDENTITY = [1, 0, 0, 1, 0, 0];

    function matMul(m, n) {
      return [
        m[0] * n[0] + m[2] * n[1],
        m[1] * n[0] + m[3] * n[1],
        m[0] * n[2] + m[2] * n[3],
        m[1] * n[2] + m[3] * n[3],
        m[0] * n[4] + m[2] * n[5] + m[4],
        m[1] * n[4] + m[3] * n[5] + m[5]
      ];
    }

    function unitSquareCorners(m) {
      return [[0, 0], [1, 0], [0, 1], [1, 1]].map(p => pdfjsLib.Util.applyTransform(p, m));
    }

    function resolveImageData(page, objId) {
      return new Promise(resolve => {
        const maps = [page.objs, page.commonObjs].filter(Boolean);

        for (const map of maps) {
          let value = null;
          try {
            value = map.get(objId);
          } catch (e) {
            value = null;
          }
          if (value) {
            resolve(value);
            return;
          }
        }

        let settled = false;
        const timer = setTimeout(() => {
          if (!settled) {
            settled = true;
            resolve(null);
          }
        }, 2000);

        for (const map of maps) {
          try {
            map.get(objId, v => {
              if (!settled) {
                settled = true;
                clearTimeout(timer);
                resolve(v);
              }
            });
          } catch (e) {
            /* ignore */
          }
        }
      });
    }

    function decodedImageToCanvas(img) {
      if (!img || !img.width || !img.height) return null;
      try {
        const c = document.createElement('canvas');
        c.width = img.width;
        c.height = img.height;
        const cx = c.getContext('2d');

        if (img.bitmap) {
          cx.drawImage(img.bitmap, 0, 0);
          return c;
        }
        if (img.data && img.data.length === img.width * img.height * 4) {
          cx.putImageData(new ImageData(new Uint8ClampedArray(img.data), img.width, img.height), 0, 0);
          return c;
        }
      } catch (e) {
        console.warn('Falha ao decodificar imagem embutida:', e);
      }
      return null;
    }

    function cropFromPage(paint) {
      if (!cleanPdfBitmap) return null;
      try {
        const x = Math.max(0, Math.round(paint.vx));
        const y = Math.max(0, Math.round(paint.vy));
        const w = Math.max(1, Math.round(paint.vw));
        const h = Math.max(1, Math.round(paint.vh));
        const c = document.createElement('canvas');
        c.width = w;
        c.height = h;
        c.getContext('2d').drawImage(cleanPdfBitmap, x, y, w, h, 0, 0, w, h);
        return c;
      } catch (e) {
        return null;
      }
    }

    // -------------------------------------------------------------------------
    // Document model extraction (client-side parity with the Rust JSON schema)
    //
    // Everything below works in PDF points, top-down, exactly like the native
    // engine output: `{ file_name, total_pages, parse_time_ms, pages: [...] }`.
    // The canvas only rescales those points at render time.
    // -------------------------------------------------------------------------

    const round2 = (v) => Number((Number.isFinite(v) ? v : 0).toFixed(2));

    function makeBBox(x0, y0, x1, y1) {
      const ax = Math.min(x0, x1);
      const ay = Math.min(y0, y1);
      const bx = Math.max(x0, x1);
      const by = Math.max(y0, y1);
      return {
        x0: round2(ax), y0: round2(ay),
        x1: round2(bx), y1: round2(by),
        width: round2(bx - ax), height: round2(by - ay)
      };
    }

    function rgbToHex255(a) {
      if (!a || a.length < 3 || typeof a[0] !== 'number') return null;
      // pdf.js emits 0-255 ints; keep float support in case a build changes that.
      const k = (a[0] > 1 || a[1] > 1 || a[2] > 1) ? 1 : 255;
      const to = (v) => Math.max(0, Math.min(255, Math.round(v * k))).toString(16).padStart(2, '0');
      return '#' + to(a[0]) + to(a[1]) + to(a[2]);
    }

    function rgb01ToHex(rgb) {
      if (!rgb || rgb.length < 3) return null;
      const to = (v) => Math.max(0, Math.min(255, Math.round(v * 255))).toString(16).padStart(2, '0');
      return '#' + to(rgb[0]) + to(rgb[1]) + to(rgb[2]);
    }

    function hexToRgb01(hex) {
      if (!hex || hex[0] !== '#') return null;
      return [
        round2(parseInt(hex.slice(1, 3), 16) / 255),
        round2(parseInt(hex.slice(3, 5), 16) / 255),
        round2(parseInt(hex.slice(5, 7), 16) / 255)
      ];
    }

    async function sha256Hex(bytes) {
      try {
        const digest = await crypto.subtle.digest('SHA-256', bytes);
        return [...new Uint8Array(digest)].map(b => b.toString(16).padStart(2, '0')).join('');
      } catch (e) {
        return null;
      }
    }

    // Text spans in PDF points. `viewport` must be built with scale = 1 so the
    // matrix math yields points directly (page rotation already included).
    async function extractPageSpans(page, viewport, pageNum) {
      const textContent = await page.getTextContent();
      const spans = [];

      for (const item of textContent.items) {
        if (!item.str || item.str.trim() === '') continue;

        const m = pdfjsLib.Util.transform(viewport.transform, item.transform);
        const fontHeight = Math.hypot(m[2], m[3]);
        const fontScaleX = Math.hypot(m[0], m[1]);
        if (fontHeight === 0 || fontScaleX === 0) continue;

        const ux = m[0] / fontScaleX;
        const uy = m[1] / fontScaleX;
        const advance = item.width;

        // Ascent/descent vectors in page space (m[2], m[3] run baseline -> glyph top).
        const ascX = m[2] * 0.85;
        const ascY = m[3] * 0.85;
        const descX = -m[2] * 0.20;
        const descY = -m[3] * 0.20;

        const c1x = m[4] + ascX,                  c1y = m[5] + ascY;
        const c2x = m[4] + ascX + ux * advance,   c2y = m[5] + ascY + uy * advance;
        const c3x = m[4] + descX,                 c3y = m[5] + descY;
        const c4x = m[4] + descX + ux * advance,  c4y = m[5] + descY + uy * advance;

        spans.push({
          page: pageNum,
          x0: round2(Math.min(c1x, c2x, c3x, c4x)),
          y0: round2(Math.min(c1y, c2y, c3y, c4y)),
          x1: round2(Math.max(c1x, c2x, c3x, c4x)),
          y1: round2(Math.max(c1y, c2y, c3y, c4y)),
          font_size: round2(fontHeight),
          font_name: item.fontName || 'Helvetica',
          text: item.str
        });
      }

      // Spatial order: top-to-bottom in 6pt buckets, then left-to-right —
      // the same ordering the Rust parser applies before table detection.
      spans.sort((a, b) => {
        const bucketA = Math.round(a.y0 / 6);
        const bucketB = Math.round(b.y0 / 6);
        if (bucketA !== bucketB) return bucketA - bucketB;
        return a.x0 - b.x0;
      });

      return spans;
    }

    // Port of src/table.rs (TableDetector) with the same thresholds used by the
    // Space backend: min 3 columns, 16pt column tolerance, 6pt row tolerance.
    function detectTables(spans, tableIdStart = 1) {
      const MIN_COLS = 3;
      const COL_TOLERANCE = 16;
      const ROW_TOLERANCE = 6;

      if (!spans.length) return [];

      const lines = [];
      let currentLine = [];
      let currentY = spans[0].y0;

      for (const span of spans) {
        if (Math.abs(span.y0 - currentY) <= ROW_TOLERANCE) {
          currentLine.push(span);
        } else {
          if (currentLine.length) {
            currentLine.sort((a, b) => a.x0 - b.x0);
            lines.push(currentLine);
          }
          currentLine = [span];
          currentY = span.y0;
        }
      }
      if (currentLine.length) {
        currentLine.sort((a, b) => a.x0 - b.x0);
        lines.push(currentLine);
      }

      const buildTable = (rowsRaw, colsX, tableId) => {
        const numCols = colsX.length;
        let minX = Infinity;
        let minY = Infinity;
        let maxX = -Infinity;
        let maxY = -Infinity;
        const structuredRows = [];
        const cells = [];

        rowsRaw.forEach((rowSpans, rowIdx) => {
          const rowStrings = new Array(numCols).fill('');

          for (const span of rowSpans) {
            minX = Math.min(minX, span.x0);
            minY = Math.min(minY, span.y0);
            maxX = Math.max(maxX, span.x1);
            maxY = Math.max(maxY, span.y1);

            let bestCol = 0;
            let minDist = Infinity;
            colsX.forEach((cx, cIdx) => {
              const d = Math.abs(cx - span.x0);
              if (d < minDist) {
                minDist = d;
                bestCol = cIdx;
              }
            });

            if (rowStrings[bestCol]) rowStrings[bestCol] += ' ';
            rowStrings[bestCol] += span.text.trim();

            cells.push({
              row: rowIdx,
              col: bestCol,
              text: span.text.trim(),
              bbox: makeBBox(span.x0, span.y0, span.x1, span.y1)
            });
          }

          structuredRows.push(rowStrings);
        });

        return {
          table_id: tableId,
          bbox: makeBBox(minX, minY, maxX, maxY),
          col_count: numCols,
          row_count: rowsRaw.length,
          headers: structuredRows.length ? structuredRows[0].slice() : [],
          rows: structuredRows,
          cells
        };
      };

      const tables = [];
      let activeRows = [];
      let activeCols = [];
      let tableCounter = tableIdStart;

      for (const line of lines) {
        if (line.length >= MIN_COLS) {
          if (!activeCols.length) {
            activeCols = line.map(s => s.x0);
            activeRows.push(line);
          } else {
            const aligns = line.some(s => activeCols.some(c => Math.abs(c - s.x0) <= COL_TOLERANCE));
            if (aligns) {
              activeRows.push(line);
            } else {
              if (activeRows.length >= 2) {
                tables.push(buildTable(activeRows, activeCols, tableCounter++));
              }
              activeRows = [line];
              activeCols = line.map(s => s.x0);
            }
          }
        } else {
          if (activeRows.length) {
            if (activeRows.length >= 2) {
              tables.push(buildTable(activeRows, activeCols, tableCounter++));
            }
            activeRows = [];
            activeCols = [];
          }
        }
      }

      if (activeRows.length >= 2) {
        tables.push(buildTable(activeRows, activeCols, tableCounter++));
      }

      return tables;
    }

    // Groups spans into lines and paragraphs. MuPDF gives the native engine real
    // blocks; here the grouping is geometric (vertical gap + horizontal overlap).
    function buildTextBlocks(spans) {
      if (!spans.length) return [];

      const ordered = spans.slice().sort((a, b) => {
        const bucketA = Math.round(a.y0 / 3);
        const bucketB = Math.round(b.y0 / 3);
        if (bucketA !== bucketB) return bucketA - bucketB;
        return a.x0 - b.x0;
      });

      const lines = [];
      for (const span of ordered) {
        const line = lines[lines.length - 1];
        if (line) {
          const ref = line.spans[line.spans.length - 1];
          const tolerance = Math.max(2.0, Math.min(ref.font_size || 0, span.font_size || 0) * 0.4);
          const gapX = span.x0 - ref.x1;
          // Same baseline AND horizontally adjacent: words of one line. Table
          // cells share the baseline but are far apart, so they stay separate
          // lines (MuPDF emits one line per cell).
          const closeX = gapX <= Math.max(1.5, Math.min(ref.font_size || 0, span.font_size || 0) * 0.8);
          if (Math.abs(span.y0 - ref.y0) <= tolerance && closeX) {
            line.spans.push(span);
            continue;
          }
        }
        lines.push({ spans: [span] });
      }

      const unionBox = (boxes) => {
        let x0 = Infinity;
        let y0 = Infinity;
        let x1 = -Infinity;
        let y1 = -Infinity;
        for (const b of boxes) {
          x0 = Math.min(x0, b.x0);
          y0 = Math.min(y0, b.y0);
          x1 = Math.max(x1, b.x1);
          y1 = Math.max(y1, b.y1);
        }
        return makeBBox(x0, y0, x1, y1);
      };

      for (const line of lines) {
        line.spans.sort((a, b) => a.x0 - b.x0);
        line.bbox = unionBox(line.spans);
        line.blockSpans = line.spans.map(s => ({
          text: s.text,
          bbox: makeBBox(s.x0, s.y0, s.x1, s.y1),
          font_name: s.font_name || 'Helvetica',
          font_size: s.font_size,
          char_count: [...s.text].length
        }));
        line.text = line.spans.map(s => s.text).join(' ').replace(/\s+/g, ' ').trim();
      }

      const blocks = [];
      let current = null;

      for (const line of lines) {
        const lineSize = Math.max(1, ...line.spans.map(s => s.font_size || 0));

        if (current) {
          const prevLine = current.lines[current.lines.length - 1];
          const gap = line.bbox.y0 - current.bbox.y1;
          const overlap = Math.min(current.bbox.x1, line.bbox.x1) - Math.max(current.bbox.x0, line.bbox.x0);
          const minWidth = Math.min(current.bbox.width, line.bbox.width);

          // A different type size means a different block (title vs body), which is
          // how MuPDF splits them in the native output.
          const prevSize = Math.max(1, ...prevLine.spans.map(s => s.font_size || 0));
          const similarSize = Math.max(lineSize, prevSize) / Math.min(lineSize, prevSize) <= 1.5;

          // Cells on the same baseline belong to the same row/block even when
          // their boxes do not overlap horizontally.
          const sameRowTolerance = Math.max(2, lineSize * 0.3);
          const sameRow =
            Math.abs(line.bbox.y0 - prevLine.bbox.y0) <= sameRowTolerance &&
            Math.abs(line.bbox.y1 - prevLine.bbox.y1) <= sameRowTolerance;

          // Tight vertical gap = same paragraph. MuPDF keeps table rows apart
          // because their leading is much larger than their type size.
          if (similarSize && (sameRow || (gap <= Math.max(lineSize * 0.6, 3) && overlap > Math.max(minWidth * 0.15, 0)))) {
            current.lines.push(line);
            current.bbox = unionBox([current.bbox, line.bbox]);
            continue;
          }
        }

        current = { block_id: blocks.length + 1, bbox: line.bbox, lines: [line] };
        blocks.push(current);
      }

      return blocks.map(block => ({
        block_id: block.block_id,
        block_type: 'text',
        bbox: block.bbox,
        lines: block.lines.map(line => ({
          text: line.text,
          bbox: line.bbox,
          spans: line.blockSpans
        }))
      }));
    }

    // Operator-list walk: images keep metadata + sha256 (of the normalized PNG),
    // paths become SpatialDrawing objects with items, colours and stroke style.
    async function extractPageGraphicsModel(page, viewport) {
      const images = [];
      const drawings = [];

      let opList;
      try {
        opList = await page.getOperatorList();
      } catch (e) {
        console.warn('getOperatorList failed:', e);
        return { images, drawings };
      }

      const ops = pdfjsLib.OPS;

      const toPage = (p, matrix) => {
        const a = pdfjsLib.Util.applyTransform(p, matrix);
        const b = pdfjsLib.Util.applyTransform(a, viewport.transform);
        return [round2(b[0]), round2(b[1])];
      };

      const cornersToBBox = (matrix) => {
        const pts = [[0, 0], [1, 0], [0, 1], [1, 1]].map(p => toPage(p, matrix));
        const xs = pts.map(p => p[0]);
        const ys = pts.map(p => p[1]);
        return makeBBox(Math.min(...xs), Math.min(...ys), Math.max(...xs), Math.max(...ys));
      };

      const pathBBox = (bounds, matrix) => {
        // pdf.js reports path bounds as [minX, maxX, minY, maxY].
        const [minX, maxX, minY, maxY] = bounds;
        const pts = [
          toPage([minX, minY], matrix),
          toPage([maxX, minY], matrix),
          toPage([minX, maxY], matrix),
          toPage([maxX, maxY], matrix)
        ];
        const xs = pts.map(p => p[0]);
        const ys = pts.map(p => p[1]);
        return makeBBox(Math.min(...xs), Math.min(...ys), Math.max(...xs), Math.max(...ys));
      };

      const pageArea = Math.abs(viewport.width * viewport.height);

      let ctm = MAT_IDENTITY.slice();
      const stack = [];
      let fillHex = null;
      let strokeHex = null;
      let lineWidth = null;
      let lineCap = null;
      let lineJoin = null;
      let dashPattern = null;
      let dashPhase = null;
      let fillOpacity = null;
      let strokeOpacity = null;
      let seqno = 0;

      const foundImages = [];
      let pendingPath = null;

      const cmykToRgb = (c, m, y, k) => [
        255 * (1 - c) * (1 - k),
        255 * (1 - m) * (1 - k),
        255 * (1 - y) * (1 - k)
      ];

      for (let i = 0; i < opList.fnArray.length; i++) {
        const fn = opList.fnArray[i];
        const args = opList.argsArray[i];

        if (fn === ops.save) {
          stack.push(ctm.slice());
        } else if (fn === ops.restore) {
          ctm = stack.pop() || MAT_IDENTITY.slice();
        } else if (fn === ops.transform) {
          ctm = matMul(ctm, args);
        } else if (fn === ops.paintFormXObjectBegin || fn === ops.beginGroup) {
          stack.push(ctm.slice());
          if (args && Array.isArray(args[0]) && args[0].length === 6) {
            ctm = matMul(ctm, args[0]);
          }
        } else if (fn === ops.paintFormXObjectEnd || fn === ops.endGroup) {
          ctm = stack.pop() || MAT_IDENTITY.slice();
        } else if (fn === ops.setLineWidth) {
          lineWidth = round2(args[0]);
        } else if (fn === ops.setLineCap) {
          lineCap = ['butt', 'round', 'square'][args[0]] || null;
        } else if (fn === ops.setLineJoin) {
          lineJoin = ['miter', 'round', 'bevel'][args[0]] || null;
        } else if (fn === ops.setDash) {
          const pattern = Array.isArray(args[0]) ? args[0].map(round2) : [];
          dashPattern = pattern.length ? pattern : null;
          dashPhase = dashPattern ? round2(args[1] || 0) : null;
        } else if (fn === ops.setFillAlpha) {
          fillOpacity = round2(args[0]);
        } else if (fn === ops.setStrokeAlpha) {
          strokeOpacity = round2(args[0]);
        } else if (fn === ops.setGState) {
          const state = args && args[0];
          if (state) {
            if (typeof state.ca === 'number') fillOpacity = round2(state.ca);
            if (typeof state.CA === 'number') strokeOpacity = round2(state.CA);
            if (typeof state.lineWidth === 'number') lineWidth = round2(state.lineWidth);
            if (state.dash && Array.isArray(state.dash) && state.dash.length) {
              dashPattern = state.dash.map(round2);
              dashPhase = 0;
            }
          }
        } else if (fn === ops.setFillRGBColor) {
          fillHex = rgbToHex255(args);
        } else if (fn === ops.setStrokeRGBColor) {
          strokeHex = rgbToHex255(args);
        } else if (fn === ops.setFillGray) {
          fillHex = rgbToHex255([args[0] * 255, args[0] * 255, args[0] * 255]);
        } else if (fn === ops.setStrokeGray) {
          strokeHex = rgbToHex255([args[0] * 255, args[0] * 255, args[0] * 255]);
        } else if (fn === ops.setFillCMYKColor) {
          fillHex = rgbToHex255(cmykToRgb(args[0], args[1], args[2], args[3]));
        } else if (fn === ops.setStrokeCMYKColor) {
          strokeHex = rgbToHex255(cmykToRgb(args[0], args[1], args[2], args[3]));
        } else if (fn === ops.constructPath) {
          // pdf.js may emit one path in several constructPath calls (e.g. a
          // rectangle followed by closePath). Merge them until a paint op.
          const pathOps = args && args[0];
          const pathArgs = args && args[1];
          const minMax = args && args[2];

          if (pathOps && pathArgs) {
            if (!pendingPath) {
              pendingPath = { pathOps: [], pathArgs: [], minMax: null, matrix: ctm.slice() };
            }
            pendingPath.pathOps = pendingPath.pathOps.concat(Array.from(pathOps));
            pendingPath.pathArgs = pendingPath.pathArgs.concat(Array.from(pathArgs));

            if (minMax && minMax.length === 4 && Array.from(minMax).every(v => typeof v === 'number' && Number.isFinite(v))) {
              if (!pendingPath.minMax) {
                pendingPath.minMax = Array.from(minMax);
              } else {
                pendingPath.minMax = [
                  Math.min(pendingPath.minMax[0], minMax[0]),
                  Math.max(pendingPath.minMax[1], minMax[1]),
                  Math.min(pendingPath.minMax[2], minMax[2]),
                  Math.max(pendingPath.minMax[3], minMax[3])
                ];
              }
            }
          }
        } else if (fn === ops.fill || fn === ops.eoFill || fn === ops.fillStroke ||
                   fn === ops.eoFillStroke || fn === ops.closePathFillStroke ||
                   fn === ops.closePathEOFillStroke || fn === ops.stroke || fn === ops.closePathStroke) {
          if (pendingPath && !pendingPath.minMax) pendingPath = null;
          if (pendingPath) {
            const doFill = (fn === ops.fill || fn === ops.eoFill || fn === ops.fillStroke ||
                            fn === ops.eoFillStroke || fn === ops.closePathFillStroke ||
                            fn === ops.closePathEOFillStroke);
            const doStroke = (fn === ops.stroke || fn === ops.closePathStroke ||
                              fn === ops.fillStroke || fn === ops.eoFillStroke ||
                              fn === ops.closePathFillStroke || fn === ops.closePathEOFillStroke);
            const isEvenOdd = (fn === ops.eoFill || fn === ops.eoFillStroke || fn === ops.closePathEOFillStroke);

            const bbox = pathBBox(pendingPath.minMax, pendingPath.matrix);

            // Background fills (>= 95% of the page) are noise — same filter as Rust.
            const isBackground = doFill && !doStroke && pageArea > 0 &&
              (bbox.width * bbox.height) >= 0.95 * pageArea;

            if (!isBackground) {
              const matrix = pendingPath.matrix;
              const items = [];
              let ai = 0;
              let cur = null;
              let start = null;

              for (const op of pendingPath.pathOps) {
                if (op === ops.moveTo) {
                  cur = [pendingPath.pathArgs[ai++], pendingPath.pathArgs[ai++]];
                  start = cur;
                } else if (op === ops.lineTo) {
                  const p = [pendingPath.pathArgs[ai++], pendingPath.pathArgs[ai++]];
                  if (cur) items.push({ kind: 'line', p1: toPage(cur, matrix), p2: toPage(p, matrix) });
                  cur = p;
                } else if (op === ops.curveTo) {
                  const c1 = [pendingPath.pathArgs[ai++], pendingPath.pathArgs[ai++]];
                  const c2 = [pendingPath.pathArgs[ai++], pendingPath.pathArgs[ai++]];
                  const p = [pendingPath.pathArgs[ai++], pendingPath.pathArgs[ai++]];
                  if (cur) {
                    items.push({
                      kind: 'curve',
                      p1: toPage(cur, matrix),
                      p2: toPage(c1, matrix),
                      p3: toPage(c2, matrix),
                      p4: toPage(p, matrix)
                    });
                  }
                  cur = p;
                } else if (op === ops.closePath) {
                  if (cur && start) {
                    const dx = start[0] - cur[0];
                    const dy = start[1] - cur[1];
                    // Rectangles are already closed; skip degenerate segments.
                    if (Math.abs(dx) > 0.01 || Math.abs(dy) > 0.01) {
                      items.push({ kind: 'line', p1: toPage(cur, matrix), p2: toPage(start, matrix) });
                    }
                    cur = start;
                  }
                } else if (op === ops.rectangle) {
                  const x = pendingPath.pathArgs[ai++];
                  const y = pendingPath.pathArgs[ai++];
                  const w = pendingPath.pathArgs[ai++];
                  const h = pendingPath.pathArgs[ai++];
                  const pts = [
                    toPage([x, y], matrix),
                    toPage([x + w, y], matrix),
                    toPage([x, y + h], matrix),
                    toPage([x + w, y + h], matrix)
                  ];
                  const xs = pts.map(p => p[0]);
                  const ys = pts.map(p => p[1]);
                  items.push({
                    kind: 'rect',
                    bbox: makeBBox(Math.min(...xs), Math.min(...ys), Math.max(...xs), Math.max(...ys)),
                    orientation: 1
                  });
                  cur = [x, y];
                  start = cur;
                }
              }

              drawings.push({
                drawing_id: drawings.length + 1,
                bbox,
                drawing_type: (doFill && doStroke) ? 'fill_stroke' : (doFill ? 'fill' : 'stroke'),
                item_count: items.length,
                items,
                stroke_color: doStroke ? hexToRgb01(strokeHex) : null,
                fill_color: doFill ? hexToRgb01(fillHex) : null,
                width: doStroke ? lineWidth : null,
                fill_opacity: doFill ? (fillOpacity === null ? 1 : fillOpacity) : null,
                stroke_opacity: doStroke ? (strokeOpacity === null ? 1 : strokeOpacity) : null,
                even_odd: doFill ? isEvenOdd : null,
                dash_pattern: doStroke ? (dashPattern || []) : null,
                dash_phase: doStroke ? (dashPhase === null ? 0 : dashPhase) : null,
                line_join: doStroke ? (lineJoin || 'miter') : null,
                line_cap: doStroke ? (lineCap || 'butt') : null,
                layer: null,
                seqno: ++seqno
              });
            }

            pendingPath = null;
          }
        } else if (fn === ops.endPath || fn === ops.clip) {
          pendingPath = null;
        } else if (fn === ops.paintImageXObject) {
          foundImages.push({ objId: String(args[0]), inline: null, matrix: ctm.slice() });
        } else if (fn === ops.paintInlineImageXObject) {
          foundImages.push({ objId: null, inline: args[0], matrix: ctm.slice() });
        } else if (fn === ops.paintImageXObjectRepeat) {
          for (let p = 0; p < args[3].length; p += 2) {
            foundImages.push({
              objId: String(args[0]),
              inline: null,
              matrix: matMul(ctm, [args[1], 0, 0, args[2], args[3][p], args[3][p + 1]])
            });
          }
        }
      }

      // Dedupe by resource: an image painted N times is still one embedded image.
      const byKey = new Map();
      for (const item of foundImages) {
        const key = item.objId !== null ? 'x:' + item.objId : 'inline:' + images.length + ':' + foundImages.indexOf(item);
        const bbox = cornersToBBox(item.matrix);
        const existing = byKey.get(key);
        if (existing) {
          existing.count += 1;
          continue;
        }
        byKey.set(key, {
          objId: item.objId,
          inline: item.inline,
          matrix: item.matrix,
          bbox,
          count: 1
        });
      }

      let imageId = 1;
      for (const entry of byKey.values()) {
        const decoded = entry.inline ? entry.inline : await resolveImageData(page, entry.objId);

        let pixelWidth = decoded && decoded.width ? decoded.width : Math.round(entry.bbox.width);
        let pixelHeight = decoded && decoded.height ? decoded.height : Math.round(entry.bbox.height);
        let bitsPerComponent = null;
        let colorSpace = null;

        // pdf.js does not expose the original PDF colour space; infer it from the
        // decoded buffer (1bpp masks are 1 byte per 8 pixels, grey is 1 B/px).
        if (decoded) {
          if (decoded.bitmap) {
            bitsPerComponent = 8;
            colorSpace = '/DeviceRGB';
          } else if (decoded.data && decoded.width && decoded.height) {
            const bytesPerPixel = decoded.data.length / (decoded.width * decoded.height);
            if (bytesPerPixel < 1) {
              bitsPerComponent = 1;
              colorSpace = '/DeviceGray';
            } else if (bytesPerPixel < 3) {
              bitsPerComponent = 8;
              colorSpace = '/DeviceGray';
            } else {
              bitsPerComponent = 8;
              colorSpace = '/DeviceRGB';
            }
          }
        }

        // The browser only exposes decoded pixels, so the digest/file size below
        // refer to the normalized PNG (documented in the Space README).
        let sha256 = null;
        let byteLength = null;
        const canvas = decodedImageToCanvas(decoded);
        if (canvas) {
          try {
            const blob = await new Promise(resolve => canvas.toBlob(resolve, 'image/png'));
            if (blob) {
              const buffer = await blob.arrayBuffer();
              byteLength = buffer.byteLength;
              sha256 = await sha256Hex(buffer);
            }
          } catch (e) {
            /* hashing is best-effort */
          }
        }

        images.push({
          image_id: imageId++,
          name: entry.objId !== null ? entry.objId : 'inline',
          xref: 0,
          bbox: entry.bbox,
          pixel_width: pixelWidth,
          pixel_height: pixelHeight,
          bits_per_component: bitsPerComponent,
          color_space: colorSpace,
          filter: null,
          mime_type: 'image/png',
          byte_length: byteLength,
          sha256,
          file: null,
          count: entry.count,
          objId: entry.objId,
          inline: entry.inline
        });
      }

      return { images, drawings };
    }

    async function parsePageToCache(pageNum, generation = parseGeneration) {
      const doc = currentPdfDoc;
      if (!doc || pageNum < 1 || pageNum > doc.numPages) return null;
      if (pageCache[pageNum - 1]) return pageCache[pageNum - 1];

      const t0 = performance.now();
      const page = await doc.getPage(pageNum);
      const viewport = page.getViewport({ scale: 1 });

      const spans = await extractPageSpans(page, viewport, pageNum);
      const graphics = await extractPageGraphicsModel(page, viewport);

      const entry = {
        page_number: pageNum,
        width: round2(viewport.width),
        height: round2(viewport.height),
        rotation: page.rotate || 0,
        text_blocks: buildTextBlocks(spans),
        tables: detectTables(spans, 1),
        raw_span_count: spans.length,
        images: graphics.images,
        drawings: graphics.drawings,
        spans,
        parse_time_ms: performance.now() - t0
      };

      // A new file may have been dropped while this page was being extracted.
      // In that case the result belongs to a stale document: drop it instead of
      // overwriting the fresh page cache.
      if (generation !== parseGeneration || doc !== currentPdfDoc) return null;

      pageCache[pageNum - 1] = entry;
      return entry;
    }

    async function parseRemainingPages(generation) {
      if (!currentPdfDoc) return;
      const total = currentPdfDoc.numPages;

      for (let p = 2; p <= total; p++) {
        if (generation !== parseGeneration) return;
        try {
          await parsePageToCache(p, generation);
        } catch (e) {
          console.warn('page ' + p + ' extraction failed:', e);
        }
        if (generation !== parseGeneration) return;
        pageIndicator.textContent = `Page ${currentPageNum} of ${total} · extracted ${p}/${total}`;
      }

      if (generation !== parseGeneration) return;
      docParseMs = performance.now() - docParseStart;
      pageIndicator.textContent = `Page ${currentPageNum} of ${total}`;
      updateJsonViewer();
      console.log(`⚡ Client-side document model ready: ${pageCache.filter(Boolean).length}/${total} pages in ${docParseMs.toFixed(0)} ms`);
    }

    async function ensureFullDocument() {
      if (!currentPdfDoc) return;
      const total = currentPdfDoc.numPages;

      for (let p = 1; p <= total; p++) {
        if (!pageCache[p - 1]) {
          try {
            await parsePageToCache(p, parseGeneration);
          } catch (e) {
            console.warn('page ' + p + ' extraction failed:', e);
          }
        }
      }

      if (!docParseMs && docParseStart) {
        docParseMs = performance.now() - docParseStart;
      }
      updateJsonViewer();
    }

    function buildDocumentJson() {
      if (!currentPdfDoc) return null;

      const pages = pageCache.filter(Boolean).map(p => ({
        page_number: p.page_number,
        width: p.width,
        height: p.height,
        rotation: p.rotation,
        text_blocks: p.text_blocks,
        tables: p.tables,
        raw_span_count: p.raw_span_count,
        images: p.images.map(im => ({
          image_id: im.image_id,
          name: im.name,
          xref: im.xref,
          bbox: im.bbox,
          pixel_width: im.pixel_width,
          pixel_height: im.pixel_height,
          bits_per_component: im.bits_per_component,
          color_space: im.color_space,
          filter: im.filter,
          mime_type: im.mime_type,
          byte_length: im.byte_length,
          sha256: im.sha256,
          file: null
        })),
        drawings: p.drawings
      }));

      return {
        file_name: docFileName,
        total_pages: currentPdfDoc.numPages,
        parse_time_ms: round2(docParseMs),
        pages
      };
    }


    function updateImageGallery() {
      imagesGrid.innerHTML = '';
      imagesCount.textContent = `${extractedImages.length} image(s) on page ${currentPageNum}`;

      if (extractedImages.length === 0) {
        imagesGrid.innerHTML = '<div class="col-span-full p-8 text-center text-slate-500 text-xs">No embedded images found on this page.</div>';
        return;
      }

      extractedImages.forEach((im, idx) => {
        const card = document.createElement('div');
        card.className = 'bg-slate-950 border border-slate-800 rounded-lg overflow-hidden flex flex-col cursor-pointer group hover:border-orange-500/70 transition focus:outline-none focus:ring-2 focus:ring-orange-500/60';
        card.title = 'Click to view full size';
        card.setAttribute('role', 'button');
        card.setAttribute('tabindex', '0');
        card.setAttribute('aria-label',
          'Enlarge image ' + (idx + 1) +
          (im.px ? ', ' + im.px.width + ' by ' + im.px.height + ' pixels' : ''));
        card.addEventListener('click', () => openLightbox(im, idx));
        card.addEventListener('keydown', (e) => {
          if (e.key === 'Enter' || e.key === ' ') {
            e.preventDefault();
            openLightbox(im, idx);
          }
        });

        const frame = document.createElement('div');
        frame.className = 'relative bg-slate-900/60 flex items-center justify-center p-2 h-44';
        if (im.thumb) {
          im.thumb.className = 'max-h-full max-w-full object-contain shadow';
          frame.appendChild(im.thumb);
        } else {
          frame.innerHTML = '<span class="text-slate-500 text-xs">preview unavailable</span>';
        }

        const hint = document.createElement('span');
        hint.className = 'absolute bottom-1.5 right-2 text-[10px] font-mono text-slate-300 bg-slate-950/85 border border-slate-700 rounded px-1.5 py-0.5 opacity-0 group-hover:opacity-100 transition';
        hint.textContent = '🔍 enlarge';
        frame.appendChild(hint);

        const label = im.objId !== null && im.objId !== undefined
          ? 'XObject ' + im.objId
          : 'inline image';

        const meta = document.createElement('div');
        meta.className = 'p-2.5 text-[11px] font-mono text-slate-300 flex flex-col gap-1 border-t border-slate-800';
        meta.innerHTML =
          '<span class="text-orange-400 font-bold">#' + (idx + 1) + ' ' + escapeHtml(String(label)) + '</span>' +
          '<span>pixels: <span class="coord-font">' + (im.px ? im.px.width + ' x ' + im.px.height : 'unknown') + '</span></span>' +
          '<span>bbox pt: <span class="coord-font">[' + im.pt.x0 + ', ' + im.pt.y0 + ', ' + im.pt.x1 + ', ' + im.pt.y1 + ']</span></span>' +
          '<span>painted: <span class="coord-font">' + im.count + 'x</span>' +
          (im.cropped ? ' <span class="text-amber-400">(crop fallback)</span>' : '') + '</span>' +
          '<span class="text-slate-500">🔍 click to enlarge</span>';

        card.appendChild(frame);
        card.appendChild(meta);
        imagesGrid.appendChild(card);
      });
    }

    function drawCanvas(highlightSpan = null) {
      if (!cleanPdfBitmap) return;

      // Draw clean base PDF
      pdfCtx.drawImage(cleanPdfBitmap, 0, 0);

      // Embedded image placement (orange); the hovered image gets a stronger tint
      if (chkShowImages.checked) {
        extractedImages.forEach(im => {
          const isHovered = (im === hoveredImage);
          pdfCtx.fillStyle = isHovered ? 'rgba(249, 115, 22, 0.40)' : 'rgba(249, 115, 22, 0.22)';
          pdfCtx.strokeStyle = isHovered ? 'rgba(251, 146, 60, 1.0)' : 'rgba(249, 115, 22, 0.95)';
          pdfCtx.lineWidth = isHovered
            ? Math.max(2.5, 3.2 * (currentRenderScale / 1.5))
            : Math.max(1.5, 2.0 * (currentRenderScale / 1.5));
          pdfCtx.fillRect(im.paint.vx, im.paint.vy, im.paint.vw, im.paint.vh);
          pdfCtx.strokeRect(im.paint.vx, im.paint.vy, im.paint.vw, im.paint.vh);
        });
      }

      // Vector paths (magenta); the hovered path gets a stronger stroke
      if (chkShowVectors.checked) {
        extractedDrawings.forEach(d => {
          const isHovered = (d === hoveredDrawing);
          const px = d.paint;

          if (px.vw > 1.5 && px.vh > 1.5) {
            pdfCtx.fillStyle = isHovered ? 'rgba(217, 70, 239, 0.24)' : 'rgba(217, 70, 239, 0.10)';
            pdfCtx.fillRect(px.vx, px.vy, px.vw, px.vh);
          }

          pdfCtx.strokeStyle = isHovered ? 'rgba(240, 171, 252, 1.0)' : 'rgba(217, 70, 239, 0.85)';
          pdfCtx.lineWidth = isHovered
            ? Math.max(2.0, 2.6 * (currentRenderScale / 1.5))
            : Math.max(1.0, 1.2 * (currentRenderScale / 1.5));
          pdfCtx.strokeRect(px.vx, px.vy, px.vw, px.vh);
        });
      }

      if (!chkShowBoxes.checked) return;

      extractedSpans.forEach(s => {
        const isHovered = (s === highlightSpan);

        if (isHovered) {
          pdfCtx.fillStyle = 'rgba(6, 182, 212, 0.40)';
          pdfCtx.strokeStyle = 'rgba(34, 211, 238, 1.0)';
          pdfCtx.lineWidth = Math.max(1.5, 2.0 * (currentRenderScale / 1.5));
        } else {
          pdfCtx.fillStyle = 'rgba(6, 182, 212, 0.18)';
          pdfCtx.strokeStyle = 'rgba(6, 182, 212, 0.85)';
          pdfCtx.lineWidth = Math.max(1.0, 1.3 * (currentRenderScale / 1.5));
        }

        pdfCtx.fillRect(s.vx0, s.vy0, s.vw, s.vh);
        pdfCtx.strokeRect(s.vx0, s.vy0, s.vw, s.vh);
      });
    }

    // Interactive Hover on Canvas (text spans + embedded images).
    // The tooltip is position:fixed and follows the cursor.
    const TOOLTIP_MARGIN = 8;
    const TOOLTIP_OFFSET = 14;

    function positionTooltip(clientX, clientY) {
      const box = hoverInfo.getBoundingClientRect();
      let x = clientX + TOOLTIP_OFFSET;
      let y = clientY + TOOLTIP_OFFSET;

      if (x + box.width + TOOLTIP_MARGIN > window.innerWidth) {
        x = clientX - TOOLTIP_OFFSET - box.width;
      }
      if (y + box.height + TOOLTIP_MARGIN > window.innerHeight) {
        y = clientY - TOOLTIP_OFFSET - box.height;
      }

      hoverInfo.style.left = Math.max(TOOLTIP_MARGIN, Math.round(x)) + 'px';
      hoverInfo.style.top = Math.max(TOOLTIP_MARGIN, Math.round(y)) + 'px';
    }

    function setTooltipKind(kind) {
      hoverInfo.classList.remove(
        'text-cyan-200', 'border-cyan-700',
        'text-orange-200', 'border-orange-700',
        'text-fuchsia-200', 'border-fuchsia-700'
      );
      if (kind === 'image') {
        hoverInfo.classList.add('text-orange-200', 'border-orange-700');
      } else if (kind === 'vector') {
        hoverInfo.classList.add('text-fuchsia-200', 'border-fuchsia-700');
      } else {
        hoverInfo.classList.add('text-cyan-200', 'border-cyan-700');
      }
    }

    function drawingTooltipText(d) {
      const col = d.type === 'stroke' ? d.stroke : (d.fill || d.stroke);
      return 'path · ' + d.type +
        (col ? ' · ' + col : '') +
        ' · bbox [' + d.pt.x0 + ', ' + d.pt.y0 + ', ' + d.pt.x1 + ', ' + d.pt.y1 + ']';
    }

    function imageTooltipText(im) {
      const label = (im.objId !== null && im.objId !== undefined) ? 'XObject ' + im.objId : 'inline image';
      const px = im.px ? (im.px.width + '×' + im.px.height + ' px') : 'unknown size';
      return label + ' · ' + px +
        ' · bbox [' + im.pt.x0 + ', ' + im.pt.y0 + ', ' + im.pt.x1 + ', ' + im.pt.y1 + ']' +
        ' · painted ' + im.count + 'x';
    }

    pdfCanvas.addEventListener('mousemove', (e) => {
      if (!currentViewport) return;

      const rect = pdfCanvas.getBoundingClientRect();
      const scaleX = pdfCanvas.width / rect.width;
      const scaleY = pdfCanvas.height / rect.height;
      const mouseX = (e.clientX - rect.left) * scaleX;
      const mouseY = (e.clientY - rect.top) * scaleY;

      // Text spans are the smaller targets, so they win when they overlap an image.
      const span = extractedSpans.find(s =>
        mouseX >= s.vx0 && mouseX <= s.vx0 + s.vw &&
        mouseY >= s.vy0 && mouseY <= s.vy0 + s.vh
      ) || null;

      const img = (span || !chkShowImages.checked) ? null : (extractedImages.find(im =>
        mouseX >= im.paint.vx && mouseX <= im.paint.vx + im.paint.vw &&
        mouseY >= im.paint.vy && mouseY <= im.paint.vy + im.paint.vh
      ) || null);

      // Smallest matching path wins: the table's outer rect would otherwise
      // swallow its own grid lines, which are far more useful to inspect.
      const drw = (span || img || !chkShowVectors.checked) ? null : (() => {
        let best = null;
        let bestArea = Infinity;
        for (const d of extractedDrawings) {
          const p = d.paint;
          if (mouseX < p.vx || mouseX > p.vx + p.vw || mouseY < p.vy || mouseY > p.vy + p.vh) continue;
          const area = p.vw * p.vh;
          if (area < bestArea) {
            bestArea = area;
            best = d;
          }
        }
        return best;
      })();

      if (span !== hoveredSpan || img !== hoveredImage || drw !== hoveredDrawing) {
        hoveredSpan = span;
        hoveredImage = img;
        hoveredDrawing = drw;
        drawCanvas(hoveredSpan);

        if (hoveredSpan) {
          setTooltipKind('text');
          hoverInfo.textContent = `[${hoveredSpan.x0.toFixed(1)}, ${hoveredSpan.y0.toFixed(1)}, ${hoveredSpan.x1.toFixed(1)}, ${hoveredSpan.y1.toFixed(1)}] "${hoveredSpan.text}"`;
          hoverInfo.classList.remove('hidden');
        } else if (hoveredImage) {
          setTooltipKind('image');
          hoverInfo.textContent = imageTooltipText(hoveredImage);
          hoverInfo.classList.remove('hidden');
        } else if (hoveredDrawing) {
          setTooltipKind('vector');
          hoverInfo.textContent = drawingTooltipText(hoveredDrawing);
          hoverInfo.classList.remove('hidden');
        } else {
          hoverInfo.classList.add('hidden');
        }
      }

      if (hoveredSpan || hoveredImage || hoveredDrawing) positionTooltip(e.clientX, e.clientY);
    });

    pdfCanvas.addEventListener('mouseleave', () => {
      if (hoveredSpan || hoveredImage || hoveredDrawing) {
        hoveredSpan = null;
        hoveredImage = null;
        hoveredDrawing = null;
        drawCanvas(null);
        hoverInfo.classList.add('hidden');
      }
    });

    function updateTable() {
      coordsTableBody.innerHTML = '';
      tableCount.textContent = `${extractedSpans.length} spans on page ${currentPageNum}`;

      if (extractedSpans.length === 0) {
        coordsTableBody.innerHTML = '<tr><td colspan="8" class="p-8 text-center text-slate-500">No text elements found on this page.</td></tr>';
        return;
      }

      extractedSpans.forEach(s => {
        const tr = document.createElement('tr');
        tr.className = 'hover:bg-slate-800/40 transition border-b border-slate-800/40';
        tr.innerHTML = `
          <td class="p-3 text-center text-slate-400 font-mono">${s.page}</td>
          <td class="p-3 coord-font">${s.x0.toFixed(2)}</td>
          <td class="p-3 coord-font">${s.y0.toFixed(2)}</td>
          <td class="p-3 coord-font">${s.x1.toFixed(2)}</td>
          <td class="p-3 coord-font">${s.y1.toFixed(2)}</td>
          <td class="p-3 coord-font">${s.font_size}</td>
          <td class="p-3 text-slate-400 font-mono text-[11px]">${s.font_name}</td>
          <td class="p-3 text-slate-200">${escapeHtml(s.text)}</td>
        `;
        coordsTableBody.appendChild(tr);
      });
    }

    function updateTextDump() {
      let flow = `=== [CLEAN TEXT FLOW] ===\n\n`;
      extractedSpans.forEach(s => flow += s.text + '\n');

      flow += `\n=======================================================\n`;
      flow += `=== [RAW PHYSICAL COORDINATES DUMP] ===\n\n`;
      extractedSpans.forEach(s => {
        flow += `[Page ${s.page}] (X0: ${s.x0.toFixed(2).padStart(7)}, Y0: ${s.y0.toFixed(2).padStart(7)}, X1: ${s.x1.toFixed(2).padStart(7)}, Y1: ${s.y1.toFixed(2).padStart(7)}) [${s.font_size}pt] "${s.text}"\n`;
      });

      pureTextBox.value = flow;
    }

    function updateJsonViewer() {
      if (currentRustDoc && currentRustDoc.structured) {
        jsonViewer.textContent = JSON.stringify(currentRustDoc.structured, null, 2);
        return;
      }
      // Client-side model: same schema the native engine emits (pages[], tables,
      // text_blocks, images with sha256, drawings with items/colours).
      const doc = buildDocumentJson() || {
        file_name: docFileName,
        total_pages: 0,
        parse_time_ms: 0,
        pages: []
      };
      jsonViewer.textContent = JSON.stringify(doc, null, 2);
    }

    function escapeHtml(text) {
      const div = document.createElement('div');
      div.textContent = text;
      return div.innerHTML;
    }

    // ---------------------------------------------------------------------------
    // Embedded image lightbox (click a gallery thumbnail to inspect it 1:1)
    // ---------------------------------------------------------------------------
    function openLightbox(im, index) {
      if (!im || !im.thumb) return;

      const imgW = im.thumb.naturalWidth || im.thumb.width || (im.px ? im.px.width : 300);
      const imgH = im.thumb.naturalHeight || im.thumb.height || (im.px ? im.px.height : 200);

      lightboxCanvas.width = imgW;
      lightboxCanvas.height = imgH;
      const lctx = lightboxCanvas.getContext('2d');
      lctx.clearRect(0, 0, lightboxCanvas.width, lightboxCanvas.height);
      lctx.drawImage(im.thumb, 0, 0, imgW, imgH);

      const label = (im.objId !== null && im.objId !== undefined) ? 'XObject ' + im.objId : 'inline image';
      lightboxTitle.textContent = '#' + (index + 1) + '  ' + label;
      lightboxMeta.textContent =
        'bbox pt [' + im.pt.x0 + ', ' + im.pt.y0 + ', ' + im.pt.x1 + ', ' + im.pt.y1 + ']' +
        ' · painted ' + im.count + 'x' +
        (im.cropped ? ' · crop fallback' : '');
      lightboxSize.textContent = im.px
        ? (im.px.width + ' x ' + im.px.height + ' px')
        : (imgW + ' x ' + imgH + ' px');

      // Enlarge small images so the embedded pixels are actually visible.
      const maxW = Math.max(window.innerWidth * 0.85, 320);
      const maxH = Math.max(window.innerHeight * 0.72, 240);
      const k = Math.min(maxW / imgW, maxH / imgH);
      const scale = k >= 1 ? Math.min(k, 8) : 1;

      lightboxCanvas.style.width = Math.round(imgW * scale) + 'px';
      lightboxCanvas.style.height = Math.round(imgH * scale) + 'px';
      lightboxCanvas.style.imageRendering = scale >= 2 ? 'pixelated' : 'auto';

      imageLightbox.style.display = 'flex';
    }

    function closeLightbox() {
      imageLightbox.style.display = 'none';
    }

    lightboxClose.addEventListener('click', closeLightbox);
    imageLightbox.addEventListener('click', (e) => {
      if (e.target === imageLightbox) closeLightbox();
    });
    document.addEventListener('keydown', (e) => {
      if (e.key === 'Escape' && imageLightbox.style.display !== 'none') closeLightbox();
    });

    // Navigation Controls
    btnPrevPage.addEventListener('click', () => { if (currentPageNum > 1) { currentPageNum--; renderCurrentPage(); } });
    btnNextPage.addEventListener('click', () => { if (currentPdfDoc && currentPageNum < currentPdfDoc.numPages) { currentPageNum++; renderCurrentPage(); } });
    pageSlider.addEventListener('input', (e) => { currentPageNum = parseInt(e.target.value); renderCurrentPage(); });
    chkShowBoxes.addEventListener('change', () => {
      drawCanvas(hoveredSpan);
    });
    chkShowImages.addEventListener('change', () => {
      drawCanvas(hoveredSpan);
    });
    chkShowVectors.addEventListener('change', () => {
      drawCanvas(hoveredSpan);
    });

    btnCopyText.addEventListener('click', () => {
      navigator.clipboard.writeText(pureTextBox.value);
      btnCopyText.textContent = '✅ Copied!';
      setTimeout(() => btnCopyText.textContent = '📋 Copy to Clipboard', 2000);
    });

    btnDownloadJson.addEventListener('click', async () => {
      const original = btnDownloadJson.textContent;
      btnDownloadJson.textContent = '⏳ Preparing…';
      btnDownloadJson.disabled = true;
      await ensureFullDocument();
      btnDownloadJson.textContent = original;
      btnDownloadJson.disabled = false;

      const blob = new Blob([jsonViewer.textContent], { type: 'application/json' });
      const url = URL.createObjectURL(blob);
      const a = document.createElement('a');
      a.href = url;
      a.download = 'rasgapdf_document.json';
      a.click();
      URL.revokeObjectURL(url);
    });

    if (btnCopyJson) {
      btnCopyJson.addEventListener('click', async () => {
        btnCopyJson.textContent = '⏳ Preparing…';
        btnCopyJson.disabled = true;
        await ensureFullDocument();
        btnCopyJson.disabled = false;

        const text = jsonViewer.textContent || '';
        try {
          await navigator.clipboard.writeText(text);
        } catch (e) {
          // Clipboard API needs a secure context (https/localhost); fall back to a
          // hidden textarea so the button still works on plain http.
          const ta = document.createElement('textarea');
          ta.value = text;
          ta.style.position = 'fixed';
          ta.style.opacity = '0';
          document.body.appendChild(ta);
          ta.select();
          try { document.execCommand('copy'); } catch (err) { /* ignore */ }
          document.body.removeChild(ta);
        }
        btnCopyJson.textContent = '✅ Copied!';
        setTimeout(() => btnCopyJson.textContent = '📋 Copy JSON', 2000);
      });
    }

    // Auto-load sample PDF on startup
    window.addEventListener('DOMContentLoaded', () => {
      btnLoadSample.click();
    });
  </script>
</body>
</html>