feat: find wanted dumps by hash on the files page

files/?hash= read the collection, platforms, emulators and retired files,
never the Wanted list: the SHA1 of Redump's ps2-dvd-212k.bin answered
that nothing the site knows has it. The lookup now carries a wanted
layer from the rows of provenance-wanted.csv, computed once for both,
and the page names the catalog that lists the dump.

schemas/site-api-envelope.schema.json

@@ -393,7 +393,8 @@
                     "retired",
                     "data-directory",
                     "platform",
-                    "emulator"
+                    "emulator",
+                    "wanted"
                   ]
                 },
                 "left": {
@@ -433,7 +434,8 @@
                   "description": "On a platform or emulator record: the algorithm of the value its owner wrote, filed under that value and under the file's other hashes. name: the emulator reads the file by its name and declares no hash that matches it."
                 },
                 "owner": {
-                  "type": "string"
+                  "type": "string",
+                  "description": "On a platform or emulator record: the platform or profile key. On a wanted record: the dump catalog that lists the value (Redump, No-Intro, TOSEC), the collection holding no file with it."
                 },
                 "system_name": {
                   "type": "string",

scripts/generate_site.py

@@ -1620,6 +1620,7 @@ def generate_data_exports(
 
     members = data_directory_members()
     locations = file_location_items(db, profiles, members)
+    wanted = _provenance_wanted_rows(db)
     envelopes = {
         "platforms.json": ("platforms", platform_items),
         "emulators.json": ("emulators", emulator_items),
@@ -1628,7 +1629,7 @@ def generate_data_exports(
     }
     write_lookup_shards(
         api, file_lookup_records(db, coverages, profiles, locations, members, consumers,
-                                 retired_files.load(_REPO_ROOT / "retired.json")),
+                                 retired_files.load(_REPO_ROOT / "retired.json"), wanted),
         generated_at, commit,
     )
     for filename, (kind, items) in envelopes.items():
@@ -1747,7 +1748,7 @@ def generate_data_exports(
     _record(downloads / "retrobios.sqlite")
     write_if_changed(
         str(downloads / "provenance-wanted.csv"),
-        _csv_document(list(WANTED_FIELDS), _provenance_wanted_rows(db)),
+        _csv_document(list(WANTED_FIELDS), wanted),
     )
 
     assets = [
@@ -5010,12 +5011,14 @@ def file_lookup_records(
     members: dict | None = None,
     consumers: FileConsumers | None = None,
     retired: dict | None = None,
+    wanted: list[dict] | None = None,
 ) -> list[dict]:
     """Every hash the site knows, one record per value, for files/?hash=.
 
     The collection's own files lead to their card, a platform's declared
     value to the system section of its page, a profile's to the entry's
-    card. The site search indexed these values as text, 4 MB of the 21 MB
+    card, a wanted dump (``wanted``, the provenance-wanted.csv rows) to
+    its catalog on the provenance page. The site search indexed these values as text, 4 MB of the 21 MB
     it made every visitor download: the lookup reads one shard instead.
     """
     files = db.get("files", {})
@@ -5088,6 +5091,7 @@ def file_lookup_records(
                             **({"system_name": entry_label} if entry_label else {}),
                         })
     records += retired_records(retired or {}, files, locations)
+    records += wanted_records(wanted or [])
     records += _held_under_every_hash(records, files, db.get("indexes") or {})
     for record in records:
         if record["layer"] in ("platform", "emulator"):
@@ -5099,6 +5103,23 @@ def file_lookup_records(
         r["value"], r["layer"], r.get("owner", ""), r["name"], r["url"]))
 
 
+def wanted_records(rows: list[dict]) -> list[dict]:
+    """A record under each hash of a dump a catalog lists and the collection
+    lacks, from the rows of provenance-wanted.csv. A pasted hash of a
+    wanted dump (Redump's ps2-dvd-212k.bin) answered that nothing the site
+    knows has it, and never said the dump is wanted."""
+    records = []
+    for row in rows:
+        label = _PROVENANCE_LABELS.get(row["catalog"], row["catalog"])
+        url = _site_path(f"provenance.md#{_slugify_anchor(label)}")
+        for algorithm in ("sha1", "md5", "crc32"):
+            value = str(row.get(algorithm) or "").lower()
+            if value:
+                records.append({"value": value, "algorithm": algorithm, "layer": "wanted",
+                                "owner": label, "name": row["name"], "url": url})
+    return records
+
+
 def _read_by_name(records: list[dict], files: dict, consumers: FileConsumers) -> list[dict]:
     """The emulators the file's card names that no declared hash reached.
 

tests/test_site_exports.py

@@ -832,6 +832,40 @@ class AnArchiveMemberIsFoundByItsCrc(unittest.TestCase):
         self.assertIn("byLayer('archive-member')", script)
 
 
+class AWantedDumpIsFoundByItsHash(unittest.TestCase):
+    """The SHA1 of a PS2 SCPH-30005R BIOS, which Redump lists as
+    ps2-dvd-212k.bin and the Wanted page asks for, answered that no file
+    the site knows has it."""
+
+    def test_each_hash_of_a_wanted_row_is_a_record(self):
+        import generate_site  # noqa: PLC0415
+
+        row = {"catalog": "redump", "dat": "Sony - PlayStation 2 - BIOS Images",
+               "name": "ps2-dvd-212k.bin", "description": "", "size": "4194304",
+               "crc32": "1A2B3C4D", "md5": "", "sha1": "5b346eb9258d710609a9855befd35cab8f3a334a"}
+        records = generate_site.file_lookup_records(
+            {"files": {}, "indexes": {}}, {}, {}, [], wanted=[row, {**row, "dat": "other"}])
+        self.assertEqual(records, [
+            {"value": "1a2b3c4d", "algorithm": "crc32", "layer": "wanted", "owner": "Redump",
+             "name": "ps2-dvd-212k.bin", "url": "/retrobios/provenance/#redump"},
+            {"value": "5b346eb9258d710609a9855befd35cab8f3a334a", "algorithm": "sha1",
+             "layer": "wanted", "owner": "Redump", "name": "ps2-dvd-212k.bin",
+             "url": "/retrobios/provenance/#redump"},
+        ])
+
+    def test_the_schema_and_the_page_carry_the_layer(self):
+        import json as _json  # noqa: PLC0415
+
+        import generate_site  # noqa: PLC0415
+
+        root = Path(__file__).resolve().parents[1]
+        schema = _json.loads((root / "schemas" / "site-api-envelope.schema.json").read_text())
+        self.assertIn('"wanted"', _json.dumps(schema))
+        self.assertIn("byLayer('wanted')", (root / "website" / "src" / "scripts" / "site.ts").read_text())
+        source = Path(generate_site.__file__).read_text(encoding="utf-8")
+        self.assertIn('retired_files.load(_REPO_ROOT / "retired.json"), wanted)', source)
+
+
 class AFileHasAnAddressByContent(unittest.TestCase):
     """mt32_control.rom moved from the Commodore page to the Roland page and
     every link to its card broke: the anchor was content-based, the page

website/src/scripts/site.ts

@@ -558,9 +558,12 @@ const renderMatches = async (status: HTMLElement, result: HTMLElement, matched:
 	const setups = new Set(platforms.map((item) => item.owner));
 
 	const members = distinct(byLayer('archive-member'), (item) => `${item.sha1}|${item.name}`);
+	// A dump a catalog lists and the collection lacks: the Wanted list.
+	const wanted = held.length || members.length ? [] : distinct(byLayer('wanted'), (item) => `${item.owner}|${item.name}`);
 	const counted = [
 		held.length ? count(held.length, 'file in the collection', 'files in the collection')
 			: members.length ? count(members.length, 'member of a collection archive', 'members of collection archives')
+			: wanted.length ? 'a wanted dump, not in the collection yet'
 			: 'not in the collection',
 		...(platforms.length ? [`${count(platforms.length, 'declaration', 'declarations')} by ${count(setups.size, 'setup', 'setups')}`] : []),
 		...(owners.length ? [count(owners.length, 'emulator that reads it', 'emulators that read it')] : []),
@@ -617,8 +620,20 @@ const renderMatches = async (status: HTMLElement, result: HTMLElement, matched:
 		);
 	});
 	const retired = held.length ? [] : distinct(byLayer('retired'), (item) => item.sha1 ?? item.value);
-	if (!held.length && !members.length && !retired.length) blocks.push(paragraph('No file in the collection has this hash.'));
+	if (!held.length && !members.length && !retired.length && !wanted.length) blocks.push(paragraph('No file in the collection has this hash.'));
 	blocks.push(...retired.map(retiredParagraph));
+	if (wanted.length) {
+		const list = document.createElement('ul');
+		for (const item of wanted) {
+			const row = document.createElement('li');
+			row.append(link(item.url, item.owner ?? ''), ' lists it as ', code(item.name ?? item.value));
+			list.append(row);
+		}
+		blocks.push(
+			paragraph(strong('Wanted.'), ' The collection does not hold this dump yet. If you dumped it yourself, ', link('contributing/', 'add it'), '.'),
+			list,
+		);
+	}
 	if (members.length) {
 		// A ROM the collection holds inside a set: the set's card, by its name.
 		const list = document.createElement('ul');