1 files changed, 35 insertions, 8 deletions

diff --git a/org/in_abstraction_artefacts.org b/org/in_abstraction_artefacts.org
index 9da6d32..c2b4c7a 100644
--- a/org/in_abstraction_artefacts.org
+++ b/org/in_abstraction_artefacts.org
@@ -659,16 +659,41 @@ template spineAbstractionDbRead() {
     default: return "";
     }
   }
-  @trusted SSPdocument dbReadFile(string db_file) {
+  @trusted SSPdocument dbReadFile(string db_file, string _lang = "") {
     SSPdocument doc;
     if (!db_file.exists) {
       writeln("ERROR: no such file: ", db_file);
       return doc;
     }
     auto db = Database(db_file, SQLITE_OPEN_READONLY);
+    /+ ↓ which document in the file. A file holds one per language; with
+         no language named, take the only one, and say so if there is a
+         choice to be made rather than picking for the caller.
+    +/
+    long _doc_id = -1;
+    {
+      string[] _langs;
+      foreach (row; db.execute("SELECT id, lang FROM documents ORDER BY id")) {
+        string _l = row["lang"].as!string;
+        _langs ~= _l;
+        if (_lang.length > 0 && _l == _lang) { _doc_id = row["id"].as!long; }
+        else if (_lang.length == 0 && _doc_id < 0) { _doc_id = row["id"].as!long; }
+      }
+      if (_doc_id < 0) {
+        writeln("ERROR: ", db_file, " holds no document in '", _lang,
+          "'; it has: ", _langs.join(" "));
+        return doc;
+      }
+      if (_lang.length == 0 && _langs.length > 1) {
+        writeln("ERROR: ", db_file, " holds ", _langs.length,
+          " languages and none was named: ", _langs.join(" "));
+        return doc;
+      }
+    }
     /+ ↓ the four header blocks, from the metadata table. the key prefix
          says which block a row belongs to, and insertion order is kept +/
-    foreach (row; db.execute("SELECT key, value FROM metadata ORDER BY rowid")) {
+    foreach (row; db.execute("SELECT key, value FROM metadata WHERE doc_id = " ~ _doc_id.to!string
+      ~ " OR doc_id IS NULL ORDER BY rowid")) {
       string _k = row["key"].as!string;
       string _v = row["value"].as!string;
       if (_k.startsWith("make.")) {
@@ -717,7 +742,7 @@ template spineAbstractionDbRead() {
     string[][long]                  _subtoc_by_id;
     foreach (r; db.execute(
       "SELECT object_id, name, bytes, sha256, width, height, missing"
-      ~ " FROM object_images ORDER BY object_id, seq")
+      ~ " FROM object_images WHERE object_id IN (SELECT id FROM objects WHERE doc_id = " ~ _doc_id.to!string ~ ") ORDER BY object_id, seq")
     ) {
       ST_file_name_hash_size_ _img;
       _img.fileName        = r["name"].as!string;
@@ -729,18 +754,19 @@ template spineAbstractionDbRead() {
       _images_by_id[r["object_id"].as!long] ~= _img;
     }
     foreach (r; db.execute(
-      "SELECT object_id, url FROM object_links ORDER BY object_id, seq")
+      "SELECT object_id, url FROM object_links WHERE object_id IN (SELECT id FROM objects WHERE doc_id = " ~ _doc_id.to!string ~ ") ORDER BY object_id, seq")
     ) { _links_by_id[r["object_id"].as!long] ~= r["url"].as!string; }
     foreach (r; db.execute(
-      "SELECT object_id, anchor FROM object_anchors ORDER BY object_id, seq")
+      "SELECT object_id, anchor FROM object_anchors WHERE object_id IN (SELECT id FROM objects WHERE doc_id = " ~ _doc_id.to!string ~ ") ORDER BY object_id, seq")
     ) { _anchors_by_id[r["object_id"].as!long] ~= r["anchor"].as!string; }
     foreach (r; db.execute(
-      "SELECT object_id, entry FROM object_subtoc ORDER BY object_id, seq")
+      "SELECT object_id, entry FROM object_subtoc WHERE object_id IN (SELECT id FROM objects WHERE doc_id = " ~ _doc_id.to!string ~ ") ORDER BY object_id, seq")
     ) { _subtoc_by_id[r["object_id"].as!long] ~= r["entry"].as!string; }
     /+ ↓ the objects, section by section, in the order they were written +/
     string[] _sections;
     foreach (row; db.execute(
-      "SELECT section FROM objects GROUP BY section ORDER BY MIN(id)")
+      "SELECT section FROM objects WHERE doc_id = " ~ _doc_id.to!string
+      ~ " GROUP BY section ORDER BY MIN(id)")
     ) {
       _sections ~= row["section"].as!string;
     }
@@ -758,7 +784,8 @@ template spineAbstractionDbRead() {
       +/
       int[string] _col;
       foreach (row; db.execute(
-        "SELECT * FROM objects WHERE section = '" ~ section ~ "' ORDER BY seq")
+        "SELECT * FROM objects WHERE doc_id = " ~ _doc_id.to!string
+        ~ " AND section = '" ~ section ~ "' ORDER BY seq")
       ) {
         if (_col.length == 0) {
           foreach (_i; 0 .. row.length) { _col[row.columnName(_i)] = _i.to!int; }