output: the abstraction artefacts live with the pod

pod/ holds all document source representations:
  pod/<doc>/                             source tree
  pod/<doc>/media/abstraction/<uid>.ssp  abstraction, as text
  pod/<doc>.zip                          tree, zipped, .ssp included
  pod/<doc>.digests.txt                  sha256s of what is in them
  pod/<uid>.ocda.db                      abstraction, as sqlite db

<lang>/abstraction/ is gone.
pod/<doc>/media/abstraction/<uid>.ssp preferred as having the
images (found within the pod tree) which .ssp needs to reproduce a
document but does not carry on its own.

The .ocda.db sits carries the images as well and (like the
pod.zip) can be used to reproduce a document directly.

digests.txt now covers the database as well as the zip, the source
and the .ssp; (as does the metadata html page).

Two ordering issues addressed:
- the pod builder clean-slates pod/<doc>/ before regenerating it,
  and the .ssp is now written before that runs. The clean slate
  now leaves media/abstraction/ alone, and the .ssp writer clears
  that directory itself on the first language of a run, so a .ssp
  for a language the document no longer is removed and cannot be
  bundled.
- for a multi-language document the .ssp files accumulate one
  language at a time and are bundled on the last, which is why the
  directory cannot simply be emptied by whichever (language) gets
  there first.

(assisted by Claude-Code)

1 files changed, 25 insertions, 8 deletions

diff --git a/src/sisudoc/ocda/abstraction/ssp.d b/src/sisudoc/ocda/abstraction/ssp.d
index 3e80956..2501add 100644
--- a/src/sisudoc/ocda/abstraction/ssp.d
+++ b/src/sisudoc/ocda/abstraction/ssp.d
@@ -102,6 +102,7 @@ template sspObjectRecord() {
   import std.stdio;
   import std.string;
   import std.array;
+  import sisudoc.ocda.io_in.paths_source;
   mixin sspEscape;
   string[] sspObjectRecord(O)(O obj, string section, bool _vox = false) {
     string[] output;
@@ -413,6 +414,7 @@ template spineAbstractionTxt() {
   import std.stdio;
   import std.string;
   import std.array;
+  import sisudoc.ocda.io_in.paths_source;
   mixin sspObjectRecord;
   /+ ↓ the whole .ssp for a document, as lines. the file writer below emits
        these, and the abstraction db is built by reading them back, so the
@@ -562,19 +564,34 @@ template spineAbstractionTxt() {
     }
     return output;
   }
-  void spineAbstractionTxt(D)(D doc) {
+  @trusted void spineAbstractionTxt(D)(D doc) {
     auto doc_matters = doc.matters;
     string[] output = sspDocumentLines(doc);
-    /+ ↓ write to file +/
-    /+ path: <output_path>/<language>/abstraction/<doc_uid_out>.ssp +/
-    string out_root = (doc_matters.output_path.length > 0)
-      ? doc_matters.output_path : "";
-    string base_pth = (out_root
-      .chainPath(doc_matters.src.language, "abstraction")
-      .asNormalizedPath).array;
+    /+ ↓ write to file, into the pod's own tree:
+         pod/<doc>/media/abstraction/<doc_uid_out>.ssp
+         .
+         where it sits beside pod/<doc>/media/image/, which is what a .ssp
+         needs to be a document source: the file describes its images by
+         name, size, pixels and digest, and they have to be findable. Written
+         here once; --pod2 then digests and zips it where it stands rather
+         than copying it in from an output directory of its own.
+    +/
+    auto pths_pod = spinePathsPods!()(doc_matters);
+    string base_pth
+      = pths_pod.abstraction_root(doc_matters.src.filename).filesystem_open_zpod.to!string;
     try {
       if (!exists(base_pth)) {
         base_pth.mkdirRecurse;
+      } else if (doc_matters.src.language
+        == doc_matters.pod.manifest_list_of_languages[0]
+      ) {
+        /+ ↓ this directory is the one part of the pod written before the pod
+             is built, so the pod builder leaves it alone. It therefore clears
+             itself here, on the first language of a run, or a .ssp for a
+             language the document no longer has would linger and be bundled +/
+        foreach (string _f; dirEntries(base_pth, "*.ssp", SpanMode.shallow)) {
+          _f.remove;
+        }
       }
     } catch (Exception ex) {
     }