Revise the plan when the story changes, take style from frontmatter

An edited story only re-applied its frontmatter, so plan.md kept
describing the old story. The body plan.md was drafted from is now kept
in story.seen; when the story body differs, ask whether Gemma should
revise the plan to match, start a new draft, or keep the plan.

A style: frontmatter key now overrides the Style: line, so the art style
can be set before Gemma drafts anything.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2 files changed, 53 insertions, 16 deletions

diff --git a/README.md b/README.md
index ff3cec0..0de61a3 100644
--- a/README.md
+++ b/README.md
@@ -23,14 +23,19 @@ instead of letting Gemma invent them; every key is optional:
     book: Life as Daniel
     chapter: 1
     title: Meet Daniel
+    style: shoujo manga, soft pastel cel shading
     ---
 
 `series` and `book` name the library folders, `title` is the lettering on the
-chapter's page 1. With `chapter`, pages are saved as
+chapter's page 1, `style` is the art style of every page and reference sheet. With `chapter`, pages are saved as
 `01-001.png`, `01-002.png`, so every chapter of a book (one story file each)
 reads as one continuous book in book-reader. These values always override what
 Gemma writes in plan.md.
 
+Editing the story after plan.md exists asks whether Gemma should revise the
+plan to match it, draft a new one (the old one is kept as plan.md.bak), or
+keep the plan as it is. Editing only the frontmatter is applied without Gemma.
+
     fanfictioner story.md [--base zimage|krea2]
     fanfictioner --selftest
 
diff --git a/fanfictioner b/fanfictioner
index 23c06b9..8a4f164 100755
--- a/fanfictioner
+++ b/fanfictioner
@@ -136,7 +136,7 @@ def parse_front(text):
 
 def apply_front(md, meta):
     """Force the story's frontmatter into plan.md, whatever Gemma wrote there."""
-    keys = [k for k in ("Series", "Book", "Chapter") if meta.get(k.lower())]
+    keys = [k for k in ("Series", "Book", "Chapter", "Style") if meta.get(k.lower())]
     drop = keys + (["Title"] if meta.get("title") else [])
     lines = [x for x in md.splitlines()
              if not (drop and re.match(r"[-*\s]*\**(%s)\**:" % "|".join(drop), x.strip()))]
@@ -543,12 +543,54 @@ def strip_fences(s):
 GEMMA_ERRS = (OSError, ValueError, KeyError, http.client.HTTPException)
 
 
+def revise(md, meta, wd, ins):
+    """Gemma rewrites the plan; returns the new plan.md text, or None when it fails or is invalid."""
+    try:
+        new = apply_front(strip_fences(chat(
+            DRAFT_SYS, f"Current plan:\n\n{md}\n\nRevise it: {ins}\nReturn the complete new plan.")), meta)
+    except GEMMA_ERRS as e:
+        print(f"Gemma failed: {e}")
+        return None
+    nerrs = validate_plan(parse_plan(new))
+    if nerrs:
+        (wd / "plan.rejected.md").write_text(new)
+        log(f"Gemma revision rejected ({'; '.join(nerrs)}): {ins}")
+        print("revision invalid, plan.md kept, see plan.rejected.md", *nerrs, sep="\n  ")
+        return None
+    (wd / "plan.md.bak").write_text(md)
+    log(f"Gemma revision accepted: {ins}")
+    return new
+
+
 def plan_stage(story, wd):
     md_path, js_path = wd / "plan.md", wd / "plan.json"
+    seen = wd / "story.seen"  # the story body plan.md was last drafted or revised from
     if js_path.exists() and md_path.exists() and \
             js_path.stat().st_mtime >= max(md_path.stat().st_mtime, story.stat().st_mtime):
         return json.loads(js_path.read_text())
     meta, body = parse_front(story.read_text())
+    if md_path.exists() and (seen.read_text() != body if seen.exists()
+                             else story.stat().st_mtime > md_path.stat().st_mtime):
+        try:
+            k = input("\nstory changed since plan.md was drafted: "
+                      "[r]evise plan with Gemma [n]ew draft [k]eep plan [q]uit > ").strip().lower()
+        except EOFError:
+            k = "q"
+        if k == "n":
+            os.replace(md_path, wd / "plan.md.bak")
+            log("story changed, plan.md moved to plan.md.bak for a new draft")
+        elif k == "r":
+            check_llm()
+            new = revise(md_path.read_text(), meta, wd, "the story changed, update the plan to match "
+                         f"this new story and keep whatever still fits:\n\n{body}")
+            if new:
+                md_path.write_text(new)
+                seen.write_text(body)
+        elif k == "k":
+            seen.write_text(body)
+            log("story changed, plan.md kept")
+        else:
+            sys.exit("quit, run again to resume")
     if not md_path.exists():
         check_llm()
         wd.mkdir(exist_ok=True)
@@ -557,6 +599,7 @@ def plan_stage(story, wd):
         except GEMMA_ERRS as e:
             sys.exit(f"Gemma failed: {e}")
         md_path.write_text(apply_front(draft, meta))
+        seen.write_text(body)
         log("plan.md drafted by Gemma")
     while True:
         md = md_path.read_text()
@@ -588,21 +631,8 @@ def plan_stage(story, wd):
                 ins = input("instruction for Gemma: ")
             except EOFError:
                 continue
-            try:
-                new = apply_front(strip_fences(chat(
-                    DRAFT_SYS, f"Current plan:\n\n{md}\n\nRevise it: {ins}\nReturn the complete new plan.")), meta)
-            except GEMMA_ERRS as e:
-                print(f"Gemma failed: {e}")
-                continue
-            nerrs = validate_plan(parse_plan(new))
-            if nerrs:
-                (wd / "plan.rejected.md").write_text(new)
-                log(f"Gemma revision rejected ({'; '.join(nerrs)}): {ins}")
-                print("revision invalid, plan.md kept, see plan.rejected.md", *nerrs, sep="\n  ")
-            else:
-                (wd / "plan.md.bak").write_text(md)
+            if new := revise(md, meta, wd, ins):
                 md_path.write_text(new)
-                log(f"Gemma revision accepted: {ins}")
         elif k == "q":
             sys.exit(0)
 
@@ -715,6 +745,8 @@ def selftest():
                                              "Framing: wide shot, eye level, landscape\nTitle: Gemma Title"), meta)
     assert apply_front(forced, meta) == forced
     assert apply_front(SAMPLE_PLAN, {}) == SAMPLE_PLAN
+    styled = parse_plan(apply_front(SAMPLE_PLAN, {"style": "ink manga"}))
+    assert styled["style"] == "ink manga" and validate_plan(styled) == [], styled
     fp = parse_plan(forced)
     assert (fp["title"], fp["series"], fp["book"], fp["chapter"]) == ("Rooftop", "A new life", "Life as Daniel", "1"), fp
     assert fp["pages"][0]["lettering"] == "Meet Daniel" and fp["pages"][1]["lettering"] == "", fp["pages"]