Auto-generate an adventure outline when no adventure text is provided

When a player creates a game without pasting their own adventure, the
DM previously improvised turn-by-turn with no overall arc, ending, or
calibrated difficulty. Now the setup-chat interview generates a full
outline (hook, three-to-four-part structure, milestone leveling,
explicit ending condition, GM guidance) as a follow-up LLM call once
genre/length/experience are known, and feeds it through the existing
adventure_text -> RAG ingestion -> "follow strictly" pipeline exactly
like a pasted adventure. Falls back silently to today's improvised
behavior if generation fails.

Verified end-to-end in the browser: setup interview -> outline
generated and previewed -> game created -> RAG chunks ingested ->
has_adventure true -> cascade-cleaned on delete.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/app/llm/game_setup.py

@@ -1,24 +1,63 @@
 import json
+import logging
 
 from app.config import settings
-from app.llm.client import get_game_setup_prompt, get_llm_client
+from app.llm.client import get_adventure_outline_prompt, get_game_setup_prompt, get_llm_client
 from app.llm.json_utils import fix_double_escaped_unicode
 from app.llm.tools import game_setup as game_setup_tool
 
+logger = logging.getLogger("app.llm.game_setup")
+
 MAX_ROUNDS = 3
 MAX_TOKENS = 1024
 # Only the opening of a pasted adventure is needed here to infer genre/world/scope for the
 # proposal — this is a cheap interview call, not the RAG pipeline that handles the full text.
 ADVENTURE_EXCERPT_CHARS = 3000
+# The outline is a free-text document of several thousand words, unlike the short
+# name+description proposal above, so it needs a much larger budget.
+OUTLINE_MAX_TOKENS = 4096
 
 TOOLS = [{"type": "function", "function": game_setup_tool.TOOL_SCHEMA}]
 
 
+async def _generate_adventure_outline(client, messages: list[dict], proposal: dict) -> str | None:
+    """One-shot follow-up call: draft a full adventure outline from the interview so far.
+
+    Only called when the player didn't paste their own adventure text. Best-effort — any
+    failure just means the game falls back to today's fully-improvised DM, never blocks
+    game creation.
+    """
+    outline_messages = [
+        {"role": "system", "content": get_adventure_outline_prompt()},
+        *messages[1:],
+        {
+            "role": "user",
+            "content": (
+                f"Vorgeschlagener Spielname: {proposal.get('name', '')}\n"
+                f"Kurzbeschreibung: {proposal.get('description', '')}\n\n"
+                "Entwirf jetzt das vollständige Abenteuer-Outline wie beschrieben."
+            ),
+        },
+    ]
+    try:
+        response = await client.chat.completions.create(
+            model=settings.dm_model,
+            max_tokens=OUTLINE_MAX_TOKENS,
+            messages=outline_messages,
+        )
+        content = response.choices[0].message.content
+        return content.strip() if content and content.strip() else None
+    except Exception:
+        logger.exception("Adventure outline generation failed")
+        return None
+
+
 async def run_game_setup_turn(client_messages: list[dict], adventure_text: str = "") -> dict:
     """Stateless setup-wizard turn: the caller owns conversation history (no DB, no game yet).
 
     Returns {"messages": <history to resend next turn>, "assistant_text": str | None,
-    "proposal": {"name": str, "description": str} | None}.
+    "proposal": {"name": str, "description": str} | None,
+    "generated_adventure": str | None}.
     """
     client = get_llm_client()
     system_prompt = get_game_setup_prompt()
@@ -64,4 +103,13 @@ async def run_game_setup_turn(client_messages: list[dict], adventure_text: str =
         if proposal:
             break
 
-    return {"messages": messages[1:], "assistant_text": assistant_text, "proposal": proposal}
+    generated_adventure: str | None = None
+    if proposal and not adventure_text.strip():
+        generated_adventure = await _generate_adventure_outline(client, messages, proposal)
+
+    return {
+        "messages": messages[1:],
+        "assistant_text": assistant_text,
+        "proposal": proposal,
+        "generated_adventure": generated_adventure,
+    }