feat(phase-6): implement deck assembler (Ollama JSON parser)

src/commander_ai_lab/deck_builder/core/deck_assembler.py

@@ -1 +1,106 @@
-# Deck assembler (Ollama JSON output) — Phase 6
+"""
+Deck assembler – converts Ollama JSON output into validated CardEntry lists.
+
+Responsible for parsing the structured JSON that Ollama returns after the
+ratio-enforcement step and mapping card names back to Scryfall CardEntry
+objects with correct categories.
+"""
+
+from __future__ import annotations
+
+import json
+import logging
+from typing import Dict, List, Optional, Tuple
+
+from .models import CardEntry
+
+logger = logging.getLogger(__name__)
+
+
+def parse_ollama_deck_json(raw: str) -> Dict[str, List[str]]:
+    """Parse the JSON blob Ollama returns into {category: [card_names]}.
+
+    Ollama is instructed to return JSON like::
+
+        {
+            "Creatures": ["Sol Ring", ...],
+            "Instants": [...],
+            ...
+        }
+
+    This function tolerates minor formatting issues (trailing commas,
+    markdown fences, etc.).
+    """
+    # Strip markdown code fences if present
+    cleaned = raw.strip()
+    if cleaned.startswith("```"):
+        # Remove opening fence (possibly ```json)
+        first_nl = cleaned.index("\n")
+        cleaned = cleaned[first_nl + 1 :]
+    if cleaned.endswith("```"):
+        cleaned = cleaned[: -3]
+    cleaned = cleaned.strip()
+
+    # Remove trailing commas before closing braces/brackets (common LLM error)
+    import re
+    cleaned = re.sub(r",\s*([}\]])", r"\1", cleaned)
+
+    try:
+        data = json.loads(cleaned)
+    except json.JSONDecodeError as exc:
+        logger.error("Failed to parse Ollama deck JSON: %s", exc)
+        logger.debug("Raw output:\n%s", raw[:500])
+        raise ValueError(f"Ollama returned invalid JSON: {exc}") from exc
+
+    if not isinstance(data, dict):
+        raise ValueError(f"Expected dict from Ollama, got {type(data).__name__}")
+
+    result: Dict[str, List[str]] = {}
+    for key, val in data.items():
+        if isinstance(val, list):
+            result[key] = [str(v) for v in val]
+        else:
+            logger.warning("Skipping non-list category %s", key)
+    return result
+
+
+def flatten_categories(categorised: Dict[str, List[str]]) -> List[str]:
+    """Return a flat, deduplicated list of card names from categorised dict."""
+    seen: set[str] = set()
+    names: List[str] = []
+    for cards in categorised.values():
+        for name in cards:
+            lower = name.lower()
+            if lower not in seen:
+                seen.add(lower)
+                names.append(name)
+    return names
+
+
+def assign_categories(
+    entries: List[CardEntry],
+    categorised: Dict[str, List[str]],
+) -> List[CardEntry]:
+    """Set each CardEntry's category based on the Ollama categorisation."""
+    name_to_cat: Dict[str, str] = {}
+    for cat, names in categorised.items():
+        for name in names:
+            name_to_cat[name.lower()] = cat
+
+    for entry in entries:
+        cat = name_to_cat.get(entry.name.lower())
+        if cat:
+            entry.category = cat
+    return entries
+
+
+def deduplicate_entries(entries: List[CardEntry]) -> List[CardEntry]:
+    """Remove duplicate card entries, keeping the first occurrence."""
+    seen: set[str] = set()
+    unique: List[CardEntry] = []
+    for entry in entries:
+        key = entry.name.lower()
+        if key not in seen:
+            seen.add(key)
+            unique.append(entry)
+    return unique