Add character engine prompt builder

media-pipeline/core/character_engine/generation/prompt_builder.py

@@ -0,0 +1,79 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Optional
+
+from ..schema.character import Character, Outfit
+
+
+@dataclass
+class PromptConfig:
+    quality_prefix: str = "masterpiece, best quality, highly detailed"
+    negative: str = "lowres, bad anatomy, bad hands, text, error, missing fingers, cropped, worst quality, low quality, blurry, deformed"
+
+
+class PromptBuilder:
+
+    def __init__(self, config: Optional[PromptConfig] = None):
+        self.config = config or PromptConfig()
+
+    def build(
+        self,
+        character: Character,
+        outfit_name: str = "default",
+        scene: str = "",
+        extra_tags: Optional[list[str]] = None,
+    ) -> dict[str, str]:
+        segments = []
+
+        segments.append(self.config.quality_prefix)
+
+        segments.append(self._appearance_segment(character))
+
+        outfit = self._find_outfit(character, outfit_name)
+        if outfit:
+            segments.append(outfit.description)
+
+        if character.style_tags:
+            segments.append(", ".join(character.style_tags))
+
+        if scene:
+            segments.append(scene)
+
+        if extra_tags:
+            segments.append(", ".join(extra_tags))
+
+        positive = ", ".join(seg for seg in segments if seg)
+
+        return {
+            "positive": positive,
+            "negative": self.config.negative,
+        }
+
+    def _appearance_segment(self, character: Character) -> str:
+        parts = []
+        app = character.appearance
+
+        gender_map = {"female": "1girl", "male": "1boy", "other": "1person"}
+        parts.append(gender_map.get(character.gender.value, "1person"))
+
+        if app.hair:
+            parts.append(app.hair)
+        if app.eyes:
+            parts.append(app.eyes)
+        if app.skin:
+            parts.append(f"{app.skin} skin")
+        if app.build:
+            parts.append(f"{app.build} build")
+        for feat in app.features:
+            parts.append(feat)
+
+        return ", ".join(parts)
+
+    def _find_outfit(self, character: Character, name: str) -> Optional[Outfit]:
+        for outfit in character.outfits:
+            if outfit.name == name:
+                return outfit
+        if character.outfits:
+            return character.outfits[0]
+        return None