import json
from typing import Any, Optional

from .settings import MemoirImageSettings


class MemoirImagePromptService:
    CATEGORY_STYLE_MAP = {
        "childhood": "watercolor",
        "family": "watercolor",
        "career_early": "realistic",
        "career_achievement": "realistic",
        "career_challenge": "realistic",
        "beliefs": "editorial illustration",
        "summary": "editorial illustration",
    }

    def __init__(self, llm: Optional[Any], settings: MemoirImageSettings):
        self.llm = llm
        self.settings = settings

    def build_prompt(
        self,
        chapter_title: str,
        chapter_category: str,
        description: str,
        context_excerpt: str,
    ) -> dict[str, str]:
        style = self.CATEGORY_STYLE_MAP.get(chapter_category, self.settings.default_style)
        prompt_context = f"{chapter_category}: {chapter_title}"

        llm_input = {
            "chapter_title": chapter_title,
            "chapter_category": chapter_category,
            "description": description,
            "context_excerpt": context_excerpt,
            "default_style": style,
            "default_size": self.settings.default_size,
        }

        if self.llm:
            try:
                response = self.llm.invoke(
                    "Return JSON only with keys prompt, style, size. "
                    "Convert the memoir scene into an image-generation prompt.\n"
                    + json.dumps(llm_input, ensure_ascii=False)
                )
                parsed = json.loads(response.content)
                return {
                    "prompt": parsed["prompt"],
                    "style": parsed.get("style", style),
                    "size": parsed.get("size", self.settings.default_size),
                    "prompt_context": prompt_context,
                }
            except Exception:
                pass

        return {
            "prompt": f"{description}\n\nScene context: {context_excerpt}",
            "style": style,
            "size": self.settings.default_size,
            "prompt_context": prompt_context,
        }