"""
MemoirImage 模型与 API 用 dict 的互转（与 schema.normalize_image_asset 字段一致）。
"""
from datetime import datetime
from typing import Any

from app.features.memoir.models import MemoirImage


def _parse_optional_datetime(s: str | None):
    if not s:
        return None
    try:
        return datetime.fromisoformat(s.replace("Z", "+00:00"))
    except (ValueError, AttributeError):
        return None


def memoir_image_to_dict(m: MemoirImage | None) -> dict[str, Any] | None:
    """将 MemoirImage 转为前端/API 使用的单条图片 dict。"""
    if not m:
        return None
    d: dict[str, Any] = {
        "placeholder": m.placeholder or "",
        "description": m.description or "",
        "index": m.order_index,
        "status": m.status or "pending",
        "prompt": m.prompt,
        "url": m.url,
        "storage_key": m.storage_key,
        "provider": m.provider,
        "style": m.style,
        "size": m.size,
        "error": m.error,
        "retryable": m.retryable,
        "created_at": m.created_at.isoformat() if m.created_at else None,
        "updated_at": m.updated_at.isoformat() if m.updated_at else None,
    }
    return d


def image_dict_to_row_kwargs(d: dict[str, Any] | None) -> dict[str, Any]:
    """从单条图片 dict 提取可写入 MemoirImage 的字段（不含 id/chapter_id/section_id/order_index）。"""
    if not d or not isinstance(d, dict):
        return {}
    created = d.get("created_at")
    updated = d.get("updated_at")
    if isinstance(created, str):
        created = _parse_optional_datetime(created)
    elif not isinstance(created, datetime):
        created = None
    if isinstance(updated, str):
        updated = _parse_optional_datetime(updated)
    elif not isinstance(updated, datetime):
        updated = None
    return {
        "placeholder": d.get("placeholder") or None,
        "description": d.get("description") or None,
        "status": (d.get("status") or "pending").strip() or "pending",
        "prompt": d.get("prompt") or None,
        "url": d.get("url") or None,
        "storage_key": d.get("storage_key") or None,
        "provider": d.get("provider") or None,
        "style": d.get("style") or None,
        "size": d.get("size") or None,
        "error": d.get("error") or None,
        "retryable": d.get("retryable") if d.get("retryable") is not None else None,
        "created_at": created,
        "updated_at": updated,
    }