from __future__ import annotations

from pathlib import Path
from typing import Any, Optional

from context.conversation_manager import get_current_context, get_current_sketch_pad


def _content_item_type(item: Any) -> Optional[str]:
    if isinstance(item, dict):
        value = item.get("type")
        return value if isinstance(value, str) else None
    value = getattr(item, "type", None)
    return value if isinstance(value, str) else None


def _content_item_image_payload(item: Any) -> Any:
    if isinstance(item, dict):
        return item.get("image_url")
    return getattr(item, "image_url", None)


def _image_payload_local_path(image_payload: Any) -> Optional[str]:
    if isinstance(image_payload, dict):
        value = image_payload.get("local_path")
        return value if isinstance(value, str) else None
    value = getattr(image_payload, "local_path", None)
    return value if isinstance(value, str) else None


def _normalize_existing_file_path(path_value: Any) -> Optional[str]:
    if not isinstance(path_value, (str, Path)):
        return None

    raw_value = str(path_value).strip()
    if not raw_value:
        return None

    candidate = Path(raw_value).expanduser()
    if not candidate.is_absolute():
        candidate = (Path.cwd() / candidate).resolve()

    try:
        if candidate.exists() and candidate.is_file():
            return str(candidate)
    except OSError:
        return None

    return None


def _resolve_sketch_pad_image_path(reference: str) -> Optional[str]:
    if not reference.startswith("key:"):
        return None

    sketch_pad = get_current_sketch_pad()
    if sketch_pad is None:
        return None

    try:
        value = sketch_pad.get_value(reference[4:])
    except Exception:
        return None

    direct_path = _normalize_existing_file_path(value)
    if direct_path is not None:
        return direct_path

    if not isinstance(value, dict):
        return None

    for key in ("local_path", "path", "image_path", "query_image_path"):
        resolved_path = _normalize_existing_file_path(value.get(key))
        if resolved_path is not None:
            return resolved_path

    return None


def get_latest_uploaded_reference_image_path() -> Optional[str]:
    context = get_current_context()
    if context is None:
        return None

    try:
        messages = context.retrieve_full_messages()
    except Exception:
        try:
            messages = context.retrieve_messages()
        except Exception:
            return None

    for message in reversed(messages):
        if getattr(message, "role", None) != "user":
            continue

        content = getattr(message, "content", None)
        if not isinstance(content, list):
            continue

        for item in reversed(content):
            if _content_item_type(item) != "image_url":
                continue

            image_payload = _content_item_image_payload(item)
            resolved_path = _normalize_existing_file_path(
                _image_payload_local_path(image_payload)
            )
            if resolved_path is not None:
                return resolved_path

    return None


def resolve_reference_image_path(query_image_path: Optional[str]) -> Optional[str]:
    if isinstance(query_image_path, str) and query_image_path.strip():
        stripped_path = query_image_path.strip()

        sketch_pad_path = _resolve_sketch_pad_image_path(stripped_path)
        if sketch_pad_path is not None:
            return sketch_pad_path

        direct_path = _normalize_existing_file_path(stripped_path)
        if direct_path is not None:
            return direct_path

    return get_latest_uploaded_reference_image_path()