"""Mistral OCR API call — the Mistral counterpart of MinerU's `do_parse`.

Kept out of parse.py so the API client (upload → ocr.process) stays separate
from the caching/cache-key logic. Returns the raw response dict; parse.py owns
persisting and caching it. normalize_mistral.py turns it into chunks.

No GPU: this is a hosted API. The only precondition is `MISTRAL_API_KEY`. It is
read through `src.config.settings` first — the same path every other credential
in this repo takes, and the one that works in a deployed HuggingFace Space —
then falls back to the environment / repo `.env` so the standalone parser still
runs on a box without the full app config. Either way the GPU check in
parse.require_gpu never runs for this backend.
"""

from __future__ import annotations

import os
from pathlib import Path
from typing import Any

from .config import PipelineConfig


def _key_from_settings() -> str | None:
    """The key from the app Settings singleton, if it can be constructed.

    Guarded on purpose: the full `Settings` has required fields (Postgres, Redis,
    Langfuse) with no defaults, and the parser runs standalone on boxes that may
    not have them. A failure to build Settings must fall through to the
    environment, not abort a parse — so any construction error yields None.
    """
    try:
        from src.config.settings import settings
    except Exception:  # noqa: BLE001 - Settings needs the full app env; fall back
        return None
    return getattr(settings, "mistral_api_key", "") or None


def _api_key() -> str:
    key = _key_from_settings()
    if not key:
        key = os.environ.get("MISTRAL_API_KEY")
    if not key:
        try:
            from dotenv import load_dotenv

            load_dotenv()  # picks up the repo .env, same file the app reads
            key = os.environ.get("MISTRAL_API_KEY")
        except ImportError:
            pass
    if not key:
        raise RuntimeError(
            "MISTRAL_API_KEY is not set.\n"
            "  -> set it in the app settings / HuggingFace Space secret, or put it "
            "in the repo .env (MISTRAL_API_KEY=...) or the environment."
        )
    return key


def run_ocr(source: Path, cfg: PipelineConfig) -> dict[str, Any]:
    """Upload one PDF and run Mistral OCR. Returns the response as a dict."""
    try:
        from mistralai import Mistral  # type: ignore[attr-defined]
    except ImportError:  # SDK 2.x moved the class to a submodule
        from mistralai.client import Mistral

    client = Mistral(api_key=_api_key())

    with source.open("rb") as f:
        uploaded = client.files.upload(
            file={"file_name": source.name, "content": f}, purpose="ocr"
        )

    kwargs: dict[str, Any] = {
        "model": cfg.mistral_model,
        "table_format": cfg.mistral_table_format,
        "include_blocks": cfg.mistral_include_blocks,
        "include_image_base64": cfg.mistral_describe_images,
    }

    if cfg.mistral_describe_images:
        # Per-image description (generated_description). Guarded: an SDK without
        # the annotation helpers must degrade to OCR-without-descriptions, not
        # abort — exactly as MinerU's `pipeline` backend produces none.
        try:
            from mistralai.extra import response_format_from_pydantic_model
            from pydantic import BaseModel

            class _ImageDescription(BaseModel):
                description: str
                chart_type: str | None = None

            kwargs["bbox_annotation_format"] = response_format_from_pydantic_model(
                _ImageDescription
            )
        except Exception:  # noqa: BLE001, S110 - optional capability, never fatal
            pass

    # file_id is the newer path; if this SDK/model rejects it, fall back to a
    # signed URL, which works on every version.
    try:
        resp = client.ocr.process(document={"file_id": uploaded.id}, **kwargs)
    except Exception:  # noqa: BLE001
        signed = client.files.get_signed_url(file_id=uploaded.id)
        resp = client.ocr.process(
            document={"type": "document_url", "document_url": signed.url}, **kwargs
        )

    dumped: dict[str, Any] = resp.model_dump()
    return dumped