"""OpenAI Vision provider (GPT-4o)."""

import base64
import json
import re
from openai import AsyncOpenAI

from app.config import get_settings
from app.schemas.transaction import TransactionExtractItem
from app.services.llm.base import BaseLLMProvider
from app.prompts.extract_transaction import get_extract_messages


class OpenAIVisionProvider(BaseLLMProvider):
    async def extract_from_image(self, image_bytes: bytes) -> list[TransactionExtractItem]:
        settings = get_settings()
        if not settings.openai_api_key:
            raise ValueError("OPENAI_API_KEY is not set")
        client = AsyncOpenAI(api_key=settings.openai_api_key)
        b64 = base64.standard_b64encode(image_bytes).decode("ascii")
        messages = get_extract_messages(b64)
        response = await client.chat.completions.create(
            model=settings.openai_model,
            messages=messages,
            max_tokens=4096,
        )
        text = response.choices[0].message.content or "[]"
        return _parse_json_array(text)


def _parse_json_array(text: str) -> list[TransactionExtractItem]:
    """Parse LLM response into list of TransactionExtractItem. Tolerates markdown and extra text."""
    text = text.strip()
    # Remove optional markdown code block
    if text.startswith("```"):
        text = re.sub(r"^```(?:json)?\s*", "", text)
        text = re.sub(r"\s*```\s*$", "", text)
    try:
        data = json.loads(text)
    except json.JSONDecodeError:
        return []
    if not isinstance(data, list):
        return []
    result: list[TransactionExtractItem] = []
    for item in data:
        if not isinstance(item, dict):
            continue
        try:
            # Normalize transaction_time: allow string -> datetime
            if isinstance(item.get("transaction_time"), str) and item["transaction_time"]:
                from dateutil import parser as date_parser
                item["transaction_time"] = date_parser.isoparse(item["transaction_time"])
            result.append(TransactionExtractItem.model_validate(item))
        except Exception:
            continue
    return result