"""Upload service — accept file, store to DB, parse."""
import uuid, base64, json
from email.parser import BytesParser
from db import documents, contracts, supplements
from .parse import parse_file


def handle_upload(rfile, content_type, content_length):
    """Parse multipart upload, store in DB, return result dict."""
    body = rfile.read(content_length)

    msg = BytesParser().parsebytes(
        b"Content-Type: " + content_type.encode() + b"\r\n\r\n" + body
    )
    filename = None
    file_data = None
    contract_id = ""

    if msg.is_multipart():
        for part in msg.get_payload():
            fn = part.get_filename()
            if fn:
                filename = fn
                file_data = part.get_payload(decode=True)
            else:
                disp = part.get("Content-Disposition", "")
                if 'name="contract_id"' in disp:
                    contract_id = part.get_payload(decode=True).decode("utf-8", errors="ignore").strip()

    if not filename or not file_data:
        return {"ok": False, "error": "no file in request"}

    mime = _mime_for(filename)
    b64 = base64.b64encode(file_data).decode()

    # Удалить старый файл с тем же именем в этом контракте
    if contract_id:
        supplements.delete_by_document(contract_id, filename)

    doc = documents.insert(filename, mime, b64)

    # Создать контракт если нет
    if not contract_id:
        from datetime import datetime
        now = datetime.now()
        c = contracts.insert(f"б/н {now.strftime('%Y%m%d')}-{now.strftime('%H%M')}")
        contract_id = c["id"]
        supp_type = "initial"
    else:
        supp_type = "additional"

    supplements.insert(contract_id, doc["id"], supp_type)

    # Парсинг на VM
    parsed = parse_file(filename, file_data)
    if parsed and parsed.get("status") == "parsed":
        documents.set_parsed(doc["id"], parsed["elements"])
    elif parsed and parsed.get("status") == "error":
        documents.set_error(doc["id"], parsed.get("error", "parse failed"))

    return {
        "ok": True,
        "doc_id": doc["id"],
        "contract_id": contract_id,
        "filename": filename,
        "size": len(file_data),
        "parsed": parsed,
    }


def _mime_for(filename):
    ext = filename.rsplit(".", 1)[-1].lower() if "." in filename else ""
    mime_map = {
        "pdf": "application/pdf",
        "docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
        "doc": "application/msword",
        "zip": "application/zip",
    }
    return mime_map.get(ext, "application/octet-stream")