"""Upload service — accept file, store to DB, parse."""
import uuid, base64, json, io, cgi
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)

    environ = {
        "REQUEST_METHOD": "POST",
        "CONTENT_TYPE": content_type,
        "CONTENT_LENGTH": str(content_length),
    }
    fs = cgi.FieldStorage(fp=io.BytesIO(body), environ=environ, keep_blank_values=True)

    filename = None
    file_data = None
    contract_id = ""

    if "files" in fs:
        item = fs["files"]
        if isinstance(item, list):
            item = item[0]
        filename = item.filename
        file_data = item.file.read() if hasattr(item, "file") else item.value
        if isinstance(file_data, str):
            file_data = file_data.encode("utf-8")

    if "contract_id" in fs:
        contract_id = fs.getfirst("contract_id", "")

    batch_id = fs.getfirst("batch_id", None) if "batch_id" in fs else None

    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()

    if contract_id:
        supplements.delete_by_document(contract_id, filename)

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

    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)

    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")