from __future__ import annotations

from urllib.parse import parse_qs

from fastapi import Request


async def html5_form_data(request: Request) -> dict[str, list[str]]:
    content_type = request.headers.get("content-type", "")
    if content_type.startswith("multipart/form-data"):
        parsed = await request.form()
        form: dict[str, list[str]] = {}
        for key, value in parsed.multi_items():
            text = getattr(value, "filename", None) if not isinstance(value, str) else value
            form.setdefault(key, []).append(str(text or ""))
        return form
    body = (await request.body()).decode("utf-8")
    return parse_qs(body, keep_blank_values=True)


def form_value(form: dict[str, list[str]], key: str) -> str | None:
    values = form.get(key)
    if not values:
        return None
    value = values[0].strip()
    return value or None


def html5_metadata_payload(form: dict[str, list[str]]) -> dict:
    return {
        "object_kind": form_value(form, "object_kind") or "DOCUMENT",
        "name": form_value(form, "name") or "",
        "synonym": form_value(form, "synonym"),
        "attributes": html5_metadata_attributes(form_value(form, "attributes") or ""),
        "tabular_sections": html5_metadata_tabular_sections(form_value(form, "tabular_sections") or ""),
        "forms": html5_csv_values(form_value(form, "forms") or ""),
        "commands": html5_metadata_commands(form_value(form, "commands") or ""),
        "task_id": form_value(form, "task_id"),
        "session_id": form_value(form, "session_id"),
        "user_id": form_value(form, "user_id"),
        "_raw_attributes": form_value(form, "attributes") or "",
        "_raw_tabular_sections": form_value(form, "tabular_sections") or "",
        "_raw_forms": form_value(form, "forms") or "",
        "_raw_commands": form_value(form, "commands") or "",
    }


def html5_metadata_request_payload(payload: dict) -> dict:
    return {key: value for key, value in payload.items() if not key.startswith("_raw_")}


def html5_csv_values(raw: str) -> list[str]:
    return [item.strip() for item in raw.replace("\n", ",").split(",") if item.strip()]


def html5_metadata_attributes(raw: str) -> list[dict]:
    attributes: list[dict] = []
    for item in html5_csv_values(raw):
        name, _, type_name = item.partition(":")
        if name.strip():
            attributes.append({"name": name.strip(), "type": type_name.strip() or "Строка"})
    return attributes


def html5_metadata_commands(raw: str) -> list[dict]:
    commands: list[dict] = []
    for item in html5_csv_values(raw):
        name, _, handler = item.partition(":")
        if name.strip():
            commands.append({"name": name.strip(), "handler": handler.strip() or None})
    return commands


def html5_metadata_tabular_sections(raw: str) -> list[dict]:
    sections: list[dict] = []
    for item in html5_csv_values(raw):
        name, _, attrs = item.partition("[")
        if not name.strip():
            continue
        attributes = []
        for attr in attrs.rstrip("]").split(";"):
            attr_name, _, attr_type = attr.partition(":")
            if attr_name.strip():
                attributes.append({"name": attr_name.strip(), "type": attr_type.strip() or "Строка"})
        sections.append({"name": name.strip(), "attributes": attributes})
    return sections