from __future__ import annotations

from typing import Any


def merge_account_config(
    top: dict[str, Any],
    account: dict[str, Any],
) -> dict[str, Any]:
    overridable_keys = {
        "server_url",
        "password",
        "dm_policy",
        "group_policy",
        "dm_allow_from",
        "group_allow_chats",
        "require_mention",
        "tapback_enabled",
        "media_max_mb",
        "media_local_roots",
        "allow_private_network",
        "webhook_path",
        "webhook_secret",
        "send_read_receipts",
        "text_chunk_limit",
        "chunk_mode",
        "block_streaming",
        "send_timeout_ms",
        "dm_history_limit",
    }

    merged = dict(top)
    for key in overridable_keys:
        if key in account and account[key]:
            merged[key] = account[key]
    return merged


def apply_account_configs(
    top_config: dict[str, Any],
    accounts_config: dict[str, Any],
    allow_config_writes: bool = True,
) -> dict[str, dict[str, Any]]:
    if not allow_config_writes:
        return {"default": dict(top_config)}

    result: dict[str, dict[str, Any]] = {"default": dict(top_config)}

    for account_id, raw in accounts_config.items():
        if not isinstance(raw, dict):
            continue
        result[account_id] = merge_account_config(top_config, raw)

    return result