"""
Derives a trusted CallerContext from a request.
"""
from typing import Dict, Any
from contracts.common import CallerContext

# This is a placeholder for a future, more robust caller registry (e.g., Firestore).
# The key would be the hash of the API key or the IAP-verified user email.
_CALLER_REGISTRY: Dict[str, Dict[str, Any]] = {
    "agent:perplexity": {
        "profile": "operator",
        "owner_id": "sa:perplexity",
        "workspace_id": "ws:vauco",
        "allowed_tool_policy": {
            # This profile can read anything but requires approval for all writes
            "default": "requires_approval",
            "read_only": "read_only",
            "propose_only": "propose_only",
            "forbidden": "forbidden",
        }
    },
    "user:chris.christiansen@vauco.no": {
        "profile": "admin",
        "owner_id": "user:chris.c",
        "workspace_id": "ws:vauco",
        "allowed_tool_policy": {
             # Admin can do safe writes directly, but needs high approval for destructive actions
            "default": "requires_high_approval",
            "read_only": "read_only",
            "requires_approval": "requires_approval", # Can do normal writes
        }
    }
}

_DEFAULT_CALLER_CONTEXT = CallerContext(
    caller_id="anonymous:unknown",
    caller_type="system",
    profile="readonly",
    owner_id="system:public",
    workspace_id="ws:public",
    allowed_tool_policy={"default": "read_only"}
)

def derive_caller_context(auth_identifier: str) -> CallerContext:
    """
    Derives a CallerContext from a trusted, server-verified identifier.

    In a real implementation, `auth_identifier` would be the result of
    authenticating a request (e.g., looking up an API key hash or using an
    IAP-provided email address).

    Args:
        auth_identifier: The trusted identifier for the caller.

    Returns:
        A CallerContext object with the appropriate policies.
    """
    caller_data = _CALLER_REGISTRY.get(auth_identifier)
    if not caller_data:
        return _DEFAULT_CALLER_CONTEXT

    return CallerContext(
        caller_id=auth_identifier,
        caller_type='human' if auth_identifier.startswith('user:') else auth_identifier.split(":")[0], # cheap trick
        **caller_data
    )