"""
Deterministic completion evaluation engine. Single source of truth for onboarding completion.
"""

from typing import Dict, Any, List


def field_status(field_val: Any) -> str:
    """
    Returns field status: 'not_collected' | 'reported' | 'confirmed_none' | 'unknown' | 'declined'
    """
    if field_val is None:
        return "not_collected"

    if isinstance(field_val, dict):
        status = field_val.get("status")
        if status in ["reported", "confirmed_none", "unknown", "declined"]:
            return status
        items = field_val.get("items", [])
        return "reported" if items else "not_collected"

    if isinstance(field_val, list):
        return "reported" if len(field_val) > 0 else "not_collected"

    if isinstance(field_val, str) and field_val.strip():
        return "reported"

    return "not_collected"


def check_required_missing(state: Dict[str, Any]) -> List[str]:
    """
    Single source of truth evaluating missing clinical fields for onboarding completion.
    Required fields: reason_for_visit, symptoms, duration, medical_history, medications, allergies.
    """
    if not isinstance(state, dict):
        state = {}

    missing: List[str] = []

    # 1. Reason for Visit
    if field_status(state.get("reason_for_visit")) == "not_collected":
        missing.append("reason_for_visit")

    # 2. Symptoms
    symptoms = state.get("symptoms", [])
    sym_status = field_status(symptoms)
    if sym_status == "not_collected":
        missing.append("symptoms")

    # 3. Duration
    has_duration = False
    if isinstance(symptoms, list) and symptoms:
        for s in symptoms:
            if isinstance(s, dict) and s.get("duration"):
                has_duration = True
                break
    if not has_duration and state.get("duration"):
        has_duration = True

    if sym_status != "not_collected" and not has_duration:
        missing.append("duration")

    # 4. Medical History
    if field_status(state.get("medical_history")) == "not_collected":
        missing.append("medical_history")

    # 5. Medications
    if field_status(state.get("medications")) == "not_collected":
        missing.append("medications")

    # 6. Allergies
    if field_status(state.get("allergies")) == "not_collected":
        missing.append("allergies")

    return missing


def is_onboarding_complete(state: Dict[str, Any]) -> bool:
    """
    Returns True ONLY if all required fields are collected or confirmed_none.
    """
    missing = check_required_missing(state)
    return len(missing) == 0