"""Shared rule evaluation for posts and comments."""

from typing import Any, Dict


def get_nested_value(obj: Dict[str, Any], path: str) -> Any:
    """Get a nested dict value using dot notation."""
    value = obj
    for key in path.split("."):
        if isinstance(value, dict) and key in value:
            value = value[key]
        else:
            return None
    return value


def evaluate_rule(value: Any, operator: str, target: Any) -> bool:
    """Evaluate one rule operator."""
    if value is None:
        return False

    if operator == "equals":
        return value == target
    if operator == "not_equals":
        return value != target
    if operator == "in":
        return value in target
    if operator == "not_in":
        return value not in target
    if operator == "min":
        return value >= target
    if operator == "max":
        return value <= target
    if operator == "after":
        return value > target
    if operator == "before":
        return value < target
    if operator == "contains":
        return target in value
    if operator == "excludes":
        if isinstance(value, list):
            return not any(item in target for item in value)
        return value not in target
    if operator == "includes":
        if isinstance(value, list):
            return target in value
        return False
    if operator == "includes_any":
        if isinstance(value, list) and isinstance(target, list):
            for item in value:
                if isinstance(item, dict):
                    for rule in target:
                        if (
                            isinstance(rule, dict)
                            and item.get("topic") == rule.get("topic")
                            and item.get("confidence", 0) >= rule.get("confidence_min", 0)
                        ):
                            return True
                elif item in target:
                    return True
        return False
    if operator == "min_length":
        return len(str(value)) >= target
    if operator == "max_length":
        return len(str(value)) <= target

    return False


def apply_rules(item: Dict[str, Any], rules: Dict[str, Dict[str, Any]]) -> bool:
    """Return True when all field rules pass."""
    if not rules:
        return True

    for field_path, rule_def in rules.items():
        value = get_nested_value(item, field_path)
        for operator, target in rule_def.items():
            if not evaluate_rule(value, operator, target):
                return False
    return True