"""
Collection executor for Dana language.

This module provides a specialized executor for collection literals in the Dana language.

Copyright © 2025 Aitomatic, Inc.
MIT License

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    1. Attribution: Please maintain attribution to Aitomatic and Dana/Dana in derivative works.
    2. Contributions: If you find Dana/Dana valuable, consider contributing improvements back rather than creating separate, similar implementations.
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Learn more: https://aitomatic.com
GitHub: https://github.com/aitomatic/dana
Discord: https://discord.gg/6jGD4PYk
"""

from dana.core.lang.ast import (
    DictLiteral,
    FStringExpression,
    ListLiteral,
    SetLiteral,
    TupleLiteral,
)
from dana.core.lang.interpreter.executor.base_executor import BaseExecutor
from dana.core.lang.sandbox_context import SandboxContext
from dana.registry.function_registry import FunctionRegistry


def _auto_resolve_promises(items):
    """Auto-resolve any promises in a collection of items (KISS approach)."""
    from dana.core.concurrency import resolve_if_promise

    # Simple list comprehension - resolve if promise, keep if not
    return [resolve_if_promise(item) for item in items]


class CollectionExecutor(BaseExecutor):
    """Specialized executor for collection literals.

    Handles:
    - Tuple literals
    - Dict literals
    - List literals
    - Set literals
    - FString expressions
    """

    def __init__(self, parent_executor: BaseExecutor, function_registry: FunctionRegistry | None = None):
        """Initialize the collection executor.

        Args:
            parent_executor: The parent executor instance
            function_registry: Optional function registry (defaults to parent's)
        """
        super().__init__(parent_executor, function_registry)
        self.register_handlers()

    def register_handlers(self):
        """Register handlers for collection node types."""
        self._handlers = {
            TupleLiteral: self.execute_tuple_literal,
            DictLiteral: self.execute_dict_literal,
            ListLiteral: self.execute_list_literal,
            SetLiteral: self.execute_set_literal,
            FStringExpression: self.execute_fstring_expression,
        }

    def execute_tuple_literal(self, node: TupleLiteral, context: SandboxContext) -> tuple:
        """Execute a tuple literal.

        Args:
            node: The tuple literal to execute
            context: The execution context

        Returns:
            The tuple value
        """
        # Process each item in the tuple, ensuring AST nodes are evaluated
        items = [self.parent.execute(item, context) for item in node.items]
        # Auto-resolve any promises
        resolved_items = _auto_resolve_promises(items)
        return tuple(resolved_items)

    def execute_dict_literal(self, node: DictLiteral, context: SandboxContext) -> dict:
        """Execute a dict literal.

        Args:
            node: The dict literal to execute
            context: The execution context

        Returns:
            The dict value
        """
        # Process each key-value pair, ensuring AST nodes are evaluated for both key and value
        result = {}
        for key, value in node.items:
            key_result = self.parent.execute(key, context)
            value_result = self.parent.execute(value, context)
            # Auto-resolve any promises
            from dana.core.concurrency import resolve_if_promise

            resolved_key = resolve_if_promise(key_result)
            resolved_value = resolve_if_promise(value_result)
            result[resolved_key] = resolved_value
        return result

    def execute_set_literal(self, node: SetLiteral, context: SandboxContext) -> set:
        """Execute a set literal.

        Args:
            node: The set literal to execute
            context: The execution context

        Returns:
            The set value
        """
        # Process each item in the set, ensuring AST nodes are evaluated
        items = [self.parent.execute(item, context) for item in node.items]
        # Auto-resolve any promises
        resolved_items = _auto_resolve_promises(items)
        return set(resolved_items)

    def execute_fstring_expression(self, node: FStringExpression, context: SandboxContext) -> str:
        """Execute an f-string expression.

        Args:
            node: The f-string expression to execute
            context: The execution context

        Returns:
            The formatted string
        """
        # Handle both new-style expression structure (with template and expressions)
        # and old-style parts structure

        # Check if we have the new structure with template and expressions dictionary
        if hasattr(node, "template") and node.template and hasattr(node, "expressions") and node.expressions:
            result = node.template

            # Replace each placeholder with its evaluated value
            for placeholder, expr in node.expressions.items():
                # Evaluate the expression within the placeholder
                value = self.parent.execute(expr, context)
                # Replace the placeholder with the string representation of the value
                result = result.replace(placeholder, str(value))

            return result

        # Handle the older style with parts list
        elif hasattr(node, "parts") and node.parts:
            result = ""
            for part in node.parts:
                if isinstance(part, str):
                    result += part
                else:
                    # Evaluate the expression part
                    value = self.parent.execute(part, context)
                    result += str(value)
            return result

        # If neither format is present, return an empty string as fallback
        return ""

    def execute_list_literal(self, node: ListLiteral, context: SandboxContext) -> list:
        """Execute a list literal.

        Args:
            node: The list literal to execute
            context: The execution context

        Returns:
            The list value
        """
        # Process each item in the list, ensuring AST nodes are evaluated
        items = [self.parent.execute(item, context) for item in node.items]
        # Auto-resolve any promises
        resolved_items = _auto_resolve_promises(items)
        return resolved_items
