"""
Tree Sitter LookAhead Iterator implementation for Python.
"""

from typing import Optional
from .language import Language
from .types import SymbolType


class LookAheadIterator:
    """
    A lookahead iterator for generating completion suggestions and error diagnostics.
    """
    
    def __init__(self, language: Language, state_id: int):
        """
        Initialize a lookahead iterator.
        
        Args:
            language: The language to use
            state_id: The parse state to start from
            
        Raises:
            TreeSitterException: If the state is invalid
        """
        self._language = language
        self._state_id = state_id
        self._iterator_ptr = None  # Would be ts_lookahead_iterator_new result
        
        # Initialize the iterator
        self._initialize_iterator()
    
    def _initialize_iterator(self):
        """Initialize the lookahead iterator with the tree-sitter library."""
        # Implementation would call ts_lookahead_iterator_new(self._language._language_ptr, self._state_id)
        # For now, just set placeholder values
        self._current_symbol = 0
        self._current_symbol_name = "ERROR"
    
    def reset_state(self, state_id: int) -> bool:
        """
        Reset the lookahead iterator to another state.
        
        Args:
            state_id: The new state ID
            
        Returns:
            True if the iterator was reset successfully, False otherwise
        """
        # Implementation would call ts_lookahead_iterator_reset_state(self._iterator_ptr, state_id)
        self._state_id = state_id
        return True
    
    def reset(self, language: Language, state_id: int) -> bool:
        """
        Reset the lookahead iterator.
        
        Args:
            language: The new language
            state_id: The new state ID
            
        Returns:
            True if the iterator was reset successfully, False otherwise
        """
        # Implementation would call ts_lookahead_iterator_reset(self._iterator_ptr, language._language_ptr, state_id)
        self._language = language
        self._state_id = state_id
        return True
    
    def get_language(self) -> Language:
        """
        Get the current language of the lookahead iterator.
        
        Returns:
            The current language
        """
        # Implementation would call ts_lookahead_iterator_language(self._iterator_ptr)
        return self._language
    
    def next(self) -> bool:
        """
        Advance the lookahead iterator to the next symbol.
        
        Returns:
            True if there is a new symbol, False otherwise
        """
        # Implementation would call ts_lookahead_iterator_next(self._iterator_ptr)
        return False
    
    def current_symbol(self) -> int:
        """
        Get the current symbol of the lookahead iterator.
        
        Returns:
            The current symbol ID
        """
        # Implementation would call ts_lookahead_iterator_current_symbol(self._iterator_ptr)
        return self._current_symbol
    
    def current_symbol_name(self) -> str:
        """
        Get the current symbol name of the lookahead iterator.
        
        Returns:
            The current symbol name
        """
        # Implementation would call ts_lookahead_iterator_current_symbol_name(self._iterator_ptr)
        return self._current_symbol_name
    
    def __iter__(self):
        """Make the iterator iterable."""
        return self
    
    def __next__(self):
        """Get the next symbol."""
        if self.next():
            return self.current_symbol()
        else:
            raise StopIteration
    
    def __del__(self):
        """Clean up iterator resources."""
        if self._iterator_ptr is not None:
            # Implementation would call ts_lookahead_iterator_delete(self._iterator_ptr)
            pass
