"""
Base class for DSL definitions.

DSLDefinition provides the interface for defining domain-specific languages
that can be used with the DslEditor control and CodeMirror.
"""

from abc import ABC, abstractmethod
from functools import cached_property
from typing import List, Dict, Any

from myfasthtml.core.dsl.lark_to_lezer import (
  lark_to_lezer_grammar,
  extract_completions_from_grammar,
)
from myfasthtml.core.utils import make_safe_id


class DSLDefinition(ABC):
  """
  Base class for DSL definitions.

  Subclasses must implement get_grammar() to provide the Lark grammar.
  The Lezer grammar and completions are automatically derived.

  Attributes:
      name: Human-readable name of the DSL.
  """
  
  name: str = "DSL"
  
  @abstractmethod
  def get_grammar(self) -> str:
    """
    Return the Lark grammar string for this DSL.

    Returns:
        The Lark grammar as a string.
    """
    pass
  
  @cached_property
  def lezer_grammar(self) -> str:
    """
    Return the Lezer grammar derived from the Lark grammar.

    This is cached after first computation.

    Returns:
        The Lezer grammar as a string.
    """
    return lark_to_lezer_grammar(self.get_grammar())
  
  @cached_property
  def completions(self) -> Dict[str, List[str]]:
    """
    Return completion items extracted from the grammar.

    This is cached after first computation.

    Returns:
        Dictionary with completion categories:
        - 'keywords': Language keywords (if, not, and, etc.)
        - 'operators': Comparison and arithmetic operators
        - 'functions': Function-like constructs (style, format, etc.)
        - 'types': Type names (number, date, boolean, etc.)
        - 'literals': Literal values (True, False, etc.)
    """
    return extract_completions_from_grammar(self.get_grammar())
  
  def get_editor_config(self) -> Dict[str, Any]:
    """
    Return the configuration for the DslEditor JavaScript initialization.

    Returns:
        Dictionary with:
        - 'lezerGrammar': The Lezer grammar string
        - 'completions': The completion items
        - 'name': The DSL name
    """
    return {
        "name": self.name,
        "lezerGrammar": self.lezer_grammar,
        "completions": self.completions,
    }
  
  def get_id(self):
    return make_safe_id(self.name)