"""Tipos de columna y resumen de análisis."""
from __future__ import annotations

from dataclasses import dataclass, field
from typing import Optional

TYPE_INTEGER = "integer"
TYPE_DECIMAL = "decimal"
TYPE_DATE = "date"
TYPE_BOOLEAN = "boolean"
TYPE_CATEGORICAL = "categorical"
TYPE_TEXT = "text"
TYPE_MIXED = "mixed"
TYPE_EMPTY = "empty"


@dataclass
class ColumnSummary:
  """Resumen inteligente para una columna del DataFrame."""
  name: str
  inferred_type: str
  example: str = ""
  samples: list[str] = field(default_factory=list)
  null_count: int = 0
  null_pct: float = 0.0
  unique_count: int = 0
  unique_pct: float = 0.0
  min: Optional[float] = None
  max: Optional[float] = None
  mean: Optional[float] = None
  avg_length: Optional[float] = None
  top_values: list[tuple[str, int]] = field(default_factory=list)
  detected_date_format: Optional[str] = None
  applicable_rules: list[str] = field(default_factory=list)

  def info_text(self) -> str:
    """Texto humano con información adicional (para subtítulo de la UI)."""
    parts: list[str] = []
    parts.append(f"nulos: {self.null_count} ({self.null_pct:.0f}%)")
    parts.append(f"únicos: {self.unique_count}")
    if self.inferred_type in (TYPE_INTEGER, TYPE_DECIMAL):
      if self.min is not None:
        parts.append(f"min: {_fmt_num(self.min)}")
      if self.max is not None:
        parts.append(f"max: {_fmt_num(self.max)}")
      if self.mean is not None:
        parts.append(f"media: {_fmt_num(self.mean)}")
    elif self.inferred_type == TYPE_DATE:
      if self.detected_date_format:
        parts.append(f"formato: {self.detected_date_format}")
    elif self.inferred_type in (TYPE_TEXT, TYPE_CATEGORICAL):
      if self.avg_length is not None:
        parts.append(f"long. prom: {self.avg_length:.1f}")
      if self.top_values:
        tops = ", ".join(f'"{v}" ({c})' for v, c in self.top_values[:3])
        parts.append(f"top: {tops}")
    return " · ".join(parts)


def _fmt_num(x: float) -> str:
  if x is None:
    return ""
  if isinstance(x, float) and x.is_integer():
    return str(int(x))
  if isinstance(x, float):
    return f"{x:.2f}"
  return str(x)