from SwiftFloatingPointTypes import all_floating_point_types

class SwiftMathFunction(object):
  def __init__(self, name, kind=None, swiftName=None, args="x", comment=None, platforms=None):
    self.name = name
    self.swiftName = swiftName if swiftName is not None else name
    self.kind = kind if kind is not None else "library"
    self.args = args
    self.comment = comment if comment is not None else "/// The " + str(self.swiftName) + " function."
    self.platforms = platforms

  def params(self, prefix="", suffix=""):
    return ", ".join(
      map(lambda a: prefix + a + suffix, self.args)
    )
  
  def decl(self, type):
    return self.swiftName + "(" + self.params("_ ", ": " + type) + ") -> " + type
  
  def free_decl(self, constraint="T: ElementaryFunctions"):
    return self.swiftName + "<T>(" + self.params("_ ", ": T") + ") -> T where " + constraint
  
  def impl(self, type):
    if self.kind == "intrinsic":
      builtin = "Builtin.int_" + self.name + "_FPIEEE" + str(type.bits)
      return type.stdlib_name + "(" + builtin + "(" + self.params("","._value") + "))"
    return "_swift_stdlib_" + self.name + type.cFuncSuffix + "(" + self.params() + ")"

ElementaryFunctions = [
  SwiftMathFunction(name="sqrt", kind="intrinsic", comment="/// The square root of `x`."),
  SwiftMathFunction(name="cos", kind="intrinsic", comment="/// The cosine of `x`."),
  SwiftMathFunction(name="sin", kind="intrinsic", comment="/// The sine of `x`."),
  SwiftMathFunction(name="tan", comment="/// The tangent of `x`."),
  SwiftMathFunction(name="acos"),
  SwiftMathFunction(name="asin"),
  SwiftMathFunction(name="atan"),
  SwiftMathFunction(name="cosh"),
  SwiftMathFunction(name="sinh"),
  SwiftMathFunction(name="tanh"),
  SwiftMathFunction(name="acosh"),
  SwiftMathFunction(name="asinh"),
  SwiftMathFunction(name="atanh"),
  SwiftMathFunction(name="exp", kind="intrinsic"),
  SwiftMathFunction(name="exp2", kind="intrinsic"),
  SwiftMathFunction(name="exp10"),
  SwiftMathFunction(name="expm1"),
  SwiftMathFunction(name="log", kind="intrinsic"),
  SwiftMathFunction(name="log2", kind="intrinsic"),
  SwiftMathFunction(name="log10", kind="intrinsic"),
  SwiftMathFunction(name="log1p"),
# SwiftMathFunction(name="pow", kind="intrinsic", args="xy"), Handled separately for edge cases.
# SwiftMathFunction(name="root", args="xn"), Handled separately for implementation.
]

RealFunctions = [
# SwiftMathFunction(name="atan2"), Handled separately for explicit arg labels.
  SwiftMathFunction(name="erf"),
  SwiftMathFunction(name="erfc"),
  SwiftMathFunction(name="hypot", args="xy"),
  SwiftMathFunction(name="tgamma", swiftName="gamma"),
# SwiftMathFunction(name="lgamma"), Handled separately to handle sign result.
]