"""
Test Boolean Function arrays
"""

from nose.tools import assert_raises

from pyeda.boolalg.bdd import bddvar, BinaryDecisionDiagram
from pyeda.boolalg.bfarray import (
    exprzeros, exprvars,
    fcat, farray,
    uint2exprs, int2exprs,
)
from pyeda.boolalg.expr import exprvar, Expression


X = exprvars('x', 4)
Y = exprvars('y', 4)
a, b, c, d, w, x, y, z = map(exprvar, 'abcdwxyz')

def test_fcat():
    # expected Function or farray
    assert_raises(TypeError, fcat, X, Y, 0)
    assert str(fcat(X[0], X[2:], Y[3], Y[:-2])) == "farray([x[0], x[2], x[3], y[3], y[0], y[1]])"

def test_farray():
    # expected shape volume to match items
    assert_raises(ValueError, farray, [X[0], X[1]], shape=((0, 42), ))
    # could not determine ftype parameter
    assert_raises(ValueError, farray, [])
    # expected ftype to be a type
    assert_raises(TypeError, farray, [X[0], X[1]], ftype=42)
    # expected ftype to match items
    assert_raises(ValueError, farray, [X[0], X[1]], ftype=BinaryDecisionDiagram)
    # expected ftype to be a property subclass of Function
    assert_raises(TypeError, farray, [], ftype=int)
    # expected a sequence of Function
    assert_raises(TypeError, farray, 42)
    assert_raises(TypeError, farray, [1, 2, 3, 4])
    # expected uniform dimensions
    assert_raises(ValueError, farray, [[a, b], [w, x, y, z], 42])
    assert_raises(ValueError, farray, [[a, b], [w, x, y, z]])
    # expected uniform types
    assert_raises(ValueError, farray, [[a, b], [c, bddvar('d')]])
    assert_raises(ValueError, farray, [[a, b], [bddvar('c'), bddvar('d')]])
    # _check_shape errors
    assert_raises(ValueError, farray, [a, b, c, d], shape=((-1, 3), ))
    assert_raises(ValueError, farray, [a, b, c, d], shape=((3, -1), ))
    assert_raises(ValueError, farray, [a, b, c, d], shape=((5, 1), ))
    assert_raises(TypeError, farray, [a, b, c, d], shape=(('foo', 'bar'), ))
    assert_raises(TypeError, farray, [a, b, c, d], shape=42)

    temp = farray([[a, b], [c, d]])
    assert str(temp) == """\
farray([[a, b],
        [c, d]])\
"""

    # __str__
    Z = exprvars('z', 2, 2, 2)
    assert str(Z) == """\
farray([[[z[0,0,0], z[0,0,1]],
         [z[0,1,0], z[0,1,1]]],

        [[z[1,0,0], z[1,0,1]],
         [z[1,1,0], z[1,1,1]]]])\
"""

    assert str(farray([], ftype=Expression)) == "farray([])"

    # __getitem__
    # expected <= M slice dimensions, got N
    assert_raises(ValueError, X.__getitem__, (2, 2))
    sel = exprvars('s', 2)
    assert X[sel].equivalent(~sel[0] & ~sel[1] & X[0] | sel[0] & ~sel[1] & X[1] | ~sel[0] & sel[1] & X[2] | sel[0] & sel[1] & X[3])
    assert X[:2][sel[0]].equivalent(~sel[0] & X[0] | sel[0] & X[1])
    # expected clog2(N) bits
    assert_raises(ValueError, X.__getitem__, sel[0])
    # slice step not supported
    assert_raises(ValueError, X.__getitem__, slice(None, None, 2))
    # type error
    assert_raises(TypeError, X.__getitem__, 'foo')
    # norm_index
    assert X[-1] is X[3]
    assert_raises(IndexError, X.__getitem__, 42)
    # norm_indices
    assert X[-3:-1]._items == [X[-3], X[-2]]
    assert not X[-8:-10]._items
    assert not X[-10:-8]._items
    assert not X[8:10]._items
    assert not X[10:8]._items
    assert not X[3:1]._items

    # __setitem__
    Z = exprzeros(4, 4)
    Z[0,0] = X[0]
    assert Z._items[0] is X[0]
    # expected item to be a Function
    assert_raises(TypeError, Z.__setitem__, (0, 0), 42)
    Z[0,:] = X[:4]
    assert Z._items[0:4] == [X[0], X[1], X[2], X[3]]
    # expected item to be an farray
    assert_raises(TypeError, Z.__setitem__, (0, slice(None, None, None)), 42)
    # expected item.size = ...
    assert_raises(ValueError, Z.__setitem__, ..., X[:2])
    # slice step not supported
    assert_raises(ValueError, X.__setitem__, slice(None, None, 2), 42)
    # type error
    assert_raises(TypeError, X.__setitem__, 'foo', 42)

    # __add__
    assert (0 + X)._items[0].is_zero()
    assert (X + 0)._items[4].is_zero()
    assert (Y[0] + X)._items[0] is Y[0]
    assert (X + Y[0])._items[4] is Y[0]
    assert (X[:2] + Y[2:])._items == [X[0], X[1], Y[2], Y[3]]
    # expected Function or farray
    assert_raises(TypeError, X.__add__, 42)
    assert_raises(TypeError, X.__radd__, 42)

    A = exprvars('a', 2, 5, 6)
    B = exprvars('b', 2, 5, 6)
    C = exprvars('c', (1, 3), 5, 6)
    # regular MDA will retain shape
    assert (A+B).shape == ((0, 4), (0, 5), (0, 6))
    # irregular MDA will not
    assert (A+C).shape == ((0, 4*5*6), )

    # regular MDA will retain shape
    assert (A*2).shape == ((0, 4), (0, 5), (0, 6))
    # irregular MDA will not
    assert (C*2).shape == ((0, 4*5*6), )

    # __mul__
    # expected multiplier to be an int
    assert_raises(TypeError, X.__mul__, 'foo')
    # expected multiplier to be non-negative
    assert_raises(ValueError, X.__mul__, -2)
    assert (X[:2] * 2)._items == [X[0], X[1], X[0], X[1]]
    assert (2 * X[:2])._items == [X[0], X[1], X[0], X[1]]

    # offsets
    Z = exprzeros((1, 5), (17, 21))
    assert Z.offsets == (1, 17)

    # reshape
    assert Z.reshape(4, 4).shape == ((0, 4), (0, 4))
    # expected shape with equal volume
    assert_raises(ValueError, Z.reshape, 42, 42)

    # restrict
    assert str(X.vrestrict({X: '0101'})) == "farray([0, 1, 0, 1])"

    # compose
    assert X.compose({X[0]: Y[0]})._items[0] == Y[0]

    # to_uint / to_int
    assert uint2exprs(42).to_uint() == 42
    assert uint2exprs(42, 8).to_uint() == 42
    # expected all functions to be a constant (0 or 1) form
    assert_raises(ValueError, X.to_uint)
    # expected num >= 0
    assert_raises(ValueError, uint2exprs, -1)
    # overflow
    assert_raises(ValueError, uint2exprs, 42, 2)
    assert_raises(ValueError, int2exprs, 42, 2)
    assert int2exprs(-42).to_int() == -42
    assert int2exprs(-42, 8).to_int() == -42
    assert int2exprs(42).to_int() == 42
    assert int2exprs(42, 8).to_int() == 42

    # zext, sext
    assert X.zext(1)[4].is_zero()
    assert X.sext(1)[4] is X[3]

    # __invert__, __or__, __and__, __xor__
    assert str(~X) == "farray([~x[0], ~x[1], ~x[2], ~x[3]])"
    assert str(X | Y) == "farray([Or(x[0], y[0]), Or(x[1], y[1]), Or(x[2], y[2]), Or(x[3], y[3])])"
    assert str(X & Y) == "farray([And(x[0], y[0]), And(x[1], y[1]), And(x[2], y[2]), And(x[3], y[3])])"
    assert str(X ^ Y) == "farray([Xor(x[0], y[0]), Xor(x[1], y[1]), Xor(x[2], y[2]), Xor(x[3], y[3])])"
    # _op_shape
    # expected farray input
    assert_raises(TypeError, X.__or__, 42)
    Z = exprvars('z', 2, 2)
    assert str(X | Z) == "farray([Or(x[0], z[0,0]), Or(x[1], z[0,1]), Or(x[2], z[1,0]), Or(x[3], z[1,1])])"
    Z = exprvars('z', 2, 3)
    # expected operand sizes to match
    assert_raises(ValueError, X.__or__, Z)

    # lsh, rsh
    assert str(X.lsh(0)) == "(farray([x[0], x[1], x[2], x[3]]), farray([]))"
    assert str(X << 0) == "farray([x[0], x[1], x[2], x[3]])"
    assert str(X.lsh(2)) == "(farray([0, 0, x[0], x[1]]), farray([x[2], x[3]]))"
    assert str(X << 2) == "farray([0, 0, x[0], x[1]])"
    assert str(X << (2, Y[:2])) == "farray([y[0], y[1], x[0], x[1]])"
    assert str(X.rsh(0)) == "(farray([x[0], x[1], x[2], x[3]]), farray([]))"
    assert str(X >> 0) == "farray([x[0], x[1], x[2], x[3]])"
    assert str(X.rsh(2)) == "(farray([x[2], x[3], 0, 0]), farray([x[0], x[1]]))"
    assert str(X >> 2) == "farray([x[2], x[3], 0, 0])"
    assert str(X >> (2, Y[:2])) == "farray([x[2], x[3], y[0], y[1]])"
    assert_raises(TypeError, X.__lshift__, 'foo')
    assert_raises(ValueError, X.__lshift__, -1)
    assert_raises(ValueError, X.__lshift__, (2, Y))
    assert_raises(TypeError, X.__rshift__, 'foo')
    assert_raises(ValueError, X.__rshift__, -1)
    assert_raises(ValueError, X.__rshift__, (2, Y))

    # arsh
    assert str(X.arsh(0)) == "(farray([x[0], x[1], x[2], x[3]]), farray([]))"
    assert str(X.arsh(2)) == "(farray([x[2], x[3], x[3], x[3]]), farray([x[0], x[1]]))"
    assert_raises(ValueError, X.arsh, -1)

    # unary ops
    assert X.uor().equivalent(X[0] | X[1] | X[2] | X[3])
    assert X.unor().equivalent(~(X[0] | X[1] | X[2] | X[3]))
    assert X.uand().equivalent(X[0] & X[1] & X[2] & X[3])
    assert X.unand().equivalent(~(X[0] & X[1] & X[2] & X[3]))
    assert X.uxor().equivalent(X[0] ^ X[1] ^ X[2] ^ X[3])
    assert X.uxnor().equivalent(~(X[0] ^ X[1] ^ X[2] ^ X[3]))

    # decode
    assert str(farray([], ftype=Expression).decode()) == "farray([1])"
    parts = X[:2].decode()
    assert parts[0].equivalent(~X[0] & ~X[1])
    assert parts[1].equivalent(X[0] & ~X[1])
    assert parts[2].equivalent(~X[0] & X[1])
    assert parts[3].equivalent(X[0] & X[1])

def test_dims2shape():
    assert_raises(ValueError, exprzeros)
    assert_raises(ValueError, exprzeros, -1)
    assert_raises(ValueError, exprzeros, (-1, 0))
    assert_raises(ValueError, exprzeros, (0, -1))
    assert_raises(ValueError, exprzeros, (1, 0))
    assert_raises(TypeError, exprzeros, 'foo')

