from math import pi, acos

try:
    from numpy import matrix
    from numpy.linalg import norm
except ImportError:
    from numjy import matrix
    from numjy.linalg import norm

from diffcalc.util import cross3, dot3


SMALL = 1e-7
TODEG = 180 / pi

class YouReference(object):
    
    def __init__(self, get_UB):
        self.get_UB = get_UB  # callable
        self._n_phi_configured = None
        self._n_hkl_configured = None
        self._set_n_phi_configured(matrix('0; 0; 1'))
    
    def _set_n_phi_configured(self, n_phi):
        self._n_phi_configured = n_phi
        self._n_hkl_configured = None
    
    def _get_n_phi_configured(self):
        return self._n_phi_configured
    
    n_phi_configured = property(_get_n_phi_configured, _set_n_phi_configured)
                    
    def _set_n_hkl_configured(self, n_hkl):
        self._n_phi_configured = None
        self._n_hkl_configured = n_hkl
        
    def _get_n_hkl_configured(self):
        return self._n_hkl_configured
    
    n_hkl_configured = property(_get_n_hkl_configured, _set_n_hkl_configured)
    
    @property
    def n_phi(self):
        if self._n_phi_configured is None:
            n_phi = self.get_UB() * self._n_hkl_configured
            n_phi = n_phi / norm(n_phi)
        else:
            n_phi = self._n_phi_configured
        return n_phi
        
    @property
    def n_hkl(self):
        if self._n_hkl_configured is None:
            n_hkl = self.get_UB().I * self._n_phi_configured
            n_hkl = n_hkl / norm(n_hkl)
        else:
            n_hkl = self._n_hkl_configured
        return n_hkl
    
    def _pretty_vector(self, m):
        return ' '.join([('% 9.5f' % e).rjust(9) for e in m.T.tolist()[0]])
    
    def repr_lines(self, ub_calculated, WIDTH, conv):
        SET_LABEL = ' <- set'
        lines = []
        if self._n_phi_configured is not None:
            nphi_label = SET_LABEL
            nhkl_label = ''
        elif self._n_hkl_configured is not None:
            nphi_label = ''
            nhkl_label = SET_LABEL
        else:
            raise AssertionError("Neither a manual n_phi nor n_hkl is configured")
        
        if ub_calculated:
            lines.append("   n_phi:".ljust(WIDTH) + self._pretty_vector(conv.transform(self.n_phi, True)) + nphi_label)
            lines.append("   n_hkl:".ljust(WIDTH) + self._pretty_vector(self.n_hkl) + nhkl_label)
            rotation_axis = conv.transform(cross3(matrix('0; 0; 1'), self.n_phi), True)
            if abs(norm(rotation_axis)) < SMALL:
                lines.append("   normal:".ljust(WIDTH) + "  None")
            else:
                rotation_axis = rotation_axis * (1 / norm(rotation_axis))
                dot_rotation_angle = dot3(matrix('0; 0; 1'), self.n_phi)
                rotation_angle = acos(dot_rotation_angle / norm(self.n_phi))
                lines.append("   normal:")
                lines.append("      angle:".ljust(WIDTH) + "% 9.5f" % (rotation_angle * TODEG))
                lines.append("      axis:".ljust(WIDTH) + self._pretty_vector(rotation_axis))
 
        else:  # no ub calculated
            if self._n_phi_configured is not None:
                lines.append("   n_phi:".ljust(WIDTH) + self._pretty_vector(conv.transform(self._n_phi_configured, True)) + SET_LABEL)
            elif self._n_hkl_configured is not None:
                lines.append("   n_hkl:".ljust(WIDTH) + self._pretty_vector(self._n_hkl_configured) + SET_LABEL)

        return lines