#!/usr/bin/env python

from __future__ import print_function

from sympy import symbols, sin, cos
from sympy.galgebra import xdvi, Get_Program, Print_Function
from sympy.galgebra import MV, Format


def Maxwells_Equations_in_Geometric_Calculus():
    Print_Function()
    X = symbols('t x y z')
    (g0, g1, g2, g3, grad) = MV.setup('gamma*t|x|y|z', metric='[1,-1,-1,-1]', coords=X)
    I = MV.I

    B = MV('B', 'vector', fct=True)
    E = MV('E', 'vector', fct=True)
    B.set_coef(1, 0, 0)
    E.set_coef(1, 0, 0)
    B *= g0
    E *= g0
    J = MV('J', 'vector', fct=True)
    F = E + I*B

    print(r'\text{Pseudo Scalar\;\;}I =', I)
    print('\\text{Magnetic Field Bi-Vector\\;\\;} B = \\bm{B\\gamma_{t}} =', B)
    print('\\text{Electric Field Bi-Vector\\;\\;} E = \\bm{E\\gamma_{t}} =', E)
    print('\\text{Electromagnetic Field Bi-Vector\\;\\;} F = E+IB =', F)
    print('%\\text{Four Current Density\\;\\;} J =', J)
    gradF = grad*F
    print('#Geometric Derivative of Electomagnetic Field Bi-Vector')
    gradF.Fmt(3, 'grad*F')

    print('#Maxwell Equations')
    print('grad*F = J')
    print('#Div $E$ and Curl $H$ Equations')
    (gradF.grade(1) - J).Fmt(3, '%\\grade{\\nabla F}_{1} -J = 0')
    print('#Curl $E$ and Div $B$ equations')
    (gradF.grade(3)).Fmt(3, '%\\grade{\\nabla F}_{3} = 0')
    return


def Dirac_Equation_in_Geometric_Calculus():
    Print_Function()
    vars = symbols('t x y z')
    (g0, g1, g2, g3, grad) = MV.setup('gamma*t|x|y|z', metric='[1,-1,-1,-1]', coords=vars)
    I = MV.I

    (m, e) = symbols('m e')

    psi = MV('psi', 'spinor', fct=True)
    A = MV('A', 'vector', fct=True)
    sig_z = g3*g0

    print('\\text{4-Vector Potential\\;\\;}\\bm{A} =', A)
    print('\\text{8-component real spinor\\;\\;}\\bm{\\psi} =', psi)

    dirac_eq = (grad*psi)*I*sig_z - e*A*psi - m*psi*g0
    dirac_eq.simplify()

    dirac_eq.Fmt(3, r'%\text{Dirac Equation\;\;}\nabla \bm{\psi} I \sigma_{z}-e\bm{A}\bm{\psi}-m\bm{\psi}\gamma_{t} = 0')

    return


def Lorentz_Tranformation_in_Geometric_Algebra():
    Print_Function()
    (alpha, beta, gamma) = symbols('alpha beta gamma')
    (x, t, xp, tp) = symbols("x t x' t'")
    (g0, g1) = MV.setup('gamma*t|x', metric='[1,-1]')

    from sympy import sinh, cosh

    R = cosh(alpha/2) + sinh(alpha/2)*(g0 ^ g1)
    X = t*g0 + x*g1
    Xp = tp*g0 + xp*g1
    print('R =', R)

    print(r"#%t\bm{\gamma_{t}}+x\bm{\gamma_{x}} = t'\bm{\gamma'_{t}}+x'\bm{\gamma'_{x}} = R\lp t'\bm{\gamma_{t}}+x'\bm{\gamma_{x}}\rp R^{\dagger}")

    Xpp = R*Xp*R.rev()
    Xpp = Xpp.collect([xp, tp])
    Xpp = Xpp.subs({2*sinh(alpha/2)*cosh(alpha/2): sinh(alpha), sinh(alpha/2)**2 + cosh(alpha/2)**2: cosh(alpha)})
    print(r"%t\bm{\gamma_{t}}+x\bm{\gamma_{x}} =", Xpp)
    Xpp = Xpp.subs({sinh(alpha): gamma*beta, cosh(alpha): gamma})

    print(r'%\f{\sinh}{\alpha} = \gamma\beta')
    print(r'%\f{\cosh}{\alpha} = \gamma')

    print(r"%t\bm{\gamma_{t}}+x\bm{\gamma_{x}} =", Xpp.collect(gamma))
    return


def dummy():
    return


def main():
    Get_Program()
    Format()

    Maxwells_Equations_in_Geometric_Calculus()
    Dirac_Equation_in_Geometric_Calculus()
    Lorentz_Tranformation_in_Geometric_Algebra()

    xdvi()
    return

if __name__ == "__main__":
    main()
