# Copyright 2020, Brigham Young University-Idaho. All rights reserved.

from chemistry import make_periodic_table, compute_molar_mass
from formula import parse_formula, FormulaError
from pytest import approx
import pytest


# These are the indexes of the
# elements in the periodic table.
NAME_INDEX = 0
ATOMIC_MASS_INDEX = 1


def test_make_periodic_table():
    """Verify that the make_periodic_table function works correctly.
    Parameters: none
    Return: nothing
    """
    # Call the make_periodic_table function and store the returned
    # dictionary in a variable named periodic_table_dict.
    periodic_table_dict = make_periodic_table()

    # Verify that the make_periodic_table function returns a dictionary.
    assert isinstance(periodic_table_dict, dict), \
        "make_periodic_table function must return a dictionary: " \
        f" expected a dictionary but found a {type(periodic_table_dict)}"

    # Check each item in the periodic table dictionary.
    check_element(periodic_table_dict, "Ac", ["Actinium", 227])
    check_element(periodic_table_dict, "Ag", ["Silver", 107.8682])
    check_element(periodic_table_dict, "Al", ["Aluminum", 26.9815386])
    check_element(periodic_table_dict, "Ar", ["Argon", 39.948])
    check_element(periodic_table_dict, "As", ["Arsenic", 74.9216])
    check_element(periodic_table_dict, "At", ["Astatine", 210])
    check_element(periodic_table_dict, "Au", ["Gold", 196.966569])
    check_element(periodic_table_dict, "B", ["Boron", 10.811])
    check_element(periodic_table_dict, "Ba", ["Barium", 137.327])
    check_element(periodic_table_dict, "Be", ["Beryllium", 9.012182])
    check_element(periodic_table_dict, "Bi", ["Bismuth", 208.9804])
    check_element(periodic_table_dict, "Br", ["Bromine", 79.904])
    check_element(periodic_table_dict, "C", ["Carbon", 12.0107])
    check_element(periodic_table_dict, "Ca", ["Calcium", 40.078])
    check_element(periodic_table_dict, "Cd", ["Cadmium", 112.411])
    check_element(periodic_table_dict, "Ce", ["Cerium", 140.116])
    check_element(periodic_table_dict, "Cl", ["Chlorine", 35.453])
    check_element(periodic_table_dict, "Co", ["Cobalt", 58.933195])
    check_element(periodic_table_dict, "Cr", ["Chromium", 51.9961])
    check_element(periodic_table_dict, "Cs", ["Cesium", 132.9054519])
    check_element(periodic_table_dict, "Cu", ["Copper", 63.546])
    check_element(periodic_table_dict, "Dy", ["Dysprosium", 162.5])
    check_element(periodic_table_dict, "Er", ["Erbium", 167.259])
    check_element(periodic_table_dict, "Eu", ["Europium", 151.964])
    check_element(periodic_table_dict, "F", ["Fluorine", 18.9984032])
    check_element(periodic_table_dict, "Fe", ["Iron", 55.845])
    check_element(periodic_table_dict, "Fr", ["Francium", 223])
    check_element(periodic_table_dict, "Ga", ["Gallium", 69.723])
    check_element(periodic_table_dict, "Gd", ["Gadolinium", 157.25])
    check_element(periodic_table_dict, "Ge", ["Germanium", 72.64])
    check_element(periodic_table_dict, "H", ["Hydrogen", 1.00794])
    check_element(periodic_table_dict, "He", ["Helium", 4.002602])
    check_element(periodic_table_dict, "Hf", ["Hafnium", 178.49])
    check_element(periodic_table_dict, "Hg", ["Mercury", 200.59])
    check_element(periodic_table_dict, "Ho", ["Holmium", 164.93032])
    check_element(periodic_table_dict, "I", ["Iodine", 126.90447])
    check_element(periodic_table_dict, "In", ["Indium", 114.818])
    check_element(periodic_table_dict, "Ir", ["Iridium", 192.217])
    check_element(periodic_table_dict, "K", ["Potassium", 39.0983])
    check_element(periodic_table_dict, "Kr", ["Krypton", 83.798])
    check_element(periodic_table_dict, "La", ["Lanthanum", 138.90547])
    check_element(periodic_table_dict, "Li", ["Lithium", 6.941])
    check_element(periodic_table_dict, "Lu", ["Lutetium", 174.9668])
    check_element(periodic_table_dict, "Mg", ["Magnesium", 24.305])
    check_element(periodic_table_dict, "Mn", ["Manganese", 54.938045])
    check_element(periodic_table_dict, "Mo", ["Molybdenum", 95.96])
    check_element(periodic_table_dict, "N", ["Nitrogen", 14.0067])
    check_element(periodic_table_dict, "Na", ["Sodium", 22.98976928])
    check_element(periodic_table_dict, "Nb", ["Niobium", 92.90638])
    check_element(periodic_table_dict, "Nd", ["Neodymium", 144.242])
    check_element(periodic_table_dict, "Ne", ["Neon", 20.1797])
    check_element(periodic_table_dict, "Ni", ["Nickel", 58.6934])
    check_element(periodic_table_dict, "Np", ["Neptunium", 237])
    check_element(periodic_table_dict, "O", ["Oxygen", 15.9994])
    check_element(periodic_table_dict, "Os", ["Osmium", 190.23])
    check_element(periodic_table_dict, "P", ["Phosphorus", 30.973762])
    check_element(periodic_table_dict, "Pa", ["Protactinium", 231.03588])
    check_element(periodic_table_dict, "Pb", ["Lead", 207.2])
    check_element(periodic_table_dict, "Pd", ["Palladium", 106.42])
    check_element(periodic_table_dict, "Pm", ["Promethium", 145])
    check_element(periodic_table_dict, "Po", ["Polonium", 209])
    check_element(periodic_table_dict, "Pr", ["Praseodymium", 140.90765])
    check_element(periodic_table_dict, "Pt", ["Platinum", 195.084])
    check_element(periodic_table_dict, "Pu", ["Plutonium", 244])
    check_element(periodic_table_dict, "Ra", ["Radium", 226])
    check_element(periodic_table_dict, "Rb", ["Rubidium", 85.4678])
    check_element(periodic_table_dict, "Re", ["Rhenium", 186.207])
    check_element(periodic_table_dict, "Rh", ["Rhodium", 102.9055])
    check_element(periodic_table_dict, "Rn", ["Radon", 222])
    check_element(periodic_table_dict, "Ru", ["Ruthenium", 101.07])
    check_element(periodic_table_dict, "S", ["Sulfur", 32.065])
    check_element(periodic_table_dict, "Sb", ["Antimony", 121.76])
    check_element(periodic_table_dict, "Sc", ["Scandium", 44.955912])
    check_element(periodic_table_dict, "Se", ["Selenium", 78.96])
    check_element(periodic_table_dict, "Si", ["Silicon", 28.0855])
    check_element(periodic_table_dict, "Sm", ["Samarium", 150.36])
    check_element(periodic_table_dict, "Sn", ["Tin", 118.71])
    check_element(periodic_table_dict, "Sr", ["Strontium", 87.62])
    check_element(periodic_table_dict, "Ta", ["Tantalum", 180.94788])
    check_element(periodic_table_dict, "Tb", ["Terbium", 158.92535])
    check_element(periodic_table_dict, "Tc", ["Technetium", 98])
    check_element(periodic_table_dict, "Te", ["Tellurium", 127.6])
    check_element(periodic_table_dict, "Th", ["Thorium", 232.03806])
    check_element(periodic_table_dict, "Ti", ["Titanium", 47.867])
    check_element(periodic_table_dict, "Tl", ["Thallium", 204.3833])
    check_element(periodic_table_dict, "Tm", ["Thulium", 168.93421])
    check_element(periodic_table_dict, "U", ["Uranium", 238.02891])
    check_element(periodic_table_dict, "V", ["Vanadium", 50.9415])
    check_element(periodic_table_dict, "W", ["Tungsten", 183.84])
    check_element(periodic_table_dict, "Xe", ["Xenon", 131.293])
    check_element(periodic_table_dict, "Y", ["Yttrium", 88.90585])
    check_element(periodic_table_dict, "Yb", ["Ytterbium", 173.054])
    check_element(periodic_table_dict, "Zn", ["Zinc", 65.38])
    check_element(periodic_table_dict, "Zr", ["Zirconium", 91.224])


def check_element(periodic_table_dict, symbol, expected):
    """Verify that the actual element that came from the
    periodic_table_dict contains the same values as the
    expected element.

    Parameters
        symbol: a symbol for a chemical element
        expected: a list that contains the expected values for symbol
    Return: nothing
    """
    # Verify that symbol is in the periodic table dictionary.
    assert symbol in periodic_table_dict, \
        f'"{symbol}" is missing from the periodic table dictionary.'
    actual = periodic_table_dict[symbol]

    # Verify that the element's name is correct.
    act_name = actual[NAME_INDEX]
    exp_name = expected[NAME_INDEX]
    assert act_name == exp_name, \
            f'wrong name for "{symbol}": ' \
            f'expected {exp_name} but found {act_name}'

    # Verify that the element's atomic mass is correct.
    act_mass = actual[ATOMIC_MASS_INDEX]
    exp_mass = expected[ATOMIC_MASS_INDEX]
    assert act_mass == approx(exp_mass), \
            f"wrong atomic mass for {exp_name}: " \
            f"expected {exp_mass} but found {act_mass}"


def test_parse_formula():
    """Verify that the parse_formula function works correctly.

    Parameters: none
    Return: nothing
    """
    # Call the make_periodic_table function
    # and verify that it returns a dictionary.
    periodic_table_dict = make_periodic_table()
    assert isinstance(periodic_table_dict, dict), \
        "make_periodic_table function must return a dictionary: " \
        f" expected a dictionary but found a {type(periodic_table_dict)}"

    # Call the parse_formula function and
    # verify that it returns a list.
    sym_quant_list = parse_formula("H2O", periodic_table_dict)
    assert isinstance(sym_quant_list, list), \
        "parse_formula function must return a list: " \
        f" expected a list but found a {type(sym_quant_list)}"

    # Call the compute_molar_mass function four times and
    # verify that it returns the correct number each time.
    assert parse_formula("H2O", periodic_table_dict) \
            == [("H",2), ("O",1)]
    assert parse_formula("C6H6", periodic_table_dict) \
            == [("C",6), ("H",6)]
    assert parse_formula("(C2(NaCl)4H2)2C4Na", periodic_table_dict) \
            == [("C",8), ("Na",9), ("Cl",8), ("H",4)]
    assert parse_formula("Co", periodic_table_dict) \
            == [("Co",1)]

    # Call the parse_formula function six times, each time
    # with a different invalid chemical formula. Verify that
    # parse_formula function raises an exception each time.
    with pytest.raises(FormulaError):
        parse_formula("L", periodic_table_dict)
    with pytest.raises(FormulaError):
        parse_formula("4H", periodic_table_dict)
    with pytest.raises(FormulaError):
        parse_formula("H2L4", periodic_table_dict)
    with pytest.raises(FormulaError):
        parse_formula("-H", periodic_table_dict)
    with pytest.raises(FormulaError):
        parse_formula("(H2O", periodic_table_dict)
    with pytest.raises(FormulaError):
        parse_formula("H2)O3", periodic_table_dict)


def test_compute_molar_mass():
    """Verify that the compute_molar_mass function works correctly.

    Parameters: none
    Return: nothing
    """
    # Call the make_periodic_table function
    # and verify that it returns a dictionary.
    periodic_table_dict = make_periodic_table()
    assert isinstance(periodic_table_dict, dict), \
        "make_periodic_table function must return a dictionary: " \
        f" expected a dictionary but found a {type(periodic_table_dict)}"

    # Call the compute_molar_mass function
    # and verify that it returns a number.
    molar_mass = compute_molar_mass([["O",2]], periodic_table_dict)
    assert isinstance(molar_mass, int) or isinstance(molar_mass, float), \
        "compute_molar_mass function must return a number: " \
        f" expected a number but found a {type(molar_mass)}"

    # Call the compute_molar_mass function four times and
    # verify that it returns the correct number each time.
    assert compute_molar_mass([], periodic_table_dict) == 0
    assert compute_molar_mass([["O",2]], periodic_table_dict) \
            == approx(31.9988)
    assert compute_molar_mass([["C",6],["H",6]], periodic_table_dict) \
            == approx(78.11184)
    assert compute_molar_mass([["C",13],["H",16],["N",2],["O",2]],
            periodic_table_dict) == approx(232.27834)


# Call the main function that is part of pytest so that the
# computer will execute the test functions in this file.
pytest.main(["-v", "--tb=line", "-rN", __file__])