"""
Composition Unit Conversions
=============================

The same stellar composition viewed in different unit systems. ``stellar_geology`` supports wt%, mol%, and mole fraction representations.
"""

# %%
# Start with a star slightly enriched in iron.

import matplotlib.pyplot as plt
import stellar_geology as sg

star = sg.Star(
    stellar_dex={"Fe": 0.15, "Mg": 0.05, "Si": -0.02},
    name="HD 10700",
)

# %%
# Weight percent oxides
# ---------------------
# The most common representation in geochemistry.

wtpt = star.get_composition(units="wtpt_oxides")

# %%
# Mole fraction oxides
# --------------------
# Useful for thermodynamic calculations.

molfrac = star.get_composition(units="molfrac_oxides")

# %%
# Mole fraction on a single-oxygen basis
# ---------------------------------------
# Common in mineral physics and mantle geochemistry.

single_o = star.get_composition(units="molfrac_singleO")

# %%
# Compare all three unit systems
# ------------------------------
# The same composition looks quite different depending on the unit system. Weight percent emphasizes heavy oxides (FeO, SiO2), while mole fraction emphasizes the most abundant molecules.

fig, axes = plt.subplots(1, 3, figsize=(12, 4))

axes[0].bar(list(wtpt.keys()), list(wtpt.values()), color="#5e4fa2")
axes[0].set_title("wt% oxides")
axes[0].set_ylabel("wt%")
axes[0].tick_params(axis="x", rotation=45)

axes[1].bar(list(molfrac.keys()), list(molfrac.values()), color="#3288bd")
axes[1].set_title("Mole fraction oxides")
axes[1].set_ylabel("Mole fraction")
axes[1].tick_params(axis="x", rotation=45)

# Single-O basis uses element names (Si, Fe, Mg) rather than oxide formulas
axes[2].bar(list(single_o.keys()), list(single_o.values()), color="#66c2a5")
axes[2].set_title("Mole frac. (single-O)")
axes[2].set_ylabel("Mole fraction")
axes[2].tick_params(axis="x", rotation=45)

fig.suptitle(f"{star.name} — Three unit systems", fontweight="bold")
fig.tight_layout()
plt.show()