# -*- coding: utf-8 -*-
## Demonstration of Link with multiple outputs: Combined-Heat-and-Power (CHP) with fixed heat-power ratio
#
# For a CHP with a more complicated heat-power feasible operational area, see https://pypsa.readthedocs.io/en/latest/examples/power-to-gas-boiler-chp.html.
#
# This example demonstrates a Link component with more than one bus output ("bus2" in this case). In general links can have many output buses.
#
# In this example a CHP must be heat-following because there is no other supply of heat to the bus "Frankfurt heat".

import numpy as np

import pypsa

# First tell PyPSA that links will have a 2nd bus by
# overriding the component_attrs. This can be done for
# as many buses as you need with format busi for i = 2, 3, 4, 5, ....

override_component_attrs = pypsa.descriptors.Dict(
    {k: v.copy() for k, v in pypsa.components.component_attrs.items()}
)
override_component_attrs["Link"].loc["bus2"] = [
    "string",
    np.nan,
    np.nan,
    "2nd bus",
    "Input (optional)",
]
override_component_attrs["Link"].loc["efficiency2"] = [
    "static or series",
    "per unit",
    1.0,
    "2nd bus efficiency",
    "Input (optional)",
]
override_component_attrs["Link"].loc["p2"] = [
    "series",
    "MW",
    0.0,
    "2nd bus output",
    "Output",
]


network = pypsa.Network(override_component_attrs=override_component_attrs)

network.add("Bus", "Frankfurt", carrier="AC")

network.add("Load", "Frankfurt", bus="Frankfurt", p_set=5)

network.add("Bus", "Frankfurt heat", carrier="heat")

network.add("Load", "Frankfurt heat", bus="Frankfurt heat", p_set=3)

network.add("Bus", "Frankfurt gas", carrier="gas")

network.add("Store", "Frankfurt gas", e_initial=1e6, e_nom=1e6, bus="Frankfurt gas")

network.add(
    "Link",
    "OCGT",
    bus0="Frankfurt gas",
    bus1="Frankfurt",
    p_nom_extendable=True,
    capital_cost=600,
    efficiency=0.4,
)


network.add(
    "Link",
    "CHP",
    bus0="Frankfurt gas",
    bus1="Frankfurt",
    bus2="Frankfurt heat",
    p_nom_extendable=True,
    capital_cost=1400,
    efficiency=0.3,
    efficiency2=0.3,
)

network.lopf()

network.loads_t.p

network.links_t.p0

network.links_t.p1

network.links_t.p2