import altair as alt
from vega_datasets import data

source = data.seattle_weather()

scale = alt.Scale(
    domain=["sun", "fog", "drizzle", "rain", "snow"],
    range=["#e7ba52", "#a7a7a7", "#aec7e8", "#1f77b4", "#9467bd"],
)
color = alt.Color("weather:N", scale=scale)

# We create two selections:
# - a brush that is active on the top panel
# - a multi-click that is active on the bottom panel
brush = alt.selection_interval(encodings=["x"])
click = alt.selection_point(encodings=["color"])

# Top panel is scatter plot of temperature vs time
points = (
    alt.Chart()
    .mark_point()
    .encode(
        alt.X("monthdate(date):T", title="Date"),
        alt.Y(
            "temp_max:Q",
            title="Maximum Daily Temperature (C)",
            scale=alt.Scale(domain=[-5, 40]),
        ),
        color=alt.condition(brush, color, alt.value("lightgray")),
        size=alt.Size("precipitation:Q", scale=alt.Scale(range=[5, 200])),
    )
    .properties(width=550, height=300)
    .add_params(brush)
    .transform_filter(click)
)

# Bottom panel is a bar chart of weather type
bars = (
    alt.Chart()
    .mark_bar()
    .encode(
        x="count()",
        y="weather:N",
        color=alt.condition(click, color, alt.value("lightgray")),
    )
    .transform_filter(brush)
    .properties(
        width=550,
    )
    .add_params(click)
)

alt.vconcat(points, bars, data=source, title="Seattle Weather: 2012-2015")
