import streamlit as st
import pandas as pd
import altair as alt
from vega_datasets import data
import us




# -------------------------------------------------
# PAGE CONFIG + TITLE
# -------------------------------------------------
st.set_page_config(page_title="University Donor Dashboard", layout="wide")
st.title("University Donor Dashboard")
alt.data_transformers.enable("default", max_rows=None)

# -------------------------------------------------
# DATA
# -------------------------------------------------
@st.cache_data
def load_data():
    df = pd.read_csv("university-donations.csv")
    df["Gift Date"] = pd.to_datetime(
        df["Gift Date"],
        format="%m/%d/%y",
        errors="coerce"
    )
    df["Year"]      = df["Gift Date"].dt.year.astype("Int64")
    df["YearMonth"] = df["Gift Date"].dt.to_period("M").astype(str)

    # 2-letter state → FIPS
    state_id = {s.abbr: int(s.fips) for s in us.states.STATES}
    df["state_fips"] = df["State"].map(state_id)
    return df

df = load_data()
st.write("Loaded rows:", len(df))   # quick sanity check

# -------------------------------------------------
# SIDEBAR FILTERS
# -------------------------------------------------
st.sidebar.header("Filters")
col_opts = ["All"] + sorted(df["College"].dropna().unique())
mot_opts = ["All"] + sorted(df["Gift Allocation"].dropna().unique())

col_pick = st.sidebar.selectbox("College", col_opts, index=0)
mot_pick = st.sidebar.selectbox("Motivation (Gift Allocation)", mot_opts, index=0)

st.sidebar.write(f"Selected College: {col_pick}")
st.sidebar.write(f"Selected Motivation: {mot_pick}")

mask = pd.Series(True, index=df.index)
if col_pick != "All":
    mask &= df["College"] == col_pick
if mot_pick != "All":
    mask &= df["Gift Allocation"] == mot_pick
df_filt = df[mask]

# Check if the filtered dataframe is empty
if df_filt.empty:
    st.warning("No data matches the selected filters.")
else:
    # -------------------------------------------------
    # SELECTIONS (empty="all" to show all data initially)
    # -------------------------------------------------
    state_select = alt.selection_point(fields=["state_fips"], toggle=False, empty="all")
    brush = alt.selection_interval(encodings=["x"], empty="all")
    subcategory_select = alt.selection_point(
        fields=["Allocation Subcategory"],
        toggle="event.shiftKey",
        empty="all"
    )

    # -------------------------------------------------
    # CHOROPLETH MAP
    # -------------------------------------------------

    state_totals = (
        df_filt.groupby("state_fips", as_index=False)
               .agg(Gift_Amount_sum=("Gift Amount", "sum"),
                    Gift_Count=("Gift Amount", "count"))
    )


    states = alt.topo_feature(data.us_10m.url, "states")
    map_chart = (
        alt.Chart(states)
        .mark_geoshape(stroke="white", strokeWidth=0.5)
        .encode(
            color=alt.condition(
                state_select,
                alt.Color("Gift_Amount_sum:Q",
                          scale=alt.Scale(scheme="blues"),
                          title="Total Gifts ($)"),
                alt.value("lightgray")
            ),
            tooltip=[
                alt.Tooltip("Gift_Amount_sum:Q", title="Total Gifts ($)", format=",.0f"),
                alt.Tooltip("Gift_Count:Q",       title="# Gifts")
            ]
        )
        .transform_lookup(
            lookup="id",
            from_=alt.LookupData(state_totals,
                                 key="state_fips",
                                 fields=["Gift_Amount_sum", "Gift_Count"])
        )
        .add_params(state_select)
        .project(type="albersUsa")
        .properties(width=380, height=250)
    )

    # -------------------------------------------------
    # LINE – GIFTS BY YEAR
    # -------------------------------------------------
    line_chart = (
        alt.Chart(df_filt)
        .transform_filter(state_select)
        .mark_line(point=True)
        .encode(
            x=alt.X("Year:O", sort="ascending"),
            y=alt.Y("sum(Gift Amount):Q", title="Total Gifts ($)"),
            tooltip=[
                alt.Tooltip("Year:O", title="Year"),
                alt.Tooltip("sum(Gift Amount):Q", title="Total Gifts ($)", format=",.0f")
            ]
        )
        .add_params(state_select, brush)
        .properties(width=380, height=250)
    )

    # -------------------------------------------------
    # BAR – TOTAL BY COLLEGE
    # -------------------------------------------------
    bar_college = (
        alt.Chart(df_filt)
        .transform_filter(state_select)
        .mark_bar()
        .encode(
            y=alt.Y("College:N", sort="-x", title="College"),
            x=alt.X("sum(Gift Amount):Q", title="Total Gifts ($)"),
            tooltip=[
                alt.Tooltip("College:N", title="College"),
                alt.Tooltip("sum(Gift Amount):Q", title="Total Gifts ($)", format=",.0f")
            ]
        )
        .add_params(state_select)
        .properties(width=380, height=400)
    )

    # -------------------------------------------------
    # BAR – TOTAL BY SUB-CATEGORY
    # -------------------------------------------------
    bar_sub = (
        alt.Chart(df_filt)
        .transform_filter(state_select)
        .transform_filter(brush)
        .mark_bar()
        .encode(
            y=alt.Y("Allocation Subcategory:N", sort="-x", title="Allocation Sub-category"),
            x=alt.X("sum(Gift Amount):Q", title="Total Gifts ($)"),
            color=alt.condition(subcategory_select, alt.value("#1f77b4"), alt.value("lightgray")),
            tooltip=[
                alt.Tooltip("Allocation Subcategory:N", title="Sub-category"),
                alt.Tooltip("sum(Gift Amount):Q", title="Total Gifts ($)", format=",.0f")
            ]
        )
        .add_params(state_select, brush, subcategory_select)
        .properties(width=380, height=400)
    )

    # -------------------------------------------------
    # LAYOUT
    # -------------------------------------------------
    upper = alt.hconcat(map_chart, line_chart).resolve_scale(color="independent")
    lower = alt.hconcat(bar_college, bar_sub)
    st.altair_chart(alt.vconcat(upper, lower), use_container_width=True)