"""Page 3: Staffing & Enrollment."""

import duckdb
from dash import html, dcc
import plotly.graph_objects as go

from admin_analytics.dashboard.queries import (
    query_staff_composition,
    query_student_staff_ratios,
    query_growth_index,
)

_NO_DATA = html.Div(
    "No IPEDS staff data loaded. Run: admin-analytics ingest ipeds",
    style={"textAlign": "center", "padding": "40px", "color": "#888"},
)


def layout(conn: duckdb.DuckDBPyConnection):
    staff_df = query_staff_composition(conn)
    if staff_df.height == 0:
        return _NO_DATA

    staff_pd = staff_df.to_pandas()

    # Staff composition stacked area
    comp_fig = go.Figure()
    for col, label, color in [
        ("faculty_total", "Faculty", "#00539F"),
        ("management_total", "Management", "#E07A5F"),
        ("other_staff", "Other Staff", "#7FB069"),
    ]:
        comp_fig.add_trace(go.Scatter(
            x=staff_pd["year"], y=staff_pd[col],
            mode="lines", name=label,
            stackgroup="one",
            line={"color": color},
        ))
    comp_fig.update_layout(
        title="Staff Composition Over Time",
        xaxis_title="Year", yaxis_title="Headcount",
        template="plotly_white", height=420,
    )

    # Student-to-staff ratios
    ratio_df = query_student_staff_ratios(conn)
    ratio_fig = go.Figure()
    if ratio_df.height > 0:
        ratio_pd = ratio_df.to_pandas()
        ratio_fig.add_trace(go.Scatter(
            x=ratio_pd["year"], y=ratio_pd["students_per_staff"],
            mode="lines+markers", name="Students per Staff",
            line={"color": "#00539F"},
        ))
        ratio_fig.add_trace(go.Scatter(
            x=ratio_pd["year"], y=ratio_pd["students_per_faculty"],
            mode="lines+markers", name="Students per Faculty",
            line={"color": "#FFD200"},
        ))
    ratio_fig.update_layout(
        title="Student-to-Staff Ratios",
        xaxis_title="Year", yaxis_title="Ratio",
        template="plotly_white", height=380,
    )

    # Growth index
    growth_df = query_growth_index(conn)
    growth_fig = go.Figure()
    if growth_df.height > 0:
        growth_pd = growth_df.to_pandas()
        growth_fig.add_trace(go.Scatter(
            x=growth_pd["year"], y=growth_pd["mgmt_index"],
            mode="lines+markers", name="Management Growth",
            line={"color": "#E07A5F"},
        ))
        growth_fig.add_trace(go.Scatter(
            x=growth_pd["year"], y=growth_pd["enrollment_index"],
            mode="lines+markers", name="Enrollment Growth",
            line={"color": "#00539F"},
        ))
        growth_fig.add_hline(y=100, line_dash="dot", line_color="#ccc")
    growth_fig.update_layout(
        title="Management vs Enrollment Growth (Indexed, Base Year = 100)",
        xaxis_title="Year", yaxis_title="Index",
        template="plotly_white", height=380,
    )

    return html.Div([
        dcc.Graph(figure=comp_fig),
        html.Div(
            [
                html.Div(dcc.Graph(figure=ratio_fig), style={"flex": "1"}),
                html.Div(dcc.Graph(figure=growth_fig), style={"flex": "1"}),
            ],
            style={"display": "flex", "gap": "16px"},
        ),
    ])