from __future__ import annotations

import plotly.graph_objects as go

from app.analysis.spc import SPCResult


def histogram(result: SPCResult) -> dict:
    """Distribution histogram with spec limits overlay."""
    fig = go.Figure()
    fig.add_trace(go.Histogram(x=result.values, name="Measurements", nbinsx=20))
    fig.add_vline(x=result.usl, line_dash="dash", line_color="red",
                  annotation_text="USL")
    fig.add_vline(x=result.lsl, line_dash="dash", line_color="red",
                  annotation_text="LSL")
    fig.add_vline(x=result.nominal, line_dash="dot", line_color="green",
                  annotation_text="Nominal")
    fig.update_layout(
        title=f"Distribution – {result.feature_name}",
        xaxis_title="Value", yaxis_title="Count",
        template="plotly_white", height=350,
    )
    return fig.to_plotly_json()


def control_chart(result: SPCResult) -> dict:
    """Individual values control chart (I-chart)."""
    x_axis = list(range(1, result.n + 1))
    fig = go.Figure()
    fig.add_trace(go.Scatter(
        x=x_axis, y=result.values, mode="lines+markers", name="Value",
    ))
    fig.add_hline(y=result.mean, line_color="green", annotation_text="Mean")
    fig.add_hline(y=result.ucl, line_dash="dash", line_color="red",
                  annotation_text="UCL")
    fig.add_hline(y=result.lcl, line_dash="dash", line_color="red",
                  annotation_text="LCL")
    fig.add_hline(y=result.usl, line_dash="dot", line_color="orange",
                  annotation_text="USL")
    fig.add_hline(y=result.lsl, line_dash="dot", line_color="orange",
                  annotation_text="LSL")
    fig.update_layout(
        title=f"Control Chart – {result.feature_name}",
        xaxis_title="Sample #", yaxis_title="Value",
        template="plotly_white", height=350,
    )
    return fig.to_plotly_json()


def capability_bar(results: list[SPCResult]) -> dict:
    """Capability index bar chart comparing all features."""
    names = [r.feature_name for r in results]
    cpk_vals = [r.cpk if r.cpk is not None else 0.0 for r in results]
    ppk_vals = [r.ppk if r.ppk is not None else 0.0 for r in results]

    colors = ["#2ecc71" if v >= 1.33 else "#f39c12" if v >= 1.0 else "#e74c3c"
              for v in cpk_vals]

    fig = go.Figure()
    fig.add_trace(go.Bar(x=names, y=cpk_vals, name="Cpk", marker_color=colors))
    fig.add_trace(go.Bar(x=names, y=ppk_vals, name="Ppk", marker_color="rgba(52,152,219,0.6)"))
    fig.add_hline(y=1.33, line_dash="dash", line_color="green",
                  annotation_text="Cpk=1.33")
    fig.add_hline(y=1.0, line_dash="dot", line_color="orange",
                  annotation_text="Cpk=1.0")
    fig.update_layout(
        title="Process Capability Summary",
        xaxis_title="Feature", yaxis_title="Index",
        barmode="group", template="plotly_white", height=400,
    )
    return fig.to_plotly_json()


def generate_charts(results: list[SPCResult]) -> dict:
    """Generate all charts for a set of SPC results."""
    charts: dict[str, list[dict] | dict] = {
        "histograms": [],
        "control_charts": [],
    }
    for r in results:
        if r.n >= 2:
            charts["histograms"].append(histogram(r))
            charts["control_charts"].append(control_chart(r))
    if results:
        charts["capability_bar"] = capability_bar(results)
    return charts