import matplotlib
matplotlib.use("Agg")

from flask import Blueprint, render_template, session, redirect, url_for
import matplotlib.pyplot as plt
import io
import base64

dashboard_bp = Blueprint("dashboard", __name__, url_prefix="/dashboard")

# charts 
def plot_to_base64():
    img = io.BytesIO()
    plt.savefig(img, format="png", bbox_inches="tight")
    plt.close()
    img.seek(0)
    return base64.b64encode(img.getvalue()).decode()

# bar chart
def bar_chart():
    categories = ["Trench", "Manhole", "Pipe Laying", "Restoration"]
    values = [120, 80, 150, 60]

    plt.figure()
    plt.bar(categories, values)
    plt.title("Work Category Report")
    plt.xlabel("Category")
    plt.ylabel("Count")


    return plot_to_base64()

# Pie chart
def pie_chart():
    labels = ["Completed", "In Progress", "Pending"]
    sizes = [55, 20, 25]

    plt.figure()
    plt.pie(sizes, labels=labels, autopct="%1.1f%%", startangle=140)
    plt.title("Project Status")

    return plot_to_base64()

# Histogram chart
def histogram_chart():
    daily_work = [5, 10, 15, 20, 20, 25, 30, 35, 40, 45, 50]

    plt.figure()
    plt.hist(daily_work, bins=5)
    plt.title("Daily Work Distribution")
    plt.xlabel("Work Units")
    plt.ylabel("Frequency")

    return plot_to_base64()

# Dashboaed page
@dashboard_bp.route("/")
def dashboard():
    if not session.get("user_id"):
        return redirect(url_for("auth.login"))

    return render_template(
        "dashboard.html",
        title="Dashboard",
        bar_chart=bar_chart(),
        pie_chart=pie_chart(),
        histogram=histogram_chart()
    )