from flask import Flask, render_template, request, send_file
import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
import io
import os

app = Flask(__name__)

@app.route("/", methods=["GET", "POST"])
def index():
    if request.method == "POST":
        golden_file = request.files.get("golden_file")
        test_file = request.files.get("test_file")

        if not golden_file or not test_file:
            return render_template("index.html", error="Please upload both files.")

        try:
            # --- Read Data ---
            limits_df1 = pd.read_excel(golden_file, nrows=4)
            df1 = pd.read_excel(golden_file)
            df1 = df1.drop([0, 1, 2, 3])
            df2 = pd.read_excel(test_file)
            df2 = df2.drop([0, 1, 2, 3])

            df1 = df1.apply(pd.to_numeric, errors="coerce")
            df2 = df2.apply(pd.to_numeric, errors="coerce")

            # --- Build Limits ---
            limits_df1 = limits_df1.drop([0])
            ignore_cols = ["SITE_NUM", "PART_ID", "PASSFG", "SOFT_BIN", "T_TIME", "TEST_NUM"]
            cols_to_plot = [col for col in limits_df1.columns if "_" in col and col not in ignore_cols]
            limits_df1 = limits_df1.drop(columns=ignore_cols)

            limits = {
                col: {"LL": limits_df1.iloc[0][col], "UL": limits_df1.iloc[1][col]}
                for col in limits_df1.columns
            }

            # --- Plot ---
            n_cols = 3
            n_rows = (len(cols_to_plot) + n_cols - 1) // n_cols

            plt.figure(figsize=(n_cols * 5, n_rows * 3.5))
            for i, col in enumerate(cols_to_plot, 1):
                plt.subplot(n_rows, n_cols, i)
                x1 = np.arange(1, len(df1[col]) + 1)
                y1 = pd.to_numeric(df1[col], errors="coerce").values
                plt.plot(x1, y1, marker="o", linestyle="-", color="blue", label="Golden")

                if col in df2.columns:
                    x2 = np.arange(1, len(df2[col]) + 1)
                    y2 = pd.to_numeric(df2[col], errors="coerce").values
                    plt.plot(x2, y2, marker="s", linestyle="--", color="red", label="Test")

                if col in limits:
                    ll, ul = limits[col]["LL"], limits[col]["UL"]
                    plt.axhline(ll, color="green", linestyle="--", linewidth=2, label="LL")
                    plt.axhline(ul, color="orange", linestyle="--", linewidth=2, label="UL")

                plt.title(f"{col}")
                plt.xlabel("Part # (sequence)")
                plt.ylabel("Value")
                plt.grid(True, linestyle="--", alpha=0.7)
                plt.legend(fontsize="small")

            plt.tight_layout()

            # Save plot to in-memory buffer
            buf = io.BytesIO()
            plt.savefig(buf, format="png", bbox_inches="tight")
            buf.seek(0)
            plt.close()

            return send_file(buf, mimetype="image/png")

        except Exception as e:
            return render_template("index.html", error=f"Error: {str(e)}")

    return render_template("index.html")
    

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=7860, debug=True)