from flask import Flask, render_template, request, redirect, url_for, session
import qrcode
from PIL import Image
import os
import pandas as pd
import requests
from io import StringIO
from urllib.parse import quote

app = Flask(__name__)
app.secret_key = "supersecretkey"

# ==============================
# Login Credentials
# ==============================
USERNAME = "admin"
PASSWORD = "123456"

# ==============================
# Folder Setup
# ==============================
UPLOAD_FOLDER = "static/generated"
os.makedirs(UPLOAD_FOLDER, exist_ok=True)

# ==============================
# Google Sheet Configuration
# ==============================
SHEET_ID = "1F90Q1scHpX4U_OIBDA_yZF3BozUGfJtl-1XucV4XBCM"
GID = "0"

GOOGLE_SHEET_CSV = f"https://docs.google.com/spreadsheets/d/{SHEET_ID}/gviz/tq?tqx=out:csv&gid={GID}"


def fetch_sheet():
    try:
        response = requests.get(GOOGLE_SHEET_CSV)

        if response.status_code != 200:
            return None

        df = pd.read_csv(StringIO(response.text))
        df.columns = df.columns.str.strip().str.lower()

        if "asset id" not in df.columns:
            return None

        df.rename(columns={"asset id": "Asset ID"}, inplace=True)
        return df

    except:
        return None


# ==============================
# Home Page
# ==============================
@app.route("/")
def home():
    return render_template("index.html")


# ==============================
# Login Page
# ==============================
@app.route("/login", methods=["GET", "POST"])
def login():

    if request.method == "POST":
        username = request.form.get("username")
        password = request.form.get("password")
        asset_id = request.form.get("asset_id")

        if username == USERNAME and password == PASSWORD:
            session["logged_in"] = True
            return redirect(url_for("show_asset", asset_id=asset_id))

        return render_template("login.html", error="Invalid Credentials", asset_id=asset_id)

    asset_id = request.args.get("asset_id")
    return render_template("login.html", asset_id=asset_id)


# ==============================
# Generate QR
# ==============================
@app.route("/generate", methods=["POST"])
def generate_qr():

    asset_id = request.form.get("data").strip()
    fill_color = request.form.get("fill_color")
    back_color = request.form.get("back_color")
    size = int(request.form.get("size"))
    logo = request.files.get("logo")

    df = fetch_sheet()
    if df is None:
        return render_template("index.html", error="Sheet Error")

    df["Asset ID"] = df["Asset ID"].astype(str).str.strip()
    result = df[df["Asset ID"].str.lower() == asset_id.lower()]

    if result.empty:
        return render_template("index.html", error="Asset Not Found")

    row = result.iloc[0]

    asset_url = request.url_root + "login?asset_id=" + quote(asset_id)

    qr = qrcode.QRCode(
        error_correction=qrcode.constants.ERROR_CORRECT_H,
        box_size=size,
        border=4,
    )

    qr.add_data(asset_url)
    qr.make(fit=True)

    img = qr.make_image(fill_color=fill_color, back_color=back_color).convert("RGB")

    # ==============================
    # Center Logo (Uploaded OR Default)
    # ==============================
    try:
        if logo and logo.filename != "":
            logo_img = Image.open(logo)
        else:
            logo_img = Image.open("static/default_logo.png")

        qr_width, qr_height = img.size

        logo_size = qr_width // 4
        logo_img = logo_img.resize((logo_size, logo_size))

        pos = (
            (qr_width - logo_size) // 2,
            (qr_height - logo_size) // 2
        )

        img.paste(logo_img, pos)

    except:
        pass

    qr_path = os.path.join(UPLOAD_FOLDER, "qr.png")
    img.save(qr_path)

    asset_info = {
        "Asset ID": row.get("Asset ID", ""),
        "Asset Type": row.get("asset type", ""),
        "Asset Name": row.get("asset name", ""),
        "Allotted To": row.get("allotted to", ""),
        "Department": row.get("department", ""),
        "Room Number": row.get("room number", ""),
    }

    return render_template(
        "index.html",
        qr_image="generated/qr.png",
        asset=asset_info
    )


# ==============================
# Asset Details Page
# ==============================
@app.route("/asset/<path:asset_id>")
def show_asset(asset_id):

    if not session.get("logged_in"):
        return redirect(url_for("login", asset_id=asset_id))

    df = fetch_sheet()
    if df is None:
        return "Sheet Error"

    df["Asset ID"] = df["Asset ID"].astype(str).str.strip()
    result = df[df["Asset ID"].str.lower() == asset_id.lower()]

    if result.empty:
        return "Asset Not Found"

    row = result.iloc[0]

    asset_info = {
        "Asset ID": row.get("Asset ID", ""),
        "Asset Type": row.get("asset type", ""),
        "Asset Name": row.get("asset name", ""),
        "Allotted To": row.get("allotted to", ""),
        "Department": row.get("department", ""),
        "Room Number": row.get("room number", ""),
    }

    return render_template("asset_card.html", asset=asset_info)


# ==============================
# Logout
# ==============================
@app.route("/logout")
def logout():
    session.clear()
    return redirect("/")


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