"""
CASCADE – Flask app for HF Spaces
Mounted at /cascade_v1/
"""

import os
import json
import uuid

import redis
from flask import Flask, Blueprint, request, jsonify, render_template, send_file, abort, redirect, Response

from rdkit import Chem
from rdkit.Chem import AllChem
from rdkit.Chem.Draw import rdMolDraw2D

from NMR_Prediction.valid import validate_smiles

bp = Blueprint("cascade", __name__)

redis_client = redis.StrictRedis(
    host="localhost", port=6379, db=0, decode_responses=True
)

# ── Pages ─────────────────────────────────────────────────────────────────────
@bp.route("/")
@bp.route("")
@bp.route("/predict/")
@bp.route("/predict")
@bp.route("/home/")
@bp.route("/about/")
def predict():
    return render_template("cascade/predict.html")


# ── Job submission ────────────────────────────────────────────────────────────
def _submit_job(smiles, type_):
    if not validate_smiles(smiles):
        return jsonify({"message": "Invalid SMILES or molecule exceeds 50 heavy atoms", "task_id": None})
    task_id = uuid.uuid4().hex
    redis_client.set(f"task_detail_{task_id}",
                     json.dumps({"smiles": smiles, "type_": type_}))
    redis_client.rpush("task_queue", task_id)
    return task_id


@bp.route("/predict_NMR_C/", methods=["POST"])
def predict_NMR_C():
    result = _submit_job(request.form["smiles"], request.form["type_"])
    if not isinstance(result, str):
        return result
    return jsonify({"message": "Molecule submitted to C queue", "task_id": result})


@bp.route("/predict_NMR_H/", methods=["POST"])
def predict_NMR_H():
    result = _submit_job(request.form["smiles"], request.form["type_"])
    if not isinstance(result, str):
        return result
    return jsonify({"message": "Molecule submitted to H queue", "task_id": result})


# ── check_task ────────────────────────────────────────────────────────────────
@bp.route("/check_task/")
def check_task():
    raw = redis_client.get(f"task_result_{request.args['task_id']}")
    if not raw:
        return "running", 200
    result = json.loads(raw)
    if "errMessage" in result:
        return "Error1", 200
    return "done", 200


# ── get_result ────────────────────────────────────────────────────────────────
@bp.route("/get_result/")
def get_result():
    task_id = request.args["task_id"]
    raw = redis_client.get(f"task_result_{task_id}")
    if not raw:
        return jsonify({"error": "Result not found"}), 404

    result = json.loads(raw)
    if "errMessage" in result:
        return jsonify({"error": result["errMessage"]}), 500

    smiles  = result["smiles"]
    nucleus = result.get("type_", "C")

    weighted_shift_txt = result["weightedShiftTxt"]
    shift_map = {}
    for item in filter(None, weighted_shift_txt.split(";")):
        parts = item.split(",")
        if len(parts) == 2:
            shift_map[int(parts[0])] = parts[1]

    if nucleus == "H":
        mol = Chem.MolFromSmiles(smiles)
        mol = Chem.AddHs(mol)
        AllChem.Compute2DCoords(mol)
        mol_draw = rdMolDraw2D.PrepareMolForDrawing(mol, kekulize=True)
        n_label  = mol.GetNumAtoms()
        drawer   = rdMolDraw2D.MolDraw2DSVG(700, 500)
    else:
        mol = Chem.MolFromSmiles(smiles)
        AllChem.Compute2DCoords(mol)
        mol_draw = rdMolDraw2D.PrepareMolForDrawing(mol, kekulize=True)
        n_label  = mol.GetNumAtoms()
        drawer   = rdMolDraw2D.MolDraw2DSVG(600, 450)

    opts = drawer.drawOptions()
    for atom_1idx, shift_val in shift_map.items():
        atom_0idx = atom_1idx - 1
        if atom_0idx < n_label:
            opts.atomLabels[atom_0idx] = shift_val
    opts.clearBackground = False
    opts.bondLineWidth = 1
    opts.padding = 0.15
    opts.additionalAtomLabelPadding = 0.1

    drawer.DrawMolecule(mol_draw)
    drawer.FinishDrawing()
    svg = drawer.GetDrawingText().replace("svg:", "").replace(":svg", "")

    return jsonify({
        "svg": svg,
        "smiles": smiles,
        "nucleus": nucleus,
        "conf_sdfs": result.get("conf_sdfs", []),
        "weightedShift": weighted_shift_txt,
        "confShift": result["confShiftTxt"],
        "relative_E": result["relative_E"],
        "taskId": task_id,
    })


# ── Download as CSV ───────────────────────────────────────────────────────────
@bp.route("/download/<task_id>/")
def download(task_id):
    raw = redis_client.get(f"task_result_{task_id}")
    if not raw:
        abort(404)
    result = json.loads(raw)
    if "errMessage" in result:
        abort(404)

    nucleus = result.get("type_", "C")
    header = f"Atom Index,Predicted {'1H' if nucleus == 'H' else '13C'} Shift (ppm)"
    lines = [header]
    for item in filter(None, result["weightedShiftTxt"].split(";")):
        parts = item.split(",")
        if len(parts) == 2:
            lines.append(f"{parts[0]},{parts[1]}")

    return Response(
        "\n".join(lines),
        mimetype="text/csv",
        headers={"Content-Disposition": f"attachment; filename=cascade_{task_id[:8]}.csv"}
    )


def create_app():
    app = Flask(__name__, static_folder="static", template_folder="templates")
    app.register_blueprint(bp, url_prefix="/cascade_v1")

    @app.route("/")
    @app.route("/cascade_v1")
    def root():
        return '''<!DOCTYPE html>
<html>
<head>
<meta http-equiv="refresh" content="0; url=/cascade_v1/predict/">
<script>window.location.href="/cascade_v1/predict/";</script>
</head>
<body></body>
</html>'''

    @app.after_request
    def remove_iframe_restriction(response):
        response.headers.pop("X-Frame-Options", None)
        response.headers["Content-Security-Policy"] = "frame-ancestors *"
        return response

    return app

app = create_app()

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