from flask import (
    Flask,
    request,
    abort,
    Response
)
from flask_cors import cross_origin
import os
from uuid import uuid4
import subprocess
import shutil
import io
from werkzeug.wsgi import FileWrapper

app = Flask(__name__)


@app.route("/", methods=['POST'])
@cross_origin(expose_headers=["content-disposition"])
def upload_files():
    project_id = str(uuid4())

    main_file = get_and_save_file(request, "main-file", project_id)

    if main_file is False:
        abort(400)

    project_folder = f"/data/build/{project_id}"
    if not os.path.exists(project_folder):
        os.makedirs(project_folder)

    file_name = ".".join(main_file.split("/")[-1].split(".")[:-1])
    result_file_path = f"{project_folder}/{file_name}.stl"

    command = [
        "openscad",
        "-o", result_file_path
    ]

    param_file = get_and_save_file(request, "param-file", project_id)

    if param_file is not False:
        command.extend(["-p", param_file])

    keys = list(request.files.keys())
    keys.remove("main-file")

    try:
        keys.remove("param-file")
    except ValueError:
        print("List does not contain value")

    # Add other files
    for key in keys:
        get_and_save_file(request, key, project_id)

    # Add main file at the end of the command and run it!
    command.append(main_file)
    subprocess.run(command, cwd=project_folder)

    # Store the file in memory so it can be removed but still served
    return_data = io.BytesIO()
    with open(result_file_path, 'rb') as fo:
        return_data.write(fo.read())
    # (after writing, cursor will be at last byte, so move it to start)
    return_data.seek(0)

    # Remove the files
    shutil.rmtree(f"/data/upload/{project_id}")
    os.remove(result_file_path)

    # Wrap the data in a FileWrapper for uWSGI and set its headers
    w = FileWrapper(return_data)
    headers = {
        'Content-Disposition': f"attachment; filename='{file_name}.stl'"
    }

    # Send the generated file
    return Response(w, mimetype="application/stl",
                    direct_passthrough=True, headers=headers)


def get_and_save_file(request, fileId, projectId):
    # Check if the file we're requesting is in the request
    if fileId not in request.files:
        return False

    project_path = os.path.join("/data/upload", projectId)

    # Check if folder for project exist, create it if it doesn't exist
    if not os.path.exists(project_path):
        os.makedirs(project_path)

    f = request.files[fileId]

    # Check if the uploaded file is a file or an empty field
    if f.filename == "":
        return False

    file_path = os.path.join(project_path, f.filename)

    # Check if the file exists already
    if os.path.exists(file_path):
        return False

    f.save(file_path)
    return file_path


if __name__ == "__main__":
    app.run()