"""Module to handle uploading of R/qtl2 bundles."""
from pathlib import Path
from typing import Optional
from zipfile import ZipFile, is_zipfile

from flask import (
    flash,
    request,
    url_for,
    redirect,
    Response,
    Blueprint,
    render_template,
    current_app as app)

from r_qtl import r_qtl2
from r_qtl.errors import InvalidFormat

from qc_app.files import save_file, fullpath
from qc_app.dbinsert import species as all_species
from qc_app.db_utils import with_db_connection, database_connection
from qc_app.db import (
    species_by_id,
    save_population,
    populations_by_species,
    population_by_species_and_id,
    geno_dataset_by_species_and_population)

rqtl2 = Blueprint("rqtl2", __name__)

@rqtl2.route("/", methods=["GET", "POST"])
@rqtl2.route("/select-species", methods=["POST"])
def select_species():
    """Select the species."""
    if request.method == "GET":
        return render_template("rqtl2/index.html", species=with_db_connection(all_species))

    species_id = request.form.get("species_id")
    species = with_db_connection(
        lambda conn: species_by_id(conn, species_id))
    if bool(species):
        return redirect(url_for(
            "upload.rqtl2.select_population", species_id=species_id))
    flash("Invalid species or no species selected!", "alert-error error-rqtl2")
    return redirect(url_for("upload.rqtl2.select_species"))

@rqtl2.route("/upload/species/<int:species_id>/select-population",
             methods=["GET", "POST"])
def select_population(species_id: int):
    """Select/Create the population to organise data under."""
    with database_connection(app.config["SQL_URI"]) as conn:
        species = species_by_id(conn, species_id)
        if not bool(species):
            flash("Invalid species selected!", "alert-error error-rqtl2")
            return redirect(url_for("upload.rqtl2.select_species"))

        if request.method == "GET":
            return render_template(
                "rqtl2/select-population.html",
                species=species,
                populations=populations_by_species(conn, species_id))

        population = population_by_species_and_id(
            conn, species["SpeciesId"], request.form.get("inbredset_id"))
        if not bool(population):
            flash("Invalid Population!", "alert-error error-rqtl2")
            return redirect(
                url_for("upload.rqtl2.select_population", pgsrc="error"),
                code=307)

        return redirect(url_for("upload.rqtl2.upload_rqtl2_bundle",
                                species_id=species["SpeciesId"],
                                population_id=population["InbredSetId"]))

@rqtl2.route("/upload/species/<int:species_id>/create-population",
             methods=["POST"])
def create_population(species_id: int):
    """Create a new population for the given species."""
    population_page = redirect(url_for("upload.rqtl2.select_population"))
    with database_connection(app.config["SQL_URI"]) as conn:
        species = species_by_id(conn, species_id)
        population_name = request.form.get("inbredset_name", "").strip()
        population_fullname = request.form.get("inbredset_fullname", "").strip()
        if not bool(species):
            flash("Invalid species!", "alert-error error-rqtl2")
            return redirect(url_for("upload.rqtl2.select_species"))
        if not bool(population_name):
            flash("Invalid Population Name!", "alert-error error-rqtl2")
            return population_page
        if not bool(population_fullname):
            flash("Invalid Population Full Name!", "alert-error error-rqtl2")
            return population_page
        new_population = save_population(conn, {
            "SpeciesId": species["SpeciesId"],
            "Name": population_name,
            "InbredSetName": population_fullname,
            "FullName": population_fullname,
            "Family": request.form.get("inbredset_family") or None,
            "Description": request.form.get("description") or None
        })

    flash("Population created successfully.", "alert-success")
    return redirect(
        url_for("upload.rqtl2.upload_rqtl2_bundle",
                population_id=new_population["population_id"],
                pgsrc="create-population"),
        code=307)

class __RequestError__(Exception): #pylint: disable=[invalid-name]
    """Internal class to avoid pylint's `too-many-return-statements` error."""

@rqtl2.route(("/upload/species/<int:species_id>/population/<int:population_id>"
              "/rqtl2-bundle"),
    methods=["GET", "POST"])
def upload_rqtl2_bundle(species_id: int, population_id: int):
    """Allow upload of R/qtl2 bundle."""
    this_page_with_errors = redirect(url_for("upload.rqtl2.upload_rqtl2_bundle",
                                             species_id=species_id,
                                             population_id=population_id,
                                             pgsrc="error"),
                                     code=307)

    with database_connection(app.config["SQL_URI"]) as conn:
        species = species_by_id(conn, species_id)
        population = population_by_species_and_id(
            conn, species["SpeciesId"], population_id)
        if not bool(species):
            flash("Invalid species!", "alert-error error-rqtl2")
            return redirect(url_for("upload.rqtl2.select_species"))
        if not bool(population):
            flash("Invalid Population!", "alert-error error-rqtl2")
            return redirect(
                url_for("upload.rqtl2.select_population", pgsrc="error"),
                code=307)
        if request.method == "GET" or (
                request.method == "POST"
                and bool(request.args.get("pgsrc"))):
            return render_template("rqtl2/upload-rqtl2-bundle-step-01.html",
                                   species=species,
                                   population=population)

        if not bool(request.files.get("rqtl2_bundle")):
            raise __RequestError__("No R/qtl2 zip bundle provided.")

        the_file = save_file(
            request.files["rqtl2_bundle"], Path(app.config["UPLOAD_FOLDER"]))
        if not bool(the_file):
            raise __RequestError__("Please provide a valid R/qtl2 zip bundle.")

        if not is_zipfile(str(the_file)):
            raise __RequestError__("Invalid file! Expected a zip file.")

        try:
            with ZipFile(str(the_file), "r") as zfile:
                r_qtl2.validate_bundle(zfile)
                return render_template(
                    "rqtl2/upload-rqtl2-bundle-step-02.html",
                    species=species,
                    population=population,
                    rqtl2_bundle_file=the_file.name)
        except (InvalidFormat, __RequestError__) as exc:
            flash("".join(exc.args), "alert-error alert-danger error-rqtl2")
            return this_page_with_errors

def check_errors(conn, *args, **kwargs) -> Optional[Response]:
    """Check for select errors in the forms and return a page to redirect to."""
    species_id = kwargs.get("species_id") or request.form.get("species_id")
    population_id = (kwargs.get("population_id")
                     or request.form.get("population_id"))
    species = species_by_id(conn, species_id)
    population = population_by_species_and_id(conn, species_id, population_id)

    if "species" in args and not bool(species):
        flash("Invalid species!", "alert-error error-rqtl2")
        return redirect(url_for("upload.rqtl2.select_species"))

    if "population" in args and not bool(population):
        flash("Invalid Population!", "alert-error error-rqtl2")
        return redirect(
            url_for("upload.rqtl2.select_population", pgsrc="error"),
            code=307)

    if ("rqtl2_bundle_file" in args
        and not bool(request.form.get("rqtl2_bundle_file"))):
        flash("There is no file to process.",
              "alert-error alert-danger error-rqtl2")
        return redirect(url_for("upload.rqtl2.upload_rqtl2_bundle",
                                species_id=species_id,
                                population_id=population_id,
                                pgsrc="error"),
                        code=307)

    return False

@rqtl2.route(("/upload/species/<int:species_id>/population/<int:population_id>"
              "/rqtl2-bundle/dataset-info"),
             methods=["POST"])
def select_dataset_info(species_id: int, population_id: int):
    """
    If `geno` files exist in the R/qtl2 bundle, prompt user to provide the
    dataset the genotypes belong to.
    """
    form = request.form
    with database_connection(app.config["SQL_URI"]) as conn:
        error_page = check_errors(conn, "species", "population", "rqtl2_bundle_file")
        if bool(error_page):
            return error_page

        thefile = fullpath(form["rqtl2_bundle_file"])
        with ZipFile(str(thefile), "r") as zfile:
            cdata = r_qtl2.control_data(zfile)
            if "geno" in cdata and not bool(form.get("geno_datasetid")):
                return render_template(
                    "rqtl2/select-geno-dataset.html",
                    species=species_by_id(conn, species_id),
                    population=population_by_species_and_id(
                        conn, species_id, population_id),
                    rqtl2_bundle_file=thefile.name,
                    datasets=geno_dataset_by_species_and_population(
                        conn, species_id, population_id))

    return "All data points collected. Should proceed to launching the job."

@rqtl2.route(("/upload/species/<int:species_id>/population/<int:population_id>"
              "/rqtl2-bundle/select-geno-dataset"),
             methods=["POST"])
def select_geno_dataset(species_id: int, population_id: int) -> Response:
    """Select from existing geno datasets."""
    return "IMPLEMENT THIS!!!"

@rqtl2.route(("/upload/species/<int:species_id>/population/<int:population_id>"
              "/rqtl2-bundle/create-geno-dataset"),
             methods=["POST"])
def create_geno_dataset(species_id: int, population_id: int) -> Response:
    """Create a new geno dataset."""
    return "IMPLEMENT THIS!!!"