"""Handle data endpoints."""
import os
import uuid
import json
import datetime
from typing import Sequence
from functools import reduce

import redis
from email_validator import validate_email, EmailNotValidError
from authlib.integrations.flask_oauth2.errors import _HTTPException
from flask import request, jsonify, Response, Blueprint, current_app as app

import gn3.db_utils as gn3db
from gn3.db.traits import build_trait_name

from gn3.auth import db
from gn3.auth.dictify import dictify

from gn3.auth.authorisation.errors import NotFoundError

from gn3.auth.authorisation.users.views import (
    validate_password, validate_username)

from gn3.auth.authorisation.roles.models import(
    revoke_user_role_by_name, assign_user_role_by_name)

from gn3.auth.authorisation.groups.data import retrieve_ungrouped_data
from gn3.auth.authorisation.groups.models import (
    Group, user_group, add_user_to_group)

from gn3.auth.authorisation.resources.checks import authorised_for
from gn3.auth.authorisation.resources.models import (
    user_resources, public_resources, attach_resources_data)

from gn3.auth.authorisation.errors import ForbiddenAccess, AuthorisationError


from gn3.auth.authentication.users import User, user_by_id, set_user_password
from gn3.auth.authentication.oauth2.resource_server import require_oauth

data = Blueprint("data", __name__)

@data.route("/authorisation", methods=["GET"])
def authorisation() -> Response:
    """Retrive the authorisation level for datasets/traits for the user."""
    db_uri = app.config["AUTH_DB"]
    privileges = {}
    with db.connection(db_uri) as auth_conn:
        try:
            with require_oauth.acquire("profile group resource") as the_token:
                resources = attach_resources_data(
                    auth_conn, user_resources(auth_conn, the_token.user))
                privileges = {
                    resource_id: ("group:resource:view-resource",)
                    for resource_id, is_authorised
                    in authorised_for(
                        auth_conn, the_token.user,
                        ("group:resource:view-resource",), tuple(
                            resource.resource_id for resource in resources
                            if not resource.public)).items()
                    if is_authorised
                }
        except _HTTPException as exc:
            err_msg = json.loads(exc.body)
            if err_msg["error"] == "missing_authorization":
                resources = attach_resources_data(
                    auth_conn, public_resources(auth_conn))
            else:
                raise exc from None

        # Access endpoint with somethin like:
        # curl -X GET http://127.0.0.1:8080/api/oauth2/data/authorisation \
        #    -H "Content-Type: application/json" \
        #    -d '{"traits": ["HC_M2_0606_P::1442370_at", "BXDGeno::01.001.695",
        #        "BXDPublish::10001"]}'
        data_to_resource_map = {
            (f"{data_item['dataset_type'].lower()}::"
             f"{data_item['dataset_name']}"): resource.resource_id
            for resource in resources
            for data_item in resource.resource_data
        }
        privileges = {
            **privileges,
            **{
                resource.resource_id: ("system:resource:public-read",)
                for resource in resources if resource.public
            }}

        args = request.get_json()
        traits_names = args["traits"] # type: ignore[index]
        def __translate__(val):
            return {
                "ProbeSet": "mRNA",
                "Geno": "Genotype",
                "Publish": "Phenotype"
            }[val]
        return jsonify(tuple(
            {
                **{key:trait[key] for key in ("trait_fullname", "trait_name")},
                "dataset_name": trait["db"]["dataset_name"],
                "dataset_type": __translate__(trait["db"]["dataset_type"]),
                "privileges": privileges.get(
                    data_to_resource_map.get(
                        f"{__translate__(trait['db']['dataset_type']).lower()}"
                        f"::{trait['db']['dataset_name']}",
                        uuid.UUID("4afa415e-94cb-4189-b2c6-f9ce2b6a878d")),
                    tuple())
            } for trait in
            (build_trait_name(trait_fullname)
             for trait_fullname in traits_names)))

def migrate_user(conn: db.DbConnection, user_id: uuid.UUID, email: str,
                 username: str, password: str) -> User:
    """Migrate the user, if not already migrated."""
    try:
        return user_by_id(conn, user_id)
    except NotFoundError as _nfe:
        user = User(user_id, email, username)
        with db.cursor(conn) as cursor:
            cursor.execute(
                "INSERT INTO users(user_id, email, name) "
                "VALUES (?, ?, ?)",
                (str(user.user_id), user.email, user.name))
            set_user_password(cursor, user, password)
            return user

def migrate_user_group(conn: db.DbConnection, user: User) -> Group:
    """Create a group for the user if they don't already have a group."""
    group = user_group(conn, user).maybe(# type: ignore[misc]
        False, lambda grp: grp) # type: ignore[arg-type]
    if not bool(group):
        group = Group(uuid.uuid4(), f"{user.name}'s Group", {
            "created": datetime.datetime.now().isoformat(),
            "notes": "Imported from redis"
        })
        with db.cursor(conn) as cursor:
            cursor.execute(
                "INSERT INTO groups(group_id, group_name, group_metadata) "
                "VALUES(?, ?, ?)",
                (str(group.group_id), group.group_name, json.dumps(
                    group.group_metadata)))
            add_user_to_group(cursor, group, user)
            revoke_user_role_by_name(cursor, user, "group-creator")
            assign_user_role_by_name(cursor, user, "group-leader")

    return group

def __redis_datasets_by_type__(acc, item):
    if item["type"] == "dataset-probeset":
        return (acc[0] + (item["name"],), acc[1], acc[2])
    if item["type"] == "dataset-geno":
        return (acc[0], acc[1] + (item["name"],), acc[2])
    if item["type"] == "dataset-publish":
        return (acc[0], acc[1], acc[2] + (item["name"],))
    return acc

def __unmigrated_data__(ungrouped, redis_datasets):
    return (dataset for dataset in ungrouped
            if dataset["Name"] in redis_datasets)

def __parametrise__(group: Group, datasets: Sequence[dict],
                    dataset_type: str) -> tuple[dict[str, str], ...]:
    return tuple(
        {
            "group_id": str(group.group_id),
            "dataset_type": dataset_type,
            "dataset_or_trait_id": dataset["Id"],
            "dataset_name": dataset["Name"],
            "dataset_fullname": dataset["FullName"],
            "accession_id": dataset["accession_id"]
        } for dataset in datasets)

def migrate_data(
        authconn: db.DbConnection, gn3conn: gn3db.Connection,
        rconn: redis.Redis, user: User,
        group: Group) -> tuple[dict[str, str], ...]:
    """Migrate data attached to the user to the user's group."""
    redis_mrna, redis_geno, redis_pheno = reduce(# type: ignore[var-annotated]
        __redis_datasets_by_type__,
        (dataset for dataset in
         (dataset for _key,dataset in {
             key: json.loads(val)
            for key,val in rconn.hgetall("resources").items()
         }.items())
         if dataset["owner_id"] == str(user.user_id)),
        (tuple(), tuple(), tuple()))
    mrna_datasets = __unmigrated_data__(
        retrieve_ungrouped_data(authconn, gn3conn, "mrna"), redis_mrna)
    geno_datasets = __unmigrated_data__(
        retrieve_ungrouped_data(authconn, gn3conn, "genotype"), redis_geno)
    pheno_datasets = __unmigrated_data__(
        retrieve_ungrouped_data(authconn, gn3conn, "phenotype"), redis_pheno)
    params = (
        __parametrise__(group, mrna_datasets, "mRNA") +
        __parametrise__(group, geno_datasets, "Genotype") +
        __parametrise__(group, pheno_datasets, "Phenotype"))
    if len(params) > 0:
        with db.cursor(authconn) as cursor:
            cursor.executemany(
                "INSERT INTO linked_group_data VALUES"
                "(:group_id, :dataset_type, :dataset_or_trait_id, "
                ":dataset_name, :dataset_fullname, :accession_id)",
                params)

    return params

@data.route("/user/migrate", methods=["POST"])
@require_oauth("migrate-data")
def migrate_user_data():
    """
    Special, protected endpoint to enable the migration of data from the older
    system to the newer system with groups, resources and privileges.

    This is a temporary endpoint and should be removed after all the data has
    been migrated.
    """
    db_uri = app.config.get("AUTH_DB").strip()
    if bool(db_uri) and os.path.exists(db_uri):
        authorised_clients = app.config.get(
            "OAUTH2_CLIENTS_WITH_DATA_MIGRATION_PRIVILEGE", [])
        with require_oauth.acquire("migrate-data") as the_token:
            if the_token.client.client_id in authorised_clients:
                try:
                    user_id = uuid.UUID(request.form.get("user_id", ""))
                    email = validate_email(request.form.get("email", ""))
                    fullname = validate_username(
                        request.form.get("fullname", ""))
                    password = validate_password(
                        request.form.get("password", ""),
                        request.form.get("confirm_password", ""))

                    with (db.connection(db_uri) as authconn,
                          redis.Redis(decode_responses=True) as rconn,
                          gn3db.database_connection() as gn3conn):
                        user = migrate_user(
                            authconn, user_id, email["email"], fullname,
                            password)
                        group = migrate_user_group(authconn, user)
                        user_resource_data = migrate_data(
                            authconn, gn3conn, rconn, user, group)
                        ## TODO: Maybe delete user from redis...
                        return jsonify({
                            "description": (
                                f"Migrated {len(user_resource_data)} resource data "
                                "items."),
                            "user": dictify(user),
                            "group": dictify(group)
                        })
                except EmailNotValidError as enve:
                    raise AuthorisationError(f"Email Error: {str(enve)}") from enve
                except ValueError as verr:
                    raise AuthorisationError(verr.args[0]) from verr

            raise ForbiddenAccess("You cannot access this endpoint.")

    return jsonify({
        "error": "Unavailable",
        "error_description": (
            "The data migration service is currently unavailable.")
    }), 503