import json

from flask import Flask, request, Response
from pymongo import MongoClient
from flasgger import Swagger


app = Flask(__name__)
swagger = Swagger(app)
baesian = MongoClient("mongodb", 27017).demo.baesian


@app.route("/item/<int:itemid>", methods=["POST"])
def upsert_item(itemid):
    """Create item
    ---
    parameters:
      - name: itemid
        in: path
        type: string
        required: true
      - name: name
        in: formData
        type: string
        required: false
    responses:
      200:
        description: Item added
    """
    request_params = request.form
    if "name" not in request_params:
        return Response(
            "Name not present in parameters!", status=404, mimetype="application/json"
        )
    baesian.update_one(
        {"_id": itemid},
        {"$set": {"name": request_params["name"], "nr_votes": 0}},
        upsert=True,
    )

    return Response(
        json.dumps({"_id": itemid, "name": request_params["name"]}),
        status=200,
        mimetype="application/json",
    )


@app.route("/item/vote/<int:itemid>", methods=["PUT"])
def add_vote(itemid):
    """Vote an item
    ---
    parameters:
      - name: itemid
        in: path
        type: string
        required: true
      - name: mark
        in: formData
        type: integer
        required: false
      - name: userid
        in: formData
        type: integer
        required: false
    responses:
      200:
        description: Update succeded
    """
    request_params = request.form
    if "mark" not in request_params or "userid" not in request_params:
        return Response(
            "Mark and userid must be present in form data!",
            status=404,
            mimetype="application/json",
        )
    mark = int(request_params["mark"])
    if mark not in range(0, 10):
        return Response(
            "Mark must be in range (0, 10) !", status=500, mimetype="application/json"
        )
    userid = int(request_params["userid"])
    update_items_data = {
        "$push": {"marks": {"userid": userid, "mark": mark}},
        "$inc": {"nr_votes": 1, "sum_votes": mark},
    }
    baesian.update_one({"_id": itemid}, update_items_data)
    return Response("", status=200, mimetype="application/json")


@app.route("/item/<int:itemid>", methods=["GET"])
def get_item(itemid):
    """Item details
    ---
    parameters:
      - name: itemid
        in: path
        type: string
        required: true
    definitions:
      Item:
        type: object
        properties:
          _id:
            type: integer
          name:
            type: string
          marks:
            type: array
            items:
                type: integer
          sum_votes:
            type: integer
          nr_votes:
            type: integer
          baesian_average:
            type: float
    responses:
      200:
        description: Item model
        schema:
          $ref: '#/definitions/Item'
      404:
        description: Item not found
    """
    item_data = baesian.find_one({"_id": itemid})
    if None == item_data:
        return Response("", status=404, mimetype="application/json")
    if "marks" not in item_data:
        item_data["nr_votes"] = 0
        item_data["sum_votes"] = 0
        item_data["baesian_average"] = 0
        return Response(json.dumps(item_data), status=200, mimetype="application/json")

    average_nr_votes_pipeline = [
        {"$group": {"_id": "avg_nr_votes", "avg_nr_votes": {"$avg": "$nr_votes"}}},
    ]
    average_nr_votes = list(baesian.aggregate(average_nr_votes_pipeline))[0][
        "avg_nr_votes"
    ]
    average_rating = [
        {
            "$group": {
                "_id": "avg",
                "avg": {"$sum": "$sum_votes"},
                "count": {"$sum": "$nr_votes"},
            }
        },
        {"$project": {"result": {"$divide": ["$avg", "$count"]}}},
    ]
    average_rating = list(baesian.aggregate(average_rating))[0]["result"]
    item_nr_votes = item_data["nr_votes"]
    item_average_rating = item_data["sum_votes"] / item_data["nr_votes"]
    baesian_average = round(
        ((average_nr_votes * average_rating) + (item_nr_votes * item_average_rating))
        / (average_nr_votes + item_nr_votes),
        3,
    )
    item_data["baesian_average"] = baesian_average
    return Response(json.dumps(item_data), status=200, mimetype="application/json")


@app.route("/items", methods=["GET"])
def get_items():
    """All items with pagination without averages
    ---
    parameters:
      - name: limit
        in: query
        type: integer
        required: false
      - name: offset
        in: query
        type: integer
        required: false
    definitions:
      Items:
        type: array
        items:
            properties:
              _id:
                type: integer
              name:
                type: string
              marks:
                type: array
                items:
                    type: integer
    responses:
      200:
        description: List of items
        schema:
          $ref: '#/definitions/Items'
    """
    request_args = request.args
    limit = int(request_args.get("limit")) if "limit" in request_args else 10
    offset = int(request_args.get("offset")) if "offset" in request_args else 0
    item_list = baesian.find().limit(limit).skip(offset)
    if None == baesian:
        return Response(json.dumps([]), status=200, mimetype="application/json")
    extracted = [
        {
            "_id": d["_id"],
            "name": d["name"],
            "marks": d["marks"] if "marks" in d else [],
        }
        for d in item_list
    ]
    return Response(json.dumps(extracted), status=200, mimetype="application/json")


@app.route("/item/<int:itemid>", methods=["DELETE"])
def delete_item(itemid):
    """Delete operation for a item
    ---
    parameters:
      - name: itemid
        in: path
        type: string
        required: true
    responses:
      200:
        description: Item deleted
    """
    baesian.delete_one({"_id": itemid})
    return Response("", status=200, mimetype="application/json")


if __name__ == "__main__":
    # starts the app in debug mode, bind on all ip's and on port 5000
    app.run(debug=True, host="0.0.0.0", port=5000)