from flask import Flask, request, jsonify 
from flask_sqlalchemy import SQLAlchemy
from flask_marshmallow import Marshmallow 
from flask_restful import Resource, Api
from sqlalchemy import func
from datetime import datetime


#https://betterdatascience.com/develop-database-driven-rest-api-with-python-in-10-minutes/
#Initializations for DB and JSON
app = Flask(__name__) 
api = Api(app) 
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///jobs.db' 
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False 
db = SQLAlchemy(app) 
ma = Marshmallow(app)



#Create class for the Jobs, also allows for SQLAlchemy to create the table
##If you need to create another table do these commands:
### from main import app, db
### app.app_context().push()
### db.create_all()

class Job(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(32), unique=True)
    status = db.Column(db.String(32))
    lastUpdated = db.Column(db.DateTime(timezone=True), server_default=func.now())

    def __init__(self, name, status, lastUpdated):
        self.name = name
        self.status = status
        self.lastUpdated = lastUpdated

#Parses the JSON gathered from the DB
class jobSchema(ma.Schema):
    class Meta:
        fields = ('id', 'name', 'status', 'lastUpdated')

job_schema = jobSchema()
jobs_schema = jobSchema(many=True)

#Main class for handling jobs
class jobManager(Resource):
    #Logic for fetching one/all jobs
    ##Check if id was provided as a parameter, if not pull for all jobs
    ##makes a query and returns the result in json format
    @staticmethod
    def get():
        try:
            id = request.args['id']
        except Exception as _: id = None

        if not id:
            jobs = Job.query.all()
            return jsonify(jobs_schema.dump(jobs))
        job = Job.query.get(id)
        return jsonify(job_schema.dump(job))

    #Insert new Job
    ##Fetch provided json data for name, status, and last updated
    ##Create instance of the Job class with the provided data
    ##Add to the DB and commit
    ##Return message stating success
    @staticmethod
    def post():
        name = request.json['name']
        status = request.json['status']
        #lastUpdated = request.json['lastUpdated']
        lastUpdated = datetime.now()
        job = Job(name, status, lastUpdated)
        db.session.add(job)
        db.session.commit()

        return jsonify({
            'Message': f'Job {name} has been added'
        })
    
    #Update existing job
    ##check if a job id was passed in the call, if not return an error message
    ##fecth json data
    ##set values to the db according to provided data
    ##return message that it was updated

    @staticmethod
    def put():
        try: id = request.args['id']
        except Exception as _: id = None

        if not id:
            return jsonify({ 'Message': 'Must provide a job ID'})
        
        job = Job.query.get(id)
        name = request.json['name']
        status = request.json['status']
        #lastUpdated = request.json['lastUpdated']
        lastUpdated = datetime.now()

        job.name = name
        job.status = status
        job.lastUpdated = lastUpdated

        db.session.commit()
        return jsonify({
            'Message': f'Job {name} has been altered'
        })
    
    #Delete Job
    @staticmethod
    def delete():
        try: id = request.args['id']
        except Exception as _: id = None

        if not id:
            return jsonify({ 'Message': 'Must provide the job ID' })

        job = Job.query.get(id)
        db.session.delete(job)
        db.session.commit()

        return jsonify({
            'Message': f'Job {str(id)} deleted.'
        })

#Attach Job manager class to an endpoint, /api/jobs
api.add_resource(jobManager, '/api/jobs')

#Runs the Flask app
if __name__ == '__main__':
    app.run(debug=True)