app.py

# -*- coding: utf-8 -*-

import base64
from rgbmaker.fetch import query as qu, save_fig
from rgbmaker.imgplt import pl_powerlawsi
from scripts import forms #,smv

import urllib

from flask import Flask, redirect, url_for, render_template, request, jsonify, send_from_directory
import os
import pathlib
from flask_cors import CORS
from flask_restful import reqparse, abort, Api, Resource
from celery import Celery
import sqlite3
from sqlalchemy import create_engine, MetaData, Table, Column, Integer, String
from sqlalchemy.sql.expression import update

# db_url = os.environ['DATABASE_URL'].replace("postgres", "postgresql")
db_url='sqlite:///db.sqlite3'
def make_celery(app):
    celery = Celery(
        name='tasks',
        backend='db+'+db_url,
        result_backend='db+'+db_url,
        #cache='db+sqlite:///db.sqlite3',
        broker='amqp://guest:@localhost:5672//',
        # broker=os.environ['CLOUDAMQP_URL']
        # broker='db+sqlite:///celery.db',
    )
    celery.conf.update(app.config)

    class ContextTask(celery.Task):
        def __call__(self, *args, **kwargs):
            with app.app_context():
                return self.run(*args, **kwargs)

    celery.Task = ContextTask
    return celery

app = Flask(__name__)
api = Api(app)
app.secret_key = os.urandom(12)  # Generic key for dev purposes only
CORS(app)


# ======== Celery =========================================================== #

celery = make_celery(app)

@app.route('/file/<path:filename>', methods=['GET'])
def get_file(filename):
    return send_from_directory(pathlib.Path('__file__').parent.resolve() / "static" / "media", filename)
   

try:
    spidx_file = url_for('get_file', filename='spidx.fits')
   
except:
    try :
        spidx_file = pathlib.Path('__file__').parent.resolve() / "static" / "media" / "spidx.fits"
    except:
        spidx_file = None

    
@celery.task(bind=True)
def get_image(self, arg):
    info, uri, txt, otext = qu(name=arg['name'], position=arg['position'],
                                      radius=arg['radius'], imagesopt=arg['imagesopt'], archives=arg['archives'], spidx_file=spidx_file)
    self.update_state(state='PROGRESS' or info,
                      meta={'txt': txt, 'otext': otext,
                            'uri': uri})
    return {'info': info, 'message': txt, 'url': uri, 'brieftext': otext}

# ======== Routing =========================================================== #

@app.route('/powerlaw', methods=['GET', 'POST'])
def powerlaw():
    try :
        
        tgss = float(request.args.get('tgss'))
        nvss = float(request.args.get('nvss'))
        
        try:
            tgss_e = float(request.args.get('tgss_e'))            
        except:
            tgss_e = tgss*0.10
        try:
            nvss_e = float(request.args.get('nvss_e'))
        except:
            nvss_e = nvss*0.10
        
        rest = bool(request.args.get('rest'))
        S = [tgss, nvss]
        S_e = [tgss_e, nvss_e]
        plt, fig = pl_powerlawsi(S,S_e)
        string = save_fig(plt,fig, kind='base64')
                
        #-------- Output for success -----#--#
        if rest:
            return {'img': 'data:image/png;base64,' + urllib.parse.quote(string)}, 200
        else:
            return f'<img src="data:image/png;base64,{urllib.parse.quote(string)}" />'
    except:
        htmls = '<div class="alert alert-danger" role="alert"><h4 class="alert-heading"> Error!</h4><p> Please check inputs. \
        </p><hr> \
        <p class="mb-0"> :( </p> \
        </div>'
        return f'{htmls}'

# -------- Login ------------------------------------------------------------- #
@app.route('/', methods=['GET', 'POST'])
def login():
    return redirect(url_for('query'))

# -------- Task Status output --------------------------------------------- #
@app.route('/status/<idv>')
def taskstatus(idv):
    task = get_image.AsyncResult(task_id=idv)
    if task.state == 'PENDING':
        info = {'info': 'processing'}
        return info, 202
    elif task.state == 'SUCCESS':
        info = task.info
        try:
            print("success")
            deleteRecord(task.id)
        except:
            print("record not found for task")
    else:
        info = task.info
    return info

# -------- Query ---------------------------------------------------------- #
@app.route('/query', methods=['GET', 'POST'])
def query():
    qform = forms.QueryForm(request.form)
    if request.method == 'POST':
        name=request.form['name']
        position=request.form['position']
        radius=request.form['radius']
        archives=request.form['archives']
        images=request.form['images']
        
        if qform.validate():
            info, uri, txt, otext = qu(name,position,radius,archives,images)
            try :
                return jsonify([info,txt,uri,otext]) 
            except Exception as e :
                return jsonify(success=0, error_msg=str(e))
        else :
            info = jsonify(['error','validation failed','#'])
            
    else:
        info = jsonify(['info','Please enter coordinates','#'])

    return render_template('fetch.html', form=qform)

##-----------==============         Alternative API for RGBMaker       ========-----------##
@app.route('/api', methods=['GET', 'POST'])
def altapi():
    try :
        if request.method=='GET':
            return redirect(url_for('query'))
        if request.method=='POST':
            arg={'name':str(request.form['name']),
            'position':str(request.form['position']),
            'radius':str(request.form['radius']),
            'imagesopt':str(request.form['imagesopt']),
            'archives':str(request.form['archives'])}
            
            task = get_image.delay(arg)
            return {'Location': url_for('taskstatus', idv=task.id)}, 202
    except:
        return 'ERROR'


##-----------==============         API for accessing RGBMaker       ========-----------##

# parse = reqparse.RequestParser()
# parse.add_argument('name')
# parse.add_argument('position')
# parse.add_argument('radius')
# parse.add_argument('imagesopt')
# parse.add_argument('archives')

# class RGBMaker(Resource):
#     def post(self):
#         arg = parse.parse_args()
#         task = get_image.delay(arg)
#         return {'Location': url_for('taskstatus', idv=task.id)}, 202
#     def get(self):
#         return redirect(url_for('query'))
# api.add_resource(RGBMaker, '/api')



# ------------========------------ SQL function ---------=========---------#
def deleteRecord(tid):
    """
    deleting record of each task created by celery.
    """
    try:
        engine = create_engine(
            db_url)
        conn = engine.connect()

        meta = MetaData()

        celery_taskmeta = Table(
            'celery_taskmeta', meta,
            Column('task_id', Integer, primary_key=True),
            Column('status', String),
        )
        sql_exec = celery_taskmeta.delete().where(
            celery_taskmeta.c.task_id == tid, celery_taskmeta.c.status == 'SUCCESS')
        #sql = """DELETE from celery_taskmeta where task_id=?"""
        conn.execute(sql_exec)
        conn.commit()
        conn.close()
        print("status : deleted")
    except sqlite3.Error as error:
        print("Failed to delete record from sqlite table", error)

def checkRecord(tid):
    """
    checking record of each task created by celery.
    """
    try:
        engine = create_engine('sqlite:///db.sqlite3')
        conn = engine.connect()

        meta = MetaData()

        celery_taskmeta = Table(
            'celery_taskmeta', meta,
            Column('task_id', Integer, primary_key=True),
            Column('status', String),
        )
        sql_exec = celery_taskmeta.select().where(
            celery_taskmeta.c.task_id == tid, celery_taskmeta.c.status == 'SUCCESS')
        #sql = """DELETE from celery_taskmeta where task_id=?"""
        conn.execute(sql_exec)
        conn.commit()
        conn.close()
    except sqlite3.Error as error:
        print("Failed to delete record from sqlite table", error)
        
# ======== Main ============================================================== #
if __name__ == "__main__":
    app.run(debug=False, use_reloader=True)