datahuborg/datahub

import json

from django.core.context_processors import csrf
from django.shortcuts import render_to_response
from django.contrib.auth.decorators import login_required
from django.http import HttpResponse, HttpResponseServerError

from core.db.manager import DataHubManager
from distill import inference


'''
@author: Anant Bhardwaj
@date: Mar 21, 2013

Datahub Refiner
'''


def index(request):
    # if the user is authenticated, we pass them the available repos
    username = request.user.get_username()
    res = {'login': username}
    try:
        with DataHubManager(username) as m:
            repos = m.list_repos()
            res['repos'] = repos
    except:
        pass

    res.update(csrf(request))
    return render_to_response("refiner.html", res)


def refine_data(request):
    res = {'error': None}
    try:
        if request.method == 'POST':
            training_input = request.POST['training_input']
            training_output = request.POST['training_output']
            test_data = request.POST['test_data']
            record_separator = '\n'
            if 'record_separator' in request.POST:
                record_separator = request.POST['record_separator']

            o_fields_structure, i_structure = inference.learn_mapping(
                training_input, training_output)
            out = inference.extract(
                test_data, o_fields_structure, sep=record_separator)

            csv_lines = []
            for row in out:
                csv_lines.append(','.join(row.values()))

            csv_str = '\n'.join(csv_lines)
            res['output'] = csv_str
            res['csv_lines'] = csv_lines
        else:
            res['error'] = 'Invalid HTTP Method'
    except Exception, e:
        res['error'] = str(e)

    return HttpResponse(json.dumps(res), content_type="application/json")


@login_required
def create_table(request):
    username = request.user.get_username()
    csv_lines = request.POST.getlist('csv_lines[]')
    header = json.loads(request.POST['header'])
    repo = request.POST['repo_name']
    table = request.POST['table_name']

    # remove the "..." characters that refiner puts on both sides of the array
    csv_lines = csv_lines[1:len(csv_lines) - 1]

    try:
        with DataHubManager(username) as m:
            m.import_rows(
                repo=repo,
                table=table,
                rows=csv_lines,
                header=header)

            return HttpResponse('')

    except Exception as e:
        return HttpResponseServerError(e)