import csv
import json
import os
import time

from django.contrib import messages
from werkzeug.utils import secure_filename
from django.views.generic.base import TemplateView
from django.core.files.storage import default_storage
from django.core.files.base import ContentFile
from django.views.decorators.csrf import csrf_protect
from django.http import FileResponse, HttpResponsePermanentRedirect, HttpResponse
from django.urls import reverse
import os.path as ospath
from shutil import move

from os import makedirs
from tempfile import gettempdir
from .formats import *
from .convert import reindex_data, refresh_data

# Get temporary file storage
UPLOAD_PATH = gettempdir()
DATA_PATH = ospath.join(ospath.dirname(__file__), '..')
if not ospath.exists(DATA_PATH):
    makedirs(DATA_PATH)


def get_datafile(fmt):
    return ospath.join(
        DATA_PATH,
        fmt['folder'],
        fmt['filename'] + '.' + fmt['extension']
    )


# Data update tracking
c_progress = 0
c_filename = ""


class HomePageView(TemplateView):
    template_name = "app/index.html"

    def get_context_data(self, **kwargs):
        fmts = DATAFORMATS
        for f in fmts:
            f['ready'] = ospath.isfile(get_datafile(f))
        context = super().get_context_data(**kwargs)
        return context


class OfflinePageView(TemplateView):
    template_name = "app/offline.html"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        return context


class DemoPageView(TemplateView):
    template_name = "app/demo.html"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        return context


class ReindexPageView(TemplateView):
    template_name = "app/demo.html"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        return context

    def post(self, request, **kwargs):
        global c_progress
        c_progress = 0
        global c_filename
        c_filename = ""
        reindex_data()
        messages.add_message(request, messages.INFO, 'Search engine refresh complete')
        print("Search engine reindexed")
        return HttpResponsePermanentRedirect(reverse('admin:index'))


class RefreshPageView(TemplateView):
    template_name = ""

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        return context

    def post(self, request):
        global c_progress
        c_progress = 0

        def generate():
            stats = []
            total = 0
            for fmt in DATAFORMATS:
                global c_filename
                c_filename = fmt['filename']
                filename = get_datafile(fmt)
                c = 1
                c_counter = 0
                rd = refresh_data(filename, fmt)
                while c is not None:
                    try:
                        c, p = next(rd)
                    except Exception as e:
                        yield 'error: %s' % str(e)
                        #traceback.print_exc()
                        return
                    if isinstance(c, (int, float)):
                        global c_progress
                        c_counter = c
                        if isinstance(p, (int, float)):
                            c_progress = p
                        yield str(c) + "\n\n"
                    elif isinstance(p, str) and isinstance(c, str):
                        # Error condition
                        yield p + ": " + c + "\n\n"
                        return

                stats.append({'format': fmt['dataformat'], 'count': c_counter})
                print("Refresh: %d counted at %s" % (c_counter, fmt['dataformat']))
                total = total + c_counter

            yield "done: %d objects updated" % total
            print("Refresh: %d objects updated" % total)

            c_progress = 0
            c_filename = ""
        return HttpResponse(generate(), content_type='text/html')


class ConfigurationPageView(TemplateView):
    template_name = "app/admin/config.html"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        return context

    def post(self, request, **kwargs):
        global c_progress
        c_progress = 0
        global c_filename
        c_filename = ""
        reindex_data()
        messages.add_message(request, messages.INFO, 'Search engine refresh complete')
        print("Search engine reindexed")
        return HttpResponsePermanentRedirect(reverse('admin:index'))


class UploadView(TemplateView):
    template_name = "app/admin/config.html"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        return context

    def get(self, request):
        messages.add_message(request, messages.ERROR, 'Please select a valid file')
        return HttpResponsePermanentRedirect(reverse('app:config'))

    def post(self, request, **kwargs):
        if 'datafile' in request.FILES:
            fs = request.FILES['datafile']
            fs_name = secure_filename(fs.name)
            fs_path = default_storage.save(fs_name, ContentFile(fs.read()))
            print('Uploading: %s' % fs_path)

            # Validation
            fmt = None
            if fs_name.endswith('.csv'):
                with open(fs_path, 'rt', encoding='utf-8', errors='ignore') as csvfile:
                    datareader = csv.DictReader(csvfile)
                    datalist = list(datareader)
                    fmt = detect_dataformat(datalist[0])

            elif fs_name.endswith('.geojson'):
                with open(fs_path, 'rt', encoding='utf-8', errors='ignore') as jsonfile:
                    jsondata = json.load(jsonfile)
                    fmt = detect_dataformat(jsondata['features'][0]['properties'])

            # Loading
            if fmt is not None:
                fs_target = get_datafile(fmt)
                move(fs_path, fs_target)
                messages.add_message(request, message="Uploaded new data file %s" % fmt['filename'],
                                     level=messages.SUCCESS)
            else:
                messages.add_message(request, message="Could not validate data format!", level=messages.ERROR)
        else:
            messages.add_message(request, message="Please select a valid file", level=messages.ERROR)
        return HttpResponsePermanentRedirect(reverse('config'))


def get_progress(request):
    global c_progress
    global c_filename

    def generate():
        while 1:
            p = str(100*c_progress)
            yield 'data: { "p":'+p+',"f":"'+c_filename+'"}\n\n'
            time.sleep(1.0)
    if c_filename == "":
        return HttpResponse("{}", content_type='text/event-stream')
    response = HttpResponse(generate(), content_type='text/event-stream')
    response['X-Accel-Buffering'] = 'no'
    return response


def send_from_file(request, filename):
    request_for = ''
    if request.path.startswith('/geodata'):
        request_for = 'geodata'
    elif request.path.startswith('/data'):
        request_for = 'data'
    file_path = ospath.join(DATA_PATH, request_for, filename)
    file_to_send = open(file_path, 'rb')
    response = FileResponse(file_to_send)
    return response