import json, csv, datetime, copy
import requests
from flask import Flask
from flask import render_template, send_from_directory, request, Response, send_file, session
app = Flask(__name__)

class Item():
    items = {}
    def __init__(self, name, price, itemid=None):
        self.id = itemid if itemid != None else 0
        self.name = name
        self.price = price
        self.events = []
        Item.items[self.id] = self

    def newEvent(self, type, value, date=None):
        event = {}
        if date==None:
            # date = datetime.datetime.now().strftime('%Y-%m-%d')
            print ("no date given, using now")
            date = datetime.datetime.now()
        event['date'] = date
        event['type'] = type
        event['value'] = value
        self.events.append(event)

    def recount(self, count, date=None):
        if count < 0:
            return False
        self.newEvent('count', count, date)
        Item.fileSave()
        return True

    def add(self, count, date=None):
        self.newEvent('add', count, date)
        Item.fileSave()
        return True

    def howMany(self):
        count = 0
        for event in self.events:
            if event['type']=='add':
                count += event['value']
            if event['type']=='count':
                count = event['value']
        return count

    def countSold(self, fromDate=None, verbose=False):
        count = 0
        totalSold = 0
        lastDate = 'the start'
        for event in self.events:
            if event['type']=='add':
                count += event['value']
            if event['type']=='count':
                newCount = event['value']
                if newCount<count:
                    sold = count - newCount
                    totalSold += sold
                    if verbose:
                        print("sold {} between {} and {}".format(sold, lastDate, event['date'].strftime('%Y-%m-%d')))
                    lastDate = event['date']
                count = newCount
        return totalSold
    
    def soldValue(self, fromDate=None):
        return self.countSold() * self.price

    @staticmethod
    def fileSave():
        fileContent = []
        for key, item in Item.items.items():
            itemEntity = {}
            itemEntity['id'] = item.id
            itemEntity['name'] = item.name
            itemEntity['price'] = item.price
            itemEntity['events'] = copy.deepcopy(item.events)
            for event in itemEntity['events']:
                event['date'] = event['date'].strftime('%Y-%m-%d')
            fileContent.append(itemEntity)
        with open('data.json', 'w') as outfile:
            json.dump(fileContent, outfile)
            print ("Saved to file.")

    @staticmethod
    def fileLoad():
        with open('data.json', 'r') as f:
            fileContent = json.load(f)
            for itemEntry in fileContent:
                item = Item(itemEntry['name'], itemEntry['price'], itemid=itemEntry['id'])
                for event in itemEntry['events']:
                    item.newEvent(event['type'], event['value'], datetime.datetime.strptime(event['date'], '%Y-%m-%d'))
        print ("Loaded from file")

@app.route('/')
def index():
    return render_template('inventory.html')

@app.route('/recount', methods=['POST'])
def recount():
    if 'id' not in request.form or 'count' not in request.form:
        return "bad request"
    itemid = int(request.form['id'])
    count = int(request.form['count'])
    if itemid in Item.items:
        if Item.items[itemid].recount(count):
            return 'ok'
        else:
            return 'error'
    else:
        return 'item not found'

@app.route('/restock', methods=['POST'])
def restock():
    if 'id' not in request.form or 'count' not in request.form:
        return "bad request"
    itemid = int(request.form['id'])
    count = int(request.form['count'])
    if itemid in Item.items:
        if Item.items[itemid].add(count):
            return 'ok'
        else:
            return 'error'
    else:
        return 'item not found'

@app.route('/getdata')
def data():
    jsonContent = []
    for key, item in Item.items.items():
        itemEntity = {}
        itemEntity['id'] = item.id
        itemEntity['name'] = item.name
        itemEntity['price'] = str(item.price/100) + '.00'
        itemEntity['quantity'] = item.howMany()
        jsonContent.append(itemEntity)
    return json.dumps(jsonContent)

@app.route('/salestats/<startDate>')
def saleStats(startDate = 0):
    if startDate !=0:
        try:
            startDate = datetime.datetime.strptime(startDate, '%Y-%m-%d')
        except:
            return "invalid date format"
    jsonContent = {}
    jsonContent['totalCount'] = 0
    jsonContent['totalValue'] = 0
    itemTable = []
    for key, item in Item.items.items():
        itemEntity = {}
        itemEntity['id'] = item.id
        itemEntity['name'] = item.name
        itemEntity['price'] = str(item.price/100) + '.00'
        if startDate != 0:
            itemEntity['soldQuantity'] = item.countSold(startDate)
        else:
            itemEntity['soldQuantity'] = item.countSold()
        itemEntity['soldValue'] = str(itemEntity['soldQuantity'] * item.price / 100) + '.00'
        jsonContent['totalCount'] += itemEntity['soldQuantity']
        jsonContent['totalValue'] += itemEntity['soldQuantity'] * item.price/100
        itemTable.append(itemEntity)
    jsonContent['items'] = itemTable
    jsonContent['startDate'] = startDate.strftime('%Y-%m-%d') if startDate != 0 else "2018-09-01"
    jsonContent['endDate'] = datetime.datetime.now().strftime('%Y-%m-%d')
    return json.dumps(jsonContent)


@app.route('/salestats')
def saleStatsNoDate():
    return saleStats()

if __name__ == '__main__':
    # app.secret_key = 'asuiygdiahsdo[ainsfl]asfkjnb;asklnj'
    # app.config['SESSION_TYPE'] = 'memcached'
    print("is this the work?")
    Item.fileLoad()
    app.run('0.0.0.0')