import smartpy as sp
class EventPlanner(sp.Contract):
    def __init__(self, initialOwner):
        self.init(owner = sp.set_type(initialOwner, sp.TAddress),
                  nameToEvent = sp.map(tkey = sp.TString, tvalue=sp.TPair(t1=sp.TString, t2=sp.TInt)))
    @sp.entry_point
    def setDate(self, params):
        sp.verify(sp.sender == self.data.owner)
        self.checkEvent(params.name)
        self.data.nameToEvent[params.name] = sp.pair(params.newDate, sp.snd(self.data.nameToEvent[params.name]))
    @sp.entry_point
    def setNumGuests(self, params):
        #check whether the sender is the owner
        sp.verify(sp.sender == self.data.owner)
        self.checkEvent(params.name)
        #change number of guests
        self.data.nameToEvent[params.name] = sp.pair(sp.fst(self.data.nameToEvent[params.name]), params.newNumGuests)
    @sp.entry_point
    def changeOwner(self, params):
        #check whether the sender is the owner
        sp.verify(sp.sender == self.data.owner)
        #set owner to the new owner
        self.data.owner = params.newOwner
    #This function check whether the name already exists in the map, if it doesn't exist checkEvent will create it.
    def checkEvent(self, name):
        sp.if ~self.data.nameToEvent.contains(name):
            self.data.nameToEvent[name] = sp.pair("", 0)
@sp.add_test(name = "SomeTest")
def test():
    scenario = sp.test_scenario()
    scenario.h1("Event Planner")
    firstOwner = sp.address("tz1-firstOwner-address-1234")
    secondOwner = sp.address("tz1-secondOwner-address-5678")
    c1 = EventPlanner(firstOwner)
    scenario += c1
    # Invoke EventPlanner entry points and print results to HTML
    scenario.h2("Set date for Tezos Meetup to 11-28-2017")
    scenario += c1.setDate(name = "Tezos Meetup", newDate = "11-28-2017").run(sender = firstOwner)
    scenario.h2("Set number of guests for Tezos Meetup to 80")
    scenario += c1.setNumGuests(name = "Tezos Meetup", newNumGuests = 80).run(sender = firstOwner)
    scenario.h2("Change owner")
    scenario += c1.changeOwner(newOwner = secondOwner).run(sender = firstOwner)
    scenario.h2("New owner sets date for Tezos Meetup to 03-21-2019")
    scenario += c1.setDate(name = "Tezos Meetup", newDate = "03-21-2019").run(sender = secondOwner)
    scenario.h2("Old owner attempts to set date for Tezos Meetup")
    scenario += c1.setDate(name = "Tezos Meetup", newDate = "10-15-2018").run(sender = firstOwner, valid = False)
    # Verify expected results
    scenario.verify(sp.fst(c1.data.nameToEvent["Tezos Meetup"]) == '03-21-2019')
    scenario.verify(sp.snd(c1.data.nameToEvent["Tezos Meetup"]) == 80)
    scenario.verify((c1.data.owner) == sp.address('tz1-secondOwner-address-5678'))