From 6ceeff43cc360d19ba81299b472f312fa2bc68f8 Mon Sep 17 00:00:00 2001
From: Claudio Maradonna <penguyman@stronzi.org>
Date: Fri, 30 Jul 2021 16:51:21 +0200
Subject: [PATCH] Homework 4

---
 code/week04/src/Week04/Homework.hs | 38 ++++++++++++++++++++++++++----
 1 file changed, 34 insertions(+), 4 deletions(-)

diff --git a/code/week04/src/Week04/Homework.hs b/code/week04/src/Week04/Homework.hs
index b02a295..bdd06e4 100644
--- a/code/week04/src/Week04/Homework.hs
+++ b/code/week04/src/Week04/Homework.hs
@@ -9,13 +9,14 @@ module Week04.Homework where
 
 import Data.Aeson            (FromJSON, ToJSON)
 import Data.Functor          (void)
-import Data.Text             (Text)
+import Data.Text             (Text, unpack)
 import GHC.Generics          (Generic)
 import Ledger
 import Ledger.Ada            as Ada
 import Ledger.Constraints    as Constraints
 import Plutus.Contract       as Contract
 import Plutus.Trace.Emulator as Emulator
+import Wallet.Emulator.Wallet
 
 data PayParams = PayParams
     { ppRecipient :: PubKeyHash
@@ -29,16 +30,45 @@ payContract = do
     pp <- endpoint @"pay"
     let tx = mustPayToPubKey (ppRecipient pp) $ lovelaceValueOf $ ppLovelace pp
     void $ submitTx tx
-    payContract
+
+handlePayContract :: Contract () PaySchema Text ()
+handlePayContract = do
+    Contract.handleError
+        (\err -> Contract.logError $ "cannot execute contract! " ++ unpack err)
+        payContract
+    handlePayContract
 
 -- A trace that invokes the pay endpoint of payContract on Wallet 1 twice, each time with Wallet 2 as
 -- recipient, but with amounts given by the two arguments. There should be a delay of one slot
--- after each endpoint call.
+-- after each endpoint call.EmulatorTrace
 payTrace :: Integer -> Integer -> EmulatorTrace ()
-payTrace _ _ = undefined -- IMPLEMENT ME!
+payTrace a b = do
+    h <- activateContractWallet (Wallet 1) handlePayContract
+
+    let recipient = (pubKeyHash $ walletPubKey $ Wallet 2)
+    let ppa = PayParams {
+                ppRecipient = recipient,
+                ppLovelace = a
+            }
+    callEndpoint @"pay" h ppa
+    void $ Emulator.waitNSlots 1
+
+    let ppb = PayParams {
+                ppRecipient = recipient,
+                ppLovelace = b
+            }
+
+    callEndpoint @"pay" h ppb
+    void $ Emulator.waitNSlots 1
 
 payTest1 :: IO ()
 payTest1 = runEmulatorTraceIO $ payTrace 1000000 2000000
 
 payTest2 :: IO ()
 payTest2 = runEmulatorTraceIO $ payTrace 1000000000 2000000
+
+payTest3 :: IO ()
+payTest3 = runEmulatorTraceIO $ payTrace 1000000000 1000000000
+
+payTest4 :: IO ()
+payTest4 = runEmulatorTraceIO $ payTrace 2000000 1000000000