Dylan Reid - Pet Park Assignment

contracts/PetPark.sol

@@ -1,7 +1,114 @@
 //SPDX-License-Identifier: Unlicense
 pragma solidity ^0.8.0;
 
-
 contract PetPark {
+    address owner;
+
+    // define struct of animal type, age, and gender
+    struct animalAndDemo {
+        uint animalType;
+        uint age;
+        uint gender;
+    }
+
+    // animals in zoo: animalType and count of that animal in the zoo
+    mapping (uint => uint) public animalsInZoo;
+    // borrwed animals: address -> animal type and demo of owner
+    mapping (address => animalAndDemo) public borrowedAnimal;
+
+    constructor() {
+        owner = msg.sender;
+    }
+
+    modifier animalRange(uint animalType) {
+        // revert when animal type is invalid
+        require(animalType > 0 && animalType < 6, "Invalid animal type");
+        _;
+    }
+
+    // define events
+    event Added(uint animalType, uint animalCount);
+    event Borrowed(uint animalType);
+    event Returned(uint animalType);
+
+    function add(uint animalType, uint count) public animalRange(animalType) {
+        // check that only owner has access
+        require(owner == msg.sender, "Not an owner");
+
+        // increase the animals in the zoo of that type by the count
+        animalsInZoo[animalType] += count;
+
+        // emit added event
+        emit Added(animalType, count);
+    }
+
+    function borrow(uint age, uint gender, uint animalType) public animalRange(animalType) {
+
+        animalAndDemo memory currentBorrow = borrowedAnimal[msg.sender];
+
+        // revert when age is zero
+        require(age > 0, "Invalid Age");
+
+        // revert when animal not available in park
+        require(animalsInZoo[animalType] > 0, "Selected animal not available");
+
+        // revert when address details do not match from previous calls
+        if (currentBorrow.age > 0) {
+            // check age
+            require(currentBorrow.age == age, "Invalid Age");
+            // check gender
+            require(currentBorrow.gender == gender, "Invalid Gender");
+        }
+
+        // revert when pet is already borrowed
+        require(currentBorrow.animalType == 0, "Already adopted a pet");
+
+        // revert when men attempt to borrow animals other than fish and dog
+        if (gender == 0) {
+            require(animalType == 1 || animalType == 3, "Invalid animal for men");
+        }
+
+        // revert when women under 40 attempt to borrow cat
+        if (gender == 1) {
+            if (age < 40) {
+                require(animalType != 2, "Invalid animal for women under 40");
+            }
+        }
+
+        // set up the animal and demo of the item to be added
+        animalAndDemo memory animalAndDemoToAdd = animalAndDemo(animalType, age, gender);
+
+        // store info into borrowedAnimal mapping
+        borrowedAnimal[msg.sender] = animalAndDemoToAdd;
+
+        // remove from zoo
+        animalsInZoo[animalType]--;
+
+        // emit borrowed event
+        emit Borrowed(animalType);
+    }
+
+    function giveBackAnimal() public {
+        // set current amimal variable
+        uint currentAnimal = borrowedAnimal[msg.sender].animalType;
+
+        // ensure that there are no borrowed pets
+        require(currentAnimal > 0, "No borrowed pets");
+
+        // set animal type back to zero in borrow mapping
+        uint currentAge = borrowedAnimal[msg.sender].age;
+        uint currentGender = borrowedAnimal[msg.sender].gender;
+        animalAndDemo memory inputAnimalAndDemo = animalAndDemo(0, currentAge, currentGender);
+        borrowedAnimal[msg.sender] = inputAnimalAndDemo;
+
+        // increment animal count in zoo
+        animalsInZoo[currentAnimal]++;
+
+        // emit returned event
+        emit Returned(currentAnimal);
+    }
 
+    function animalCounts(uint animalType) public view returns(uint) {
+        return animalsInZoo[animalType];
+    }
 }