import unittest
import json

from rest_api import RestAPI


# Tests adapted from `problem-specifications//canonical-data.json` @ v1.0.1

class RestAPITest(unittest.TestCase):
    def test_no_users(self):
        database = {"users": []}
        api = RestAPI(database)
        response = api.get('/users')
        self.assertDictEqual(json.loads(response), database)

    def test_add_user(self):
        database = {"users": []}
        api = RestAPI(database)
        payload = json.dumps({
            'user': 'Adam'
        })
        response = api.post('/add', payload)
        expected = {
            'name': 'Adam',
            'owes': {},
            'owed_by': {},
            'balance': 0
        }
        self.assertDictEqual(json.loads(response), expected)

    def test_get_single_user(self):
        database = {
            'users': [
                {
                    'name': 'Adam',
                    'owes': {},
                    'owed_by': {},
                    'balance': 0
                },
                {
                    'name': 'Bob',
                    'owes': {},
                    'owed_by': {},
                    'balance': 0
                }
            ]
        }
        api = RestAPI(database)
        payload = json.dumps({
            'users': 'Bob'
        })
        response = api.get('/users', payload)
        expected = {
            'users': [
                {
                    'name': 'Bob',
                    'owes': {},
                    'owed_by': {},
                    'balance': 0
                }
            ]
        }
        self.assertDictEqual(json.loads(response), expected)

    def test_iou_both_users_have_0_balance(self):
        database = {
            'users': [
                {
                    'name': 'Adam',
                    'owes': {},
                    'owed_by': {},
                    'balance': 0
                },
                {
                    'name': 'Bob',
                    'owes': {},
                    'owed_by': {},
                    'balance': 0
                }
            ]
        }
        api = RestAPI(database)
        payload = json.dumps({
            'lender': 'Adam',
            'borrower': 'Bob',
            'amount': 3
        })
        response = api.post('/iou', payload)
        expected = {
            'users': [
                {
                    'name': 'Adam',
                    'owes': {},
                    'owed_by': {
                        'Bob': 3
                    },
                    'balance': 3
                },
                {
                    'name': 'Bob',
                    'owes': {
                        'Adam': 3
                    },
                    'owed_by': {},
                    'balance': -3
                }
            ]
        }
        self.assertDictEqual(json.loads(response), expected)

    def test_borrower_has_negative_balance(self):
        database = {
            'users': [
                {
                    'name': 'Adam',
                    'owes': {},
                    'owed_by': {},
                    'balance': 0
                },
                {
                    'name': 'Bob',
                    'owes': {
                        'Chuck': 3
                    },
                    'owed_by': {},
                    'balance': -3
                },
                {
                    'name': 'Chuck',
                    'owes': {},
                    'owed_by': {
                        'Bob': 3
                    },
                    'balance': 3
                }
            ]
        }
        api = RestAPI(database)
        payload = json.dumps({
            'lender': 'Adam',
            'borrower': 'Bob',
            'amount': 3
        })
        response = api.post('/iou', payload)
        expected = {
            'users': [
                {
                    'name': 'Adam',
                    'owes': {},
                    'owed_by': {
                        'Bob': 3
                    },
                    'balance': 3
                },
                {
                    'name': 'Bob',
                    'owes': {
                        'Adam': 3,
                        'Chuck': 3
                    },
                    'owed_by': {},
                    'balance': -6
                }
            ]
        }
        self.assertDictEqual(json.loads(response), expected)

    def test_lender_has_negative_balance(self):
        database = {
            'users': [
                {
                    'name': 'Adam',
                    'owes': {},
                    'owed_by': {},
                    'balance': 0
                },
                {
                    'name': 'Bob',
                    'owes': {
                        'Chuck': 3
                    },
                    'owed_by': {},
                    'balance': -3
                },
                {
                    'name': 'Chuck',
                    'owes': {},
                    'owed_by': {
                        'Bob': 3
                    },
                    'balance': 3
                }
            ]
        }
        api = RestAPI(database)
        payload = json.dumps({
            'lender': 'Bob',
            'borrower': 'Adam',
            'amount': 3
        })
        response = api.post('/iou', payload)
        expected = {
            'users': [
                {
                    'name': 'Adam',
                    'owes': {
                        'Bob': 3
                    },
                    'owed_by': {},
                    'balance': -3
                },
                {
                    'name': 'Bob',
                    'owes': {
                        'Chuck': 3
                    },
                    'owed_by': {
                        'Adam': 3
                    },
                    'balance': 0
                }
            ]
        }
        self.assertDictEqual(json.loads(response), expected)

    def test_lender_owes_borrower(self):
        database = {
            "users": [
                {
                    "name": "Adam",
                    "owes": {
                        "Bob": 3.0
                    },
                    "owed_by": {},
                    "balance": -3.0
                },
                {
                    "name": "Bob",
                    "owes": {},
                    "owed_by": {
                        "Adam": 3.0
                    },
                    "balance": 3.0
                }
            ]
        }
        api = RestAPI(database)
        payload = json.dumps({
            'lender': 'Adam',
            'borrower': 'Bob',
            'amount': 2
        })
        response = api.post('/iou', payload)
        expected = {
            'users': [
                {
                    "name": "Adam",
                    "owes": {
                        "Bob": 1.0
                    },
                    "owed_by": {},
                    "balance": -1.0
                },
                {
                    "name": "Bob",
                    "owes": {},
                    "owed_by": {
                        "Adam": 1.0
                    },
                    "balance": 1.0
                }
            ]
        }
        self.assertDictEqual(json.loads(response), expected)

    def test_lender_owes_borrower_less_than_new_loan(self):
        database = {
            "users": [
                {
                    "name": "Adam",
                    "owes": {
                        "Bob": 3.0
                    },
                    "owed_by": {},
                    "balance": -3.0
                },
                {
                    "name": "Bob",
                    "owes": {},
                    "owed_by": {
                        "Adam": 3.0
                    },
                    "balance": 3.0
                }
            ]
        }
        api = RestAPI(database)
        payload = json.dumps({
            'lender': 'Adam',
            'borrower': 'Bob',
            'amount': 4.0
        })
        response = api.post('/iou', payload)
        expected = {
            'users': [
                {
                    "name": "Adam",
                    "owes": {
                    },
                    "owed_by": {
                        "Bob": 1.0
                    },
                    "balance": 1.0
                },
                {
                    "name": "Bob",
                    "owes": {
                        "Adam": 1.0
                    },
                    "owed_by": {
                    },
                    "balance": -1.0
                }
            ]
        }
        self.assertDictEqual(json.loads(response), expected)


if __name__ == '__main__':
    unittest.main()