"""
Урок 58. Файлы JSON и модуль datetime — весь код примеров одним файлом.

Источник: subjects/python-fundamentals/course/lessons/58-json-datetime/examples.html
Файл собран автоматически (tools/build_lesson_examples.py): правьте страницу урока.
Запуск: python lesson-58.py
"""



# ====================================================================
# Пример 1. dumps/loads и соответствие типов
# ====================================================================
import json

data = {
    "name": "Alice",
    "age": 25,
    "is_student": False,
    "score": None,
    "tags": ("python", "beginner"),
}
text = json.dumps(data, ensure_ascii=False)
print(text)
# {"name": "Alice", "age": 25, "is_student": false, "score": null, "tags": ["python", "beginner"]}

restored = json.loads(text)
print(type(data["tags"]), type(restored["tags"]))
# <class 'tuple'> <class 'list'>
print(restored)
# {'name': 'Alice', 'age': 25, 'is_student': False, 'score': None, 'tags': ['python', 'beginner']}


# ====================================================================
# Пример 2. Форматирование: indent, ensure_ascii, sort_keys
# ====================================================================
payload = {"b": 2, "a": 1, "city": "Москва"}

print(json.dumps(payload))
# {"b": 2, "a": 1, "city": "\u041c\u043e\u0441\u043a\u0432\u0430"}

print(json.dumps(payload, sort_keys=True))
# {"a": 1, "b": 2, "city": "\u041c\u043e\u0441\u043a\u0432\u0430"}

print(json.dumps(payload, ensure_ascii=False))
# {"b": 2, "a": 1, "city": "Москва"}

print(json.dumps(payload, indent=2, sort_keys=True))
# {
#   "a": 1,
#   "b": 2,
#   "city": "\u041c\u043e\u0441\u043a\u0432\u0430"
# }


# ====================================================================
# Пример 3. Запись и чтение файла
# ====================================================================
from pathlib import Path

weather = {"city": "Berlin", "temperature": 22.5}
path = Path("weather.json")
path.write_text(json.dumps(weather, ensure_ascii=False, indent=2), encoding="utf-8")
print(path.read_text(encoding="utf-8"))
# {
#   "city": "Berlin",
#   "temperature": 22.5
# }

with path.open(encoding="utf-8") as f:
    loaded = json.load(f)
print(loaded)          # {'city': 'Berlin', 'temperature': 22.5}

path.unlink()
print(path.exists())   # False


# ====================================================================
# Пример 4. JSONDecodeError на битом JSON
# ====================================================================
bad_variants = [
    '{"name": "Alice", "age": 25,}',   # лишняя запятая перед }
    "{'name': 'Alice'}",               # одинарные кавычки
]
for variant in bad_variants:
    try:
        json.loads(variant)
    except json.JSONDecodeError as error:
        print(f"Ошибка: {error}")
# Ошибка: Expecting property name enclosed in double quotes: line 1 column 29 (char 28)
# Ошибка: Expecting property name enclosed in double quotes: line 1 column 2 (char 1)


# ====================================================================
# Пример 5. Что JSON не умеет сериализовать: set
# ====================================================================
try:
    json.dumps({"values": {1, 2, 3}})
except TypeError as error:
    print(f"TypeError: {error}")
# TypeError: Object of type set is not JSON serializable

print(json.dumps({"values": list({1, 2, 3})}))          # {"values": [1, 2, 3]}
print(json.dumps({"values": {1, 2, 3}}, default=list))  # {"values": [1, 2, 3]}


# ====================================================================
# Пример 6. Вложенные структуры: конфиг с массивом объектов
# ====================================================================
config = {
    "app": "shop",
    "servers": [
        {"host": "api-1", "port": 8000},
        {"host": "api-2", "port": 8001},
    ],
}
text = json.dumps(config, indent=2)
print(text)
# {
#   "app": "shop",
#   "servers": [
#     {
#       "host": "api-1",
#       "port": 8000
#     },
#     {
#       "host": "api-2",
#       "port": 8001
#     }
#   ]
# }

parsed = json.loads(text)
print(parsed["servers"][1]["host"])   # api-2


# ====================================================================
# Пример 7. Создание даты и strftime
# ====================================================================
from datetime import datetime

launch = datetime(2025, 6, 15, 9, 30)
print(launch)                                   # 2025-06-15 09:30:00
print(launch.strftime("%d.%m.%Y %H:%M"))        # 15.06.2025 09:30
print(launch.strftime("%A, %d %B %Y"))          # Sunday, 15 June 2025
print(launch.weekday())                         # 6 — воскресенье (0 = понедельник)


# ====================================================================
# Пример 8. strptime: строка → дата, и что будет при несовпадении формата
# ====================================================================
deadline = datetime.strptime("01.12.2025", "%d.%m.%Y")
print(deadline)   # 2025-12-01 00:00:00

try:
    datetime.strptime("15-06-2025", "%d/%m/%Y")
except ValueError as error:
    print(f"ValueError: {error}")
# ValueError: time data '15-06-2025' does not match format '%d/%m/%Y'


# ====================================================================
# Пример 9. timedelta: арифметика и сравнение дат
# ====================================================================
from datetime import date, timedelta

start = datetime(2025, 6, 15)
end = start + timedelta(days=14)
print(end.strftime("%Y-%m-%d"))   # 2025-06-29

difference = deadline - launch
print(difference)        # 168 days, 14:30:00
print(difference.days)   # 168

today = date(2025, 6, 20)
print(today > start.date())   # True


# ====================================================================
# Пример 10. Наивные и осведомлённые о часовом поясе даты
# ====================================================================
from datetime import timezone

naive = datetime(2025, 6, 15, 12, 0)
aware = datetime(2025, 6, 15, 12, 0, tzinfo=timezone.utc)
print(naive.tzinfo)   # None
print(aware.tzinfo)   # UTC

try:
    print(naive < aware)
except TypeError as error:
    print(f"TypeError: {error}")
# TypeError: can't compare offset-naive and offset-aware datetimes


# ====================================================================
# Пример 11. Совмещаем темы: datetime внутри JSON
# ====================================================================
event = {"title": "Deploy", "when": datetime(2025, 6, 15, 9, 30)}
try:
    json.dumps(event)
except TypeError as error:
    print(f"TypeError: {error}")
# TypeError: Object of type datetime is not JSON serializable

serializable = {**event, "when": event["when"].isoformat()}
text = json.dumps(serializable, ensure_ascii=False)
print(text)   # {"title": "Deploy", "when": "2025-06-15T09:30:00"}

restored = json.loads(text)
restored["when"] = datetime.fromisoformat(restored["when"])
print(restored)             # {'title': 'Deploy', 'when': datetime.datetime(2025, 6, 15, 9, 30)}
print(type(restored["when"]))   # <class 'datetime.datetime'>