# Задание 5. Финал: мини-скрапер с aiofiles
# Объедини всё: стяни 10 постов с jsonplaceholder, 
# ограничь конкурентность семафором, 
# и асинхронно сохрани каждый в отдельный JSON-файл через aiofiles. 
# Бонус: добавь обработку ошибок так, чтобы падение одного запроса не роняло остальные (подумай, gather или TaskGroup тут уместнее и почему).


import asyncio
import aiofiles
from datetime import datetime
import random
import httpx
import json


async def fetch(url: str, client: httpx.AsyncClient, sem: asyncio.Semaphore) -> dict:
    async with sem:
        try:
            print(f"Fetching of {url} started at {datetime.today()}")
            r = await client.get(url)
            data = r.json()
            print(f"Fetching of {url} ended at {datetime.today()}")
            return {f"Post_{url.split("/")[-1]}.json": data}
        except httpx.HTTPStatusError as e:
            print(f"HTTP error: {e}")
        except httpx.RequestError as e:
            print(f"Request failed: {e}")


async def save_file(file_name: str, data: str):
        try:
            async with aiofiles.open(file_name, "w") as file:
                await file.write(json.dumps(data))
                print(f"Written {file_name}")
        except IOError:
            print(f"Can't write file {file_name}...")


async def main():
    urls = [f"https://jsonplaceholder.typicode.com/posts/{n}" for n in range(1, 11)]
    semaphor = asyncio.Semaphore(2)
    
    async with httpx.AsyncClient(timeout=10) as client:
        results = await asyncio.gather(
            *[fetch(url, client, semaphor) for url in urls], return_exceptions=True
        )

    for result in results:
        for file_name, json in result.items():
            await save_file(file_name, json)    

if __name__ == "__main__":
    asyncio.run(main())