from collections.abc import Generator

from flask import Flask
from qcloud_cos import CosConfig, CosS3Client

from extensions.storage.base_storage import BaseStorage


class TencentCosStorage(BaseStorage):
    """Implementation for Tencent Cloud COS storage."""

    def __init__(self, app: Flask):
        super().__init__(app)
        app_config = self.app.config
        self.bucket_name = app_config.get("TENCENT_COS_BUCKET_NAME")
        config = CosConfig(
            Region=app_config.get("TENCENT_COS_REGION"),
            SecretId=app_config.get("TENCENT_COS_SECRET_ID"),
            SecretKey=app_config.get("TENCENT_COS_SECRET_KEY"),
            Scheme=app_config.get("TENCENT_COS_SCHEME"),
        )
        self.client = CosS3Client(config)

    def save(self, filename, data):
        self.client.put_object(Bucket=self.bucket_name, Body=data, Key=filename)

    def load_once(self, filename: str) -> bytes:
        data = self.client.get_object(Bucket=self.bucket_name, Key=filename)["Body"].get_raw_stream().read()
        return data

    def load_stream(self, filename: str) -> Generator:
        def generate(filename: str = filename) -> Generator:
            response = self.client.get_object(Bucket=self.bucket_name, Key=filename)
            yield from response["Body"].get_stream(chunk_size=4096)

        return generate()

    def download(self, filename, target_filepath):
        response = self.client.get_object(Bucket=self.bucket_name, Key=filename)
        response["Body"].get_stream_to_file(target_filepath)

    def exists(self, filename):
        return self.client.object_exists(Bucket=self.bucket_name, Key=filename)

    def delete(self, filename):
        self.client.delete_object(Bucket=self.bucket_name, Key=filename)