import os
import unittest
from unittest.mock import Mock, patch

from api.services.memoir_images.storage import (
    TencentCosStorageService,
    normalize_cos_url,
    resolve_image_storage_key,
)


class MemoirImageStorageTest(unittest.TestCase):
    @patch.dict(
        os.environ,
        {
            "TENCENT_COS_SECRET_ID": "id",
            "TENCENT_COS_SECRET_KEY": "key",
            "TENCENT_COS_REGION": "ap-shanghai",
            "TENCENT_COS_BUCKET": "memoir-1250000000",
            "TENCENT_COS_BASE_URL": "https://memoir-1250000000.cos.ap-shanghai.myqcloud.com",
        },
        clear=False,
    )
    @patch("api.services.memoir_images.storage.CosS3Client")
    def test_from_env_reuses_singleton_for_same_config(self, client_cls):
        TencentCosStorageService._instance = None
        TencentCosStorageService._instance_config = None
        client_cls.return_value = Mock()

        first = TencentCosStorageService.from_env()
        second = TencentCosStorageService.from_env()

        self.assertIs(first, second)
        client_cls.assert_called_once()

    @patch("api.services.memoir_images.storage.CosS3Client")
    def test_upload_bytes_returns_persistent_cos_url(self, client_cls):
        client = Mock()
        client_cls.return_value = client
        storage = TencentCosStorageService(
            secret_id="id",
            secret_key="key",
            region="ap-shanghai",
            bucket="memoir-1250000000",
            base_url="https://memoir-1250000000.cos.ap-shanghai.myqcloud.com",
        )

        url = storage.upload_bytes(
            image_bytes=b"png-bytes",
            key="memoirs/u1/c1/0-demo.png",
            content_type="image/png",
        )

        self.assertEqual(
            url,
            "https://memoir-1250000000.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png",
        )
        client.put_object.assert_called_once()

    @patch("api.services.memoir_images.storage.CosS3Client")
    def test_upload_bytes_normalizes_duplicate_appid_suffix_in_base_url(self, client_cls):
        client = Mock()
        client_cls.return_value = client
        storage = TencentCosStorageService(
            secret_id="id",
            secret_key="key",
            region="ap-shanghai",
            bucket="life-echo-dev-1319381411",
            base_url="https://life-echo-dev-1319381411-appid.cos.ap-shanghai.myqcloud.com",
        )

        url = storage.upload_bytes(
            image_bytes=b"png-bytes",
            key="memoirs/u1/c1/0-demo.png",
            content_type="image/png",
        )

        self.assertEqual(
            url,
            "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png",
        )
        client.put_object.assert_called_once()

    def test_normalize_cos_url_repairs_existing_duplicate_appid_host(self):
        normalized = normalize_cos_url(
            "https://life-echo-dev-1319381411-appid.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png",
            bucket="life-echo-dev-1319381411",
            region="ap-shanghai",
        )

        self.assertEqual(
            normalized,
            "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png",
        )

    @patch("api.services.memoir_images.storage.CosS3Client")
    def test_get_download_url_returns_presigned_download_url(self, client_cls):
        client = Mock()
        client.get_presigned_download_url.return_value = "https://cos.example.com/0.png?q-sign-algorithm=sha1"
        client_cls.return_value = client
        storage = TencentCosStorageService(
            secret_id="id",
            secret_key="key",
            region="ap-shanghai",
            bucket="life-echo-dev-1319381411",
            base_url="https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com",
        )

        url = storage.get_download_url("memoirs/u1/c1/0-demo.png", expires=1800)

        self.assertEqual(url, "https://cos.example.com/0.png?q-sign-algorithm=sha1")
        client.get_presigned_download_url.assert_called_once_with(
            Bucket="life-echo-dev-1319381411",
            Key="memoirs/u1/c1/0-demo.png",
            Expired=1800,
        )

    def test_resolve_image_storage_key_prefers_explicit_storage_key(self):
        key = resolve_image_storage_key(
            {
                "storage_key": "memoirs/u1/c1/0-demo.png",
                "url": "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/other.png",
            }
        )

        self.assertEqual(key, "memoirs/u1/c1/0-demo.png")

    def test_resolve_image_storage_key_derives_key_from_existing_url(self):
        key = resolve_image_storage_key(
            {
                "url": "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png?q-sign-algorithm=sha1"
            }
        )

        self.assertEqual(key, "memoirs/u1/c1/0-demo.png")