"""
Test configuration and fixtures for Orchard backend tests.

This module provides:
- Database fixtures with test isolation
- Mock S3 storage using moto
- Test data factories for common scenarios
"""

import os
import pytest
import hashlib
from typing import Generator, BinaryIO
from unittest.mock import MagicMock, patch
import io

# Set test environment before importing app modules
os.environ["ORCHARD_DATABASE_HOST"] = "localhost"
os.environ["ORCHARD_DATABASE_PORT"] = "5432"
os.environ["ORCHARD_DATABASE_USER"] = "test"
os.environ["ORCHARD_DATABASE_PASSWORD"] = "test"
os.environ["ORCHARD_DATABASE_DBNAME"] = "orchard_test"
os.environ["ORCHARD_S3_ENDPOINT"] = "http://localhost:9000"
os.environ["ORCHARD_S3_BUCKET"] = "test-bucket"
os.environ["ORCHARD_S3_ACCESS_KEY_ID"] = "test"
os.environ["ORCHARD_S3_SECRET_ACCESS_KEY"] = "test"


# =============================================================================
# Test Data Factories
# =============================================================================


def create_test_file(content: bytes = None, size: int = 1024) -> io.BytesIO:
    """
    Create a test file with known content.

    Args:
        content: Specific content to use, or None to generate random-ish content
        size: Size of generated content if content is None

    Returns:
        BytesIO object with the content
    """
    if content is None:
        content = os.urandom(size)
    return io.BytesIO(content)


def compute_sha256(content: bytes) -> str:
    """Compute SHA256 hash of content as lowercase hex string."""
    return hashlib.sha256(content).hexdigest()


def compute_md5(content: bytes) -> str:
    """Compute MD5 hash of content as lowercase hex string."""
    return hashlib.md5(content).hexdigest()


def compute_sha1(content: bytes) -> str:
    """Compute SHA1 hash of content as lowercase hex string."""
    return hashlib.sha1(content).hexdigest()


# Known test data with pre-computed hashes
TEST_CONTENT_HELLO = b"Hello, World!"
TEST_HASH_HELLO = "dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f"
TEST_MD5_HELLO = "65a8e27d8879283831b664bd8b7f0ad4"
TEST_SHA1_HELLO = "0a0a9f2a6772942557ab5355d76af442f8f65e01"

TEST_CONTENT_EMPTY = b""
# Note: Empty content should be rejected by the storage layer

TEST_CONTENT_BINARY = bytes(range(256))
TEST_HASH_BINARY = compute_sha256(TEST_CONTENT_BINARY)


# =============================================================================
# Mock Storage Fixtures
# =============================================================================


class MockS3Client:
    """Mock S3 client for unit testing without actual S3/MinIO."""

    def __init__(self):
        self.objects = {}  # key -> content
        self.bucket = "test-bucket"

    def put_object(self, Bucket: str, Key: str, Body: bytes) -> dict:
        self.objects[Key] = Body
        return {"ETag": f'"{compute_md5(Body)}"'}

    def get_object(self, Bucket: str, Key: str, **kwargs) -> dict:
        if Key not in self.objects:
            raise Exception("NoSuchKey")
        content = self.objects[Key]
        return {
            "Body": io.BytesIO(content),
            "ContentLength": len(content),
        }

    def head_object(self, Bucket: str, Key: str) -> dict:
        if Key not in self.objects:
            from botocore.exceptions import ClientError

            error_response = {"Error": {"Code": "404", "Message": "Not Found"}}
            raise ClientError(error_response, "HeadObject")
        content = self.objects[Key]
        return {
            "ContentLength": len(content),
            "ETag": f'"{compute_md5(content)}"',
        }

    def delete_object(self, Bucket: str, Key: str) -> dict:
        if Key in self.objects:
            del self.objects[Key]
        return {}

    def head_bucket(self, Bucket: str) -> dict:
        return {}

    def create_multipart_upload(self, Bucket: str, Key: str) -> dict:
        return {"UploadId": "test-upload-id"}

    def upload_part(
        self, Bucket: str, Key: str, UploadId: str, PartNumber: int, Body: bytes
    ) -> dict:
        return {"ETag": f'"{compute_md5(Body)}"'}

    def complete_multipart_upload(
        self, Bucket: str, Key: str, UploadId: str, MultipartUpload: dict
    ) -> dict:
        return {"ETag": '"test-etag"'}

    def abort_multipart_upload(self, Bucket: str, Key: str, UploadId: str) -> dict:
        return {}

    def generate_presigned_url(
        self, ClientMethod: str, Params: dict, ExpiresIn: int
    ) -> str:
        return f"https://test-bucket.s3.amazonaws.com/{Params['Key']}?presigned=true"


@pytest.fixture
def mock_s3_client() -> MockS3Client:
    """Provide a mock S3 client for unit tests."""
    return MockS3Client()


@pytest.fixture
def mock_storage(mock_s3_client):
    """
    Provide a mock storage instance for unit tests.

    Uses the MockS3Client to avoid actual S3/MinIO calls.
    """
    from app.storage import S3Storage

    storage = S3Storage.__new__(S3Storage)
    storage.client = mock_s3_client
    storage.bucket = "test-bucket"
    storage._active_uploads = {}

    return storage


# =============================================================================
# Database Fixtures (for integration tests)
# =============================================================================


@pytest.fixture(scope="session")
def test_db_url():
    """Get the test database URL."""
    return (
        f"postgresql://{os.environ['ORCHARD_DATABASE_USER']}:"
        f"{os.environ['ORCHARD_DATABASE_PASSWORD']}@"
        f"{os.environ['ORCHARD_DATABASE_HOST']}:"
        f"{os.environ['ORCHARD_DATABASE_PORT']}/"
        f"{os.environ['ORCHARD_DATABASE_DBNAME']}"
    )


# =============================================================================
# HTTP Client Fixtures (for API tests)
# =============================================================================


@pytest.fixture
def test_app():
    """
    Create a test FastAPI application.

    Note: This requires the database to be available for integration tests.
    For unit tests, use mock_storage fixture instead.
    """
    from fastapi.testclient import TestClient
    from app.main import app

    return TestClient(app)