"""
Copyright 2024-2026 ReplyPier

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Delivery of help-center article images on both storage backends.
"""
import os
from unittest.mock import MagicMock, patch

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient

from app.api.help_center_images import router
from app.core.config import settings
from app.services.help_center_images import UPLOAD_FOLDER, store_article_image

VALID_NAME = "7b6fe1aa-1234-4c5d-9e0f-0123456789ab.png"


@pytest.fixture
def client() -> TestClient:
    app = FastAPI()
    app.include_router(router, prefix=f"{settings.API_V1_STR}/help-center")
    # follow_redirects=False so the S3 redirect is asserted, not chased to AWS.
    return TestClient(app, follow_redirects=False)


def _url(name: str) -> str:
    return f"{settings.API_V1_STR}/help-center/images/{name}"


def test_s3_mode_redirects_to_a_freshly_signed_url(client):
    signed = f"https://s3.us-east-1.amazonaws.com/b/{UPLOAD_FOLDER}/{VALID_NAME}?Signature=S"
    signing_client = MagicMock()
    signing_client.generate_presigned_url.return_value = signed

    # settings is a single shared object, so one patch covers both modules.
    with patch.object(settings, 'S3_FILE_STORAGE', True), \
         patch('app.core.s3.get_s3_client', return_value=signing_client):
        response = client.get(_url(VALID_NAME))

    assert response.status_code == 307
    assert response.headers["location"] == signed
    # Signed from the key, not from a stored URL.
    assert signing_client.generate_presigned_url.call_args.kwargs['Params']['Key'] == (
        f"{UPLOAD_FOLDER}/{VALID_NAME}"
    )


def test_local_mode_redirects_to_the_uploads_mount(client):
    """The local flow must keep working with S3_FILE_STORAGE=false.

    Delivery is delegated to the /api/v1/uploads static mount, which both the
    main app and public_app already serve this directory from.
    """
    with patch.object(settings, 'S3_FILE_STORAGE', False):
        response = client.get(_url(VALID_NAME))

    assert response.status_code == 307
    assert response.headers["location"] == (
        f"{settings.API_V1_STR}/uploads/{UPLOAD_FOLDER}/{VALID_NAME}"
    )


def test_never_redirects_off_s3(client):
    """Defence in depth: only ever bounce a visitor to an S3 host."""
    with patch.object(settings, 'S3_FILE_STORAGE', True), \
         patch('app.api.help_center_images.sign_s3_key', return_value="https://evil.example.com/x"):
        response = client.get(_url(VALID_NAME))

    assert response.status_code == 404
    assert "location" not in response.headers


@pytest.mark.asyncio
async def test_local_upload_then_serve_round_trip(client, tmp_path, monkeypatch):
    """End-to-end with S3_FILE_STORAGE=false: the path store_article_image bakes
    into the answer Markdown is the one this route can serve."""
    monkeypatch.chdir(tmp_path)

    with patch.object(settings, 'S3_FILE_STORAGE', False):
        baked = await store_article_image(b"\x89PNG round trip", "image/png")
        assert baked.startswith(f"{settings.API_V1_STR}/help-center/images/")

        name = baked.rsplit("/", 1)[-1]
        response = client.get(baked)

    # The route resolves the baked path to the mount, and the bytes really are
    # on disk where that mount serves from.
    assert response.status_code == 307
    assert response.headers["location"] == (
        f"{settings.API_V1_STR}/uploads/{UPLOAD_FOLDER}/{name}"
    )
    served_from = os.path.join("uploads", UPLOAD_FOLDER, name)
    assert os.path.isfile(served_from)
    with open(served_from, "rb") as f:
        assert f.read() == b"\x89PNG round trip"


@pytest.mark.parametrize("name", [
    "../../etc/passwd",
    "..%2f..%2fagents%2fphoto.png",
    "not-a-uuid.png",
    f"{VALID_NAME[:-4]}.svg",   # extension outside FAQ_IMAGE_TYPES
    f"{VALID_NAME}.exe",
])
def test_rejects_names_that_are_not_ours(client, name):
    """The name is interpolated into an S3 key and a filesystem path, so a
    non-matching name must 404 before either happens."""
    signing_client = MagicMock()
    with patch('app.api.help_center_images.settings.S3_FILE_STORAGE', True), \
         patch('app.core.s3.get_s3_client', return_value=signing_client):
        response = client.get(_url(name))

    assert response.status_code == 404
    signing_client.generate_presigned_url.assert_not_called()