import threading
from http.server import HTTPServer, BaseHTTPRequestHandler
import pytest
from flask import Flask
from upload.backend.upload_refs.blueprint import create_upload_refs_blueprint
from upload.backend.session import get_files, cleanup


class MockBufferHandler(BaseHTTPRequestHandler):
    storage = {}

    def do_PUT(self):
        length = int(self.headers.get("Content-Length", 0))
        data = self.rfile.read(length)
        MockBufferHandler.storage[self.path] = data
        self.send_response(201)
        self.end_headers()

    def do_GET(self):
        data = MockBufferHandler.storage.get(self.path)
        if data is None:
            self.send_response(404)
            self.end_headers()
            return
        self.send_response(200)
        self.send_header("Content-Length", str(len(data)))
        self.end_headers()
        self.wfile.write(data)

    def do_DELETE(self):
        MockBufferHandler.storage.pop(self.path, None)
        self.send_response(204)
        self.end_headers()

    def log_message(self, format, *args):
        pass  # suppress console logs in tests


@pytest.fixture(scope="module")
def mock_server():
    server = HTTPServer(("127.0.0.1", 0), MockBufferHandler)
    port = server.server_port
    thread = threading.Thread(target=server.serve_forever, daemon=True)
    thread.start()
    yield f"http://127.0.0.1:{port}/buffer/"
    server.shutdown()


def test_upload_refs_pull_and_delete(mock_server):
    # Put a file into mock buffer
    file_path = "/buffer/token123_0"
    content = b"Content of test document for layer 2 transit"
    MockBufferHandler.storage[file_path] = content

    received_events = []
    def on_received(sid, name, data):
        received_events.append((sid, name, data))

    app = Flask(__name__)
    bp = create_upload_refs_blueprint({
        "vmUploadPrefix": mock_server,
        "pullRetries": 1,
        "pullRetryDelay": 0.1,
        "onFileReceived": on_received,
    })
    app.register_blueprint(bp)
    client = app.test_client()

    file_url = mock_server + "token123_0"
    resp = client.post("/api/upload_refs", json={
        "files": [
            {"name": "test_doc.pdf", "size": len(content), "url": file_url}
        ]
    })

    assert resp.status_code == 200
    data = resp.get_json()
    assert data["ok"] is True
    sid = data["session"]
    assert data["count"] == 1
    assert data["added"] == 1

    # Verify file is in session memory
    files = get_files(sid)
    assert len(files) == 1
    assert files[0] == ("test_doc.pdf", content)

    # Verify callback for Layer 3 was triggered
    assert len(received_events) == 1
    assert received_events[0] == (sid, "test_doc.pdf", content)

    # Verify file was DELETED from mock buffer (RAM clean!)
    assert file_path not in MockBufferHandler.storage

    cleanup(sid)


def test_upload_refs_ssrf_protection(mock_server):
    app = Flask(__name__)
    bp = create_upload_refs_blueprint({
        "vmUploadPrefix": mock_server,
    })
    app.register_blueprint(bp)
    client = app.test_client()

    # Try to pass an evil URL outside vmUploadPrefix
    evil_url = "http://169.254.169.254/latest/meta-data/"
    resp = client.post("/api/upload_refs", json={
        "files": [
            {"name": "evil.txt", "size": 100, "url": evil_url}
        ]
    })
    assert resp.status_code == 200
    data = resp.get_json()
    assert data["ok"] is True
    sid = data["session"]
    assert data["added"] == 0
    assert data["count"] == 0

    cleanup(sid)