# Copyright 2025 Google LLC
#
# 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.

import asyncio
import contextlib
from typing import AsyncGenerator
from typing import Generator
from typing import Union

from google.adk.agents.invocation_context import InvocationContext
from google.adk.agents.live_request_queue import LiveRequestQueue
from google.adk.agents.llm_agent import Agent
from google.adk.agents.llm_agent import LlmAgent
from google.adk.agents.run_config import RunConfig
from google.adk.artifacts.in_memory_artifact_service import InMemoryArtifactService
from google.adk.events.event import Event
from google.adk.memory.in_memory_memory_service import InMemoryMemoryService
from google.adk.models.base_llm import BaseLlm
from google.adk.models.base_llm_connection import BaseLlmConnection
from google.adk.models.llm_request import LlmRequest
from google.adk.models.llm_response import LlmResponse
from google.adk.plugins.base_plugin import BasePlugin
from google.adk.plugins.plugin_manager import PluginManager
from google.adk.runners import InMemoryRunner as AfInMemoryRunner
from google.adk.runners import Runner
from google.adk.sessions.in_memory_session_service import InMemorySessionService
from google.adk.sessions.session import Session
from google.adk.utils.context_utils import Aclosing
from google.genai import types
from google.genai.types import Part
from typing_extensions import override


def create_test_agent(name: str = 'test_agent') -> LlmAgent:
  """Create a simple test agent for use in unit tests.

  Args:
    name: The name of the test agent.

  Returns:
    A configured LlmAgent instance suitable for testing.
  """
  return LlmAgent(name=name)


class UserContent(types.Content):

  def __init__(self, text_or_part: str):
    parts = [
        types.Part.from_text(text=text_or_part)
        if isinstance(text_or_part, str)
        else text_or_part
    ]
    super().__init__(role='user', parts=parts)


class ModelContent(types.Content):

  def __init__(self, parts: list[types.Part]):
    super().__init__(role='model', parts=parts)


async def create_invocation_context(
    agent: Agent,
    user_content: str = '',
    run_config: RunConfig = None,
    plugins: list[BasePlugin] = [],
):
  invocation_id = 'test_id'
  artifact_service = InMemoryArtifactService()
  session_service = InMemorySessionService()
  memory_service = InMemoryMemoryService()
  invocation_context = InvocationContext(
      artifact_service=artifact_service,
      session_service=session_service,
      memory_service=memory_service,
      plugin_manager=PluginManager(plugins=plugins),
      invocation_id=invocation_id,
      agent=agent,
      session=await session_service.create_session(
          app_name='test_app', user_id='test_user'
      ),
      user_content=types.Content(
          role='user', parts=[types.Part.from_text(text=user_content)]
      ),
      run_config=run_config or RunConfig(),
  )
  if user_content:
    append_user_content(
        invocation_context, [types.Part.from_text(text=user_content)]
    )
  return invocation_context


def append_user_content(
    invocation_context: InvocationContext, parts: list[types.Part]
) -> Event:
  session = invocation_context.session
  event = Event(
      invocation_id=invocation_context.invocation_id,
      author='user',
      content=types.Content(role='user', parts=parts),
  )
  session.events.append(event)
  return event


# Extracts the contents from the events and transform them into a list of
# (author, simplified_content) tuples.
def simplify_events(events: list[Event]) -> list[(str, types.Part)]:
  return [(event.author, simplify_content(event.content)) for event in events]


# Simplifies the contents into a list of (author, simplified_content) tuples.
def simplify_contents(contents: list[types.Content]) -> list[(str, types.Part)]:
  return [(content.role, simplify_content(content)) for content in contents]


# Simplifies the content so it's easier to assert.
# - If there is only one part, return part
# - If the only part is pure text, return stripped_text
# - If there are multiple parts, return parts
# - remove function_call_id if it exists
def simplify_content(
    content: types.Content,
) -> Union[str, types.Part, list[types.Part]]:
  for part in content.parts:
    if part.function_call and part.function_call.id:
      part.function_call.id = None
    if part.function_response and part.function_response.id:
      part.function_response.id = None
  if len(content.parts) == 1:
    if content.parts[0].text:
      return content.parts[0].text.strip()
    else:
      return content.parts[0]
  return content.parts


def get_user_content(message: types.ContentUnion) -> types.Content:
  return message if isinstance(message, types.Content) else UserContent(message)


class TestInMemoryRunner(AfInMemoryRunner):
  """InMemoryRunner that is tailored for tests, features async run method.

  app_name is hardcoded as InMemoryRunner in the parent class.
  """

  async def run_async_with_new_session(
      self, new_message: types.ContentUnion
  ) -> list[Event]:

    collected_events: list[Event] = []
    async for event in self.run_async_with_new_session_agen(new_message):
      collected_events.append(event)

    return collected_events

  async def run_async_with_new_session_agen(
      self, new_message: types.ContentUnion
  ) -> AsyncGenerator[Event, None]:
    session = await self.session_service.create_session(
        app_name='InMemoryRunner', user_id='test_user'
    )
    agen = self.run_async(
        user_id=session.user_id,
        session_id=session.id,
        new_message=get_user_content(new_message),
    )
    async with Aclosing(agen):
      async for event in agen:
        yield event


class InMemoryRunner:
  """InMemoryRunner that is tailored for tests."""

  def __init__(
      self,
      root_agent: Union[Agent, LlmAgent],
      response_modalities: list[str] = None,
      plugins: list[BasePlugin] = [],
  ):
    self.root_agent = root_agent
    self.runner = Runner(
        app_name='test_app',
        agent=root_agent,
        artifact_service=InMemoryArtifactService(),
        session_service=InMemorySessionService(),
        memory_service=InMemoryMemoryService(),
        plugins=plugins,
    )
    self.session_id = None

  @property
  def session(self) -> Session:
    if not self.session_id:
      session = self.runner.session_service.create_session_sync(
          app_name='test_app', user_id='test_user'
      )
      self.session_id = session.id
      return session
    return self.runner.session_service.get_session_sync(
        app_name='test_app', user_id='test_user', session_id=self.session_id
    )

  def run(self, new_message: types.ContentUnion) -> list[Event]:
    return list(
        self.runner.run(
            user_id=self.session.user_id,
            session_id=self.session.id,
            new_message=get_user_content(new_message),
        )
    )

  async def run_async(self, new_message: types.ContentUnion) -> list[Event]:
    events = []
    async for event in self.runner.run_async(
        user_id=self.session.user_id,
        session_id=self.session.id,
        new_message=get_user_content(new_message),
    ):
      events.append(event)
    return events

  def run_live(
      self, live_request_queue: LiveRequestQueue, run_config: RunConfig = None
  ) -> list[Event]:
    collected_responses = []

    async def consume_responses(session: Session):
      run_res = self.runner.run_live(
          session=session,
          live_request_queue=live_request_queue,
          run_config=run_config or RunConfig(),
      )

      async for response in run_res:
        collected_responses.append(response)
        # When we have enough response, we should return
        if len(collected_responses) >= 1:
          return

    try:
      session = self.session
      asyncio.run(consume_responses(session))
    except asyncio.TimeoutError:
      print('Returning any partial results collected so far.')

    return collected_responses


class MockModel(BaseLlm):
  model: str = 'mock'

  requests: list[LlmRequest] = []
  responses: list[LlmResponse]
  error: Union[Exception, None] = None
  response_index: int = -1

  @classmethod
  def create(
      cls,
      responses: Union[
          list[types.Part], list[LlmResponse], list[str], list[list[types.Part]]
      ],
      error: Union[Exception, None] = None,
  ):
    if error and not responses:
      return cls(responses=[], error=error)
    if not responses:
      return cls(responses=[])
    elif isinstance(responses[0], LlmResponse):
      # responses is list[LlmResponse]
      return cls(responses=responses)
    else:
      responses = [
          LlmResponse(content=ModelContent(item))
          if isinstance(item, list) and isinstance(item[0], types.Part)
          # responses is list[list[Part]]
          else LlmResponse(
              content=ModelContent(
                  # responses is list[str] or list[Part]
                  [Part(text=item) if isinstance(item, str) else item]
              )
          )
          for item in responses
          if item
      ]

      return cls(responses=responses)

  @classmethod
  @override
  def supported_models(cls) -> list[str]:
    return ['mock']

  def generate_content(
      self, llm_request: LlmRequest, stream: bool = False
  ) -> Generator[LlmResponse, None, None]:
    if self.error:
      raise self.error
    # Increasement of the index has to happen before the yield.
    self.response_index += 1
    self.requests.append(llm_request)
    # yield LlmResponse(content=self.responses[self.response_index])
    yield self.responses[self.response_index]

  @override
  async def generate_content_async(
      self, llm_request: LlmRequest, stream: bool = False
  ) -> AsyncGenerator[LlmResponse, None]:
    # Increasement of the index has to happen before the yield.
    self.response_index += 1
    self.requests.append(llm_request)
    yield self.responses[self.response_index]

  @contextlib.asynccontextmanager
  async def connect(self, llm_request: LlmRequest) -> BaseLlmConnection:
    """Creates a live connection to the LLM."""
    self.requests.append(llm_request)
    yield MockLlmConnection(self.responses)


class MockLlmConnection(BaseLlmConnection):

  def __init__(self, llm_responses: list[LlmResponse]):
    self.llm_responses = llm_responses

  async def send_history(self, history: list[types.Content]):
    pass

  async def send_content(self, content: types.Content):
    pass

  async def send(self, data):
    pass

  async def send_realtime(self, blob: types.Blob):
    pass

  async def receive(self) -> AsyncGenerator[LlmResponse, None]:
    """Yield each of the pre-defined LlmResponses."""
    for response in self.llm_responses:
      yield response

  async def close(self):
    pass
