# Copyright (c) Microsoft. All rights reserved.

from collections.abc import AsyncIterable, Awaitable
from typing import Any, Literal, overload

import pytest
from agent_framework import (
    AgentExecutorResponse,
    AgentResponse,
    AgentResponseUpdate,
    AgentRunInputs,
    AgentSession,
    BaseAgent,
    Content,
    Executor,
    Message,
    ResponseStream,
    TypeCompatibilityError,
    WorkflowContext,
    WorkflowRunState,
    handler,
)
from agent_framework._workflows._checkpoint import InMemoryCheckpointStorage
from agent_framework.orchestrations import SequentialBuilder


class _EchoAgent(BaseAgent):
    """Simple agent that appends a single assistant message with its name."""

    @overload
    def run(
        self,
        messages: AgentRunInputs | None = ...,
        *,
        stream: Literal[False] = ...,
        session: AgentSession | None = ...,
        **kwargs: Any,
    ) -> Awaitable[AgentResponse[Any]]: ...
    @overload
    def run(
        self,
        messages: AgentRunInputs | None = ...,
        *,
        stream: Literal[True],
        session: AgentSession | None = ...,
        **kwargs: Any,
    ) -> ResponseStream[AgentResponseUpdate, AgentResponse[Any]]: ...

    def run(
        self,
        messages: AgentRunInputs | None = None,
        *,
        stream: bool = False,
        session: AgentSession | None = None,
        **kwargs: Any,
    ) -> Awaitable[AgentResponse[Any]] | ResponseStream[AgentResponseUpdate, AgentResponse[Any]]:
        if stream:

            async def _stream() -> AsyncIterable[AgentResponseUpdate]:
                yield AgentResponseUpdate(contents=[Content.from_text(text=f"{self.name} reply")])

            return ResponseStream(_stream(), finalizer=AgentResponse.from_updates)

        async def _run() -> AgentResponse:
            return AgentResponse(messages=[Message("assistant", [f"{self.name} reply"])])

        return _run()


class _SummarizerExec(Executor):
    """Custom executor that summarizes by appending a short assistant message."""

    @handler
    async def summarize(self, agent_response: AgentExecutorResponse, ctx: WorkflowContext[list[Message]]) -> None:
        conversation = agent_response.full_conversation or []
        user_texts = [m.text for m in conversation if m.role == "user"]
        agents = [m.author_name or m.role for m in conversation if m.role == "assistant"]
        summary = Message("assistant", [f"Summary of users:{len(user_texts)} agents:{len(agents)}"])
        await ctx.send_message(list(conversation) + [summary])


class _InvalidExecutor(Executor):
    """Invalid executor that does not have a handler that accepts a list of chat messages"""

    @handler
    async def summarize(self, conversation: list[str], ctx: WorkflowContext[list[Message]]) -> None:
        pass


def test_sequential_builder_rejects_empty_participants() -> None:
    with pytest.raises(ValueError):
        SequentialBuilder(participants=[])


def test_sequential_builder_validation_rejects_invalid_executor() -> None:
    """Test that adding an invalid executor to the builder raises an error."""
    with pytest.raises(TypeCompatibilityError):
        SequentialBuilder(participants=[_EchoAgent(id="agent1", name="A1"), _InvalidExecutor(id="invalid")]).build()


async def test_sequential_agents_append_to_context() -> None:
    a1 = _EchoAgent(id="agent1", name="A1")
    a2 = _EchoAgent(id="agent2", name="A2")

    wf = SequentialBuilder(participants=[a1, a2]).build()

    completed = False
    output: list[Message] | None = None
    async for ev in wf.run("hello sequential", stream=True):
        if ev.type == "status" and ev.state == WorkflowRunState.IDLE:
            completed = True
        elif ev.type == "output":
            output = ev.data  # type: ignore[assignment]
        if completed and output is not None:
            break

    assert completed
    assert output is not None
    assert isinstance(output, list)
    msgs: list[Message] = output
    assert len(msgs) == 3
    assert msgs[0].role == "user" and "hello sequential" in msgs[0].text
    assert msgs[1].role == "assistant" and (msgs[1].author_name == "A1" or True)
    assert msgs[2].role == "assistant" and (msgs[2].author_name == "A2" or True)
    assert "A1 reply" in msgs[1].text
    assert "A2 reply" in msgs[2].text


async def test_sequential_with_custom_executor_summary() -> None:
    a1 = _EchoAgent(id="agent1", name="A1")
    summarizer = _SummarizerExec(id="summarizer")

    wf = SequentialBuilder(participants=[a1, summarizer]).build()

    completed = False
    output: list[Message] | None = None
    async for ev in wf.run("topic X", stream=True):
        if ev.type == "status" and ev.state == WorkflowRunState.IDLE:
            completed = True
        elif ev.type == "output":
            output = ev.data
        if completed and output is not None:
            break

    assert completed
    assert output is not None
    msgs: list[Message] = output
    # Expect: [user, A1 reply, summary]
    assert len(msgs) == 3
    assert msgs[0].role == "user"
    assert msgs[1].role == "assistant" and "A1 reply" in msgs[1].text
    assert msgs[2].role == "assistant" and msgs[2].text.startswith("Summary of users:")


async def test_sequential_checkpoint_resume_round_trip() -> None:
    storage = InMemoryCheckpointStorage()

    initial_agents = (_EchoAgent(id="agent1", name="A1"), _EchoAgent(id="agent2", name="A2"))
    wf = SequentialBuilder(participants=list(initial_agents), checkpoint_storage=storage).build()

    baseline_output: list[Message] | None = None
    async for ev in wf.run("checkpoint sequential", stream=True):
        if ev.type == "output":
            baseline_output = ev.data  # type: ignore[assignment]
        if ev.type == "status" and ev.state == WorkflowRunState.IDLE:
            break

    assert baseline_output is not None

    checkpoints = await storage.list_checkpoints(workflow_name=wf.name)
    assert checkpoints
    checkpoints.sort(key=lambda cp: cp.timestamp)
    resume_checkpoint = checkpoints[0]

    resumed_agents = (_EchoAgent(id="agent1", name="A1"), _EchoAgent(id="agent2", name="A2"))
    wf_resume = SequentialBuilder(participants=list(resumed_agents), checkpoint_storage=storage).build()

    resumed_output: list[Message] | None = None
    async for ev in wf_resume.run(checkpoint_id=resume_checkpoint.checkpoint_id, stream=True):
        if ev.type == "output":
            resumed_output = ev.data  # type: ignore[assignment]
        if ev.type == "status" and ev.state in (
            WorkflowRunState.IDLE,
            WorkflowRunState.IDLE_WITH_PENDING_REQUESTS,
        ):
            break

    assert resumed_output is not None
    assert [m.role for m in resumed_output] == [m.role for m in baseline_output]
    assert [m.text for m in resumed_output] == [m.text for m in baseline_output]


async def test_sequential_checkpoint_runtime_only() -> None:
    """Test checkpointing configured ONLY at runtime, not at build time."""
    storage = InMemoryCheckpointStorage()

    agents = (_EchoAgent(id="agent1", name="A1"), _EchoAgent(id="agent2", name="A2"))
    wf = SequentialBuilder(participants=list(agents)).build()

    baseline_output: list[Message] | None = None
    async for ev in wf.run("runtime checkpoint test", checkpoint_storage=storage, stream=True):
        if ev.type == "output":
            baseline_output = ev.data  # type: ignore[assignment]
        if ev.type == "status" and ev.state == WorkflowRunState.IDLE:
            break

    assert baseline_output is not None

    checkpoints = await storage.list_checkpoints(workflow_name=wf.name)
    assert checkpoints
    checkpoints.sort(key=lambda cp: cp.timestamp)
    resume_checkpoint = checkpoints[0]

    resumed_agents = (_EchoAgent(id="agent1", name="A1"), _EchoAgent(id="agent2", name="A2"))
    wf_resume = SequentialBuilder(participants=list(resumed_agents)).build()

    resumed_output: list[Message] | None = None
    async for ev in wf_resume.run(
        checkpoint_id=resume_checkpoint.checkpoint_id, checkpoint_storage=storage, stream=True
    ):
        if ev.type == "output":
            resumed_output = ev.data  # type: ignore[assignment]
        if ev.type == "status" and ev.state in (
            WorkflowRunState.IDLE,
            WorkflowRunState.IDLE_WITH_PENDING_REQUESTS,
        ):
            break

    assert resumed_output is not None
    assert [m.role for m in resumed_output] == [m.role for m in baseline_output]
    assert [m.text for m in resumed_output] == [m.text for m in baseline_output]


async def test_sequential_checkpoint_runtime_overrides_buildtime() -> None:
    """Test that runtime checkpoint storage overrides build-time configuration."""
    import tempfile

    with tempfile.TemporaryDirectory() as temp_dir1, tempfile.TemporaryDirectory() as temp_dir2:
        from agent_framework._workflows._checkpoint import FileCheckpointStorage

        buildtime_storage = FileCheckpointStorage(temp_dir1)
        runtime_storage = FileCheckpointStorage(temp_dir2)

        agents = (_EchoAgent(id="agent1", name="A1"), _EchoAgent(id="agent2", name="A2"))
        wf = SequentialBuilder(participants=list(agents), checkpoint_storage=buildtime_storage).build()

        baseline_output: list[Message] | None = None
        async for ev in wf.run("override test", checkpoint_storage=runtime_storage, stream=True):
            if ev.type == "output":
                baseline_output = ev.data  # type: ignore[assignment]
            if ev.type == "status" and ev.state == WorkflowRunState.IDLE:
                break

        assert baseline_output is not None

        buildtime_checkpoints = await buildtime_storage.list_checkpoints(workflow_name=wf.name)
        runtime_checkpoints = await runtime_storage.list_checkpoints(workflow_name=wf.name)

        assert len(runtime_checkpoints) > 0, "Runtime storage should have checkpoints"
        assert len(buildtime_checkpoints) == 0, "Build-time storage should have no checkpoints when overridden"


async def test_sequential_builder_reusable_after_build_with_participants() -> None:
    """Test that the builder can be reused to build multiple identical workflows with participants()."""
    a1 = _EchoAgent(id="agent1", name="A1")
    a2 = _EchoAgent(id="agent2", name="A2")

    builder = SequentialBuilder(participants=[a1, a2])

    # Build first workflow
    builder.build()

    assert builder._participants[0] is a1  # type: ignore
    assert builder._participants[1] is a2  # type: ignore


# ---------------------------------------------------------------------------
# chain_only_agent_responses tests
# ---------------------------------------------------------------------------


class _CapturingAgent(BaseAgent):
    """Agent that records the messages it received and returns a configurable reply."""

    def __init__(self, *, reply_text: str = "reply", **kwargs: Any):
        super().__init__(**kwargs)
        self.reply_text = reply_text
        self.last_messages: list[Message] = []

    @overload
    def run(
        self,
        messages: AgentRunInputs | None = ...,
        *,
        stream: Literal[False] = ...,
        session: AgentSession | None = ...,
        **kwargs: Any,
    ) -> Awaitable[AgentResponse[Any]]: ...
    @overload
    def run(
        self,
        messages: AgentRunInputs | None = ...,
        *,
        stream: Literal[True],
        session: AgentSession | None = ...,
        **kwargs: Any,
    ) -> ResponseStream[AgentResponseUpdate, AgentResponse[Any]]: ...

    def run(
        self,
        messages: AgentRunInputs | None = None,
        *,
        stream: bool = False,
        session: AgentSession | None = None,
        **kwargs: Any,
    ) -> Awaitable[AgentResponse[Any]] | ResponseStream[AgentResponseUpdate, AgentResponse[Any]]:
        captured: list[Message] = []
        if messages:
            for m in messages:  # type: ignore[union-attr]
                if isinstance(m, Message):
                    captured.append(m)
                elif isinstance(m, str):
                    captured.append(Message("user", [m]))
        self.last_messages = captured

        if stream:

            async def _stream() -> AsyncIterable[AgentResponseUpdate]:
                yield AgentResponseUpdate(contents=[Content.from_text(text=self.reply_text)])

            return ResponseStream(_stream(), finalizer=AgentResponse.from_updates)

        async def _run() -> AgentResponse:
            return AgentResponse(messages=[Message("assistant", [self.reply_text])])

        return _run()


async def test_chain_only_agent_responses_false_passes_full_conversation() -> None:
    """Default (chain_only_agent_responses=False) passes full conversation to the second agent."""
    a1 = _CapturingAgent(id="agent1", name="A1", reply_text="A1 reply")
    a2 = _CapturingAgent(id="agent2", name="A2", reply_text="A2 reply")

    wf = SequentialBuilder(participants=[a1, a2], chain_only_agent_responses=False).build()

    async for ev in wf.run("hello", stream=True):
        if ev.type == "status" and ev.state == WorkflowRunState.IDLE:
            break

    # Second agent should see full conversation: [user("hello"), assistant("A1 reply")]
    seen = a2.last_messages
    assert len(seen) == 2
    assert seen[0].role == "user" and "hello" in (seen[0].text or "")
    assert seen[1].role == "assistant" and "A1 reply" in (seen[1].text or "")


async def test_chain_only_agent_responses_true_passes_only_agent_messages() -> None:
    """chain_only_agent_responses=True passes only the previous agent's response messages."""
    a1 = _CapturingAgent(id="agent1", name="A1", reply_text="A1 reply")
    a2 = _CapturingAgent(id="agent2", name="A2", reply_text="A2 reply")

    wf = SequentialBuilder(participants=[a1, a2], chain_only_agent_responses=True).build()

    async for ev in wf.run("hello", stream=True):
        if ev.type == "status" and ev.state == WorkflowRunState.IDLE:
            break

    # Second agent should see only the assistant message: [assistant("A1 reply")]
    seen = a2.last_messages
    assert len(seen) == 1
    assert seen[0].role == "assistant" and "A1 reply" in (seen[0].text or "")


async def test_chain_only_agent_responses_three_agents() -> None:
    """chain_only_agent_responses=True with three agents: each sees only the prior agent's reply."""
    a1 = _CapturingAgent(id="agent1", name="A1", reply_text="A1 reply")
    a2 = _CapturingAgent(id="agent2", name="A2", reply_text="A2 reply")
    a3 = _CapturingAgent(id="agent3", name="A3", reply_text="A3 reply")

    wf = SequentialBuilder(participants=[a1, a2, a3], chain_only_agent_responses=True).build()

    async for ev in wf.run("hello", stream=True):
        if ev.type == "status" and ev.state == WorkflowRunState.IDLE:
            break

    # a2 should see only A1's reply
    assert len(a2.last_messages) == 1
    assert a2.last_messages[0].role == "assistant" and "A1 reply" in (a2.last_messages[0].text or "")

    # a3 should see only A2's reply
    assert len(a3.last_messages) == 1
    assert a3.last_messages[0].role == "assistant" and "A2 reply" in (a3.last_messages[0].text or "")