"""Unit tests for the intake driver loop + event normalization.

SDK-free: the `claude-agent-sdk` message types are stood in by tiny fakes named
the same way `normalize` keys off (`StreamEvent`, `AssistantMessage`, ...), and
the driver loop runs against a fake session/source/sink. The real
`SdkIntakeSession` adapter needs the live `claude` binary and is excluded from
coverage.
"""

from __future__ import annotations

from contextlib import asynccontextmanager
from typing import TYPE_CHECKING

import pytest
from roboco.agent_sdk.intake_driver import (
    IntakeDriver,
    StreamChunk,
    normalize,
)

if TYPE_CHECKING:
    from collections.abc import AsyncIterator, Awaitable, Callable

# ---------------------------------------------------------------------------
# Fakes mirroring the claude-agent-sdk message/block shapes
# ---------------------------------------------------------------------------


class StreamEvent:
    def __init__(self, event: dict) -> None:
        self.event = event


class AssistantMessage:
    def __init__(self, content: list) -> None:
        self.content = content


class ResultMessage:
    def __init__(self, session_id: str, total_cost_usd: float | None = None) -> None:
        self.session_id = session_id
        self.total_cost_usd = total_cost_usd


class SystemMessage:
    def __init__(self, subtype: str) -> None:
        self.subtype = subtype


class TextBlock:
    def __init__(self, text: str) -> None:
        self.text = text


class ThinkingBlock:
    def __init__(self, thinking: str) -> None:
        self.thinking = thinking


class ToolUseBlock:
    def __init__(self, name: str, tool_input: dict) -> None:
        self.name = name
        self.input = tool_input


# ---------------------------------------------------------------------------
# normalize()
# ---------------------------------------------------------------------------


def test_normalize_stream_event_text_delta() -> None:
    msg = StreamEvent({"delta": {"type": "text_delta", "text": "hel"}})
    chunks = normalize(msg)
    assert chunks == [StreamChunk(kind="text", text="hel")]


def test_normalize_stream_event_non_text_delta_is_dropped() -> None:
    assert normalize(StreamEvent({"delta": {"type": "input_json_delta"}})) == []
    assert normalize(StreamEvent({})) == []


def test_normalize_assistant_message_blocks() -> None:
    # Text is NOT re-emitted from the AssistantMessage (the StreamEvent deltas
    # already carried it live) — only thinking + tool_use, which have no deltas.
    msg = AssistantMessage(
        [
            TextBlock("hello"),
            ThinkingBlock("hmm"),
            ToolUseBlock("Read", {"file": "metrics.tsx"}),
        ]
    )
    chunks = normalize(msg)
    assert [c.kind for c in chunks] == ["thinking", "tool_use"]
    assert chunks[0].text == "hmm"
    assert chunks[1].tool == "Read"
    assert chunks[1].data["input"] == {"file": "metrics.tsx"}


def test_normalize_assistant_message_extracts_draft_block() -> None:
    # A finished reply that ends with a fenced roboco-draft block yields a
    # single `draft` chunk carrying the parsed object — and no `text` chunk.
    text = (
        "Here is the task.\n"
        "```roboco-draft\n"
        '{"title": "Add metrics", "acceptance_criteria": ["x"], "scale": "single"}\n'
        "```\n"
    )
    chunks = normalize(AssistantMessage([TextBlock(text)]))
    assert [c.kind for c in chunks] == ["draft"]
    assert chunks[0].data["title"] == "Add metrics"
    assert chunks[0].data["scale"] == "single"


def test_normalize_assistant_message_malformed_draft_is_ignored() -> None:
    bad = "```roboco-draft\n{not valid json}\n```"
    assert normalize(AssistantMessage([TextBlock(bad)])) == []
    # A draft block with no title is not a usable draft either.
    no_title = '```roboco-draft\n{"acceptance_criteria": []}\n```'
    assert normalize(AssistantMessage([TextBlock(no_title)])) == []


def test_normalize_propose_draft_tool_becomes_draft_chunk() -> None:
    # The canonical signal: the agent CALLS propose_draft → one `draft` chunk
    # (not a tool_use chunk).
    msg = AssistantMessage(
        [
            ToolUseBlock(
                "propose_draft",
                {"draft": {"title": "Add metrics", "acceptance_criteria": ["x"]}},
            )
        ]
    )
    chunks = normalize(msg)
    assert [c.kind for c in chunks] == ["draft"]
    assert chunks[0].data["title"] == "Add metrics"


def test_normalize_propose_draft_accepts_flat_input() -> None:
    # Tolerant of the draft fields passed flat (no "draft" wrapper).
    msg = AssistantMessage([ToolUseBlock("propose_draft", {"title": "Flat", "x": 1})])
    chunks = normalize(msg)
    assert [c.kind for c in chunks] == ["draft"]
    assert chunks[0].data["title"] == "Flat"


def test_normalize_propose_draft_namespaced_name() -> None:
    # However the SDK namespaces it (e.g. mcp__intake__propose_draft).
    msg = AssistantMessage(
        [ToolUseBlock("mcp__intake__propose_draft", {"draft": {"title": "NS"}})]
    )
    assert [c.kind for c in normalize(msg)] == ["draft"]


def test_normalize_other_tool_stays_tool_use() -> None:
    chunks = normalize(AssistantMessage([ToolUseBlock("Read", {"file": "x.py"})]))
    assert [c.kind for c in chunks] == ["tool_use"]
    assert chunks[0].tool == "Read"


def test_normalize_propose_draft_without_title_is_ignored() -> None:
    msg = AssistantMessage(
        [ToolUseBlock("propose_draft", {"draft": {"acceptance_criteria": []}})]
    )
    assert normalize(msg) == []


def test_normalize_result_message_carries_session_id() -> None:
    cost = 0.01
    chunks = normalize(ResultMessage(session_id="sess-123", total_cost_usd=cost))
    assert len(chunks) == 1
    assert chunks[0].kind == "turn_end"
    assert chunks[0].data["session_id"] == "sess-123"
    assert chunks[0].data["cost_usd"] == cost


def test_normalize_system_message() -> None:
    chunks = normalize(SystemMessage(subtype="init"))
    assert chunks == [StreamChunk(kind="system", data={"subtype": "init"})]


def test_normalize_unknown_message_is_empty() -> None:
    assert normalize(object()) == []


# ---------------------------------------------------------------------------
# IntakeDriver loop
# ---------------------------------------------------------------------------


class _FakeSession:
    """Scripts each input text to a list of chunks to stream back."""

    def __init__(self, scripted: dict[str, list[StreamChunk]]) -> None:
        self.scripted = scripted
        self.seen: list[str] = []

    async def send(self, text: str) -> AsyncIterator[StreamChunk]:
        self.seen.append(text)
        for chunk in self.scripted.get(text, []):
            yield chunk


class _RaisingSession:
    """Streams one chunk, then fails mid-turn (faithful to a live SDK error)."""

    async def send(self, _text: str) -> AsyncIterator[StreamChunk]:
        yield StreamChunk(kind="text", text="partial")
        raise RuntimeError("boom")


def _source(messages: list[str | None]) -> Callable[[], Awaitable[str | None]]:
    queue = list(messages)

    async def _next() -> str | None:
        return queue.pop(0) if queue else None

    return _next


@pytest.mark.asyncio
async def test_driver_streams_turns_until_shutdown() -> None:
    session = _FakeSession(
        {
            "hi": [StreamChunk(kind="text", text="hello there")],
            "more": [
                StreamChunk(kind="tool_use", tool="Read"),
                StreamChunk(kind="text", text="done"),
            ],
        }
    )

    @asynccontextmanager
    async def factory() -> AsyncIterator[_FakeSession]:
        yield session

    collected: list[StreamChunk] = []

    async def emit(chunk: StreamChunk) -> None:
        collected.append(chunk)

    driver = IntakeDriver(factory, _source(["hi", "more", None]), emit)
    await driver.run()

    assert session.seen == ["hi", "more"]  # stopped on None, did not call send(None)
    assert [c.kind for c in collected] == ["text", "tool_use", "text"]
    assert collected[0].text == "hello there"


@pytest.mark.asyncio
async def test_driver_turn_failure_emits_error_and_continues() -> None:
    @asynccontextmanager
    async def factory() -> AsyncIterator[_RaisingSession]:
        yield _RaisingSession()

    collected: list[StreamChunk] = []

    async def emit(chunk: StreamChunk) -> None:
        collected.append(chunk)

    driver = IntakeDriver(factory, _source(["boom-please", None]), emit)
    await driver.run()  # must not raise

    # The partial chunk made it out, then the failure surfaced as an error chunk.
    assert [c.kind for c in collected] == ["text", "error"]
    assert collected[0].text == "partial"
    assert "boom" in collected[1].text
