"""Structured stream-event protocol + dispatcher behavior.

Covers the agent→gateway delivery contract introduced to decouple *what
happened* (typed events) from *how it's delivered* (adapter decides).  The
default BasePlatformAdapter rendering must reproduce today's behavior exactly;
an adapter may override format_tool_event to eat tool chrome on platforms that
can't render it.
"""

from __future__ import annotations

from unittest.mock import MagicMock

from gateway.stream_dispatch import GatewayEventDispatcher
from gateway.stream_events import (
    Commentary,
    GatewayNotice,
    LongToolHint,
    MessageChunk,
    MessageStop,
    ToolCallChunk,
    ToolCallFinished,
)


def _base_adapter():
    """A real BasePlatformAdapter instance (abstractmethods cleared) so we
    exercise the genuine default render hooks, not a mock."""
    from gateway.platforms.base import BasePlatformAdapter

    Concrete = type("Concrete", (BasePlatformAdapter,), {})
    Concrete.__abstractmethods__ = frozenset()
    return Concrete.__new__(Concrete)


class _FakeSink:
    def __init__(self):
        self.deltas = []
        self.commentary = []
        self.segment_breaks = 0

    def on_delta(self, text):
        self.deltas.append(text)

    def on_commentary(self, text):
        self.commentary.append(text)

    def on_segment_break(self):
        self.segment_breaks += 1


# ── Message events → sink ────────────────────────────────────────────────────

def test_message_chunk_flows_to_sink_on_delta():
    sink = _FakeSink()
    d = GatewayEventDispatcher(_base_adapter(), sink)
    d.dispatch(MessageChunk("hello "))
    d.dispatch(MessageChunk("world"))
    assert sink.deltas == ["hello ", "world"]


def test_intermediate_message_stop_breaks_segment_but_final_does_not():
    sink = _FakeSink()
    d = GatewayEventDispatcher(_base_adapter(), sink)
    d.dispatch(MessageStop(final=False))
    d.dispatch(MessageStop(final=True))
    assert sink.segment_breaks == 1  # only the non-final stop breaks


def test_commentary_flows_to_sink():
    sink = _FakeSink()
    d = GatewayEventDispatcher(_base_adapter(), sink)
    d.dispatch(Commentary("I'll inspect the repo first."))
    assert sink.commentary == ["I'll inspect the repo first."]


def test_message_events_dropped_when_no_sink():
    # streaming disabled → no sink → message events are no-ops, no crash.
    d = GatewayEventDispatcher(_base_adapter(), sink=None)
    d.dispatch(MessageChunk("x"))  # must not raise


# ── Tool events → progress queue, formatted by adapter ───────────────────────

def test_tool_call_chunk_renders_default_chrome():
    lines = []
    d = GatewayEventDispatcher(
        _base_adapter(), _FakeSink(),
        enqueue_tool_line=lines.append, tool_mode="all",
    )
    d.dispatch(ToolCallChunk(tool_name="terminal", preview="ls -la"))
    assert len(lines) == 1
    assert "terminal" in lines[0]
    assert "ls -la" in lines[0]


def test_tool_preview_truncated_to_cap():
    lines = []
    d = GatewayEventDispatcher(
        _base_adapter(), _FakeSink(),
        enqueue_tool_line=lines.append, tool_mode="all", preview_max_len=10,
    )
    d.dispatch(ToolCallChunk(tool_name="x", preview="0123456789ABCDEF"))
    # capped at 10 → 7 chars + "..." (then wrapped in quotes by the renderer)
    assert '"0123456..."' in lines[0]
    assert "89ABCDEF" not in lines[0]


def test_new_mode_dedups_same_tool():
    lines = []
    d = GatewayEventDispatcher(
        _base_adapter(), _FakeSink(),
        enqueue_tool_line=lines.append, tool_mode="new",
    )
    d.dispatch(ToolCallChunk(tool_name="terminal", preview="a"))
    d.dispatch(ToolCallChunk(tool_name="terminal", preview="b"))  # deduped
    d.dispatch(ToolCallChunk(tool_name="read_file", preview="c"))
    assert len(lines) == 2  # terminal once, read_file once


def test_off_mode_emits_nothing():
    lines = []
    d = GatewayEventDispatcher(
        _base_adapter(), _FakeSink(),
        enqueue_tool_line=lines.append, tool_mode="off",
    )
    d.dispatch(ToolCallChunk(tool_name="terminal", preview="ls"))
    assert lines == []


def test_adapter_can_eat_tool_chrome():
    """An adapter that returns None from format_tool_event drops the event —
    the 'iMessage can't render tool chrome' case."""
    adapter = _base_adapter()
    adapter.format_tool_event = lambda event, **kw: None  # eat everything
    lines = []
    d = GatewayEventDispatcher(
        adapter, _FakeSink(), enqueue_tool_line=lines.append, tool_mode="all",
    )
    d.dispatch(ToolCallChunk(tool_name="terminal", preview="ls"))
    assert lines == []  # eaten


def test_tool_finished_emits_no_chrome():
    lines = []
    d = GatewayEventDispatcher(
        _base_adapter(), _FakeSink(),
        enqueue_tool_line=lines.append, tool_mode="all",
    )
    d.dispatch(ToolCallFinished(tool_name="terminal", duration=2.0, ok=True))
    assert lines == []


# ── Control events → gateway-owned hooks ─────────────────────────────────────

def test_long_tool_hint_routes_to_hook():
    seen = []
    d = GatewayEventDispatcher(
        _base_adapter(), _FakeSink(), on_long_tool=seen.append,
    )
    d.dispatch(LongToolHint(tool_name="terminal", duration=45.0))
    assert len(seen) == 1
    assert seen[0].tool_name == "terminal"


def test_gateway_notice_routes_to_hook():
    seen = []
    d = GatewayEventDispatcher(
        _base_adapter(), _FakeSink(), on_notice=seen.append,
    )
    d.dispatch(GatewayNotice(kind="restart", text="Gateway restarted"))
    assert seen[0].kind == "restart"


def test_dispatch_swallows_render_errors():
    """A render error must never propagate into the agent worker thread."""
    adapter = _base_adapter()
    def _boom(event, sink):
        raise RuntimeError("render blew up")
    adapter.render_message_event = _boom
    d = GatewayEventDispatcher(adapter, _FakeSink())
    d.dispatch(MessageChunk("x"))  # must not raise