from __future__ import annotations

from typing import Any

import pytest

from core.errors import TaskFailedError
from core.models import Bounds, Scene, SceneElement
from runtime.ai_planner import AIPlanner
from runtime.context import TaskContext
from runtime.planner_config import PlannerConfig
from runtime.tool_calling_client import ToolCallDecision
from runtime.tool_specs import ALL_TOOL_SPECS


class FakeToolCallingClient:
    def __init__(self, decision: ToolCallDecision) -> None:
        self.decision = decision
        self.calls: list[dict[str, Any]] = []

    def decide(
        self,
        *,
        system_prompt: str,
        user_prompt: str,
        screenshot: bytes | None,
        tools: list[Any],
        timeout: float,
    ) -> ToolCallDecision:
        self.calls.append(
            {
                "system_prompt": system_prompt,
                "user_prompt": user_prompt,
                "screenshot": screenshot,
                "tools": tools,
                "timeout": timeout,
            }
        )
        return self.decision


def _scene() -> Scene:
    return Scene(
        width=10,
        height=20,
        elements=[
            SceneElement(
                id="send", type="button", text="Send", bounds=Bounds(1, 2, 3, 4)
            )
        ],
    )


def _context() -> TaskContext:
    return TaskContext(task_id="task-1", goal="send a message")


def test_ai_planner_returns_single_planned_step_for_action_decision() -> None:
    client = FakeToolCallingClient(
        ToolCallDecision(
            tool_name="tap",
            arguments={"x": 1, "y": 2},
            purpose="Open the send control.",
            expected_outcome="The message composer is focused.",
        )
    )
    planner = AIPlanner(client=client)

    steps = planner.plan(goal="send a message", scene=_scene(), context=_context())

    assert len(steps) == 1
    step = steps[0]
    assert step.action == "tap"
    assert step.description == "AI planner: Open the send control."
    assert step.args == {"x": 1, "y": 2}
    assert step.purpose == "Open the send control."
    assert step.expected_outcome == "The message composer is focused."
    assert step.expected_text == "The message composer is focused."


def test_ai_planner_finish_task_success_returns_empty_plan() -> None:
    client = FakeToolCallingClient(
        ToolCallDecision(
            tool_name="finish_task", arguments={"success": True, "reason": "done"}
        )
    )
    planner = AIPlanner(client=client)

    steps = planner.plan(goal="send a message", scene=_scene(), context=_context())

    assert steps == []


def test_ai_planner_finish_task_failure_raises_task_failed_error_with_reason() -> None:
    client = FakeToolCallingClient(
        ToolCallDecision(
            tool_name="finish_task",
            arguments={"success": False, "reason": "stuck on login"},
        )
    )
    planner = AIPlanner(client=client)

    with pytest.raises(TaskFailedError, match="stuck on login"):
        planner.plan(goal="send a message", scene=_scene(), context=_context())


def test_ai_planner_finish_task_failure_without_reason_uses_default_message() -> None:
    client = FakeToolCallingClient(
        ToolCallDecision(tool_name="finish_task", arguments={"success": False})
    )
    planner = AIPlanner(client=client)

    with pytest.raises(TaskFailedError, match="task failed"):
        planner.plan(goal="send a message", scene=_scene(), context=_context())


def test_ai_planner_goal_reached_is_always_false() -> None:
    client = FakeToolCallingClient(
        ToolCallDecision(tool_name="tap", arguments={"x": 1, "y": 2})
    )
    planner = AIPlanner(client=client)

    assert (
        planner.goal_reached(goal="anything", scene=_scene(), context=_context())
        is False
    )


def test_ai_planner_forwards_tools_screenshot_and_timeout_to_client() -> None:
    client = FakeToolCallingClient(
        ToolCallDecision(tool_name="tap", arguments={"x": 1, "y": 2})
    )
    planner = AIPlanner(client=client, config=PlannerConfig(timeout=12.5))

    planner.plan(
        goal="send a message",
        scene=_scene(),
        context=_context(),
        screenshot=b"fake-bytes",
    )

    call = client.calls[0]
    assert call["tools"] == ALL_TOOL_SPECS
    assert call["screenshot"] == b"fake-bytes"
    assert call["timeout"] == 12.5
    assert "send a message" in call["user_prompt"]


def test_ai_planner_includes_device_platform_from_task_context() -> None:
    client = FakeToolCallingClient(
        ToolCallDecision(tool_name="tap", arguments={"x": 1, "y": 2})
    )
    planner = AIPlanner(client=client)
    context = TaskContext(
        task_id="task-1",
        goal="send a message",
        device_platform="android",
    )

    planner.plan(goal="send a message", scene=_scene(), context=context)

    assert "Device type: android" in client.calls[0]["user_prompt"]


def test_ai_planner_populates_step_prompt_from_user_prompt() -> None:
    """PlannedStep.prompt should carry the actual user prompt sent to the LLM,
    not the bare task goal."""
    client = FakeToolCallingClient(
        ToolCallDecision(tool_name="tap", arguments={"x": 1, "y": 2})
    )
    planner = AIPlanner(client=client)

    steps = planner.plan(goal="send a message", scene=_scene(), context=_context())

    assert len(steps) == 1
    assert steps[0].prompt is not None
    # The per-step prompt contains the goal but also scene JSON and instruction text
    assert "send a message" in steps[0].prompt
    assert "Current Scene (JSON)" in steps[0].prompt
    assert "Call exactly one tool" in steps[0].prompt


def test_ai_planner_step_prompt_reflects_scene_changes() -> None:
    """Per-step prompts differ when the scene changes, proving they are not
    just the repeated task goal."""
    from runtime.context import TaskContext

    client = FakeToolCallingClient(
        ToolCallDecision(tool_name="tap", arguments={"x": 1, "y": 2})
    )
    planner = AIPlanner(client=client)

    scene_a = Scene(
        width=10,
        height=20,
        elements=[
            SceneElement(
                id="btn_a", type="button", text="Alpha", bounds=Bounds(1, 2, 3, 4)
            )
        ],
    )
    scene_b = Scene(
        width=10,
        height=20,
        elements=[
            SceneElement(
                id="btn_b", type="button", text="Beta", bounds=Bounds(5, 6, 7, 8)
            )
        ],
    )

    steps_a = planner.plan(
        goal="test", scene=scene_a, context=TaskContext(task_id="t", goal="test")
    )
    steps_b = planner.plan(
        goal="test", scene=scene_b, context=TaskContext(task_id="t", goal="test")
    )

    assert steps_a[0].prompt != steps_b[0].prompt
    assert "Alpha" in steps_a[0].prompt
    assert "Beta" in steps_b[0].prompt


def test_ai_planner_propagates_rationale_and_thinking_to_planned_step() -> None:
    client = FakeToolCallingClient(
        ToolCallDecision(
            tool_name="tap",
            arguments={"x": 1, "y": 2},
            text_output="Previous step opened settings. Now tapping account.",
            thinking="I need to navigate deeper.",
            purpose="Open account settings.",
            expected_outcome="The account settings page is visible.",
        )
    )
    planner = AIPlanner(client=client)

    steps = planner.plan(goal="open account", scene=_scene(), context=_context())

    assert steps[0].rationale == "Previous step opened settings. Now tapping account."
    assert steps[0].thinking == "I need to navigate deeper."
    assert steps[0].purpose == "Open account settings."
    assert steps[0].expected_outcome == "The account settings page is visible."


def test_history_summary_returns_compact_format() -> None:
    from collections import deque
    from runtime.ai_planner import _history_summary
    from world.models import WorldEvent, WorldState

    state = WorldState(
        history=deque(
            [
                WorldEvent(
                    action="tap",
                    success=True,
                    rationale="Opened settings.",
                    arguments={"x": 1, "y": 2},
                    purpose="Open settings.",
                    expected_outcome="Settings is visible.",
                    page="Home",
                ),
                WorldEvent(
                    action="swipe",
                    success=False,
                    rationale=None,
                    arguments={"start_y": 700, "end_y": 200},
                    page="Settings",
                ),
            ]
        )
    )

    summary = _history_summary(state)

    assert summary == [
        {
            "page": "Home",
            "action": "tap",
            "arguments": {"x": 1, "y": 2},
            "rationale": "Opened settings.",
            "purpose": "Open settings.",
            "expected_outcome": "Settings is visible.",
            "success": True,
        },
        {
            "page": "Settings",
            "action": "swipe",
            "arguments": {"start_y": 700, "end_y": 200},
            "rationale": None,
            "purpose": None,
            "expected_outcome": None,
            "success": False,
        },
    ]
    # Must not contain scene element data
    for entry in summary:
        assert "scene_summary" not in entry
        assert "elements" not in entry


def test_history_summary_returns_empty_for_none_world() -> None:
    from runtime.ai_planner import _history_summary

    assert _history_summary(None) == []