#!/usr/bin/env python3
"""Dependency-light tests for the SPAgent grid-puzzle training environment."""

from __future__ import annotations

import importlib.util
import os
import sys
import tempfile
import types
from pathlib import Path

from PIL import Image


ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT))

from spagent.frozenlake_v3_protocol import count_explicit_images  # noqa: E402
from spagent.grid_puzzle_protocol import (  # noqa: E402
    FIFTEEN_TASK,
    SOKOBAN_TASK,
    build_system_prompt,
    build_user_prompt,
    canonical_fifteen_state,
    canonical_sokoban_state,
    decode_initial_state,
    encode_initial_state,
    is_solved,
    parse_action_tokens,
    render_state,
    replay_actions,
    state_text,
    step_state,
)

_builder_spec = importlib.util.spec_from_file_location(
    "build_grid_puzzle_training_data",
    ROOT / "train" / "build_grid_puzzle_training_data.py",
)
builder = importlib.util.module_from_spec(_builder_spec)
assert _builder_spec.loader is not None
_builder_spec.loader.exec_module(builder)


def simple_sokoban_state() -> dict:
    return canonical_sokoban_state(
        rows=3,
        cols=5,
        walls={
            (0, 0), (0, 1), (0, 2), (0, 3), (0, 4),
            (1, 0), (1, 4),
            (2, 0), (2, 1), (2, 2), (2, 3), (2, 4),
        },
        goals={(1, 3)},
        boxes={(1, 2)},
        player=(1, 1),
    )


def one_move_fifteen_state() -> dict:
    return canonical_fifteen_state(
        [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 0, 15]
    )


def test_action_parser() -> None:
    assert parse_action_tokens("left, DOWN; right. up") == [
        "Left", "Down", "Right", "Up"
    ]
    assert parse_action_tokens("junk") == []


def test_state_json_round_trip() -> None:
    state = simple_sokoban_state()
    assert decode_initial_state(encode_initial_state(state)) == state


def test_sokoban_push_and_replay() -> None:
    state = simple_sokoban_state()
    outcome = step_state(SOKOBAN_TASK, state, "Right")
    assert outcome.changed
    assert outcome.success
    assert outcome.done
    assert state["player"] == [1, 2]
    assert state["boxes"] == [[1, 3]]
    assert replay_actions(
        SOKOBAN_TASK, encode_initial_state(simple_sokoban_state()), ["Right"]
    )


def test_sokoban_blocked_push() -> None:
    state = simple_sokoban_state()
    state["goals"] = [[1, 2]]
    state["boxes"] = [[1, 3]]
    state["player"] = [1, 2]
    outcome = step_state(SOKOBAN_TASK, state, "Right")
    assert not outcome.changed
    assert outcome.tool_result["error"] == "blocked_box"


def test_fifteen_direction_matches_upstream() -> None:
    state = one_move_fifteen_state()
    outcome = step_state(FIFTEEN_TASK, state, "Left")
    assert outcome.changed
    assert outcome.success
    assert state["board"] == list(range(1, 16)) + [0]
    assert replay_actions(
        FIFTEEN_TASK,
        encode_initial_state(one_move_fifteen_state()),
        ["Left"],
    )


def test_fifteen_invalid_slide() -> None:
    solved = canonical_fifteen_state(list(range(1, 16)) + [0])
    outcome = step_state(FIFTEEN_TASK, solved, "Left")
    assert not outcome.changed
    assert outcome.tool_result["error"] == "invalid_slide"
    assert is_solved(FIFTEEN_TASK, solved)


def test_invalid_direction_type() -> None:
    state = one_move_fifteen_state()
    outcome = step_state(FIFTEEN_TASK, state, ["Left"])
    assert not outcome.changed
    assert outcome.tool_result["error"] == "invalid_direction"
    assert not replay_actions(
        FIFTEEN_TASK,
        encode_initial_state(state),
        [["Left"]],
    )


def test_fifteen_solvability_filter() -> None:
    solved = list(range(1, 16)) + [0]
    unsolvable = solved.copy()
    unsolvable[0], unsolvable[1] = unsolvable[1], unsolvable[0]
    assert builder.is_fifteen_solvable(solved)
    assert not builder.is_fifteen_solvable(unsolvable)


def test_sokoban_padding_is_deterministic() -> None:
    base = [
        {
            "id": "sokoban_000000",
            "task_id": SOKOBAN_TASK,
            "initial_state": "state-a",
        },
        {
            "id": "sokoban_000001",
            "task_id": SOKOBAN_TASK,
            "initial_state": "state-b",
        },
    ]
    padded = builder.pad_records(base, count=5, seed=0)
    assert len(padded) == 5
    assert len({row["initial_state"] for row in padded}) == 2
    assert [row["id"] for row in padded] == [
        f"sokoban_{index:06d}" for index in range(5)
    ]
    assert all("duplicate_of" in row for row in padded[2:])
    assert builder.pad_records(base, count=5, seed=0) == padded


def test_text_and_prompt_contract(tmp: Path) -> None:
    state = simple_sokoban_state()
    image_path = tmp / "initial.png"
    render_state(SOKOBAN_TASK, state, image_path)
    prompt = build_user_prompt(SOKOBAN_TASK, state, image_path)
    assert "# Initial Grid (text view, 3x5)" in prompt
    assert state_text(SOKOBAN_TASK, state) in prompt
    assert count_explicit_images(prompt) == 1
    assert '"name": "move"' in build_system_prompt(SOKOBAN_TASK)


def test_renderers(tmp: Path) -> None:
    sokoban_path = tmp / "sokoban.png"
    fifteen_path = tmp / "fifteen.png"
    render_state(SOKOBAN_TASK, simple_sokoban_state(), sokoban_path)
    render_state(FIFTEEN_TASK, one_move_fifteen_state(), fifteen_path)
    with Image.open(sokoban_path) as image:
        assert image.mode == "RGB"
        assert image.size == (360, 232)
    with Image.open(fifteen_path) as image:
        assert image.mode == "RGB"
        assert image.size == (360, 360)


def load_plugin_with_stubs():
    class FakeRolloutInferRequest:
        def __init__(self, **kwargs):
            self.__dict__.update(kwargs)

    class FakeScheduler:
        def __init__(self, max_turns=20, *args, **kwargs):
            self.max_turns = max_turns

        def check_finished(self, infer_request, response_choice, current_turn):
            return current_turn >= self.max_turns

    class FakeORM:
        pass

    class FakeLogger:
        def info(self, *args, **kwargs):
            pass

        def warning(self, *args, **kwargs):
            pass

    swift = types.ModuleType("swift")
    swift_llm = types.ModuleType("swift.llm")
    swift_llm.RolloutInferRequest = FakeRolloutInferRequest
    swift_infer = types.ModuleType("swift.llm.infer")
    swift_protocol = types.ModuleType("swift.llm.infer.protocol")
    swift_protocol.ChatCompletionResponseChoice = object
    swift_plugin = types.ModuleType("swift.plugin")
    swift_plugin.ORM = FakeORM
    swift_plugin.orms = {}
    swift_multi = types.ModuleType("swift.plugin.multi_turn")
    swift_multi.MultiTurnScheduler = FakeScheduler
    swift_multi.multi_turns = {}
    swift_utils = types.ModuleType("swift.utils")
    swift_utils.get_logger = lambda: FakeLogger()
    trainer = types.ModuleType("grpo_filtered_trainer")
    trainer.CURRENT_STEP = 0

    modules = {
        "swift": swift,
        "swift.llm": swift_llm,
        "swift.llm.infer": swift_infer,
        "swift.llm.infer.protocol": swift_protocol,
        "swift.plugin": swift_plugin,
        "swift.plugin.multi_turn": swift_multi,
        "swift.utils": swift_utils,
        "grpo_filtered_trainer": trainer,
    }
    previous = {name: sys.modules.get(name) for name in modules}
    sys.modules.update(modules)
    try:
        spec = importlib.util.spec_from_file_location(
            "grid_puzzle_plugin_under_test",
            ROOT / "train" / "grid_puzzle_plugin.py",
        )
        module = importlib.util.module_from_spec(spec)
        assert spec.loader is not None
        spec.loader.exec_module(module)
        return module, FakeRolloutInferRequest
    finally:
        for name, old in previous.items():
            if old is None:
                sys.modules.pop(name, None)
            else:
                sys.modules[name] = old


def test_reward_and_scheduler_step(tmp: Path) -> None:
    plugin, request_type = load_plugin_with_stubs()
    initial = one_move_fifteen_state()
    encoded = encode_initial_state(initial)
    completion = "<think>One move.</think><answer>Left</answer>"
    assert plugin.GridPuzzleReward()(
        [completion], [FIFTEEN_TASK], [encoded]
    ) == [1.0]
    assert plugin.GridPuzzleReward()(
        ["<think>Push.</think><answer>Right</answer>"],
        [SOKOBAN_TASK],
        [encode_initial_state(simple_sokoban_state())],
    ) == [1.0]
    assert plugin.GridPuzzleFormatReward()([completion]) == [0.5]

    initial_image = tmp / "initial_fifteen.png"
    render_state(FIFTEEN_TASK, initial, initial_image)
    old_dir = os.environ.get("GRID_PUZZLE_IMG_DIR")
    os.environ["GRID_PUZZLE_IMG_DIR"] = str(tmp / "rollout")
    try:
        scheduler = plugin.GridPuzzleScheduler(max_turns=5)
        request = request_type(
            messages=[
                {"role": "system", "content": "system"},
                {"role": "user", "content": "user"},
            ],
            images=[str(initial_image)],
            audios=None,
            videos=None,
            tools=None,
            objects=None,
            data_dict={
                "task_id": FIFTEEN_TASK,
                "initial_state": encoded,
            },
        )
        choice = types.SimpleNamespace(
            message=types.SimpleNamespace(
                content=(
                    "<think>Slide 15 left.</think>"
                    '<tool_call>{"name":"move","arguments":'
                    '{"direction":"Left"}}</tool_call>'
                )
            )
        )
        result = scheduler.step(request, choice, 1)
        assert result["rollout_infos"]["gp_success"]
        next_request = result["infer_request"]
        assert len(next_request.images) == 2
        assert Path(next_request.images[-1]).is_file()
        assert "<image>[image:" in next_request.messages[-1]["content"]
        final_choice = types.SimpleNamespace(
            message=types.SimpleNamespace(content=completion)
        )
        assert scheduler.check_finished(next_request, final_choice, 2)

        for malformed_content, expected_phrase in (
            (
                "<think>Bad shape.</think><tool_call>[]</tool_call>",
                "JSON value must be an object",
            ),
            (
                (
                    "<think>Bad arguments.</think>"
                    '<tool_call>{"name":"move","arguments":["Left"]}'
                    "</tool_call>"
                ),
                "`arguments` must be a JSON object",
            ),
        ):
            malformed_request = request_type(
                messages=[
                    {"role": "system", "content": "system"},
                    {"role": "user", "content": "user"},
                ],
                images=[str(initial_image)],
                audios=None,
                videos=None,
                tools=None,
                objects=None,
                data_dict={
                    "task_id": FIFTEEN_TASK,
                    "initial_state": encoded,
                },
            )
            malformed_choice = types.SimpleNamespace(
                message=types.SimpleNamespace(content=malformed_content)
            )
            malformed_result = scheduler.step(
                malformed_request, malformed_choice, 1
            )
            assert len(malformed_result["infer_request"].images) == 1
            assert count_explicit_images(
                malformed_result["infer_request"].messages[-1]["content"]
            ) == 1
            logged_tool_result = malformed_result["rollout_infos"]
            assert not logged_tool_result["gp_success"]
            continuation = malformed_result["infer_request"].messages[-1][
                "content"
            ]
            assert expected_phrase in continuation
    finally:
        if old_dir is None:
            os.environ.pop("GRID_PUZZLE_IMG_DIR", None)
        else:
            os.environ["GRID_PUZZLE_IMG_DIR"] = old_dir


def main() -> None:
    with tempfile.TemporaryDirectory() as directory:
        tmp = Path(directory)
        test_action_parser()
        test_state_json_round_trip()
        test_sokoban_push_and_replay()
        test_sokoban_blocked_push()
        test_fifteen_direction_matches_upstream()
        test_fifteen_invalid_slide()
        test_invalid_direction_type()
        test_fifteen_solvability_filter()
        test_sokoban_padding_is_deterministic()
        test_text_and_prompt_contract(tmp)
        test_renderers(tmp)
        test_reward_and_scheduler_step(tmp)
    print("grid-puzzle training tests passed")


if __name__ == "__main__":
    main()