"""TensorLens 集成测试: KDA 模型张量 -> trace -> 全局 store -> Flask 端点.

依赖: tensorlens (未安装时整个模块 skip, 用 `pip install tensorlens` 启用).

测三层:
1. trace     — KDA 前向的真实 1D/2D/3D 张量 (embed/block 输出/logits/权重)
                规范化成 int8 存入 tensorlens 全局 store
2. normalize — 四种策略 (clip/minmax/zscore/none) 的边界行为
3. HTTP      — 用 Flask test_client 验证 /api/list_tensors 与 /api/get_tensor,
                不启动阻塞的 gunicorn server (viewer() 为交互式入口, 不做自动化)
"""
import numpy as np
import pytest
import torch

pytest.importorskip("tensorlens")

from tensorlens.core import global_store
from tensorlens.tensorlens import normalize_to_int8, trace
from tensorlens.web.server import app

from kda.models.causal_lm import CausalLM
from kda.models.config import KDAConfig


def _model():
    torch.manual_seed(51)
    config = KDAConfig(
        hidden_size=16,
        num_hidden_layers=1,
        num_heads=2,
        num_value_heads=2,
        head_dim=4,
        chunk_size=4,
        vocab_size=32,
        intermediate_size=32,
        kda_backend="reference",
    )
    return CausalLM(config).eval()


@pytest.fixture(autouse=True)
def _clean_store():
    """global_store 是模块级单例, 每个测试前后清空, 避免互相污染."""
    global_store.INMEMORY_TENSORS.clear()
    yield
    global_store.INMEMORY_TENSORS.clear()


def _trace_kda_tensors(model):
    """前向一次, 把 KDA 的 1D/2D/3D 张量全部 trace 进 store, 返回 logits numpy."""
    x = torch.tensor([[1, 2, 3, 4]])
    hidden = {}

    def hook_fn(name):
        def hook(module, inp, out):
            hidden[name] = out.detach()

        return hook

    model.embedding.register_forward_hook(hook_fn("embed"))
    model.blocks[0].register_forward_hook(hook_fn("block0"))

    with torch.no_grad():
        logits = model(x)

    logits_np = logits.detach().numpy()            # [1, T, vocab] 3D
    trace("lm_head.weight", model.lm_head.weight.detach().numpy())  # [vocab, hidden] 2D
    trace("embed", hidden["embed"].numpy())        # [1, T, hidden] 3D
    trace("block0.out", hidden["block0"].numpy())  # [1, T, hidden] 3D
    trace("logits", logits_np)                     # [1, T, vocab] 3D
    trace("logits.row0", logits_np[0, 0])          # [vocab] 1D
    return logits_np


# ---------------------------------------------------------------------------
# Layer 1: trace — KDA 张量进 store
# ---------------------------------------------------------------------------


def test_trace_stores_int8_with_expected_shape():
    model = _model()
    logits_np = _trace_kda_tensors(model)
    store = global_store.INMEMORY_TENSORS

    assert set(store) == {"lm_head.weight", "embed", "block0.out", "logits", "logits.row0"}
    assert store["logits"].dtype == np.int8
    assert store["logits"].shape == logits_np.shape
    assert store["lm_head.weight"].shape == (32, 16)
    assert store["logits.row0"].ndim == 1
    assert store["logits"].min() >= -128 and store["logits"].max() <= 127


# ---------------------------------------------------------------------------
# Layer 2: normalize_to_int8 — 四种策略边界行为
# ---------------------------------------------------------------------------


def test_clip_normalization_bounds():
    t = np.array([[-100.0, 0.0, 100.0]])
    out = normalize_to_int8(t, (-1.0, 1.0), "clip")
    assert out.dtype == np.int8
    assert out[0, 0] == -127 and out[0, 2] == 127
    assert out[0, 1] == 0


def test_minmax_constant_tensor_returns_zeros():
    t = np.full((2, 3), 0.5)
    out = normalize_to_int8(t, (-1.0, 1.0), "minmax")
    assert (out == 0).all()


def test_zscore_zero_std_returns_zeros():
    t = np.ones((4, 4))
    out = normalize_to_int8(t, (-1.0, 1.0), "zscore")
    assert (out == 0).all()


def test_none_strategy_scales_by_127():
    t = np.array([[0.5, -0.5]])
    out = normalize_to_int8(t, (-1.0, 1.0), "none")
    assert out[0, 0] == 63 and out[0, 1] == -63  # int8 cast 向零截断


def test_unsupported_normalization_raises():
    with pytest.raises(ValueError):
        normalize_to_int8(np.zeros(3), (-1.0, 1.0), "bogus")


# ---------------------------------------------------------------------------
# Layer 2.5: trace 输入校验
# ---------------------------------------------------------------------------


def test_trace_rejects_non_ndarray():
    with pytest.raises(TypeError):
        trace("bad", torch.zeros(3))


def test_trace_rejects_empty_key():
    with pytest.raises(ValueError):
        trace("", np.zeros(3))


# ---------------------------------------------------------------------------
# Layer 3: Flask 端点 (test_client, 不起真实 server)
# ---------------------------------------------------------------------------


def test_list_tensors_endpoint_reports_kda_tensors():
    model = _model()
    _trace_kda_tensors(model)
    resp = app.test_client().get("/api/list_tensors")
    assert resp.status_code == 200
    body = resp.get_json()
    assert body["count"] == 5
    keys = [t["key"] for t in body["available_tensors"]]
    assert "logits" in keys and "lm_head.weight" in keys


def test_get_tensor_endpoint_returns_data():
    model = _model()
    logits_np = _trace_kda_tensors(model)
    resp = app.test_client().get("/api/get_tensor?tensor_key=logits")
    assert resp.status_code == 200
    body = resp.get_json()
    assert body["shape"] == list(logits_np.shape)
    assert len(body["data"]) == logits_np.shape[0]


def test_get_tensor_missing_key_returns_400():
    model = _model()
    _trace_kda_tensors(model)
    resp = app.test_client().get("/api/get_tensor")
    assert resp.status_code == 400
    assert "tensor_key" in resp.get_json()["error"]


def test_get_tensor_unknown_key_returns_404():
    resp = app.test_client().get("/api/get_tensor?tensor_key=nope")
    assert resp.status_code == 404


def test_config_endpoint():
    resp = app.test_client().get("/api/config")
    assert resp.status_code == 200
    assert resp.get_json()["status"] == "ok"


if __name__ == "__main__":
    import sys

    sys.exit(pytest.main([__file__, "-v"]))