"""Tests for real data interfaces (scPerturb + PDGrapher).

Norman2019 and PDGrapher real_lognorm are loaded from disk; tests skip
gracefully when the files are not present.
"""
import sys
import os

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "src"))

import pytest
import torch
from torch.utils.data import DataLoader

from gidflow.data import (
    ScPerturbPopulationDataset,
    PDGrapherPseudobulkDataset,
    population_collate_fn,
    select_hvg_by_variance,
    normalize_counts,
)
import numpy as np

NORMAN_PATH = (
    "/data/boom/Protein/regulatory_field/data/raw/"
    "scPerturb/rna_protein/NormanWeissman2019_filtered.h5ad"
)
PDG_DIR = "/data/boom/Protein/PDGrapher/data/processed/torch_data/real_lognorm"

norman_available   = pytest.mark.skipif(not os.path.exists(NORMAN_PATH),   reason="Norman2019 h5ad not found")
pdgrapher_available = pytest.mark.skipif(not os.path.isdir(PDG_DIR),        reason="PDGrapher real_lognorm not found")


# ---------------------------------------------------------------------------
# gene_selection utils
# ---------------------------------------------------------------------------
class TestGeneSelection:

    def test_hvg_shape(self):
        X = np.random.randn(100, 500).astype(np.float32)
        idx = select_hvg_by_variance(X, n_genes=50)
        assert idx.shape == (50,)
        assert len(set(idx)) == 50

    def test_hvg_fewer_than_requested(self):
        X = np.random.randn(10, 20).astype(np.float32)
        idx = select_hvg_by_variance(X, n_genes=100)
        assert len(idx) == 20   # capped at n_genes

    def test_normalize_no_log(self):
        X = np.array([[1.0, 3.0], [2.0, 2.0]], dtype=np.float32)
        out = normalize_counts(X, target_sum=4.0, log1p=False)
        assert np.allclose(out.sum(axis=1), [4.0, 4.0])

    def test_normalize_log1p(self):
        X = np.ones((5, 10), dtype=np.float32) * 100
        out = normalize_counts(X, target_sum=1e4, log1p=True)
        assert (out > 0).all()
        assert out.dtype == np.float32


# ---------------------------------------------------------------------------
# ScPerturbPopulationDataset (Norman2019)
# ---------------------------------------------------------------------------
@norman_available
class TestScPerturbPopulationDataset:

    @pytest.fixture(scope="class")
    def ds(self):
        import warnings; warnings.filterwarnings("ignore")
        return ScPerturbPopulationDataset(
            NORMAN_PATH,
            n_hvg=500,
            min_cells_per_cond=30,
            max_source_cells=16,
            max_target_cells=16,
            use_single_pert_only=True,
            force_include_pert_genes=True,
            seed=0,
        )

    def test_num_conditions(self, ds):
        assert len(ds) >= 50, f"Expected ≥50 conditions, got {len(ds)}"

    def test_item_shapes(self, ds):
        item = ds[0]
        G = ds.num_genes
        assert item["source_cells"].shape == (16, G)
        assert item["target_cells"].shape == (16, G)
        assert item["perturbation"].shape == (G,)

    def test_perturbation_is_multihot(self, ds):
        item = ds[0]
        pert = item["perturbation"]
        assert ((pert == 0) | (pert == 1)).all()
        assert pert.sum() >= 1

    def test_most_perts_in_gene_space(self, ds):
        covered = ds.n_genes_in_hvg_that_are_targets
        assert covered / len(ds) >= 0.8, f"Only {covered}/{len(ds)} pert genes covered"

    def test_source_target_differ(self, ds):
        item = ds[5]
        src_mean = item["source_cells"].mean()
        tgt_mean = item["target_cells"].mean()
        # They come from different cell populations — means will differ slightly
        assert item["source_cells"].shape == item["target_cells"].shape

    def test_collate_fn_integration(self, ds):
        loader = DataLoader(ds, batch_size=4, collate_fn=population_collate_fn, shuffle=False)
        batch = next(iter(loader))
        assert batch.source_cells.shape[0] == 4
        assert batch.source_cells.shape[2] == ds.num_genes
        assert not batch.source_cells.isnan().any()

    def test_reproducibility(self):
        import warnings; warnings.filterwarnings("ignore")
        ds1 = ScPerturbPopulationDataset(NORMAN_PATH, n_hvg=200, min_cells_per_cond=30,
                                          max_source_cells=8, seed=7)
        ds2 = ScPerturbPopulationDataset(NORMAN_PATH, n_hvg=200, min_cells_per_cond=30,
                                          max_source_cells=8, seed=7)
        item1 = ds1[0]
        item2 = ds2[0]
        assert torch.allclose(item1["perturbation"], item2["perturbation"])


# ---------------------------------------------------------------------------
# PDGrapherPseudobulkDataset
# ---------------------------------------------------------------------------
@pdgrapher_available
class TestPDGrapherPseudobulkDataset:

    @pytest.fixture(scope="class")
    def ds(self):
        return PDGrapherPseudobulkDataset(PDG_DIR, cell_lines=["A549"], max_items=200)

    def test_length(self, ds):
        assert len(ds) == 200

    def test_item_shapes(self, ds):
        item = ds[0]
        G = ds.num_genes
        assert item["source_cells"].shape == (1, G)
        assert item["target_cells"].shape == (1, G)
        assert item["perturbation"].shape == (G,)

    def test_num_genes(self, ds):
        assert ds.num_genes == 10716

    def test_perturbation_nonzero(self, ds):
        for i in range(10):
            item = ds[i]
            assert item["perturbation"].sum() >= 1

    def test_collate_fn_integration(self, ds):
        loader = DataLoader(ds, batch_size=4, collate_fn=population_collate_fn)
        batch = next(iter(loader))
        assert batch.source_cells.shape == (4, 1, ds.num_genes)
        assert batch.target_cells.shape == (4, 1, ds.num_genes)

    def test_no_nan(self, ds):
        for i in range(5):
            item = ds[i]
            assert not item["source_cells"].isnan().any()
            assert not item["target_cells"].isnan().any()