import hashlib
import json
from pathlib import Path

from typer.testing import CliRunner

from tht.cli import app
from tht.jobs.dwh_pipeline import DwhPreprocessPipeline
from tht.jobs.dwh_pipeline import resolve_dwh_snapshot
from tht.jobs.dwh_pipeline import lease_dwh_snapshot
from tht.jobs.locking import _lock_name


FP = "sha256:" + hashlib.sha256(b"test").hexdigest()


def test_dwh_and_evidence_jobs_have_distinct_lock_names():
    assert _lock_name("demo", "dwh") != _lock_name("demo", "evidence")


def test_selected_dwh_stages_run_in_declared_order(tmp_path):
    calls = []
    pipeline = DwhPreprocessPipeline(
        workspace_id="demo",
        workspace_root=tmp_path,
        config_fingerprint=FP,
        input_fingerprint=FP,
        introspect=lambda output: (calls.append("introspect"), output.write_text("catalog")),
        build_lsh=lambda physical, output: _write_lsh(calls, physical, output),
    )

    report = pipeline.run(("introspect", "lsh"))

    assert report.status == "succeeded"
    assert calls == ["introspect", "lsh"]
    assert [stage.name for stage in report.stages] == ["introspect", "lsh"]
    active = (tmp_path / ".tht-dwh" / "ACTIVE").read_text().strip()
    published = tmp_path / ".tht-dwh" / "generations" / active
    assert (published / "physical.yaml").read_text() == "catalog"
    assert sorted(path.name for path in published.iterdir()) == [
        "demo_lsh.pkl", "demo_meta.json", "demo_minhashes.pkl",
        "generation-manifest.json", "physical.yaml",
    ]


def _write_lsh(calls, physical: Path, output: Path):
    calls.append("lsh")
    assert physical.read_text() == "catalog"
    for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json"):
        (output / name).write_text(name)


def test_preprocess_dwh_json_is_pristine(monkeypatch, tmp_path):
    import tht.cli.preprocess_cmd as command

    class Report:
        status = "succeeded"

        def model_dump(self, mode=None):
            return {"status": "succeeded", "run_id": "a" * 32, "stages": []}

    seen = {}

    def run(config, *, steps, resume):
        seen.update(config=config, steps=steps, resume=resume)
        return Report()

    monkeypatch.setattr(command, "run_dwh_from_config", run)
    response = CliRunner().invoke(
        app,
        [
            "preprocess", "dwh", "--steps", "introspect,lsh", "--json",
            "-c", str(tmp_path / "workspace.yaml"),
        ],
    )

    assert response.exit_code == 0, response.output
    assert json.loads(response.output)["run_id"] == "a" * 32
    assert seen["steps"] == ("introspect", "lsh")


def test_preprocess_dwh_rejects_unknown_or_duplicate_steps(monkeypatch, tmp_path):
    import tht.cli.preprocess_cmd as command

    called = False

    def forbidden(*args, **kwargs):
        nonlocal called
        called = True

    monkeypatch.setattr(command, "run_dwh_from_config", forbidden)
    runner = CliRunner()
    for value in ("introspect,unknown", "lsh,lsh", ""):
        response = runner.invoke(
            app,
            ["preprocess", "dwh", "--steps", value, "--json", "-c", str(tmp_path / "w.yaml")],
        )
        assert response.exit_code == 2
        assert json.loads(response.output)["status"] == "failed"
    assert called is False


def test_failed_multi_file_build_never_replaces_active_generation(tmp_path):
    def catalog(output):
        output.write_text("old-catalog")

    first = DwhPreprocessPipeline(
        workspace_id="demo", workspace_root=tmp_path,
        config_fingerprint=FP, input_fingerprint=FP,
        introspect=catalog,
        build_lsh=lambda physical, output: [
            (output / name).write_text(name)
            for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json")
        ],
    ).run(("introspect", "lsh"))
    assert first.status == "succeeded"
    old_active = (tmp_path / ".tht-dwh" / "ACTIVE").read_text()

    def partial_lsh(physical, output):
        (output / "demo_lsh.pkl").write_text("new-but-partial")
        raise RuntimeError("crash between LSH files")

    failed = DwhPreprocessPipeline(
        workspace_id="demo", workspace_root=tmp_path,
        config_fingerprint=FP, input_fingerprint=FP,
        introspect=lambda output: output.write_text("new-catalog"),
        build_lsh=partial_lsh,
    ).run(("introspect", "lsh"))

    assert failed.status == "failed"
    assert (tmp_path / ".tht-dwh" / "ACTIVE").read_text() == old_active

    resumed = DwhPreprocessPipeline(
        workspace_id="demo", workspace_root=tmp_path,
        config_fingerprint=FP, input_fingerprint=FP,
        introspect=lambda output: (_ for _ in ()).throw(
            AssertionError("completed introspection must not repeat")
        ),
        build_lsh=lambda physical, output: [
            (output / name).write_text("recovered")
            for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json")
        ],
    ).run(("introspect", "lsh"), resume_run_id=failed.run_id)
    assert resumed.status == "succeeded"


def test_unsafe_lsh_filename_is_rejected(tmp_path):
    import pytest

    with pytest.raises(ValueError, match="flat safe"):
        DwhPreprocessPipeline(
            workspace_id="demo", workspace_root=tmp_path,
            config_fingerprint=FP, input_fingerprint=FP,
            introspect=lambda output: None, build_lsh=lambda physical, output: None,
            lsh_filenames=("../escape.pkl", "ok.pkl", "meta.json"),
        )


def test_active_fsync_failure_restores_previous_pointer(monkeypatch, tmp_path):
    def build(physical, output):
        for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json"):
            (output / name).write_text(name)

    first_pipeline = DwhPreprocessPipeline(
        workspace_id="demo", workspace_root=tmp_path,
        config_fingerprint=FP, input_fingerprint=FP,
        introspect=lambda output: output.write_text("old"), build_lsh=build,
    )
    first = first_pipeline.run()
    original_fsync = first_pipeline._fsync
    failed_once = False

    def fail_active_once(path):
        nonlocal failed_once
        if path.name == ".tht-dwh" and not failed_once:
            failed_once = True
            raise OSError("injected directory fsync failure")
        original_fsync(path)

    second = DwhPreprocessPipeline(
        workspace_id="demo", workspace_root=tmp_path,
        config_fingerprint=FP, input_fingerprint=FP,
        introspect=lambda output: output.write_text("new"), build_lsh=build,
    )
    monkeypatch.setattr(second, "_fsync", fail_active_once)
    failed = second.run()
    assert failed.status == "failed"
    assert (tmp_path / ".tht-dwh" / "ACTIVE").read_text().strip() == first.run_id


def test_snapshot_stays_on_one_generation_across_publish(tmp_path):
    from types import SimpleNamespace

    def pipeline(content):
        return DwhPreprocessPipeline(
            workspace_id="demo", workspace_root=tmp_path,
            config_fingerprint=FP, input_fingerprint=FP,
            introspect=lambda output: output.write_text(content),
            build_lsh=lambda physical, output: [
                (output / name).write_text(content)
                for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json")
            ],
        )

    first = pipeline("old").run()
    cfg = SimpleNamespace(paths=SimpleNamespace(
        artifacts=tmp_path / "artifacts", indexes=tmp_path / "indexes"
    ))
    snapshot = resolve_dwh_snapshot(cfg)
    pipeline("new").run()
    assert snapshot.generation == first.run_id
    assert snapshot.physical.read_text() == "old"
    assert (snapshot.lsh_dir / "demo_meta.json").read_text() == "old"


def test_generation_retention_keeps_active_and_one_rollback(tmp_path):
    run_ids = []
    for index in range(5):
        report = DwhPreprocessPipeline(
            workspace_id="demo", workspace_root=tmp_path,
            config_fingerprint=FP, input_fingerprint=FP,
            introspect=lambda output, i=index: output.write_text(str(i)),
            build_lsh=lambda physical, output, i=index: [
                (output / name).write_text(str(i))
                for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json")
            ],
            retain_generations=2,
        ).run()
        run_ids.append(report.run_id)
    remaining = {path.name for path in (tmp_path / ".tht-dwh" / "generations").iterdir()}
    assert remaining == set(run_ids[-2:])


def test_corrupt_newer_directory_does_not_consume_rollback_slot(tmp_path):
    run_ids = []
    pipeline = None
    for index in range(3):
        pipeline = DwhPreprocessPipeline(
            workspace_id="demo", workspace_root=tmp_path,
            config_fingerprint=FP, input_fingerprint=FP,
            introspect=lambda output, i=index: output.write_text(str(i)),
            build_lsh=lambda physical, output, i=index: [
                (output / name).write_text(str(i))
                for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json")
            ],
            retain_generations=3,
        )
        run_ids.append(pipeline.run().run_id)
    generations = tmp_path / ".tht-dwh" / "generations"
    corrupt = generations / ("f" * 32)
    corrupt.mkdir(mode=0o700)
    (corrupt / "junk").write_text("not a published generation")

    pipeline.retain_generations = 2
    pipeline._cleanup_generations()

    assert (generations / run_ids[-1]).is_dir()
    assert (generations / run_ids[-2]).is_dir()
    assert not (generations / run_ids[0]).exists()
    assert corrupt.is_dir()


def test_retention_n_counts_active_plus_n_minus_one_rollbacks_even_if_active_is_old(tmp_path):
    import os

    run_ids = []
    pipeline = None
    for index in range(3):
        pipeline = DwhPreprocessPipeline(
            workspace_id="demo", workspace_root=tmp_path,
            config_fingerprint=FP, input_fingerprint=FP,
            introspect=lambda output, i=index: output.write_text(str(i)),
            build_lsh=lambda physical, output, i=index: [
                (output / name).write_text(str(i))
                for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json")
            ], retain_generations=3,
        )
        run_ids.append(pipeline.run().run_id)
    generations = tmp_path / ".tht-dwh" / "generations"
    os.utime(generations / run_ids[-1], ns=(1, 1))

    pipeline.retain_generations = 2
    pipeline._cleanup_generations()

    remaining = {path.name for path in generations.iterdir() if path.is_dir()}
    assert remaining == {run_ids[-1], run_ids[-2]}


def test_retention_candidate_swap_to_symlink_is_never_followed(monkeypatch, tmp_path):
    import tht.jobs.dwh_pipeline as module

    pipeline = DwhPreprocessPipeline(
        workspace_id="demo", workspace_root=tmp_path,
        config_fingerprint=FP, input_fingerprint=FP,
        introspect=lambda output: output.write_text("active"),
        build_lsh=lambda physical, output: [
            (output / name).write_text("active")
            for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json")
        ], retain_generations=1,
    )
    pipeline.run()
    generations = tmp_path / ".tht-dwh" / "generations"
    candidate_name = "e" * 32
    candidate = generations / candidate_name
    candidate.mkdir(mode=0o700)
    external = tmp_path / "external-crafted"
    external.mkdir()
    sentinel = external / "sentinel"
    sentinel.write_text("must-not-read-or-mutate")
    real_open = module.os.open
    swapped = False

    def swapping_open(path, flags, *args, **kwargs):
        nonlocal swapped
        if path == candidate_name and kwargs.get("dir_fd") is not None and not swapped:
            swapped = True
            candidate.rmdir()
            candidate.symlink_to(external, target_is_directory=True)
        return real_open(path, flags, *args, **kwargs)

    monkeypatch.setattr(module.os, "open", swapping_open)
    pipeline._cleanup_generations()
    assert swapped
    assert sentinel.read_text() == "must-not-read-or-mutate"
    assert candidate.is_symlink()


def test_reader_lease_blocks_retain_one_publisher_until_file_reads_finish(tmp_path):
    import threading
    import time
    from types import SimpleNamespace

    def make(content, retain=1):
        return DwhPreprocessPipeline(
            workspace_id="demo", workspace_root=tmp_path,
            config_fingerprint=FP, input_fingerprint=FP,
            introspect=lambda output: output.write_text(content),
            build_lsh=lambda physical, output: [
                (output / name).write_text(content)
                for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json")
            ], retain_generations=retain,
        )

    first = make("old").run()
    cfg = SimpleNamespace(paths=SimpleNamespace(
        artifacts=tmp_path / "artifacts", indexes=tmp_path / "indexes"
    ))
    completed = threading.Event()
    with lease_dwh_snapshot(cfg) as snapshot:
        thread = threading.Thread(target=lambda: (make("new").run(), completed.set()))
        thread.start()
        time.sleep(0.05)
        assert not completed.is_set()
        assert snapshot.physical.read_text() == "old"
        assert snapshot.generation == first.run_id
    thread.join(timeout=2)
    assert completed.is_set()
    assert not (tmp_path / ".tht-dwh" / "generations" / first.run_id).exists()


def test_cleanup_never_follows_top_level_or_child_symlinks(tmp_path):
    external = tmp_path / "external"
    external.mkdir()
    victim = external / "victim"
    victim.write_text("safe")

    generations = tmp_path / ".tht-dwh" / "generations"
    generations.mkdir(parents=True)
    (generations / ("a" * 32)).symlink_to(external, target_is_directory=True)

    def make(content, retain=1):
        return DwhPreprocessPipeline(
            workspace_id="demo", workspace_root=tmp_path,
            config_fingerprint=FP, input_fingerprint=FP,
            introspect=lambda output: output.write_text(content),
            build_lsh=lambda physical, output: [
                (output / name).write_text(content)
                for name in ("demo_lsh.pkl", "demo_minhashes.pkl", "demo_meta.json")
            ], retain_generations=retain,
        )

    first = make("one", retain=2).run()
    make("two", retain=2).run()
    old = generations / first.run_id
    old.chmod(0o700)
    (old / "hostile-link").symlink_to(victim)
    make("three").run()
    assert victim.read_text() == "safe"
    assert victim.stat().st_mode & 0o200