import json

import pytest
from typer.testing import CliRunner

from tht.cli.decision_cmd import decision_app
from tht.decisions import append_decision, append_decisions, list_decisions
from tht.phase import current_phase


def _walk_to_phase(session, target):
    while current_phase(session) < target:
        append_decision(session, type="phase_approved", subject=f"phase:{current_phase(session)}")


def _configure_command(monkeypatch, sessions):
    import tht.cli.decision_cmd as mod

    class _Cfg:
        class paths:
            pass

    _Cfg.paths.sessions = sessions
    monkeypatch.setattr(mod, "_load_config_or_exit", lambda _c: _Cfg())
    monkeypatch.setattr(mod, "load_session_or_exit", lambda _cfg, _s: None)
    monkeypatch.setattr(mod, "session_dir", lambda _cfg, sid: sessions / sid)


def test_add_join_set_rejects_the_whole_batch_when_one_item_is_invalid(tmp_path, monkeypatch):
    session_id = "s1"
    session = tmp_path / session_id
    session.mkdir()
    _walk_to_phase(session, 4)
    _configure_command(monkeypatch, tmp_path)

    payload = [
        {"type": "join_modified", "subject": "a-b", "detail": "a.id = b.a_id"},
        {"type": "not_a_decision", "subject": "b-c", "detail": "b.id = c.b_id"},
    ]
    result = CliRunner().invoke(
        decision_app,
        ["add-join-set", "--session", session_id, "--doc", "-"],
        input=json.dumps(payload),
    )

    assert result.exit_code != 0
    assert not [decision for decision in list_decisions(session) if decision.type == "join_modified"]


def test_add_join_set_appends_the_complete_valid_batch(tmp_path, monkeypatch):
    session_id = "s1"
    session = tmp_path / session_id
    session.mkdir()
    _walk_to_phase(session, 4)
    _configure_command(monkeypatch, tmp_path)

    payload = [
        {"type": "join_modified", "subject": "a-b", "detail": "a.id = b.a_id"},
        {"type": "join_modified", "subject": "b-c", "detail": "b.id = c.b_id"},
    ]
    result = CliRunner().invoke(
        decision_app,
        ["add-join-set", "--session", session_id, "--doc", "-"],
        input=json.dumps(payload),
    )

    assert result.exit_code == 0, result.output
    joins = [decision for decision in list_decisions(session) if decision.type == "join_modified"]
    assert [decision.subject for decision in joins] == ["a-b", "b-c"]


def test_atomic_replace_failure_keeps_the_original_ledger(tmp_path, monkeypatch):
    session = tmp_path / "s1"
    session.mkdir()
    append_decision(session, type="phase_approved", subject="phase:1")
    original = (session / "review_decisions.jsonl").read_text()

    import tht.decisions as mod

    def fail_replace(_source, _target):
        raise OSError("disk failure")

    monkeypatch.setattr(mod.os, "replace", fail_replace)
    with pytest.raises(OSError, match="disk failure"):
        append_decisions(
            session,
            [
                {"type": "join_modified", "subject": "a-b"},
                {"type": "join_modified", "subject": "b-c"},
            ],
        )

    assert (session / "review_decisions.jsonl").read_text() == original