"""Unit tests for the Phase-3 level ladder (harness.level), plan-phase3-results-ux.md §4.1 / R1.

Pure function — no I/O. Proves the YunoHost gap-caps-the-level semantics, including the U0 gate
acceptance: a recipe that climbs through L4 reports 4, and one that fails at L2 is capped at 1
(the level just below the failed rung). Run cold with:  cc-ci-run -m pytest tests/unit/test_level.py -q
"""

from __future__ import annotations

import os
import sys

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "runner"))
from harness import level as L  # noqa: E402


def _rungs(
    install="pass",
    upgrade="pass",
    backup_restore="pass",
    functional="pass",
):
    return {
        "install": install,
        "upgrade": upgrade,
        "backup_restore": backup_restore,
        "functional": functional,
    }


# ---- the ladder: four essential rungs, top is L4 (functional) ----


def test_full_clean_climb_to_L4():
    # All four essential rungs pass → L4 (the top; integration/recipe-local are optional, not leveled).
    lvl, reason = L.compute_level(_rungs())
    assert lvl == 4
    assert reason == ""


def test_fails_at_L2_capped_at_L1():
    # GATE: upgrade fails → capped at L1 even though higher rungs would pass.
    lvl, reason = L.compute_level(_rungs(upgrade="fail", backup_restore="pass", functional="pass"))
    assert lvl == 1
    assert "L2" in reason and "FAILED" in reason


# ---- L0 / install ----


def test_install_fail_is_L0():
    lvl, reason = L.compute_level(_rungs(install="fail"))
    assert lvl == 0
    assert "L1" in reason and "FAILED" in reason


# ---- gap-caps semantics: a higher pass can't rescue a lower gap ----


def test_higher_pass_does_not_rescue_lower_na():
    # backup/restore N/A (stateless app) caps at L2 even though functional would pass.
    lvl, reason = L.compute_level(_rungs(backup_restore="na", functional="pass"))
    assert lvl == 2
    assert "L3" in reason and "N/A" in reason


def test_upgrade_na_caps_at_L1():
    # only one published version → no upgrade possible → N/A caps at L1 (upgrade is essential).
    lvl, reason = L.compute_level(_rungs(upgrade="na"))
    assert lvl == 1
    assert "L2" in reason and "N/A" in reason


def test_functional_na_caps_at_L3():
    # no recipe-specific functional tests → functional N/A caps at L3.
    lvl, reason = L.compute_level(_rungs(functional="na"))
    assert lvl == 3
    assert "L4" in reason and "N/A" in reason


def test_functional_fail_caps_at_L3():
    lvl, reason = L.compute_level(_rungs(functional="fail"))
    assert lvl == 3
    assert "L4" in reason and "FAILED" in reason


# ---- input validation ----


def test_invalid_status_raises():
    bad = _rungs()
    bad["functional"] = "passed"  # not in the vocabulary
    try:
        L.compute_level(bad)
    except ValueError:
        return
    raise AssertionError("expected ValueError on invalid rung status")


# ---- helpers: backup_restore_status ----


def test_backup_restore_status_pass():
    assert L.backup_restore_status("pass", "pass", True) == "pass"


def test_backup_restore_status_not_capable_is_na():
    assert L.backup_restore_status("skip", "skip", False) == "na"


def test_backup_restore_status_fail_on_either():
    assert L.backup_restore_status("pass", "fail", True) == "fail"
    assert L.backup_restore_status("fail", "pass", True) == "fail"


def test_backup_restore_partial_is_na():
    # backup-capable but restore didn't run cleanly (not pass, not fail) → cannot claim L3
    assert L.backup_restore_status("pass", "skip", True) == "na"


# ---- helpers: tier_to_rung ----


def test_tier_to_rung_mapping():
    assert L.tier_to_rung("pass") == "pass"
    assert L.tier_to_rung("fail") == "fail"
    assert L.tier_to_rung("skip") == "na"
    assert L.tier_to_rung(None) == "na"