"""Reject broken preview contracts before publishing generated references."""
import hashlib
import importlib.util
import json
from pathlib import Path
import shutil
import sys

import pytest

ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT / 'scripts'))
spec = importlib.util.spec_from_file_location('reference_preview', ROOT / 'scripts/reference_preview.py')
preview = importlib.util.module_from_spec(spec)
spec.loader.exec_module(preview)


@pytest.fixture
def copy(tmp_path):
    for name in ('research', 'canon', 'workplans', 'sequences', 'technologies', 'reference'):
        shutil.copytree(ROOT / name, tmp_path / name)
    shutil.copy(ROOT / 'START.md', tmp_path / 'START.md')
    (tmp_path / '.git').symlink_to(ROOT / '.git', target_is_directory=True)
    return tmp_path


def mutate(root, edit):
    path = root / 'reference/0.1/manifest.json'
    data = json.loads(path.read_text())
    edit(data)
    path.write_text(json.dumps(data))


def test_current_export():
    for name, content in preview.build().items():
        assert (ROOT / 'reference/0.1' / name).read_text() == content


@pytest.mark.parametrize('field,value', [('target', 'CAND-9999'), ('type', 'magically-guarantees'), ('condition', ''), ('evidence_refs', ['missing.md'])])
def test_bad_relation(copy, field, value):
    mutate(copy, lambda m: m['relations'][0].update({field: value}))
    with pytest.raises(ValueError):
        preview.build(copy)


def test_duplicate_identity(copy):
    mutate(copy, lambda m: m['core'].append(m['core'][0]))
    with pytest.raises(ValueError):
        preview.build(copy)


def test_live_candidate_change_does_not_break_frozen_preview(copy):
    with (copy / 'research/candidates/ConflictCopy.md').open('a') as f:
        f.write('\nChanged contract.\n')
    assert preview.build(copy) == preview.build(ROOT)
    import research_evolution as evolution
    with pytest.raises(ValueError, match='Stale profile'):
        evolution.validate(evolution.load(copy), copy)


def test_escaping_reference(copy):
    mutate(copy, lambda m: m['entrypoints'].update(start='/etc/passwd'))
    with pytest.raises(ValueError, match='Published manifest changed'):
        preview.build(copy)


def test_missing_metadata(copy):
    path = copy / 'reference/0.1/manifest.json'
    data = json.loads(path.read_text())
    del data['relations'][0]['rationale']
    path.write_text(json.dumps(data))
    with pytest.raises((ValueError, KeyError)):
        preview.build(copy)


def test_legitimate_new_research_remains_separate_from_old_release(copy):
    import research_evolution as evolution
    candidate = copy / 'research/candidates/ConflictCopy.md'
    candidate.write_text(candidate.read_text() + '\nNew research clarification.\n')
    digest = hashlib.sha256(candidate.read_bytes()).hexdigest()
    profiles = copy / 'research/evolution/profiles.json'
    data = json.loads(profiles.read_text())
    data['profiles'][0]['sha256'] = digest
    profiles.write_text(json.dumps(data))
    classes = copy / 'research/catalog/ClassificationCoverage.json'
    data = json.loads(classes.read_text())
    next(c for c in data['candidates'] if c['path'] == 'research/candidates/ConflictCopy.md')['sha256'] = digest
    classes.write_text(json.dumps(data))
    evolution.validate(evolution.load(copy), copy)
    assert preview.build(copy, '0.1') == preview.build(ROOT, '0.1')


def test_unknown_version_and_forged_release_pin(copy):
    with pytest.raises(ValueError, match='Unknown'):
        preview.build(copy, '9.9')
    path = copy / 'reference/releases.json'
    data = json.loads(path.read_text())
    data['releases']['0.1']['manifest_sha256'] = '0' * 64
    path.write_text(json.dumps(data))
    with pytest.raises(ValueError, match='digest mismatch'):
        preview.build(copy)


def test_published_cases_cannot_be_rewritten(copy):
    path = copy / 'reference/0.1/development-cases.json'
    path.write_text('{}')
    with pytest.raises(ValueError, match='Published artifact changed'):
        preview.build(copy)


@pytest.mark.parametrize('path', ['/etc/passwd', '../README.md', 'research/../README.md', 'research//README.md'])
def test_git_blob_rejects_escaping_paths(path):
    with pytest.raises(ValueError, match='Invalid reference'):
        preview.git_blob(ROOT, '0' * 40, path)