import ast
import subprocess
import sys
import warnings

import pytest

from model_schema import PipelineResult, SolverCode, SolverRun, SolverStatus
from report import build_document, to_html
from script_export import build_solver_script
from solver_stage import CodeRejected, assemble_script, run_solver_code, validate_structure
from test_model_checks import make_spec
from test_review import make_review

# min 3x + 2y  s.t.  x + y >= 4, 0 <= x, y <= 3  ->  Zielwert 9
STRUCTURED_CODE = '''
from scipy.optimize import linprog

# Kosten je Tonne Rohstoff X und Y [Tsd. €]
COSTS = [3, 2]


def solve_model():
    """Baut das LP auf und löst es."""
    # Bedarf: x + y >= 4  ->  -x - y <= -4
    return linprog(COSTS, A_ub=[[-1, -1]], b_ub=[-4], bounds=[(0, 3), (0, 3)], method="highs")


def main():
    """Löst das Modell und gibt das Ergebnis aus."""
    res = solve_model()
    x, y = float(res.x[0]), float(res.x[1])
    report(
        "optimal" if res.status == 0 else "error", res.fun, {"x": x, "y": y},
        constraints=[{"name": "Bedarf", "lhs": x + y, "sense": ">=", "rhs": 4}],
        variables=[{"name": "x", "value": x, "var_type": "continuous", "lb": 0, "ub": 3},
                   {"name": "y", "value": y, "var_type": "continuous", "lb": 0, "ub": 3}],
    )


if __name__ == "__main__":
    main()
'''


def make_result(task="Minimiere die Kosten für mindestens 4 t Rohstoff.", code=STRUCTURED_CODE):
    return PipelineResult(
        task=task,
        specification=make_spec(),
        review=make_review(),
        revisions=0,
        solver_code=SolverCode(code=code, data_assumptions=["Lieferfrist: keine (nicht im Text)"]),
        solver_run=SolverRun(status=SolverStatus.OPTIMAL, objective_value=9.0),
    )


def test_script_layout_order():
    script = build_solver_script(make_result())
    assert script.startswith('#!/usr/bin/env python3\nr"""\n')
    tree = ast.parse(script)
    docstring = ast.get_docstring(tree)
    positions = [docstring.index(h) for h in ("AUFGABE", "MATHEMATISCHES MODELL", "ALGORITHMUS")]
    assert positions == sorted(positions)
    assert "Minimiere die Kosten" in docstring
    assert "\\sum_{j \\in J} x_j \\ge b" in docstring      # Restriktion in LaTeX
    assert "Branch-and-Cut" not in docstring                # SciPy-Stack, nicht HiGHS-Text
    assert "linprog" in docstring
    assert "Lieferfrist" in docstring                       # angenommene Daten
    # Imports vor report(), report() vor dem abschließenden main-Guard
    names = [type(n).__name__ + ":" + getattr(n, "name", "") for n in tree.body]
    guard_index = len(names) - 1
    assert names.index("ImportFrom:") < names.index("FunctionDef:main") < names.index("FunctionDef:report") < guard_index
    assert isinstance(tree.body[guard_index], ast.If) and script.rstrip().endswith("main()")


def test_script_is_standalone_runnable(tmp_path):
    path = tmp_path / "solve.py"
    path.write_text(build_solver_script(make_result()), encoding="utf-8")
    proc = subprocess.run([sys.executable, str(path)], capture_output=True, text=True, timeout=60)
    assert proc.returncode == 0, proc.stderr
    assert "Status:   optimal" in proc.stdout
    assert "Zielwert: 9.0" in proc.stdout
    assert proc.stdout.strip().splitlines()[-1].startswith("RESULT_JSON:")


def test_latex_backslashes_and_quotes_do_not_break_script():
    task = 'Text mit \\sum, \\( x \\), """ Anführungszeichen """ und Backslash am Ende \\'
    script = build_solver_script(make_result(task=task))
    with warnings.catch_warnings():
        warnings.simplefilter("error")  # SyntaxWarning (ungültige Escapes) wäre ein Fehler
        compile(script, "solve.py", "exec")


def test_run_solver_code_with_structured_code():
    run = run_solver_code(STRUCTURED_CODE)
    assert run.status == SolverStatus.OPTIMAL
    assert run.objective_value == pytest.approx(9)


def test_assemble_without_guard_prepends_helpers():
    script = assemble_script("x = 1")
    assert "def report(" in script and "_apply_data_override(globals())" in script
    assert script.index("def report(") < script.index("x = 1")


def test_valid_structure_passes():
    validate_structure(STRUCTURED_CODE)


@pytest.mark.parametrize("code, reason", [
    ("def solve():\n    pass\n\nif __name__ == '__main__':\n    solve()\n", "main()"),
    ("def main():\n    pass\n\nmain()\n", "__main__"),
    ("def main():\n    pass\n\nif __name__ == '__main__':\n    main()\n\nx = 1\n", "__main__"),
])
def test_invalid_structure_is_rejected(code, reason):
    with pytest.raises(CodeRejected, match=reason.replace("(", r"\(").replace(")", r"\)")):
        validate_structure(code)


def test_html_report_has_copy_button_with_full_script():
    page = to_html(build_document(make_result()))
    assert page.count('class="copy-btn"') == 1
    assert "navigator.clipboard" in page and "execCommand('copy')" in page
    assert "#!/usr/bin/env python3" in page
    assert "if __name__ == &quot;__main__&quot;:" in page


def test_inline_math_delimiters_are_removed_from_docstring():
    spec = make_spec(indices=["Tage: \\(d \\in D = \\{Mo,Di\\}\\)"])
    result = make_result()
    result.specification = spec
    docstring = ast.get_docstring(ast.parse(build_solver_script(result)))
    assert "Tage: d \\in D = \\{Mo,Di\\}" in docstring
    assert "\\(" not in docstring and "\\)" not in docstring


def test_every_stack_and_class_has_algorithm_text():
    # Synchron-Regel: neuer TargetStack/ProblemClass braucht Texte in script_export
    from model_schema import ProblemClass, TargetStack
    from script_export import ALGORITHMS, CLASS_FIT
    assert set(ALGORITHMS) == set(TargetStack)
    assert set(CLASS_FIT) == set(ProblemClass)