from pathlib import Path
import ast
import json
import os
import sys

if __package__ in {None, ""}:
    sys.path.insert(0, str(Path(__file__).resolve().parents[1]))

from scripts.run_secret_static_checks import run_secret_static_checks

ROOT = Path(__file__).resolve().parents[1]
SCRIPT_DIR = ROOT / "scripts"

FORBIDDEN_PATTERNS = (
    "env " + "= env or " + "os.environ",
    "env or " + "os.environ",
)


def run_script_static_checks(env=None, script_dir: Path = SCRIPT_DIR) -> dict:
    env = os.environ if env is None else env
    findings = []
    for path in sorted(script_dir.glob("*.py")):
        findings.extend(check_script_file(path))
    findings.extend(run_secret_static_checks(env=env)["findings"])
    return {
        "passed": len(findings) == 0,
        "script_count": len(list(script_dir.glob("*.py"))),
        "findings": findings,
    }


def check_script_file(path: Path) -> list[dict]:
    findings = []
    source = path.read_text(encoding="utf-8")
    tree = None
    try:
        tree = ast.parse(source, filename=str(path))
    except SyntaxError as exc:
        findings.append(
            {
                "file": display_path(path),
                "line": exc.lineno or 1,
                "pattern": "python_syntax",
                "reason": "script_python_syntax_error",
            }
        )
    if tree is not None:
        findings.extend(find_python39_incompatible_annotations(tree, path))
    for line_number, line in enumerate(source.splitlines(), start=1):
        for pattern in FORBIDDEN_PATTERNS:
            if pattern in line:
                findings.append(
                    {
                        "file": display_path(path),
                        "line": line_number,
                        "pattern": pattern,
                        "reason": forbidden_pattern_reason(pattern),
                    }
                )
    if tree is not None and has_main_function(tree) and "raise SystemExit(main(" not in source:
        findings.append(
            {
                "file": display_path(path),
                "line": 1,
                "pattern": "raise SystemExit(main())",
                "reason": "automation_entrypoint_must_preserve_exit_code",
            }
        )
    return findings


def forbidden_pattern_reason(pattern: str) -> str:
    return "empty_env_must_not_fall_back_to_ambient_environment"


def has_main_function(tree: ast.AST) -> bool:
    return any(isinstance(node, ast.FunctionDef) and node.name == "main" for node in ast.walk(tree))


def find_python39_incompatible_annotations(tree: ast.AST, path: Path) -> list[dict]:
    findings = []

    def inspect_annotation(annotation) -> None:
        if annotation is not None and has_pep604_optional_annotation(annotation):
            findings.append(
                {
                    "file": display_path(path),
                    "line": getattr(annotation, "lineno", 1),
                    "pattern": "PEP604 Optional",
                    "reason": "python39_incompatible_pep604_optional_annotation",
                }
            )

    for node in ast.walk(tree):
        if isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef)):
            inspect_annotation(node.returns)
            for arg in list(node.args.args) + list(node.args.kwonlyargs) + list(node.args.posonlyargs):
                inspect_annotation(arg.annotation)
            if node.args.vararg:
                inspect_annotation(node.args.vararg.annotation)
            if node.args.kwarg:
                inspect_annotation(node.args.kwarg.annotation)
        elif isinstance(node, ast.AnnAssign):
            inspect_annotation(node.annotation)
    return findings


def has_pep604_optional_annotation(annotation) -> bool:
    if isinstance(annotation, ast.BinOp) and isinstance(annotation.op, ast.BitOr):
        return is_none_annotation(annotation.left) or is_none_annotation(annotation.right)
    return any(has_pep604_optional_annotation(child) for child in ast.iter_child_nodes(annotation))


def is_none_annotation(node) -> bool:
    return isinstance(node, ast.Constant) and node.value is None


def display_path(path: Path) -> str:
    try:
        return str(path.relative_to(ROOT))
    except ValueError:
        return path.name


def main(env=None) -> int:
    env = os.environ if env is None else env
    result = run_script_static_checks(env=env)
    if _get_bool(env, "SCRIPT_CHECKS_OUTPUT_JSON", False):
        print(json.dumps(result, ensure_ascii=False, sort_keys=True))
    else:
        print(f"Script static checks passed: {result['passed']}")
        print(f"Script files checked: {result['script_count']}")
        for finding in result["findings"]:
            print(
                f"{finding['file']}:{finding['line']} "
                f"{finding['reason']} pattern={finding['pattern']}"
            )
    return 0 if result["passed"] else 2


def _get_bool(env, key: str, default: bool) -> bool:
    value = env.get(key)
    if value is None or value == "":
        return default
    return str(value).strip().lower() in {"1", "true", "yes", "on"}


if __name__ == "__main__":
    raise SystemExit(main())