"""Lean-build safety: core must not hard-import a plugin (ADR-013 Phase 5).

For a per-site build that omits a plugin, any core `from plugins.<name> import`
outside a try/except would crash the whole app when that plugin is absent. This
statically asserts every such import in shopdb/core and shopdb/cli is guarded.
"""

import ast
import os

CORE_ROOTS = ['shopdb/core', 'shopdb/cli']


def _imports_plugin(node):
    if isinstance(node, ast.ImportFrom):
        return bool(node.module and node.module.startswith('plugins.'))
    if isinstance(node, ast.Import):
        return any(alias.name.startswith('plugins.') for alias in node.names)
    return False


def _unguarded_in(path):
    found = []
    tree = ast.parse(open(path).read())

    class Visitor(ast.NodeVisitor):
        def __init__(self):
            self.try_depth = 0

        def visit_Try(self, node):
            self.try_depth += 1
            for child in node.body:
                self.visit(child)
            self.try_depth -= 1
            for handler in node.handlers:
                for child in handler.body:
                    self.visit(child)
            for child in node.orelse + node.finalbody:
                self.visit(child)

        def generic_visit(self, node):
            if _imports_plugin(node) and self.try_depth == 0:
                found.append(f"{path}:{node.lineno}")
            super().generic_visit(node)

    Visitor().visit(tree)
    return found


def test_no_unguarded_plugin_imports_in_core():
    unguarded = []
    for root in CORE_ROOTS:
        for dirpath, _, filenames in os.walk(root):
            for name in filenames:
                if name.endswith('.py'):
                    unguarded += _unguarded_in(os.path.join(dirpath, name))
    assert unguarded == [], (
        "Core imports a plugin without a try/except ImportError guard; a lean "
        "build omitting that plugin would crash. Wrap in try/except:\n  "
        + "\n  ".join(unguarded))
