"""Structural rules for the NiceGUI page layer.

`.github/instructions/ui.instructions.md:23,31` forbids pages from owning
persistence or query-building concerns, and forbids components from resolving
request or application state. HIGH-07 recorded three violations of those rules;
these tests keep them from coming back.
"""

from __future__ import annotations

import ast
from pathlib import Path

UI_DIR = Path(__file__).resolve().parents[1] / "src" / "transcription" / "ui"
PAGES_DIR = UI_DIR / "pages"
COMPONENTS_DIR = UI_DIR / "components"

FORBIDDEN_PAGE_MODULES = frozenset({"sqlalchemy", "sqlmodel"})

# Sensitive modules are allowlisted, not blocklisted, so newly added persistence
# helpers cannot slip through by using an unlisted name.
PAGE_IMPORT_ALLOWLIST: dict[tuple[str, int], frozenset[str]] = {
    ("db.session", 3): frozenset({"SessionFactoryDep"}),
    ("transcription.config", 0): frozenset({"Settings"}),
}


def _page_paths() -> list[Path]:
    return sorted(path for path in PAGES_DIR.glob("*.py") if path.stem != "__init__")


def _component_paths() -> list[Path]:
    return sorted(COMPONENTS_DIR.rglob("*.py"))


def _imports(tree: ast.Module) -> tuple[set[str], set[str]]:
    """Return (imported names, imported root modules)."""
    names: set[str] = set()
    modules: set[str] = set()
    for node in ast.walk(tree):
        if isinstance(node, ast.ImportFrom):
            if node.module and node.level == 0:
                modules.add(node.module.split(".")[0])
            names.update(alias.name for alias in node.names)
        elif isinstance(node, ast.Import):
            for alias in node.names:
                modules.add(alias.name.split(".")[0])
                names.add(alias.name)
    return names, modules


def _page_allowlist_violations(tree: ast.Module) -> set[str]:
    violations: set[str] = set()
    for node in ast.walk(tree):
        if not isinstance(node, ast.ImportFrom) or not node.module:
            continue
        allowed = PAGE_IMPORT_ALLOWLIST.get((node.module, node.level))
        if allowed is None:
            continue
        for alias in node.names:
            imported_name = alias.name
            if imported_name not in allowed:
                violations.add(f"{'.' * node.level}{node.module}.{imported_name}")
    return violations


def test_page_modules_are_discovered():
    """Guard the guard: the rules below are meaningless if nothing is scanned."""
    discovered = {path.stem for path in _page_paths()}
    assert discovered >= {"documents_page", "jobs_page", "people_page", "sources_page"}


def test_no_page_imports_persistence_or_process_globals():
    """HIGH-07: pages orchestrate services; they do not own sessions or settings."""
    violations: dict[str, list[str]] = {}
    for path in _page_paths():
        tree = ast.parse(path.read_text(encoding="utf-8"))
        _, modules = _imports(tree)
        allowlist_violations = _page_allowlist_violations(tree)
        found = sorted((modules & FORBIDDEN_PAGE_MODULES) | allowlist_violations)
        if found:
            violations[path.stem] = found
    assert violations == {}


def test_no_component_resolves_request_or_application_state():
    """`ui.instructions.md:31`: components render, they do not resolve app state."""
    violations: dict[str, list[str]] = {}
    for path in _component_paths():
        names, modules = _imports(ast.parse(path.read_text(encoding="utf-8")))
        forbidden_names = {"get_settings", "get_engine", "session_scope", "transaction_scope"}
        found = sorted((names & forbidden_names) | (modules & (FORBIDDEN_PAGE_MODULES | {"fastapi"})))
        if found:
            violations[str(path.relative_to(COMPONENTS_DIR))] = found
    assert violations == {}


# `build_table` owns the interactive table styling; `print_preview_page` owns the
# print-only table, which must never paginate or expose a search box.
TABLE_OWNERS = frozenset({"components/table/common.py", "pages/print_preview_page.py"})


def _calls_ui_table(tree: ast.Module) -> bool:
    for node in ast.walk(tree):
        if not isinstance(node, ast.Call):
            continue
        func = node.func
        if (
            isinstance(func, ast.Attribute)
            and func.attr == "table"
            and isinstance(func.value, ast.Name)
            and func.value.id == "ui"
        ):
            return True
    return False


def test_only_the_designated_owners_construct_a_raw_table():
    """Review section 4: table styling lives in one place, not in every page."""
    offenders = sorted(
        str(path.relative_to(UI_DIR)).replace("\\", "/")
        for path in UI_DIR.rglob("*.py")
        if _calls_ui_table(ast.parse(path.read_text(encoding="utf-8")))
    )
    assert set(offenders) == TABLE_OWNERS


def _notifies_negative(tree: ast.Module) -> bool:
    """Return True if the module calls ``ui.notify(..., type="negative")``."""
    for node in ast.walk(tree):
        if not isinstance(node, ast.Call):
            continue
        func = node.func
        if not (
            isinstance(func, ast.Attribute)
            and func.attr == "notify"
            and isinstance(func.value, ast.Name)
            and func.value.id == "ui"
        ):
            continue
        for keyword in node.keywords:
            if keyword.arg == "type" and isinstance(keyword.value, ast.Constant) and keyword.value.value == "negative":
                return True
    return False


def test_no_page_hand_rolls_error_notifications():
    """HIGH-02: `ui.instructions.md:42` routes all error display through error_presenter.

    Hand-rolled ``ui.notify(str(exc), type="negative")`` discards the correlation
    ``error_id``, the canonical category, and the actionable suggestion that
    ``show_error`` renders, leaving the user with nothing to report. Eight such sites
    existed in ``home_page`` and ``people_page``; this keeps them from returning.
    """
    offenders = sorted(
        path.stem for path in _page_paths() if _notifies_negative(ast.parse(path.read_text(encoding="utf-8")))
    )
    assert offenders == [], f"Pages must render errors via error_presenter.show_error, not ui.notify: {offenders}"