"""Every process the app runs as sees every table before its first query.

The units declare their tables in their own `models` modules, and a core model names a unit's by
string (`User.subscriptions` → `Subscription`). A fresh interpreter that never imported the unit's
module fails to configure its mappers on its first query: the download child once did exactly that,
and every job failed, while this suite stayed green — it imports `app.tables` in-process, which hides
the gap. So each entry point is imported here in a clean interpreter, and must register the whole
schema on its own.
"""

import ast
import json
import subprocess
import sys
from pathlib import Path

import app.tables  # noqa: F401
from app.db import Base

BACKEND = Path(__file__).parent.parent
APP = BACKEND / "app"

# Each `python -m` module the deployment starts, and the API's app module.
ENTRY_POINTS = ("app.main", "app.worker", "app.downloads.runner")

# The table list goes out on one marked line: the API's logging writes to the same stdout, and a
# line it logs while importing is not the probe's answer.
_MARK = "entry-point-tables:"
_PROBE = (
    "import importlib, json, sys\n"
    "importlib.import_module(sys.argv[1])\n"
    "from sqlalchemy.orm import configure_mappers\n"
    "from app.db import Base\n"
    "configure_mappers()\n"
    f"print({_MARK!r} + json.dumps(sorted(Base.metadata.tables)))\n"
)


def test_each_entry_point_registers_the_whole_schema_on_its_own():
    whole = sorted(Base.metadata.tables)
    for module in ENTRY_POINTS:
        r = subprocess.run(
            [sys.executable, "-c", _PROBE, module],
            cwd=BACKEND,
            capture_output=True,
            text=True,
            timeout=120,
            check=False,
        )
        assert r.returncode == 0, (module, r.stderr[-2000:])
        answer = [ln for ln in r.stdout.splitlines() if ln.startswith(_MARK)]
        assert len(answer) == 1, (module, r.stdout[-2000:])
        assert json.loads(answer[0].removeprefix(_MARK)) == whole, module


def test_every_module_that_runs_as_a_process_is_listed():
    mains = set()
    for path in APP.rglob("*.py"):
        tree = ast.parse(path.read_text(encoding="utf-8"))
        for node in tree.body:
            if (
                isinstance(node, ast.If)
                and isinstance(node.test, ast.Compare)
                and isinstance(node.test.left, ast.Name)
                and node.test.left.id == "__name__"
            ):
                rel = path.relative_to(BACKEND).with_suffix("").as_posix()
                mains.add(rel.replace("/", "."))
    assert mains <= set(ENTRY_POINTS), mains - set(ENTRY_POINTS)