"""Unit: the shared git-source resolver (phase 35, task 03).

``effective_git_sources`` is driven with a stubbed session (no Postgres)
and a fresh ``Settings(_env_file=None)`` env (monkeypatched into the
resolver's module — the dev ``.env`` never leaks in, same pattern as the
integration suites): DB rows win in ``(added_at, id)`` order (env
ignored), the ``BOR_GIT_SOURCES`` list is a fallback only while the
table is empty (phase-28 CSV parse reused), and both-empty yields
``([], "env")`` so the callers keep their fail-loud behavior.
"""
from __future__ import annotations

import re
from typing import Any

import pytest

from app.config import Settings
from app.models import GitSource
from app.rag import git_sources as resolver


class _FakeScalars:
    """The ``.scalars(stmt).all()`` tail of the resolver's query."""

    def __init__(self, rows: list[GitSource]) -> None:
        self._rows = rows

    def all(self) -> list[GitSource]:
        return self._rows


class _FakeSession:
    """Just enough of a SQLAlchemy session for the resolver (test_steering
    pattern). Records the statement so the ordering can be asserted."""

    def __init__(self, rows: list[GitSource]) -> None:
        self._rows = rows
        self.statements: list[Any] = []

    def scalars(self, stmt: Any) -> _FakeScalars:
        self.statements.append(stmt)
        return _FakeScalars(self._rows)


def _stub_env(monkeypatch: pytest.MonkeyPatch, git_sources: str) -> None:
    """Point the resolver's env fallback at a fresh Settings (no .env)."""
    monkeypatch.setattr(
        resolver,
        "get_settings",
        lambda: Settings(_env_file=None, git_sources=git_sources),  # pyright: ignore[reportCallIssue]
    )


# --- the three branches ----------------------------------------------------


def test_db_rows_win_over_env(monkeypatch: pytest.MonkeyPatch) -> None:
    """Seeded table + env set → the DB list, origin ``db`` (env ignored)."""
    _stub_env(monkeypatch, "https://env.example/ignored.git")
    session = _FakeSession([GitSource(url="https://db.example/a.git"), GitSource(url="https://db.example/b.git")])

    urls, origin = resolver.effective_git_sources(session)  # pyright: ignore[reportArgumentType]

    assert urls == ["https://db.example/a.git", "https://db.example/b.git"]
    assert origin == "db"


def test_env_fallback_while_table_empty(monkeypatch: pytest.MonkeyPatch) -> None:
    """Empty table + env set → the env list, origin ``env``.

    The CSV parse is ``Settings.git_source_list`` itself (phase 28):
    whitespace-trimmed, empty entries dropped, order preserved.
    """
    _stub_env(monkeypatch, " https://env.example/one.git , ,git@env.example:two.git ")
    session = _FakeSession([])

    urls, origin = resolver.effective_git_sources(session)  # pyright: ignore[reportArgumentType]

    assert urls == ["https://env.example/one.git", "git@env.example:two.git"]
    assert origin == "env"


def test_both_empty_returns_empty_env(monkeypatch: pytest.MonkeyPatch) -> None:
    """Empty table + unset env → ``([], "env")`` — the callers fail loudly."""
    _stub_env(monkeypatch, " , ")  # whitespace-only is just as unconfigured as empty
    session = _FakeSession([])

    urls, origin = resolver.effective_git_sources(session)  # pyright: ignore[reportArgumentType]

    assert urls == []
    assert origin == "env"


# --- the ordering ----------------------------------------------------------


def test_db_rows_ordered_by_added_at_then_id(monkeypatch: pytest.MonkeyPatch) -> None:
    """The statement orders by ``(added_at, id)`` — oldest first, the id
    tie-break deciding same-timestamp inserts (matches the API's GET)."""
    _stub_env(monkeypatch, "")
    session = _FakeSession([GitSource(url="https://db.example/a.git")])

    resolver.effective_git_sources(session)  # pyright: ignore[reportArgumentType]

    assert len(session.statements) == 1
    compiled = str(session.statements[0].compile(compile_kwargs={"literal_binds": True}))
    assert re.search(
        r"ORDER BY\s+git_sources\.added_at ASC,\s+git_sources\.id ASC", compiled
    ), compiled