import subprocess
from pathlib import Path

import pytest

from app.flow.messages import MessageSpec
from app.flow.schemas import FlowDef, NodeDef
from app.flow.store import FlowNotFound, FlowStore


@pytest.fixture
def store(tmp_path: Path) -> FlowStore:
    return FlowStore(tmp_path / "flows")


def commit_count(store: FlowStore) -> int:
    result = subprocess.run(
        ["git", "-C", str(store.root), "rev-list", "--count", "HEAD"],
        capture_output=True,
        text=True,
        check=True,
    )
    return int(result.stdout.strip())


def a_flow() -> FlowDef:
    return FlowDef(
        name="heating",
        nodes=[NodeDef(id="sensor", provides=[MessageSpec(name="temp")])],
    )


def test_flow_round_trips(store: FlowStore):
    store.write_flow(a_flow())

    assert store.list_flows() == ["heating"]
    assert store.read_flow("heating").nodes[0].provides[0].name == "temp"


def test_every_change_is_committed(store: FlowStore):
    before = commit_count(store)

    store.write_flow(a_flow())
    assert commit_count(store) == before + 1

    store.write_node_source(
        "heating", "sensor", "def process(params):\n    return {}\n"
    )
    assert commit_count(store) == before + 2


def test_saving_unchanged_content_does_nothing(store: FlowStore):
    store.write_flow(a_flow())
    commits = commit_count(store)

    # Autosave repeats the same document; history should not grow.
    assert store.write_flow(a_flow()) is False
    assert commit_count(store) == commits


def test_missing_flow_is_reported(store: FlowStore):
    with pytest.raises(FlowNotFound):
        store.read_flow("nope")


def test_deleting_removes_flow_and_its_nodes(store: FlowStore):
    store.write_flow(a_flow())
    store.write_node_source(
        "heating", "sensor", "def process(params):\n    return {}\n"
    )

    store.delete_flow("heating")

    assert store.list_flows() == []
    assert not (store.root / "heating").exists()