from pathlib import Path
import importlib.util
import sys

import geopandas as gpd
from shapely.geometry import LineString, Point


SCRIPTS = Path(__file__).resolve().parents[1] / "scripts"
sys.path.insert(0, str(SCRIPTS))

from flow_network import FlowNetwork  # noqa: E402

BUILD_SCRIPT = SCRIPTS / "07_build_flow_network.py"
spec = importlib.util.spec_from_file_location("build_flow_network", BUILD_SCRIPT)
build_flow_network = importlib.util.module_from_spec(spec)
assert spec.loader is not None
spec.loader.exec_module(build_flow_network)
build_binational_edges = build_flow_network.build_binational_edges


def test_cross_border_path_emerson():
    net = FlowNetwork([("ca_up", "border_emerson"), ("border_emerson", "us_down")])
    assert "ca_up" in net.upstream_reaches("us_down")


def test_real_layers_exist_after_build():
    import os

    if os.environ.get("RUN_NETWORK_INTEGRATION") != "1":
        return
    layers = Path(__file__).resolve().parents[1] / "layers"
    assert (layers / "hydro_edges.parquet").exists() or any(layers.glob("*hydro*"))


def test_build_binational_edges_links_canadian_and_us_arcs_at_emerson():
    canada = gpd.GeoDataFrame(
        {"source_reach_id": ["ca_mainstem"], "source_name": ["Red River"]},
        geometry=[LineString([(-97.2, 49.2), (-97.2, 49.0)])],
        crs="EPSG:4326",
    )
    united_states = gpd.GeoDataFrame(
        {"source_reach_id": ["us_mainstem"], "source_name": ["Red River"]},
        geometry=[LineString([(-97.2, 49.0), (-97.2, 48.8)])],
        crs="EPSG:4326",
    )

    edges = build_binational_edges(canada, united_states, border_point=(-97.2, 49.0))

    graph = FlowNetwork(zip(edges["from_node"], edges["to_node"]))
    assert "ca_mainstem:start" in graph.upstream_reaches("us_mainstem:end")
    assert bool(edges.loc[edges["edge_id"].eq("border_emerson"), "border_crossing"].iloc[0])


def test_build_binational_edges_accepts_nhdplus_point_directions():
    canada = gpd.GeoDataFrame(
        {"source_reach_id": ["ca_mainstem"]},
        geometry=[LineString([(-97.2, 49.1), (-97.2, 49.0)])],
        crs="EPSG:4326",
    )
    united_states = gpd.GeoDataFrame(
        {"comid": [101], "angle_direction": [180]},
        geometry=[Point(-97.2, 48.99)],
        crs="EPSG:4326",
    )

    edges = build_binational_edges(canada, united_states, border_point=(-97.2, 49.0))

    us_edge = edges.loc[edges["source_reach_id"].eq("101")].iloc[0]
    assert us_edge.geometry.geom_type == "LineString"
    assert us_edge.from_node == "101:start"