import json
import os
import pytest
from src.zone_config import load_zone_config, build_static_roi, list_zone_presets


def test_load_zone_config_reads_json(tmp_path):
    cfg = {"presets": {"test": {"count_line": {"x_start": 100, "x_end": 200, "y": 150}}}, "active_preset": "test"}
    p = tmp_path / "zones.json"
    p.write_text(json.dumps(cfg))
    result = load_zone_config(str(p))
    assert result["active_preset"] == "test"
    assert result["presets"]["test"]["count_line"]["y"] == 150


def test_build_static_roi_from_zone_config():
    zone = {
        "truck_area": [[100, 50], [110, 300], [400, 310], [390, 40]],
        "count_line": {"x_start": 110, "x_end": 400, "y": 150},
    }
    roi = build_static_roi(zone, video_w=640, video_h=480)
    assert roi.line_y == 150
    assert roi.confidence == 1.0
    assert roi.x1 < roi.x2
    assert roi.y1 < roi.y2


def test_build_static_roi_scales_coords():
    zone = {
        "truck_area": [[600, 385], [609, 1076], [1404, 1078], [1381, 343]],
        "count_line": {"x_start": 577, "x_end": 1401, "y": 330},
    }
    roi = build_static_roi(zone, video_w=1920, video_h=1080)
    assert roi.line_y == 330
    assert roi.x1 == 600
    assert roi.x2 == 1404


def test_list_zone_presets(tmp_path):
    cfg = {"presets": {"p1": {"description": "Zone 1"}, "p2": {"description": "Zone 2"}}}
    p = tmp_path / "zones.json"
    p.write_text(json.dumps(cfg))
    presets = list_zone_presets(str(p))
    assert len(presets) == 2
    names = [p["name"] for p in presets]
    assert "p1" in names
    assert "p2" in names