"""Tests for Tools/visual_loop.py — metrics, comparison and feedback rules.

Synthetic 8-bit images are written to a temp directory and measured, so the
numbers can be reasoned about directly (a mid-grey flat frame has near-zero edge
density and contrast; a checkerboard has a lot of both).
"""

import os
import sys

_TOOLS = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
sys.path.insert(0, _TOOLS)
for _sub in ("review", "gen", "unreal", "blender", "input"):
    sys.path.insert(0, os.path.join(_TOOLS, _sub))


import os
import sys
import tempfile
import unittest

from PIL import Image

ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
sys.path.insert(0, os.path.join(ROOT, "Tools"))

import visual_loop as vl  # noqa: E402


def write_image(path, kind, size=(64, 64)):
    img = Image.new("RGB", size)
    if kind == "flat":
        img.paste((128, 128, 128), (0, 0, size[0], size[1]))
    elif kind == "dark":
        img.paste((10, 10, 10), (0, 0, size[0], size[1]))
    elif kind == "checker":
        px = img.load()
        for y in range(size[1]):
            for x in range(size[0]):
                px[x, y] = (240, 240, 240) if (x // 4 + y // 4) % 2 else (20, 20, 20)
    elif kind == "sky":
        # bright top third, mid stone bottom: composition like an elevation
        px = img.load()
        for y in range(size[1]):
            for x in range(size[0]):
                px[x, y] = (150, 190, 230) if y < size[1] // 3 else (170, 165, 155)
    img.save(path)
    return path


class MetricsTest(unittest.TestCase):
    def test_flat_frame_has_no_edges_and_no_contrast(self):
        with tempfile.TemporaryDirectory() as tmp:
            m = vl.metrics(write_image(os.path.join(tmp, "a.png"), "flat"))
        self.assertEqual(m["size"], [64, 64])
        self.assertAlmostEqual(m["mean_luma"], 128.0, delta=1.0)
        self.assertLess(m["rms_contrast"], 1.0)
        self.assertLess(m["edge_density"], vl.MIN_EDGE_DENSITY)

    def test_checker_frame_has_edges_and_contrast(self):
        with tempfile.TemporaryDirectory() as tmp:
            m = vl.metrics(write_image(os.path.join(tmp, "b.png"), "checker"))
        self.assertGreater(m["edge_density"], 0.01)
        self.assertGreater(m["rms_contrast"], 50.0)

    def test_composition_grid_is_nine_cells(self):
        with tempfile.TemporaryDirectory() as tmp:
            m = vl.metrics(write_image(os.path.join(tmp, "c.png"), "sky"))
        self.assertEqual(len(m["grid_luma"]), 9)
        # sky row should be brighter than the stone rows
        self.assertGreater(m["grid_luma"][0], m["grid_luma"][8])

    def test_dominant_palette_is_reported(self):
        with tempfile.TemporaryDirectory() as tmp:
            m = vl.metrics(write_image(os.path.join(tmp, "d.png"), "flat"))
        self.assertTrue(m["dominant"])
        self.assertAlmostEqual(m["dominant"][0]["share"], 1.0, delta=0.05)


class CompareTest(unittest.TestCase):
    def _metrics(self, kind):
        with tempfile.TemporaryDirectory() as tmp:
            return vl.metrics(write_image(os.path.join(tmp, "x.png"), kind))

    def test_identical_images_score_high(self):
        m = self._metrics("checker")
        delta = vl.compare(m, m)
        self.assertGreater(delta["score"], 0.9)
        self.assertEqual(delta["delta_luma"], 0.0)

    def test_flat_against_checker_scores_low_on_edges(self):
        flat, checker = self._metrics("flat"), self._metrics("checker")
        delta = vl.compare(flat, checker)
        self.assertLess(delta["edge_ratio"], 0.5)
        self.assertLess(delta["score"], 0.9)

    def test_dark_against_bright_reports_a_luma_delta(self):
        dark, bright = self._metrics("dark"), self._metrics("checker")
        delta = vl.compare(dark, bright)
        self.assertLess(delta["delta_luma"], -50)


class FeedbackTest(unittest.TestCase):
    def test_low_edge_ratio_names_the_modelling_skills(self):
        notes = vl.feedback("x", {}, {}, {
            "delta_luma": 0, "contrast_ratio": 1.0, "edge_ratio": 0.3,
            "palette_distance": 10, "composition_correlation": 0.8, "score": 0.5})
        joined = " ".join(notes)
        self.assertIn("Relief", joined)
        self.assertIn("blender-modeler", joined)

    def test_bright_and_compressed_flags_lighting_and_lookdev(self):
        notes = vl.feedback("x", {}, {}, {
            "delta_luma": 40, "contrast_ratio": 0.5, "edge_ratio": 1.0,
            "palette_distance": 10, "composition_correlation": 0.8, "score": 0.5})
        joined = " ".join(notes)
        self.assertIn("Too bright", joined)
        self.assertIn("lookdev", joined)

    def test_framing_mismatch_names_the_camera_skill(self):
        notes = vl.feedback("x", {}, {}, {
            "delta_luma": 0, "contrast_ratio": 1.0, "edge_ratio": 1.0,
            "palette_distance": 10, "composition_correlation": 0.1, "score": 0.5})
        self.assertIn("camera-cinematography", " ".join(notes))

    def test_no_delta_reports_no_action(self):
        notes = vl.feedback("x", {}, {}, {
            "delta_luma": 0, "contrast_ratio": 1.0, "edge_ratio": 1.0,
            "palette_distance": 5, "composition_correlation": 0.9, "score": 0.95})
        self.assertIn("No metric is outside its tolerance", notes[0])


class TargetSpecTest(unittest.TestCase):
    def test_every_target_has_expectation_and_reference(self):
        for target in vl.load_targets():
            self.assertTrue(target["expect"].strip(), target["name"])
            self.assertTrue(target["references"], target["name"])
            self.assertTrue(target["shot"].startswith("Screenshots/demo/"),
                            f"{target['name']} must be a demo-map shot")

    def test_iteration_output_is_gitignored(self):
        # Iterations are deliberately uncommitted until the owner confirms a shot.
        ignore = open(os.path.join(ROOT, ".gitignore"), encoding="utf-8").read()
        self.assertIn("/Art/reference/iterations/", ignore)


if __name__ == "__main__":
    unittest.main()