"""
测试推理流水线组件。

- math_eval: 加减乘除正确性 + 异常输入
- CTC greedy decode (构造 logits)
- SlideSolver (合成图 → OpenCV 检测)
- generate_slide_track 轨迹合理性
"""

import math

import numpy as np
import pytest

from inference.math_eval import eval_captcha_math
from inference.pipeline import CaptchaPipeline


# ============================================================
# math_eval 测试
# ============================================================
class TestMathEval:
    def test_addition(self):
        assert eval_captcha_math("3+8=?") == "11"
        assert eval_captcha_math("12+5") == "17"
        assert eval_captcha_math("0+0=?") == "0"

    def test_subtraction(self):
        assert eval_captcha_math("15-7=?") == "8"
        assert eval_captcha_math("20-20") == "0"

    def test_multiplication(self):
        assert eval_captcha_math("12×3=?") == "36"
        assert eval_captcha_math("5*4") == "20"
        assert eval_captcha_math("6x7") == "42"
        assert eval_captcha_math("6X7") == "42"

    def test_division(self):
        assert eval_captcha_math("20÷4=?") == "5"
        assert eval_captcha_math("9÷3") == "3"

    def test_division_by_zero(self):
        with pytest.raises(ValueError, match="除数为零"):
            eval_captcha_math("5÷0=?")

    def test_invalid_expression(self):
        with pytest.raises(ValueError, match="无法解析"):
            eval_captcha_math("abc")

    def test_with_spaces(self):
        assert eval_captcha_math("3 + 8 = ?") == "11"


# ============================================================
# CTC greedy decode 测试
# ============================================================
class TestCTCGreedyDecode:
    """Test the static _ctc_greedy_decode method from CaptchaPipeline."""

    def test_simple_decode(self):
        chars = "ABC"  # index 0=blank, 1=A, 2=B, 3=C
        T = 6
        C = 4  # blank + 3 chars
        logits = np.full((T, 1, C), -10.0, dtype=np.float32)
        # Spell out "AB": A, A, blank, B, B, B
        logits[0, 0, 1] = 10.0  # A
        logits[1, 0, 1] = 10.0  # A (dup, collapsed)
        logits[2, 0, 0] = 10.0  # blank
        logits[3, 0, 2] = 10.0  # B
        logits[4, 0, 2] = 10.0  # B (dup)
        logits[5, 0, 2] = 10.0  # B (dup)
        result = CaptchaPipeline._ctc_greedy_decode(logits, chars)
        assert result == "AB"

    def test_all_blank(self):
        chars = "ABC"
        T = 5
        C = 4
        logits = np.full((T, 1, C), -10.0, dtype=np.float32)
        for t in range(T):
            logits[t, 0, 0] = 10.0
        result = CaptchaPipeline._ctc_greedy_decode(logits, chars)
        assert result == ""

    def test_repeated_chars_with_blank_separator(self):
        chars = "ABC"
        T = 5
        C = 4
        logits = np.full((T, 1, C), -10.0, dtype=np.float32)
        # Spell "AA": A, blank, A, blank, blank
        logits[0, 0, 1] = 10.0  # A
        logits[1, 0, 0] = 10.0  # blank
        logits[2, 0, 1] = 10.0  # A
        logits[3, 0, 0] = 10.0  # blank
        logits[4, 0, 0] = 10.0  # blank
        result = CaptchaPipeline._ctc_greedy_decode(logits, chars)
        assert result == "AA"


# ============================================================
# SlideSolver 测试
# ============================================================
class TestSlideSolver:
    def test_solve_with_synthetic_image(self):
        """Generate a synthetic slide image and verify the solver detects a gap."""
        try:
            import cv2
        except ImportError:
            pytest.skip("OpenCV not installed")

        from generators.slide_gen import SlideDataGenerator
        from solvers.slide_solver import SlideSolver

        gen = SlideDataGenerator(seed=42)
        img, label = gen.generate()
        expected_gap_x = int(label)

        solver = SlideSolver()
        result = solver.solve(img)

        assert "gap_x" in result
        assert "gap_x_percent" in result
        assert "confidence" in result
        assert "method" in result
        assert isinstance(result["gap_x"], int)
        assert 0.0 <= result["gap_x_percent"] <= 1.0


# ============================================================
# generate_slide_track 测试
# ============================================================
class TestSlideTrack:
    def test_track_basic(self):
        from utils.slide_utils import generate_slide_track

        track = generate_slide_track(100, seed=42)
        assert isinstance(track, list)
        assert len(track) >= 10

    def test_track_point_structure(self):
        from utils.slide_utils import generate_slide_track

        track = generate_slide_track(150, seed=0)
        for pt in track:
            assert "x" in pt
            assert "y" in pt
            assert "t" in pt

    def test_track_starts_at_origin(self):
        from utils.slide_utils import generate_slide_track

        track = generate_slide_track(100, seed=1)
        assert track[0]["x"] == 0.0 or abs(track[0]["x"]) < 1e-6

    def test_track_ends_near_distance(self):
        from utils.slide_utils import generate_slide_track

        distance = 120
        track = generate_slide_track(distance, seed=2)
        final_x = track[-1]["x"]
        assert abs(final_x - distance) < 1.0, f"final x={final_x}, expected ~{distance}"

    def test_track_time_increases(self):
        from utils.slide_utils import generate_slide_track

        track = generate_slide_track(100, seed=3)
        for i in range(1, len(track)):
            assert track[i]["t"] >= track[i - 1]["t"]

    def test_track_y_has_jitter(self):
        from utils.slide_utils import generate_slide_track

        track = generate_slide_track(200, seed=4)
        y_vals = [pt["y"] for pt in track]
        # At least some y values should be non-zero (jitter)
        assert any(abs(y) > 0 for y in y_vals)