from manim import *
import numpy as np


class AnimatedFunctionPlot(Scene):
    def construct(self):
        # 创建坐标系（修正数学符号显示）
        axes = Axes(
            x_range=[-3.5 * PI, 3.5 * PI, PI / 2],
            y_range=[-1.5, 1.5, 0.5],
            axis_config={"color": BLUE},
            x_axis_config={
                "numbers_to_include": np.arange(-3 * PI, 3.5 * PI, PI),
                "numbers_with_elongated_ticks": np.arange(-3 * PI, 3.5 * PI, PI),
                "decimal_number_config": {
                    "num_decimal_places": 0,
                },
            },
            y_axis_config={
                "decimal_number_config": {
                    "num_decimal_places": 1,
                }
            },
            tips=False,
        ).scale(0.9)

        # 修正1：使用MathTex并正确转义π符号
        x_labels = VGroup(*[
            MathTex(r"%d\pi" % i if i != 0 else "0").scale(0.7).move_to(axes.c2p(i * PI, 0))
            for i in range(-3, 4)
        ])

        self.play(
            Create(axes, run_time=2),
            LaggedStart(*[Write(label) for label in x_labels], lag_ratio=0.3),
        )
        self.wait(0.5)

        # 修正2：使用MathTex包装数学公式
        sin_graph = axes.plot(lambda x: np.sin(x), color=GREEN)
        sin_label = axes.get_graph_label(
            sin_graph,
            MathTex(r"\sin(x)", color=GREEN),  # 使用MathTex替代Tex
            x_val=-3 * PI,
            direction=UP
        )

        self.play(
            Create(sin_graph, run_time=3),
            Write(sin_label, run_time=1),
            rate_func=linear
        )
        self.wait()

        # 修正3：余弦公式同样使用MathTex
        cos_graph = axes.plot(lambda x: np.cos(x), color=RED)
        cos_label = axes.get_graph_label(
            cos_graph,
            MathTex(r"\cos(x)", color=RED),  # 使用MathTex替代Tex
            x_val=3 * PI,
            direction=DOWN
        )

        self.play(
            TransformFromCopy(sin_graph, cos_graph, path_arc=PI / 2, run_time=3),
            FadeIn(cos_label, shift=DOWN),
        )
        self.wait()

        # 动态垂直线（追踪动画）
        tracker = ValueTracker(-3 * PI)
        vert_line = always_redraw(lambda:
                                  DashedLine(
                                      axes.c2p(tracker.get_value(), -1.5),
                                      axes.c2p(tracker.get_value(), 1.5),
                                      color=YELLOW
                                  )
                                  )

        dot_sin = always_redraw(lambda:
                                Dot(color=GREEN).move_to(axes.i2gp(tracker.get_value(), sin_graph))
                                )
        dot_cos = always_redraw(lambda:
                                Dot(color=RED).move_to(axes.i2gp(tracker.get_value(), cos_graph))
                                )

        self.play(
            Create(vert_line),
            GrowFromCenter(dot_sin),
            GrowFromCenter(dot_cos)
        )
        self.play(
            tracker.animate.set_value(3 * PI),
            run_time=6,
            rate_func=linear
        )
        self.wait()

        # 修正4：相位差公式使用正确数学环境
        equation = MathTex(
            r"\cos(x) = \sin\left(x + \frac{\pi}{2}\right)",  # 使用MathTex
            color=YELLOW
        ).to_edge(UP)

        self.play(
            Write(equation),
            sin_graph.animate.shift(LEFT * PI / 2).set_color(ORANGE),
            run_time=2
        )
        self.wait(2)


if __name__ == '__main__':
    config = {
        "quality": "high_quality",
        "preview": True,
        "media_dir": "./output",
        "pixel_height": 1080,
        "pixel_width": 1920,
        "background_color": "#1E1E1E"
    }

    with tempconfig(config):
        scene = AnimatedFunctionPlot()
        scene.render()