"""
作者：太一
微信：taiyi1224
邮箱：shuobo1224@qq.com
"""

import math

import cv2
import numpy as np

class ResizeHandle:
    """图片缩放控制点"""

    def __init__(self, position):
        # 位置: 'tl', 'tr', 'bl', 'br' 分别代表四个顶点
        self.position = position
        self.active = False
        self.x = 0
        self.y = 0
        self.radius = 5  # 控制点半径，从8减小到5

    def hit_test(self, x, y):
        """检查点是否在控制范围内"""
        dx = x - self.x
        dy = y - self.y
        return math.sqrt(dx * dx + dy * dy) <= self.radius

class TransformHelper:
    """图片变形辅助工具"""

    @staticmethod
    def calculate_handles(fg, canvas):
        """计算四个顶点的控制点位置"""
        handles = {
            'tl': ResizeHandle('tl'),
            'tr': ResizeHandle('tr'),
            'bl': ResizeHandle('bl'),
            'br': ResizeHandle('br')
        }

        # 转换顶点坐标到画布坐标
        for i, pos in enumerate(['tl', 'tr', 'bl', 'br']):
            x, y = fg.vertices[i]
            canvas_x, canvas_y = canvas.template_to_canvas(x, y)
            handles[pos].x = canvas_x
            handles[pos].y = canvas_y

        return handles

    @staticmethod
    def update_vertices(fg, handle_pos, dx, dy, canvas):
        """根据拖动的控制点更新顶点坐标和图片尺寸"""
        t_dx, t_dy = canvas.canvas_to_template(dx, dy)
        idx_map = {'tl': 0, 'tr': 1, 'bl': 2, 'br': 3}
        idx = idx_map[handle_pos]

        # 更新对应顶点
        x, y = fg.vertices[idx]
        new_x, new_y = x + t_dx, y + t_dy
        
        # 获取其他顶点
        tl = fg.vertices[0] if idx != 0 else (new_x, new_y)
        tr = fg.vertices[1] if idx != 1 else (new_x, new_y)
        bl = fg.vertices[2] if idx != 2 else (new_x, new_y)
        br = fg.vertices[3] if idx != 3 else (new_x, new_y)
        
        # 计算宽度和高度
        width = max(abs(tr[0] - tl[0]), abs(br[0] - bl[0]))
        height = max(abs(bl[1] - tl[1]), abs(br[1] - tr[1]))
        
        # 确保最小尺寸
        if width < 10 or height < 10:
            # 如果太小，则不更新
            return fg
            
        fg.vertices[idx] = (new_x, new_y)

        return fg

    @staticmethod
    def get_perspective_matrix(src_vertices, dst_size):
        """计算透视变换矩阵"""
        # 源坐标：图片四个角
        src = np.float32([
            [0, 0],
            [dst_size[0], 0],
            [0, dst_size[1]],
            [dst_size[0], dst_size[1]]
        ])

        # 目标坐标：变形后的四个角
        dst = np.float32(src_vertices)

        # 计算透视变换矩阵
        return cv2.getPerspectiveTransform(src, dst)
    @staticmethod
    def update_image_size(fg, handle_pos, dx, dy, canvas):
        """根据拖动的控制点更新图片尺寸"""
        t_dx, t_dy = canvas.canvas_to_template(dx, dy)

        if handle_pos in ['nw', 'sw', 'w']:
            fg.x += t_dx
            fg.w -= t_dx
        if handle_pos in ['ne', 'se', 'e']:
            fg.w += t_dx
        if handle_pos in ['nw', 'ne', 'n']:
            fg.y += t_dy
            fg.h -= t_dy
        if handle_pos in ['sw', 'se', 's']:
            fg.h += t_dy

        # 确保尺寸为正值
        fg.w = max(10, fg.w)
        fg.h = max(10, fg.h)

        return fg