import sys
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QLabel
from PyQt5.QtWidgets import QLineEdit
import sympy as sp
import sympy.parsing.sympy_parser as spp
from sympy.abc import x

class AnswerWidget(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setGeometry(210, 100, 300, len(answer) * 30 + 60)

        for i in range(len(answer)):
            self.new_label = QLabel(self)
            self.new_label.setText('Интервал [' + str(answer[i][0]) + ';' + str(answer[i][1]) + ']' + '\n' +
                                  '  Решение: ' + str(answer[i][2]))
            self.new_label.move(30, 30 + i * 30)
        answer.clear()


class MainWidget(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setGeometry(100, 100, 300, 400)

        self.eq_label = QLabel(self)
        self.eq_label.setText('Введите уравнение:')
        self.eq_label.move(80, 30)

        self.eq_gap = QLineEdit(self)
        self.eq_gap.move(80, 100)

        self.solve_btn1 = QPushButton('Решить 1', self)
        self.solve_btn1.resize(self.solve_btn1.sizeHint())
        self.solve_btn1.move(75, 170)
        self.solve_btn1.clicked.connect(self.solve1)

        self.solve_btn2 = QPushButton('Решить 2', self)
        self.solve_btn2.resize(self.solve_btn2.sizeHint())
        self.solve_btn2.move(75, 230)
        self.solve_btn2.clicked.connect(self.solve2)

    def get_f(self):
        s = self.eq_gap.text()
        transform = spp.standard_transformations + (spp.implicit_multiplication_application, spp.convert_xor)
        lhs = spp.parse_expr(s.split("=")[0], transformations=transform)
        rhs = spp.parse_expr(s.split("=")[1], transformations=transform)
        self.f = sp.lambdify(x, lhs - rhs)

    def solve1(self):
        global answer
        self.get_f()
        L = -50
        while L + 5 <= 50:
            R = L + 5
            if self.f(L / 10) * self.f(R / 10) <= 0:
                ep = 0.001
                delta = 2 * ep
                a = L
                while self.f(a / 10) * self.f((a + delta) / 10) > 0:
                    a += delta
                answer.append((L / 10, R / 10, (a + ep) / 10))
            L += 5
        self.open_show_wind = AnswerWidget()
        self.open_show_wind.show()

    def solve2(self):
        global answer
        self.get_f()
        L = -50
        while L + 5 <= 50:
            R = L + 5
            if self.f(L / 10) * self.f(R / 10) <= 0:
                ep = 0.001
                a = L
                b = R
                while b - a > 2 * ep:
                    c = (a + b) / 2
                    if self.f(a / 10) * self.f(c / 10) <= 0:
                        b = c
                    else:
                        a = c
                answer.append((L / 10, R / 10, ((a + b) / 2) / 10))
            L += 5
        self.open_show_wind = AnswerWidget()
        self.open_show_wind.show()


if __name__ == '__main__':
    global answer
    answer = []
    app = QApplication(sys.argv)
    wid = MainWidget()
    wid.show()
    sys.exit(app.exec())