import sympy
from flask import Flask, render_template, request
import re
from sympy import latex

app = Flask(__name__)


@app.route('/')
def home():
  return render_template('index.html')


@app.route('/factorize', methods=['GET'])
def factorize():

  expression = request.args.get('expression')
  print(expression)
  if re.match(r'^[a-zA-Z0-9+\-*/()]+$', expression):
    expression = re.sub(r'([A-Za-z])([A-Za-z])', r'\1*\2', expression)
    expression = re.sub(r'([0-9])([A-Za-z])', r'\1*\2', expression)
  else:
    error = "您输入的字符不合规"
    return render_template('index.html', error=error)

  variables = list(set(expression))
  try:
    symbols = sympy.symbols(variables)
    symbol_dict = dict(zip(variables, symbols))
    expr = sympy.sympify(expression, locals=symbol_dict)
    factors = sympy.factor(expr)
    result = latex(factors)
    return render_template('index.html', result=result)
  except Exception:
    error_message = "*表示乘法，**表示乘方，括号统一使用小括号,数字与字母中间（或字母与字母中间）的乘号可以省略。"
    return render_template('index.html', error=error_message)

if __name__ == '__main__':
  app.run(host='0.0.0.0', port=5001)