text: /**
   * @license
   * Copyright 2012 Google LLC
   * SPDX-License-Identifier: Apache-2.0
   */
  
  /**
   * @fileoverview Generating Python for math blocks.
   * @author q.neutron@gmail.com (Quynh Neutron)
   */
  'use strict';
  
  goog.provide('Blockly.Python.math');
  
  goog.require('Blockly.Python');
  
  
  // If any new block imports any library, add that library name here.
  Blockly.Python.addReservedWords('math,random,Number');
  
  Blockly.Python['math_number'] = function(block) {
    // Numeric value.
    var code = parseFloat(block.getFieldValue('NUM'));
    var order;
    if (code == Infinity) {
      code = 'float("inf")';
      order = Blockly.Python.ORDER_FUNCTION_CALL;
    } else if (code == -Infinity) {
      code = '-float("inf")';
      order = Blockly.Python.ORDER_UNARY_SIGN;
    } else {
      order = code < 0 ? Blockly.Python.ORDER_UNARY_SIGN :
              Blockly.Python.ORDER_ATOMIC;
    }
    return [code, order];
  };
  
  Blockly.Python['math_arithmetic'] = function(block) {
    // Basic arithmetic operators, and power.
    var OPERATORS = {
      'ADD': [' + ', Blockly.Python.ORDER_ADDITIVE],
      'MINUS': [' - ', Blockly.Python.ORDER_ADDITIVE],
      'MULTIPLY': [' * ', Blockly.Python.ORDER_MULTIPLICATIVE],
      'DIVIDE': [' / ', Blockly.Python.ORDER_MULTIPLICATIVE],
      'POWER': [' ** ', Blockly.Python.ORDER_EXPONENTIATION]
    };
    var tuple = OPERATORS[block.getFieldValue('OP')];
    var operator = tuple[0];
    var order = tuple[1];
    var argument0 = Blockly.Python.valueToCode(block, 'A', order) || '0';
    var argument1 = Blockly.Python.valueToCode(block, 'B', order) || '0';
    var code = argument0 + operator + argument1;
    return [code, order];
    // In case of 'DIVIDE', division between integers returns different results
    // in Python 2 and 3. However, is not an issue since Blockly does not
    // guarantee identical results in all languages.  To do otherwise would
    // require every operator to be wrapped in a function call.  This would kill
    // legibility of the generated code.
  };
  
  Blockly.Python['math_single'] = function(block) {
    // Math operators with single operand.
    var operator = block.getFieldValue('OP');
    var code;
    var arg;
    if (operator == 'NEG') {
      // Negation is a special case given its different operator precedence.
      var code = Blockly.Python.valueToCode(block, 'NUM',
          Blockly.Python.ORDER_UNARY_SIGN) || '0';
      return ['-' + code, Blockly.Python.ORDER_UNARY_SIGN];
    }
    Blockly.Python.definitions_['import_math'] = 'import math';
    if (operator == 'SIN' || operator == 'COS' || operator == 'TAN') {
      arg = Blockly.Python.valueToCode(block, 'NUM',
          Blockly.Python.ORDER_MULTIPLICATIVE) || '0';
    } else {
      arg = Blockly.Python.valueToCode(block, 'NUM',
          Blockly.Python.ORDER_NONE) || '0';
    }
    // First, handle cases which generate values that don't need parentheses
    // wrapping the code.
    switch (operator) {
      case 'ABS':
        code = 'math.fabs(' + arg + ')';
        break;
      case 'ROOT':
        code = 'math.sqrt(' + arg + ')';
        break;
      case 'LN':
        code = 'math.log(' + arg + ')';
        break;
      case 'LOG10':
        code = 'math.log10(' + arg + ')';
        break;
      case 'EXP':
        code = 'math.exp(' + arg + ')';
        break;
      case 'POW10':
        code = 'math.pow(10,' + arg + ')';
        break;
      case 'ROUND':
        code = 'round(' + arg + ')';
        break;
      case 'ROUNDUP':
        code = 'math.ceil(' + arg + ')';
        break;
      case 'ROUNDDOWN':
        code = 'math.floor(' + arg + ')';
        break;
      case 'SIN':
        code = 'math.sin(' + arg + ' / 180.0 * math.pi)';
        break;
      case 'COS':
        code = 'math.cos(' + arg + ' / 180.0 * math.pi)';
        break;
      case 'TAN':
        code = 'math.tan(' + arg + ' / 180.0 * math.pi)';
        break;
    }
    if (code) {
      return [code, Blockly.Python.ORDER_FUNCTION_CALL];
    }
    // Second, handle cases which generate values that may need parentheses
    // wrapping the code.
    switch (operator) {
      case 'ASIN':
        code = 'math.asin(' + arg + ') / math.pi * 180';
        break;
      case 'ACOS':
        code = 'math.acos(' + arg + ') / math.pi * 180';
        break;
      case 'ATAN':
        code = 'math.atan(' + arg + ') / math.pi * 180';
        break;
      default:
        throw Error('Unknown math operator: ' + operator);
    }
    return [code, Blockly.Python.ORDER_MULTIPLICATIVE];
  };
  
  Blockly.Python['math_constant'] = function(block) {
    // Constants: PI, E, the Golden Ratio, sqrt(2), 1/sqrt(2), INFINITY.
    var CONSTANTS = {
      'PI': ['math.pi', Blockly.Python.ORDER_MEMBER],
      'E': ['math.e', Blockly.Python.ORDER_MEMBER],
      'GOLDEN_RATIO': ['(1 + math.sqrt(5)) / 2',
                       Blockly.Python.ORDER_MULTIPLICATIVE],
      'SQRT2': ['math.sqrt(2)', Blockly.Python.ORDER_MEMBER],
      'SQRT1_2': ['math.sqrt(1.0 / 2)', Blockly.Python.ORDER_MEMBER],
      'INFINITY': ['float(\'inf\')', Blockly.Python.ORDER_ATOMIC]
    };
    var constant = block.getFieldValue('CONSTANT');
    if (constant != 'INFINITY') {
      Blockly.Python.definitions_['import_math'] = 'import math';
    }
    return CONSTANTS[constant];
  };
  
  Blockly.Python['math_number_property'] = function(block) {
    // Check if a number is even, odd, prime, whole, positive, or negative
    // or if it is divisible by certain number. Returns true or false.
    var number_to_check = Blockly.Python.valueToCode(block, 'NUMBER_TO_CHECK',
        Blockly.Python.ORDER_MULTIPLICATIVE) || '0';
    var dropdown_property = block.getFieldValue('PROPERTY');
    var code;
    if (dropdown_property == 'PRIME') {
      Blockly.Python.definitions_['import_math'] = 'import math';
      Blockly.Python.definitions_['from_numbers_import_Number'] =
          'from numbers import Number';
      var functionName = Blockly.Python.provideFunction_(
          'math_isPrime',
          ['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(n):',
           '  # https://en.wikipedia.org/wiki/Primality_test#Naive_methods',
           '  # If n is not a number but a string, try parsing it.',
           '  if not isinstance(n, Number):',
           '    try:',
           '      n = float(n)',
           '    except:',
           '      return False',
           '  if n == 2 or n == 3:',
           '    return True',
           '  # False if n is negative, is 1, or not whole,' +
               ' or if n is divisible by 2 or 3.',
           '  if n <= 1 or n % 1 != 0 or n % 2 == 0 or n % 3 == 0:',
           '    return False',
           '  # Check all the numbers of form 6k +/- 1, up to sqrt(n).',
           '  for x in range(6, int(math.sqrt(n)) + 2, 6):',
           '    if n % (x - 1) == 0 or n % (x + 1) == 0:',
           '      return False',
           '  return True']);
      code = functionName + '(' + number_to_check + ')';
      return [code, Blockly.Python.ORDER_FUNCTION_CALL];
    }
    switch (dropdown_property) {
      case 'EVEN':
        code = number_to_check + ' % 2 == 0';
        break;
      case 'ODD':
        code = number_to_check + ' % 2 == 1';
        break;
      case 'WHOLE':
        code = number_to_check + ' % 1 == 0';
        break;
      case 'POSITIVE':
        code = number_to_check + ' > 0';
        break;
      case 'NEGATIVE':
        code = number_to_check + ' < 0';
        break;
      case 'DIVISIBLE_BY':
        var divisor = Blockly.Python.valueToCode(block, 'DIVISOR',
            Blockly.Python.ORDER_MULTIPLICATIVE);
        // If 'divisor' is some code that evals to 0, Python will raise an error.
        if (!divisor || divisor == '0') {
          return ['False', Blockly.Python.ORDER_ATOMIC];
        }
        code = number_to_check + ' % ' + divisor + ' == 0';
        break;
    }
    return [code, Blockly.Python.ORDER_RELATIONAL];
  };
  
  Blockly.Python['math_change'] = function(block) {
    // Add to a variable in place.
    Blockly.Python.definitions_['from_numbers_import_Number'] =
        'from numbers import Number';
    var argument0 = Blockly.Python.valueToCode(block, 'DELTA',
        Blockly.Python.ORDER_ADDITIVE) || '0';
    var varName = Blockly.Python.nameDB_.getName(block.getFieldValue('VAR'),
        Blockly.VARIABLE_CATEGORY_NAME);
    return varName + ' = (' + varName + ' if isinstance(' + varName +
        ', Number) else 0) + ' + argument0 + '\n';
  };
  
  // Rounding functions have a single operand.
  Blockly.Python['math_round'] = Blockly.Python['math_single'];
  // Trigonometry functions have a single operand.
  Blockly.Python['math_trig'] = Blockly.Python['math_single'];
  
  Blockly.Python['math_on_list'] = function(block) {
    // Math functions for lists.
    var func = block.getFieldValue('OP');
    var list = Blockly.Python.valueToCode(block, 'LIST',
        Blockly.Python.ORDER_NONE) || '[]';
    var code;
    switch (func) {
      case 'SUM':
        code = 'sum(' + list + ')';
        break;
      case 'MIN':
        code = 'min(' + list + ')';
        break;
      case 'MAX':
        code = 'max(' + list + ')';
        break;
      case 'AVERAGE':
        Blockly.Python.definitions_['from_numbers_import_Number'] =
            'from numbers import Number';
        var functionName = Blockly.Python.provideFunction_(
            'math_mean',
            // This operation excludes null and values that aren't int or float:',
            // math_mean([null, null, "aString", 1, 9]) == 5.0.',
            ['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(myList):',
             '  localList = [e for e in myList if isinstance(e, Number)]',
             '  if not localList: return',
             '  return float(sum(localList)) / len(localList)']);
        code = functionName + '(' + list + ')';
        break;
      case 'MEDIAN':
        Blockly.Python.definitions_['from_numbers_import_Number'] =
            'from numbers import Number';
        var functionName = Blockly.Python.provideFunction_(
            'math_median',
            // This operation excludes null values:
            // math_median([null, null, 1, 3]) == 2.0.
            ['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(myList):',
             '  localList = sorted([e for e in myList if isinstance(e, Number)])',
             '  if not localList: return',
             '  if len(localList) % 2 == 0:',
             '    return (localList[len(localList) // 2 - 1] + ' +
                 'localList[len(localList) // 2]) / 2.0',
             '  else:',
             '    return localList[(len(localList) - 1) // 2]']);
        code = functionName + '(' + list + ')';
        break;
      case 'MODE':
        var functionName = Blockly.Python.provideFunction_(
            'math_modes',
            // As a list of numbers can contain more than one mode,
            // the returned result is provided as an array.
            // Mode of [3, 'x', 'x', 1, 1, 2, '3'] -> ['x', 1].
            ['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(some_list):',
             '  modes = []',
             '  # Using a lists of [item, count] to keep count rather than dict',
             '  # to avoid "unhashable" errors when the counted item is ' +
                 'itself a list or dict.',
             '  counts = []',
             '  maxCount = 1',
             '  for item in some_list:',
             '    found = False',
             '    for count in counts:',
             '      if count[0] == item:',
             '        count[1] += 1',
             '        maxCount = max(maxCount, count[1])',
             '        found = True',
             '    if not found:',
             '      counts.append([item, 1])',
             '  for counted_item, item_count in counts:',
             '    if item_count == maxCount:',
             '      modes.append(counted_item)',
             '  return modes']);
        code = functionName + '(' + list + ')';
        break;
      case 'STD_DEV':
        Blockly.Python.definitions_['import_math'] = 'import math';
        var functionName = Blockly.Python.provideFunction_(
            'math_standard_deviation',
            ['def ' + Blockly.Python.FUNCTION_NAME_PLACEHOLDER_ + '(numbers):',
             '  n = len(numbers)',
             '  if n == 0: return',
             '  mean = float(sum(numbers)) / n',
             '  variance = sum((x - mean) ** 2 for x in numbers) / n',
             '  return math.sqrt(variance)']);
        code = functionName + '(' + list + ')';
        break;
      case 'RANDOM':
        Blockly.Python.definitions_['import_random'] = 'import random';
        code = 'random.choice(' + list + ')';
        break;
      default:
        throw Error('Unknown operator: ' + func);
    }
    return [code, Blockly.Python.ORDER_FUNCTION_CALL];
  };
  
  Blockly.Python['math_modulo'] = function(block) {
    // Remainder computation.
    var argument0 = Blockly.Python.valueToCode(block, 'DIVIDEND',
        Blockly.Python.ORDER_MULTIPLICATIVE) || '0';
    var argument1 = Blockly.Python.valueToCode(block, 'DIVISOR',
        Blockly.Python.ORDER_MULTIPLICATIVE) || '0';
    var code = argument0 + ' % ' + argument1;
    return [code, Blockly.Python.ORDER_MULTIPLICATIVE];
  };
  
  Blockly.Python['math_constrain'] = function(block) {
    // Constrain a number between two limits.
    var argument0 = Blockly.Python.valueToCode(block, 'VALUE',
        Blockly.Python.ORDER_NONE) || '0';
    var argument1 = Blockly.Python.valueToCode(block, 'LOW',
        Blockly.Python.ORDER_NONE) || '0';
    var argument2 = Blockly.Python.valueToCode(block, 'HIGH',
        Blockly.Python.ORDER_NONE) || 'float(\'inf\')';
    var code = 'min(max(' + argument0 + ', ' + argument1 + '), ' +
        argument2 + ')';
    return [code, Blockly.Python.ORDER_FUNCTION_CALL];
  };
  
  Blockly.Python['math_random_int'] = function(block) {
    // Random integer between [X] and [Y].
    Blockly.Python.definitions_['import_random'] = 'import random';
    var argument0 = Blockly.Python.valueToCode(block, 'FROM',
        Blockly.Python.ORDER_NONE) || '0';
    var argument1 = Blockly.Python.valueToCode(block, 'TO',
        Blockly.Python.ORDER_NONE) || '0';
    var code = 'random.randint(' + argument0 + ', ' + argument1 + ')';
    return [code, Blockly.Python.ORDER_FUNCTION_CALL];
  };
  
  Blockly.Python['math_random_float'] = function(block) {
    // Random fraction between 0 and 1.
    Blockly.Python.definitions_['import_random'] = 'import random';
    return ['random.random()', Blockly.Python.ORDER_FUNCTION_CALL];
  };
  
  Blockly.Python['math_atan2'] = function(block) {
    // Arctangent of point (X, Y) in degrees from -180 to 180.
    Blockly.Python.definitions_['import_math'] = 'import math';
    var argument0 = Blockly.Python.valueToCode(block, 'X',
        Blockly.Python.ORDER_NONE) || '0';
    var argument1 = Blockly.Python.valueToCode(block, 'Y',
        Blockly.Python.ORDER_NONE) || '0';
    return ['math.atan2(' + argument1 + ', ' + argument0 + ') / math.pi * 180',
        Blockly.Python.ORDER_MULTIPLICATIVE];
  };
  