/// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
/// for details. All rights reserved. Use of this source code is governed by a
/// BSD-style license that can be found in the LICENSE file.

/// Tests for compact format numbers, e.g. 1.2M rather than 1,200,000
import 'dart:math';
import 'package:unittest/unittest.dart';
import 'package:intl/intl.dart';
import 'package:fixnum/fixnum.dart';
import 'compact_number_test_data.dart' as testdata;

/// A place to put a case that's causing a problem and have it run first when
/// debugging
var interestingCases = {
//  "mn" : [["4321", "4.32M", "whatever"]]
};

main() {
  interestingCases.forEach(validate);
  testdata.compactNumberTestData.forEach(validate);
}

// TODO(alanknight): Don't just skip the whole locale if there's one problem
// case.
// TODO(alanknight): Fix the problems, or at least figure out precisely where
// the differences are.
var problemLocalesShort = [
  "am", // AM Suffixes differ, not sure why.
  "ca", // For CA, CLDR rules are different. Jumps from 0000 to 00 prefix, so
  // 11 digits prints as 11900.
  "es_419", // Some odd formatting rules for these which seem to be different
  // from CLDR. wants e.g. '160000000000k' Actual: '160 B'
  "es_ES", // The reverse of es_419 for a few cases. We're printing a longer
  // form.
  "es_US", // Like es_419 but not as many of them. e.g. Expected: '87700k'
  // Actual: '87.7 M'
  "es_MX", // like es_419
  "es",
  "fa",
  "fr_CA", // Several where PyICU isn't compacting. Expected: '988000000'
  // Actual: '988 M'.
  "gsw", // Suffixes disagree
  "in", // IN not compacting 54321, looks similar to tr.
  "id", // ID not compacting 54321, looks similar to tr.
  "ka", // K Slight difference in the suffix
  "lo", "mk", "my",
  "pt_PT", // Seems to differ in appending mil or not after thousands. pt_BR
  // does it.
  "th", // TH Expected abbreviations as '1.09 พ.ล.' rather than '1.09 พ'
  "tr", // TR Doesn't have a 0B format, goes directly to 00B, as a result 54321
  // just prints as 54321
  "ur", // UR Fails one with Expected: '15 ٹریلین'  Actual: '150 کھرب'
];

/// Locales that have problems in the long format.
///
/// These are mostly minor differences in the characters, and many I can't read,
/// but I'm suspicious many of them are essentially the difference between
/// million and millions, which we don't distinguish. That's definitely the case
/// with e.g. DE, but our data definitely has Millionen throughout.
///
//TODO(alanknight): Narrow these down to particular numbers. Often it's just
// 999999.
var problemLocalesLong = [
  "ar",
  "be", "bg", "bs",
  "ca", "cs", "da", "de", "de_AT", "de_CH", "el", "es", "es_419", "es_ES",
  "es_MX", "es_US", "et", "fi",
  "fil", // FIL is different, seems like a genuine difference in suffixes
  "fr", "fr_CA", "ga", "gl",
  "gsw", // GSW seems like we have long forms and pyICU doesn't
  "hr", "is", "it", "lo", // LO seems to be picking up a different pattern.
  "lt", "lv", "mk", "nb", "ne", "no", "no_NO", "pl",
  "pt", // PT has some issues with scale as well, but I think it's differences
  // in the patterns.
  "pt_BR", "pt_PT", "ro", "ru", "sk", "sl", "sr", "sr_Latn", "sv", "te", "tl",
  "ur",
  "uk",
];

void validate(String locale, List<List<String>> expected) {
  validateShort(locale, expected);
   validateLong(locale, expected);
}

/// Check each bit of test data against the short compact format, both
/// formatting and parsing.
void validateShort(String locale, List<List<String>> expected) {
  if (problemLocalesShort.contains(locale)) {
    print("Skipping problem locale '$locale' for SHORT compact number tests");
    return;
  }
  var shortFormat = new NumberFormat.compact(locale: locale);
  for (var data in expected) {
    var number = num.parse(data.first);
    test("Validate $locale SHORT for ${data.first}", () {
      validateNumber(number, shortFormat, data[1]);
    });
    var int64Number = new Int64(number);
    test("Validate Int64 SHORT on $locale for ${data.first}", () {
      validateNumber(int64Number, shortFormat, data[1]);
    });
    // TODO(alanknight): Make this work for MicroMoney
  }
}

void validateLong(String locale, List<List<String>> expected) {
 if (problemLocalesLong.contains(locale)) {
   print("Skipping problem locale '$locale' for LONG compact number tests");
   return;
 }
 var longFormat = new NumberFormat.compactLong(locale: locale);
 for (var data in expected) {
   var number = num.parse(data.first);
   test("Validate $locale LONG for ${data.first}", () {
     validateNumber(number, longFormat, data[2]);
   });
 }
}

void validateNumber(number, NumberFormat format, String expected) {
  var formatted = format.format(number);
  var ok = closeEnough(formatted, expected);
  if (!ok) {
    expect(
        "$formatted ${formatted.codeUnits}", "$expected ${expected.codeUnits}");
  }
  var parsed = format.parse(formatted);
  var rounded = roundForPrinting(number, format);
  expect((parsed - rounded) / rounded < 0.001, isTrue);
}

/// Duplicate a bit of the logic in formatting, where if we have a
/// number that will round to print differently depending on the number
/// of significant digits, we need to check that as well, e.g.
/// 999999 may print as 1M.
roundForPrinting(number, NumberFormat format) {
  var originalLength = NumberFormat.numberOfIntegerDigits(number);
  var additionalDigits = originalLength - format.significantDigits;
  if (additionalDigits > 0) {
    var divisor = pow(10, additionalDigits);
    // If we have an Int64, value speed over precision and make it double.
    var rounded = (number.toDouble() / divisor).round() * divisor;
    return rounded;
  }
  return number.toDouble();
}

final _nbsp = 0xa0;
final _nbspString = new String.fromCharCode(_nbsp);

/// Return true if the strings are close enough to what we
/// expected to consider a pass.
///
/// In particular, there seem to be minor differences between what PyICU is
/// currently producing and the CLDR data. So if the strings differ only in the
/// presence or absence of a period at the end or of a space between the number
/// and the suffix, consider it close enough and return true.
bool closeEnough(String result, String reference) {
  var expected = reference.replaceAll(' ', _nbspString);
  if (result == expected) {
    return true;
  }
  if ('$result.' == expected) {
    return true;
  }
  if (result == '$expected.') {
    return true;
  }
  if (_oneSpaceOnlyDifference(result, expected)) {
    return true;
  }
  return false;
}

/// Do the two strings differ only by a single space being
/// omitted in one of them.
///
/// We assume non-breaking spaces because we
/// know that's what the Intl data uses. We already know the strings aren't
/// equal because that's checked first in the only caller.
bool _oneSpaceOnlyDifference(String result, String expected) {
  var resultWithoutSpaces =
      new String.fromCharCodes(result.codeUnits.where((x) => x != _nbsp));
  var expectedWithoutSpaces =
      new String.fromCharCodes(expected.codeUnits.where((x) => x != _nbsp));
  var resultDifference = result.length - resultWithoutSpaces.length;
  var expectedDifference = expected.length - expectedWithoutSpaces.length;
  return (resultWithoutSpaces == expectedWithoutSpaces &&
      resultDifference <= 1 &&
      expectedDifference <= 1);
}