// Copyright 2015 Huan Du. All rights reserved.
// Licensed under the MIT license that can be found in the LICENSE file.

package xstrings

import (
	"sort"
	"strings"
	"testing"
)

func TestToSnakeCase(t *testing.T) {
	runTestCases(t, ToSnakeCase, _M{
		"HTTPServer":         "http_server",
		"_camelCase":         "_camel_case",
		"NoHTTPS":            "no_https",
		"Wi_thF":             "wi_th_f",
		"_AnotherTES_TCaseP": "_another_tes_t_case_p",
		"ALL":                "all",
		"_HELLO_WORLD_":      "_hello_world_",
		"HELLO_WORLD":        "hello_world",
		"HELLO____WORLD":     "hello____world",
		"TW":                 "tw",
		"_C":                 "_c",

		"  sentence case  ":                                    "__sentence_case__",
		" Mixed-hyphen case _and SENTENCE_case and UPPER-case": "_mixed_hyphen_case__and_sentence_case_and_upper_case",
	})
}

func TestToCamelCase(t *testing.T) {
	runTestCases(t, ToCamelCase, _M{
		"http_server":     "HttpServer",
		"_camel_case":     "_CamelCase",
		"no_https":        "NoHttps",
		"_complex__case_": "_Complex_Case_",
		"all":             "All",
	})
}

func TestSwapCase(t *testing.T) {
	runTestCases(t, SwapCase, _M{
		"swapCase": "SWAPcASE",
		"Θ~λa云Ξπ":  "θ~ΛA云ξΠ",
	})
}

func TestFirstRuneToUpper(t *testing.T) {
	runTestCases(t, FirstRuneToUpper, _M{
		"hello, world!": "Hello, world!",
		"Hello, world!": "Hello, world!",
		"你好，世界！":        "你好，世界！",
	})
}

func TestFirstRuneToLower(t *testing.T) {
	runTestCases(t, FirstRuneToLower, _M{
		"hello, world!": "hello, world!",
		"Hello, world!": "hello, world!",
		"你好，世界！":        "你好，世界！",
	})
}

func TestShuffle(t *testing.T) {
	// It seems there is no reliable way to test shuffled string.
	// Runner just make sure shuffled string has the same runes as origin string.
	runner := func(str string) string {
		s := Shuffle(str)
		slice := sort.StringSlice(strings.Split(s, ""))
		slice.Sort()
		return strings.Join(slice, "")
	}

	runTestCases(t, runner, _M{
		"":            "",
		"facgbheidjk": "abcdefghijk",
		"尝试中文":        "中尝文试",
		"zh英文hun排":    "hhnuz排文英",
	})
}

type testShuffleSource int

// A generated random number sequance just for testing.
var testShuffleTable = []int64{
	1874068156324778273,
	3328451335138149956,
	5263531936693774911,
	7955079406183515637,
	2703501726821866378,
	2740103009342231109,
	6941261091797652072,
	1905388747193831650,
	7981306761429961588,
	6426100070888298971,
	4831389563158288344,
	261049867304784443,
	1460320609597786623,
	5600924393587988459,
	8995016276575641803,
	732830328053361739,
	5486140987150761883,
	545291762129038907,
	6382800227808658932,
	2781055864473387780,
	1598098976185383115,
	4990765271833742716,
	5018949295715050020,
	2568779411109623071,
	3902890183311134652,
	4893789450120281907,
	2338498362660772719,
	2601737961087659062,
	7273596521315663110,
	3337066551442961397,
	8121576815539813105,
	2740376916591569721,
	8249030965139585917,
	898860202204764712,
	9010467728050264449,
	685213522303989579,
	2050257992909156333,
	6281838661429879825,
	2227583514184312746,
	2873287401706343734,
}

func (src testShuffleSource) Int63() int64 {
	n := testShuffleTable[int(src)%len(testShuffleTable)]
	src++
	return n
}

func (src testShuffleSource) Seed(int64) {}

func TestShuffleSource(t *testing.T) {
	var src testShuffleSource
	runner := func(str string) string {
		return ShuffleSource(str, src)
	}

	runTestCases(t, runner, _M{
		"":            "",
		"facgbheidjk": "bakefjgichd",
		"尝试中文怎么样":     "怎试中样尝么文",
		"zh英文hun排":    "hh英nzu文排",
	})
}

func TestSuccessor(t *testing.T) {
	runTestCases(t, Successor, _M{
		"":          "",
		"abcd":      "abce",
		"THX1138":   "THX1139",
		"<<koala>>": "<<koalb>>",
		"1999zzz":   "2000aaa",
		"ZZZ9999":   "AAAA0000",
		"***":       "**+",

		"来点中文试试":               "来点中文试诖",
		"中cZ英ZZ文zZ混9zZ9杂99进z位": "中dA英AA文aA混0aA0杂00进a位",
	})
}