// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package display

import (
	"fmt"
	"reflect"
	"testing"
	"unicode"

	"golang.org/x/text/language"
)

// TODO: test that tables are properly dropped by the linker for various use
// cases.

var (
	firstLang2aa  = language.MustParseBase("aa")
	lastLang2zu   = language.MustParseBase("zu")
	firstLang3ace = language.MustParseBase("ace")
	lastLang3zza  = language.MustParseBase("zza")
	firstTagAr001 = language.MustParse("ar-001")
	lastTagZhHant = language.MustParse("zh-Hant")
)

// TestValues tests that for all languages, regions, and scripts in Values, at
// least one language has a name defined for it by checking it exists in
// English, which is assumed to be the most comprehensive. It is also tested
// that a Namer returns "" for unsupported values.
func TestValues(t *testing.T) {
	type testcase struct {
		kind string
		n    Namer
	}
	// checkDefined checks that a value exists in a Namer.
	checkDefined := func(x interface{}, namers []testcase) {
		for _, n := range namers {
			if n.n.Name(x) == "" {
				// As of version 28 there is no data for az-Arab in English,
				// although there is useful data in other languages.
				if x.(fmt.Stringer).String() == "az-Arab" {
					continue
				}
				t.Errorf("%s.Name(%s): supported but no result", n.kind, x)
			}
		}
	}
	// checkUnsupported checks that a value does not exist in a Namer.
	checkUnsupported := func(x interface{}, namers []testcase) {
		for _, n := range namers {
			if got := n.n.Name(x); got != "" {
				t.Fatalf("%s.Name(%s): unsupported tag gave non-empty result: %q", n.kind, x, got)
			}
		}
	}

	tags := map[language.Tag]bool{}
	namers := []testcase{
		{"Languages(en)", Languages(language.English)},
		{"Tags(en)", Tags(language.English)},
		{"English.Languages()", English.Languages()},
		{"English.Tags()", English.Tags()},
	}
	for _, tag := range Values.Tags() {
		checkDefined(tag, namers)
		tags[tag] = true
	}
	for _, base := range language.Supported.BaseLanguages() {
		tag, _ := language.All.Compose(base)
		if !tags[tag] {
			checkUnsupported(tag, namers)
		}
	}

	regions := map[language.Region]bool{}
	namers = []testcase{
		{"Regions(en)", Regions(language.English)},
		{"English.Regions()", English.Regions()},
	}
	for _, r := range Values.Regions() {
		checkDefined(r, namers)
		regions[r] = true
	}
	for _, r := range language.Supported.Regions() {
		if r = r.Canonicalize(); !regions[r] {
			checkUnsupported(r, namers)
		}
	}

	scripts := map[language.Script]bool{}
	namers = []testcase{
		{"Scripts(en)", Scripts(language.English)},
		{"English.Scripts()", English.Scripts()},
	}
	for _, s := range Values.Scripts() {
		checkDefined(s, namers)
		scripts[s] = true
	}
	for _, s := range language.Supported.Scripts() {
		// Canonicalize the script.
		tag, _ := language.DeprecatedScript.Compose(s)
		if _, s, _ = tag.Raw(); !scripts[s] {
			checkUnsupported(s, namers)
		}
	}
}

// TestSupported tests that we have at least some Namers for languages that we
// claim to support. To test the claims in the documentation, it also verifies
// that if a Namer is returned, it will have at least some data.
func TestSupported(t *testing.T) {
	supportedTags := Supported.Tags()
	if len(supportedTags) != numSupported {
		t.Errorf("number of supported was %d; want %d", len(supportedTags), numSupported)
	}

	namerFuncs := []struct {
		kind string
		fn   func(language.Tag) Namer
	}{
		{"Tags", Tags},
		{"Languages", Languages},
		{"Regions", Regions},
		{"Scripts", Scripts},
	}

	// Verify that we have at least one Namer for all tags we claim to support.
	tags := make(map[language.Tag]bool)
	for _, tag := range supportedTags {
		// Test we have at least one Namer for this supported Tag.
		found := false
		for _, kind := range namerFuncs {
			if defined(t, kind.kind, kind.fn(tag), tag) {
				found = true
			}
		}
		if !found {
			t.Errorf("%s: supported, but no data available", tag)
		}
		if tags[tag] {
			t.Errorf("%s: included in Supported.Tags more than once", tag)
		}
		tags[tag] = true
	}

	// Verify that we have no Namers for tags we don't claim to support.
	for _, base := range language.Supported.BaseLanguages() {
		tag, _ := language.All.Compose(base)
		// Skip tags that are supported after matching.
		if _, _, conf := matcher.Match(tag); conf != language.No {
			continue
		}
		// Test there are no Namers for this tag.
		for _, kind := range namerFuncs {
			if defined(t, kind.kind, kind.fn(tag), tag) {
				t.Errorf("%[1]s(%[2]s) returns a Namer, but %[2]s is not in the set of supported Tags.", kind.kind, tag)
			}
		}
	}
}

// defined reports whether n is a proper Namer, which means it is non-nil and
// must have at least one non-empty value.
func defined(t *testing.T, kind string, n Namer, tag language.Tag) bool {
	if n == nil {
		return false
	}
	switch kind {
	case "Tags":
		for _, t := range Values.Tags() {
			if n.Name(t) != "" {
				return true
			}
		}
	case "Languages":
		for _, t := range Values.BaseLanguages() {
			if n.Name(t) != "" {
				return true
			}
		}
	case "Regions":
		for _, t := range Values.Regions() {
			if n.Name(t) != "" {
				return true
			}
		}
	case "Scripts":
		for _, t := range Values.Scripts() {
			if n.Name(t) != "" {
				return true
			}
		}
	}
	t.Errorf("%s(%s) returns non-nil Namer without content", kind, tag)
	return false
}

func TestCoverage(t *testing.T) {
	en := language.English
	tests := []struct {
		n Namer
		x interface{}
	}{
		{Languages(en), Values.Tags()},
		{Scripts(en), Values.Scripts()},
		{Regions(en), Values.Regions()},
	}
	for i, tt := range tests {
		uniq := make(map[string]interface{})

		v := reflect.ValueOf(tt.x)
		for j := 0; j < v.Len(); j++ {
			x := v.Index(j).Interface()
			// As of version 28 there is no data for az-Arab in English,
			// although there is useful data in other languages.
			if x.(fmt.Stringer).String() == "az-Arab" {
				continue
			}
			s := tt.n.Name(x)
			if s == "" {
				t.Errorf("%d:%d:%s: missing content", i, j, x)
			} else if uniq[s] != nil {
				t.Errorf("%d:%d:%s: identical return value %q for %v and %v", i, j, x, s, x, uniq[s])
			}
			uniq[s] = x
		}
	}
}

// TestUpdate tests whether dictionary entries for certain languages need to be
// updated. For some languages, some of the headers may be empty or they may be
// identical to the parent. This code detects if such entries need to be updated
// after a table update.
func TestUpdate(t *testing.T) {
	tests := []struct {
		d   *Dictionary
		tag string
	}{
		{ModernStandardArabic, "ar-001"},
		{AmericanEnglish, "en-US"},
		{EuropeanSpanish, "es-ES"},
		{BrazilianPortuguese, "pt-BR"},
		{SimplifiedChinese, "zh-Hans"},
	}

	for _, tt := range tests {
		_, i, _ := matcher.Match(language.MustParse(tt.tag))
		if !reflect.DeepEqual(tt.d.lang, langHeaders[i]) {
			t.Errorf("%s: lang table update needed", tt.tag)
		}
		if !reflect.DeepEqual(tt.d.script, scriptHeaders[i]) {
			t.Errorf("%s: script table update needed", tt.tag)
		}
		if !reflect.DeepEqual(tt.d.region, regionHeaders[i]) {
			t.Errorf("%s: region table update needed", tt.tag)
		}
	}
}

func TestIndex(t *testing.T) {
	notIn := []string{"aa", "xx", "zz", "aaa", "xxx", "zzz", "Aaaa", "Xxxx", "Zzzz"}
	tests := []tagIndex{
		{
			"",
			"",
			"",
		},
		{
			"bb",
			"",
			"",
		},
		{
			"",
			"bbb",
			"",
		},
		{
			"",
			"",
			"Bbbb",
		},
		{
			"bb",
			"bbb",
			"Bbbb",
		},
		{
			"bbccddyy",
			"bbbcccdddyyy",
			"BbbbCcccDdddYyyy",
		},
	}
	for i, tt := range tests {
		// Create the test set from the tagIndex.
		cnt := 0
		for sz := 2; sz <= 4; sz++ {
			a := tt[sz-2]
			for j := 0; j < len(a); j += sz {
				s := a[j : j+sz]
				if idx := tt.index(s); idx != cnt {
					t.Errorf("%d:%s: index was %d; want %d", i, s, idx, cnt)
				}
				cnt++
			}
		}
		if n := tt.len(); n != cnt {
			t.Errorf("%d: len was %d; want %d", i, n, cnt)
		}
		for _, x := range notIn {
			if idx := tt.index(x); idx != -1 {
				t.Errorf("%d:%s: index was %d; want -1", i, x, idx)
			}
		}
	}
}

func TestTag(t *testing.T) {
	tests := []struct {
		dict string
		tag  string
		name string
	}{
		{"agq", "sr", ""}, // sr is in Value.Languages(), but is not supported by agq.
		{"nl", "nl", "Nederlands"},
		{"nl", "nl-BE", "Vlaams"},
		{"en", "en", "English"},
		{"en", "en-GB", "British English"},
		{"en", "en-US", "American English"}, // American English in CLDR 24+
		{"ru", "ru", "русский"},
		{"ru", "ru-RU", "русский (Россия)"},
		{"ru", "ru-Cyrl", "русский (кириллица)"},
		{"en", lastLang2zu.String(), "Zulu"},
		{"en", firstLang2aa.String(), "Afar"},
		{"en", lastLang3zza.String(), "Zaza"},
		{"en", firstLang3ace.String(), "Achinese"},
		{"en", firstTagAr001.String(), "Modern Standard Arabic"},
		{"en", lastTagZhHant.String(), "Traditional Chinese"},
		{"en", "aaa", ""},
		{"en", "zzj", ""},
		// If full tag doesn't match, try without script or region.
		{"en", "aa-Hans", "Afar (Simplified Han)"},
		{"en", "af-Arab", "Afrikaans (Arabic)"},
		{"en", "zu-Cyrl", "Zulu (Cyrillic)"},
		{"en", "aa-GB", "Afar (United Kingdom)"},
		{"en", "af-NA", "Afrikaans (Namibia)"},
		{"en", "zu-BR", "Zulu (Brazil)"},
		// Correct inheritance and language selection.
		{"zh", "zh-TW", "中文 (台湾)"},
		{"zh", "zh-Hant-TW", "繁体中文 (台湾)"},
		{"zh-Hant", "zh-TW", "中文 (台灣)"},
		{"zh-Hant", "zh-Hant-TW", "繁體中文 (台灣)"},
		// Some rather arbitrary interpretations for Serbian. This is arguably
		// correct and consistent with the way zh-[Hant-]TW is handled. It will
		// also give results more in line with the expectations if users
		// explicitly use "sh".
		{"sr-Latn", "sr-ME", "srpski (Crna Gora)"},
		{"sr-Latn", "sr-Latn-ME", "Srpskohrvatski (Crna Gora)"},
		// Double script and region
		{"nl", "en-Cyrl-BE", "Engels (Cyrillisch, België)"},
		// Canonical equivalents.
		{"ro", "ro-MD", "moldovenească"},
		{"ro", "mo", "moldovenească"},
	}
	for i, tt := range tests {
		d := Tags(language.MustParse(tt.dict))
		if n := d.Name(language.Raw.MustParse(tt.tag)); n != tt.name {
			// There are inconsistencies w.r.t. capitalization in the tests
			// due to CLDR's update procedure which treats modern and other
			// languages differently.
			// See http://unicode.org/cldr/trac/ticket/8051.
			// TODO: use language capitalization to sanitize the strings.
			t.Errorf("%d:%s:%s: was %q; want %q", i, tt.dict, tt.tag, n, tt.name)
		}
	}
}

func TestLanguage(t *testing.T) {
	tests := []struct {
		dict string
		tag  string
		name string
	}{
		{"agq", "sr", ""}, // sr is in Value.Languages(), but is not supported by agq.
		{"nl", "nl", "Nederlands"},
		{"nl", "nl-BE", "Vlaams"},
		{"en", "pt", "Portuguese"},
		{"en", "pt-PT", "European Portuguese"},
		{"en", "pt-BR", "Brazilian Portuguese"},
		{"en", "en", "English"},
		{"en", "en-GB", "British English"},
		{"en", "en-US", "American English"}, // American English in CLDR 24+
		{"en", lastLang2zu.String(), "Zulu"},
		{"en", firstLang2aa.String(), "Afar"},
		{"en", lastLang3zza.String(), "Zaza"},
		{"en", firstLang3ace.String(), "Achinese"},
		{"en", firstTagAr001.String(), "Modern Standard Arabic"},
		{"en", lastTagZhHant.String(), "Traditional Chinese"},
		{"en", "aaa", ""},
		{"en", "zzj", ""},
		// If full tag doesn't match, try without script or region.
		{"en", "aa-Hans", "Afar"},
		{"en", "af-Arab", "Afrikaans"},
		{"en", "zu-Cyrl", "Zulu"},
		{"en", "aa-GB", "Afar"},
		{"en", "af-NA", "Afrikaans"},
		{"en", "zu-BR", "Zulu"},
		{"agq", "zh-Hant", ""},
		// Canonical equivalents.
		{"ro", "ro-MD", "moldovenească"},
		{"ro", "mo", "moldovenească"},
		{"en", "sh", "Serbo-Croatian"},
		{"en", "sr-Latn", "Serbo-Croatian"},
		{"en", "sr", "Serbian"},
		{"en", "sr-ME", "Serbian"},
		{"en", "sr-Latn-ME", "Serbo-Croatian"}, // See comments in TestTag.
	}
	for i, tt := range tests {
		d := Languages(language.Raw.MustParse(tt.dict))
		if n := d.Name(language.Raw.MustParse(tt.tag)); n != tt.name {
			t.Errorf("%d:%s:%s: was %q; want %q", i, tt.dict, tt.tag, n, tt.name)
		}
		if len(tt.tag) <= 3 {
			if n := d.Name(language.MustParseBase(tt.tag)); n != tt.name {
				t.Errorf("%d:%s:base(%s): was %q; want %q", i, tt.dict, tt.tag, n, tt.name)
			}
		}
	}
}

func TestScript(t *testing.T) {
	tests := []struct {
		dict string
		scr  string
		name string
	}{
		{"nl", "Arab", "Arabisch"},
		{"en", "Arab", "Arabic"},
		{"en", "Zzzz", "Unknown Script"},
		{"zh-Hant", "Hang", "韓文字"},
		{"zh-Hant-HK", "Hang", "韓文字母"},
		{"zh", "Arab", "阿拉伯文"},
		{"zh-Hans-HK", "Arab", "阿拉伯文"}, // same as zh
		{"zh-Hant", "Arab", "阿拉伯文"},
		{"zh-Hant-HK", "Arab", "阿拉伯文"}, // same as zh
		// Canonicalized form
		{"en", "Qaai", "Inherited"},    // deprecated script, now is Zinh
		{"en", "sh", "Unknown Script"}, // sh canonicalizes to sr-Latn
		{"en", "en", "Unknown Script"},
		// Don't introduce scripts with canonicalization.
		{"en", "sh", "Unknown Script"}, // sh canonicalizes to sr-Latn
	}
	for i, tt := range tests {
		d := Scripts(language.MustParse(tt.dict))
		var x interface{}
		if unicode.IsUpper(rune(tt.scr[0])) {
			x = language.MustParseScript(tt.scr)
			tag, _ := language.Raw.Compose(x)
			if n := d.Name(tag); n != tt.name {
				t.Errorf("%d:%s:%s: was %q; want %q", i, tt.dict, tt.scr, n, tt.name)
			}
		} else {
			x = language.Raw.MustParse(tt.scr)
		}
		if n := d.Name(x); n != tt.name {
			t.Errorf("%d:%s:%s: was %q; want %q", i, tt.dict, tt.scr, n, tt.name)
		}
	}
}

func TestRegion(t *testing.T) {
	tests := []struct {
		dict string
		reg  string
		name string
	}{
		{"nl", "NL", "Nederland"},
		{"en", "US", "United States"},
		{"en", "ZZ", "Unknown Region"},
		{"en", "UM", "U.S. Outlying Islands"},
		{"en-GB", "UM", "U.S. Outlying Islands"},
		{"en-GB", "NL", "Netherlands"},
		// Canonical equivalents
		{"en", "UK", "United Kingdom"},
		// No region
		{"en", "pt", "Unknown Region"},
		{"en", "und", "Unknown Region"},
		// Don't introduce regions with canonicalization.
		{"en", "mo", "Unknown Region"},
	}
	for i, tt := range tests {
		d := Regions(language.MustParse(tt.dict))
		var x interface{}
		if unicode.IsUpper(rune(tt.reg[0])) {
			// Region
			x = language.MustParseRegion(tt.reg)
			tag, _ := language.Raw.Compose(x)
			if n := d.Name(tag); n != tt.name {
				t.Errorf("%d:%s:%s: was %q; want %q", i, tt.dict, tt.reg, n, tt.name)
			}
		} else {
			// Tag
			x = language.Raw.MustParse(tt.reg)
		}
		if n := d.Name(x); n != tt.name {
			t.Errorf("%d:%s:%s: was %q; want %q", i, tt.dict, tt.reg, n, tt.name)
		}
	}
}

func TestSelf(t *testing.T) {
	tests := []struct {
		tag  string
		name string
	}{
		{"nl", "Nederlands"},
		{"nl-BE", "Vlaams"},
		{"en-GB", "British English"},
		{lastLang2zu.String(), "isiZulu"},
		{firstLang2aa.String(), ""},  // not defined
		{lastLang3zza.String(), ""},  // not defined
		{firstLang3ace.String(), ""}, // not defined
		{firstTagAr001.String(), "العربية الرسمية الحديثة"},
		{"ar", "العربية"},
		{lastTagZhHant.String(), "繁體中文"},
		{"aaa", ""},
		{"zzj", ""},
		// Drop entries that are not in the requested script, even if there is
		// an entry for the language.
		{"aa-Hans", ""},
		{"af-Arab", ""},
		{"zu-Cyrl", ""},
		// Append the country name in the language of the matching language.
		{"af-NA", "Afrikaans"},
		{"zh", "中文"},
		// zh-TW should match zh-Hant instead of zh!
		{"zh-TW", "繁體中文"},
		{"zh-Hant", "繁體中文"},
		{"zh-Hans", "简体中文"},
		{"zh-Hant-TW", "繁體中文"},
		{"zh-Hans-TW", "简体中文"},
		// Take the entry for sr which has the matching script.
		// TODO: Capitalization changed as of CLDR 26, but change seems
		// arbitrary. Revisit capitalization with revision 27. See
		// http://unicode.org/cldr/trac/ticket/8051.
		{"sr", "српски"},
		// TODO: sr-ME should show up as Serbian or Montenegrin, not Serbo-
		// Croatian. This is an artifact of the current algorithm, which is the
		// way it is to have the preferred behavior for other languages such as
		// Chinese. We can hardwire this case in the table generator or package
		// code, but we first check if CLDR can be updated.
		// {"sr-ME", "Srpski"}, // Is Srpskohrvatski
		{"sr-Latn-ME", "Srpskohrvatski"},
		{"sr-Cyrl-ME", "српски"},
		{"sr-NL", "српски"},
		// Canonical equivalents.
		{"ro-MD", "moldovenească"},
		{"mo", "moldovenească"},
		// NOTE: kk is defined, but in Cyrillic script. For China, Arab is the
		// dominant script. We do not have data for kk-Arab and we chose to not
		// fall back in such cases.
		{"kk-CN", ""},
	}
	for i, tt := range tests {
		d := Self
		if n := d.Name(language.Raw.MustParse(tt.tag)); n != tt.name {
			t.Errorf("%d:%s: was %q; want %q", i, tt.tag, n, tt.name)
		}
	}
}

func TestDictionaryLang(t *testing.T) {
	tests := []struct {
		d    *Dictionary
		tag  string
		name string
	}{
		{English, "en", "English"},
		{Portuguese, "af", "africâner"},
		{EuropeanPortuguese, "af", "africânder"},
		{English, "nl-BE", "Flemish"},
	}
	for i, test := range tests {
		tag := language.MustParse(test.tag)
		if got := test.d.Tags().Name(tag); got != test.name {
			t.Errorf("%d:%v: got %s; want %s", i, tag, got, test.name)
		}
		if base, _ := language.Compose(tag.Base()); base == tag {
			if got := test.d.Languages().Name(base); got != test.name {
				t.Errorf("%d:%v: got %s; want %s", i, tag, got, test.name)
			}
		}
	}
}

func TestDictionaryRegion(t *testing.T) {
	tests := []struct {
		d      *Dictionary
		region string
		name   string
	}{
		{English, "FR", "France"},
		{Portuguese, "009", "Oceania"},
		{EuropeanPortuguese, "009", "Oceânia"},
	}
	for i, test := range tests {
		tag := language.MustParseRegion(test.region)
		if got := test.d.Regions().Name(tag); got != test.name {
			t.Errorf("%d:%v: got %s; want %s", i, tag, got, test.name)
		}
	}
}

func TestDictionaryScript(t *testing.T) {
	tests := []struct {
		d      *Dictionary
		script string
		name   string
	}{
		{English, "Cyrl", "Cyrillic"},
		{Portuguese, "Gujr", "gujerati"},
		{EuropeanPortuguese, "Gujr", "guzerate"},
	}
	for i, test := range tests {
		tag := language.MustParseScript(test.script)
		if got := test.d.Scripts().Name(tag); got != test.name {
			t.Errorf("%d:%v: got %s; want %s", i, tag, got, test.name)
		}
	}
}