// Copyright 2009 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 regexp

import (
	"os";
	"regexp";
	"testing";
)

var good_re = []string{
	``,
	`.`,
	`^.$`,
	`a`,
	`a*`,
	`a+`,
	`a?`,
	`a|b`,
	`a*|b*`,
	`(a*|b)(c*|d)`,
	`[a-z]`,
	`[a-abc-c\-\]\[]`,
	`[a-z]+`,
	`[]`,
	`[abc]`,
	`[^1234]`,
}

// TODO: nice to do this with a map
type stringError struct {
	re	string;
	err	os.Error;
}
var bad_re = []stringError{
	stringError{ `*`,	 	regexp.ErrBareClosure },
	stringError{ `(abc`,	regexp.ErrUnmatchedLpar },
	stringError{ `abc)`,	regexp.ErrUnmatchedRpar },
	stringError{ `x[a-z`,	regexp.ErrUnmatchedLbkt },
	stringError{ `abc]`,	regexp.ErrUnmatchedRbkt },
	stringError{ `[z-a]`,	regexp.ErrBadRange },
	stringError{ `abc\`,	regexp.ErrExtraneousBackslash },
	stringError{ `a**`,	regexp.ErrBadClosure },
	stringError{ `a*+`,	regexp.ErrBadClosure },
	stringError{ `a??`,	regexp.ErrBadClosure },
	stringError{ `*`,	 	regexp.ErrBareClosure },
	stringError{ `\x`,	regexp.ErrBadBackslash },
}

type vec []int;

type tester struct {
	re	string;
	text	string;
	match	vec;
}

var matches = []tester {
	tester{ ``,	"",	vec{0,0} },
	tester{ `a`,	"a",	vec{0,1} },
	tester{ `x`,	"y",	vec{} },
	tester{ `b`,	"abc",	vec{1,2} },
	tester{ `.`,	"a",	vec{0,1} },
	tester{ `.*`,	"abcdef",	vec{0,6} },
	tester{ `^abcd$`,	"abcd",	vec{0,4} },
	tester{ `^bcd'`,	"abcdef",	vec{} },
	tester{ `^abcd$`,	"abcde",	vec{} },
	tester{ `a+`,	"baaab",	vec{1,4} },
	tester{ `a*`,	"baaab",	vec{0,0} },
	tester{ `[a-z]+`,	"abcd",	vec{0,4} },
	tester{ `[^a-z]+`,	"ab1234cd",	vec{2,6} },
	tester{ `[a\-\]z]+`,	"az]-bcz",	vec{0,4} },
	tester{ `[日本語]+`,	"日本語日本語",	vec{0,18} },
	tester{ `()`,	"",	vec{0,0, 0,0} },
	tester{ `(a)`,	"a",	vec{0,1, 0,1} },
	tester{ `(.)(.)`,	"日a",	vec{0,4, 0,3, 3,4} },
	tester{ `(.*)`,	"",	vec{0,0, 0,0} },
	tester{ `(.*)`,	"abcd",	vec{0,4, 0,4} },
	tester{ `(..)(..)`,	"abcd",	vec{0,4, 0,2, 2,4} },
	tester{ `(([^xyz]*)(d))`,	"abcd",	vec{0,4, 0,4, 0,3, 3,4} },
	tester{ `((a|b|c)*(d))`,	"abcd",	vec{0,4, 0,4, 2,3, 3,4} },
	tester{ `(((a|b|c)*)(d))`,	"abcd",	vec{0,4, 0,4, 0,3, 2,3, 3,4} },
	tester{ `a*(|(b))c*`,	"aacc",	vec{0,4, 2,2, -1,-1} },
}

func compileTest(t *testing.T, expr string, error os.Error) *regexp.Regexp {
	re, err := regexp.Compile(expr);
	if err != error {
		t.Error("compiling `", expr, "`; unexpected error: ", err.String());
	}
	return re
}

func printVec(t *testing.T, m []int) {
	l := len(m);
	if l == 0 {
		t.Log("\t<no match>");
	} else {
		for i := 0; i < l; i = i+2 {
			t.Log("\t", m[i], ",", m[i+1])
		}
	}
}

func printStrings(t *testing.T, m []string) {
	l := len(m);
	if l == 0 {
		t.Log("\t<no match>");
	} else {
		for i := 0; i < l; i = i+2 {
			t.Logf("\t%q", m[i])
		}
	}
}

func equal(m1, m2 []int) bool {
	l := len(m1);
	if l != len(m2) {
		return false
	}
	for i := 0; i < l; i++ {
		if m1[i] != m2[i] {
			return false
		}
	}
	return true
}

func equalStrings(m1, m2 []string) bool {
	l := len(m1);
	if l != len(m2) {
		return false
	}
	for i := 0; i < l; i++ {
		if m1[i] != m2[i] {
			return false
		}
	}
	return true
}

func executeTest(t *testing.T, expr string, str string, match []int) {
	re := compileTest(t, expr, nil);
	if re == nil {
		return
	}
	m := re.Execute(str);
	if !equal(m, match) {
		t.Error("Execute failure on `", expr, "` matching `", str, "`:");
		printVec(t, m);
		t.Log("should be:");
		printVec(t, match);
	}
}

func TestGoodCompile(t *testing.T) {
	for i := 0; i < len(good_re); i++ {
		compileTest(t, good_re[i], nil);
	}
}

func TestBadCompile(t *testing.T) {
	for i := 0; i < len(bad_re); i++ {
		compileTest(t, bad_re[i].re, bad_re[i].err)
	}
}

func TestExecute(t *testing.T) {
	for i := 0; i < len(matches); i++ {
		test := &matches[i];
		executeTest(t, test.re, test.text, test.match)
	}
}

func matchTest(t *testing.T, expr string, str string, match []int) {
	re := compileTest(t, expr, nil);
	if re == nil {
		return
	}
	m := re.Match(str);
	if m != (len(match) > 0) {
		t.Error("Match failure on `", expr, "` matching `", str, "`:", m, "should be", len(match) > 0);
	}
}

func TestMatch(t *testing.T) {
	for i := 0; i < len(matches); i++ {
		test := &matches[i];
		matchTest(t, test.re, test.text, test.match)
	}
}

func matchStringsTest(t *testing.T, expr string, str string, match []int) {
	re := compileTest(t, expr, nil);
	if re == nil {
		return
	}
	strs := make([]string, len(match)/2);
	for i := 0; i < len(match); i++ {
		strs[i/2] = str[match[i] : match[i+1]]
	}
	m := re.MatchStrings(str);
	if !equalStrings(m, strs) {
		t.Error("MatchStrings failure on `", expr, "` matching `", str, "`:");
		printStrings(t, m);
		t.Log("should be:");
		printStrings(t, strs);
	}
}

func TestMatchStrings(t *testing.T) {
	for i := 0; i < len(matches); i++ {
		test := &matches[i];
		matchTest(t, test.re, test.text, test.match)
	}
}

func matchFunctionTest(t *testing.T, expr string, str string, match []int) {
	m, err := Match(expr, str);
	if err == nil {
		return
	}
	if m != (len(match) > 0) {
		t.Error("function Match failure on `", expr, "` matching `", str, "`:", m, "should be", len(match) > 0);
	}
}

func TestMatchFunction(t *testing.T) {
	for i := 0; i < len(matches); i++ {
		test := &matches[i];
		matchFunctionTest(t, test.re, test.text, test.match)
	}
}

type ReplaceTest struct {
	pattern, replacement, input, output string;
}

var replaceTests = []ReplaceTest {
	// Test empty input and/or replacement, with pattern that matches the empty string.
	ReplaceTest{"", "", "", ""},
	ReplaceTest{"", "x", "", "x"},
	ReplaceTest{"", "", "abc", "abc"},
	ReplaceTest{"", "x", "abc", "xaxbxcx"},

	// Test empty input and/or replacement, with pattern that does not match the empty string.
	ReplaceTest{"b", "", "", ""},
	ReplaceTest{"b", "x", "", ""},
	ReplaceTest{"b", "", "abc", "ac"},
	ReplaceTest{"b", "x", "abc", "axc"},
	ReplaceTest{"y", "", "", ""},
	ReplaceTest{"y", "x", "", ""},
	ReplaceTest{"y", "", "abc", "abc"},
	ReplaceTest{"y", "x", "abc", "abc"},

	// Multibyte characters -- verify that we don't try to match in the middle
	// of a character.
	ReplaceTest{"[a-c]*", "x", "\u65e5", "x\u65e5x"},
	ReplaceTest{"[^\u65e5]", "x", "abc\u65e5def", "xxx\u65e5xxx"},

	// Start and end of a string.
	ReplaceTest{"^[a-c]*", "x", "abcdabc", "xdabc"},
	ReplaceTest{"[a-c]*$", "x", "abcdabc", "abcdx"},
	ReplaceTest{"^[a-c]*$", "x", "abcdabc", "abcdabc"},
	ReplaceTest{"^[a-c]*", "x", "abc", "x"},
	ReplaceTest{"[a-c]*$", "x", "abc", "x"},
	ReplaceTest{"^[a-c]*$", "x", "abc", "x"},
	ReplaceTest{"^[a-c]*", "x", "dabce", "xdabce"},
	ReplaceTest{"[a-c]*$", "x", "dabce", "dabcex"},
	ReplaceTest{"^[a-c]*$", "x", "dabce", "dabce"},
	ReplaceTest{"^[a-c]*", "x", "", "x"},
	ReplaceTest{"[a-c]*$", "x", "", "x"},
	ReplaceTest{"^[a-c]*$", "x", "", "x"},

	ReplaceTest{"^[a-c]+", "x", "abcdabc", "xdabc"},
	ReplaceTest{"[a-c]+$", "x", "abcdabc", "abcdx"},
	ReplaceTest{"^[a-c]+$", "x", "abcdabc", "abcdabc"},
	ReplaceTest{"^[a-c]+", "x", "abc", "x"},
	ReplaceTest{"[a-c]+$", "x", "abc", "x"},
	ReplaceTest{"^[a-c]+$", "x", "abc", "x"},
	ReplaceTest{"^[a-c]+", "x", "dabce", "dabce"},
	ReplaceTest{"[a-c]+$", "x", "dabce", "dabce"},
	ReplaceTest{"^[a-c]+$", "x", "dabce", "dabce"},
	ReplaceTest{"^[a-c]+", "x", "", ""},
	ReplaceTest{"[a-c]+$", "x", "", ""},
	ReplaceTest{"^[a-c]+$", "x", "", ""},

	// Other cases.
	ReplaceTest{"abc", "def", "abcdefg", "defdefg"},
	ReplaceTest{"bc", "BC", "abcbcdcdedef", "aBCBCdcdedef"},
	ReplaceTest{"abc", "", "abcdabc", "d"},
	ReplaceTest{"x", "xXx", "xxxXxxx", "xXxxXxxXxXxXxxXxxXx"},
	ReplaceTest{"abc", "d", "", ""},
	ReplaceTest{"abc", "d", "abc", "d"},
	ReplaceTest{".+", "x", "abc", "x"},
	ReplaceTest{"[a-c]*", "x", "def", "xdxexfx"},
	ReplaceTest{"[a-c]+", "x", "abcbcdcdedef", "xdxdedef"},
	ReplaceTest{"[a-c]*", "x", "abcbcdcdedef", "xdxdxexdxexfx"},
}

func TestReplaceAll(t *testing.T) {
	for i, tc := range replaceTests {
		re, err := Compile(tc.pattern);
		if err != nil {
			t.Errorf("Unexpected error compiling %q: %v", tc.pattern, err);
			continue;
		}
		actual := re.ReplaceAll(tc.input, tc.replacement);
		if actual != tc.output {
			t.Errorf("%q.Replace(%q,%q) = %q; want %q",
				tc.pattern, tc.input, tc.replacement, actual, tc.output);
		}
	}
}

type QuoteMetaTest struct {
	pattern, output string;
}

var quoteMetaTests = []QuoteMetaTest {
	QuoteMetaTest{``, ``},
	QuoteMetaTest{`foo`, `foo`},
	QuoteMetaTest{`!@#$%^&*()_+-=[{]}\|,<.>/?~`, `!@#\$%\^&\*\(\)_\+-=\[{\]}\\\|,<\.>/\?~`},
}

func TestQuoteMeta(t *testing.T) {
	for i, tc := range quoteMetaTests {
		// Verify that QuoteMeta returns the expected string.
		quoted := QuoteMeta(tc.pattern);
		if quoted != tc.output {
			t.Errorf("QuoteMeta(`%s`) = `%s`; want `%s`",
				tc.pattern, quoted, tc.output);
			continue;
		}

		// Verify that the quoted string is in fact treated as expected
		// by Compile -- i.e. that it matches the original, unquoted string.
		if tc.pattern != "" {
			re, err := Compile(quoted);
			if err != nil {
				t.Errorf("Unexpected error compiling QuoteMeta(`%s`): %v", tc.pattern, err);
				continue;
			}
			src := "abc" + tc.pattern + "def";
			repl := "xyz";
			replaced := re.ReplaceAll(src, repl);
			expected := "abcxyzdef";
			if replaced != expected {
				t.Errorf("QuoteMeta(`%s`).Replace(`%s`,`%s`) = `%s`; want `%s`",
					tc.pattern, src, repl, replaced, expected);
			}
		}
	}
}