package glob

import (
	"errors"
	"fmt"
	"reflect"
	"strings"
	"testing"
	"testing/fstest"
)

type test struct {
	pattern, f string
	match      bool
	err        error
}

func escape(name string) string {
	// use a math division slash for correct visual
	return strings.ReplaceAll(name, "/", "∕")
}

func TestPattern_Match(t *testing.T) {
	tests := []test{
		// Test cases not covered by path.Match
		{"main.go", "main.go", true, nil},
		{"main_test.go", "main_test.go", true, nil},
		{"foo/foo_test.go", "foo/foo_test.go", true, nil},
		{"?.go", "m.go", true, nil},
		{"*.go", "main.go", true, nil},
		{"**/*.go", "main.go", true, nil},
		{"*.go", "*.go", true, nil},

		{"//", "", false, ErrBadPattern},
		{"foo//", "", false, ErrBadPattern},
		{"*?.go", "", false, ErrBadPattern},
		{"?*.go", "", false, ErrBadPattern},
		{"**?.go", "", false, ErrBadPattern},
		{"**f", "", false, ErrBadPattern},
		{"[a-", "", false, ErrBadPattern},
		{"[a-\\", "", false, ErrBadPattern},
		{"[\\", "", false, ErrBadPattern},

		{"**/m.go", "foo.go", false, nil},
		{"**/m.go", "foo/a.go", false, nil},
		{"**/m.go", "m.go", true, nil},
		{"**/m.go", "foo/m.go", true, nil},
		{"**/m.go", "bar/m.go", true, nil},
		{"**/m.go", "foo/bar/m.go", true, nil},

		{"ab[cde]", "abc", true, nil},
		{"ab[cde]", "abd", true, nil},
		{"ab[cde]", "abe", true, nil},
		{"ab[+-\\-]", "ab-", true, nil},
		{"ab[\\--a]", "ab-", true, nil},

		{"[a-fA-F]", "a", true, nil},
		{"[a-fA-F]", "f", true, nil},
		{"[a-fA-F]", "A", true, nil},
		{"[a-fA-F]", "F", true, nil},

		// The following test cases are taken from
		// https://github.com/golang/go/blob/master/src/path/match_test.go and are
		// provided here to test compatebility of the match implementation with the
		// test cases from the golang standard lib.
		{"abc", "abc", true, nil},
		{"*", "abc", true, nil},
		{"*c", "abc", true, nil},
		{"a*", "a", true, nil},
		{"a*", "abc", true, nil},
		{"a*", "ab/c", false, nil},
		{"a*/b", "abc/b", true, nil},
		{"a*/b", "a/c/b", false, nil},
		{"a*b*c*d*e*/f", "axbxcxdxe/f", true, nil},
		{"a*b*c*d*e*/f", "axbxcxdxexxx/f", true, nil},
		{"a*b*c*d*e*/f", "axbxcxdxe/xxx/f", false, nil},
		{"a*b*c*d*e*/f", "axbxcxdxexxx/fff", false, nil},
		{"a*b?c*x", "abxbbxdbxebxczzx", true, nil},
		{"a*b?c*x", "abxbbxdbxebxczzy", false, nil},
		{"ab[c]", "abc", true, nil},
		{"ab[b-d]", "abc", true, nil},
		{"ab[e-g]", "abc", false, nil},
		{"ab[^c]", "abc", false, nil},
		{"ab[^b-d]", "abc", false, nil},
		{"ab[^e-g]", "abc", true, nil},
		{"a\\*b", "a*b", true, nil},
		{"a\\*b", "ab", false, nil},
		{"a?b", "a☺b", true, nil},
		{"a[^a]b", "a☺b", true, nil},
		{"a???b", "a☺b", false, nil},
		{"a[^a][^a][^a]b", "a☺b", false, nil},
		{"[a-ζ]*", "α", true, nil},
		{"*[a-ζ]", "A", false, nil},
		{"a?b", "a/b", false, nil},
		{"a*b", "a/b", false, nil},
		{"[\\]a]", "]", true, nil},
		{"[\\-]", "-", true, nil},
		{"[x\\-]", "x", true, nil},
		{"[x\\-]", "-", true, nil},
		{"[x\\-]", "z", false, nil},
		{"[\\-x]", "x", true, nil},
		{"[\\-x]", "-", true, nil},
		{"[\\-x]", "a", false, nil},
		{"[]a]", "]", false, ErrBadPattern},
		{"[-]", "-", false, ErrBadPattern},
		{"[x-]", "x", false, ErrBadPattern},
		{"[x-]", "-", false, ErrBadPattern},
		{"[x-]", "z", false, ErrBadPattern},
		{"[-x]", "x", false, ErrBadPattern},
		{"[-x]", "-", false, ErrBadPattern},
		{"[-x]", "a", false, ErrBadPattern},
		{"\\", "a", false, ErrBadPattern},
		{"[a-b-c]", "a", false, ErrBadPattern},
		{"[", "a", false, ErrBadPattern},
		{"[^", "a", false, ErrBadPattern},
		{"[^bc", "a", false, ErrBadPattern},
		{"a[", "a", false, ErrBadPattern},
		{"a[", "ab", false, ErrBadPattern},
		{"a[", "x", false, ErrBadPattern},
		{"a/b[", "x", false, ErrBadPattern},
		{"*x", "xxx", true, nil},
	}

	for _, tt := range tests {
		pat, err := New(tt.pattern)
		if err != tt.err && !errors.Is(err, tt.err) {
			t.Errorf("New(%#q): wanted error %v but got %v", tt.pattern, tt.err, err)
		}

		if pat != nil {
			match := pat.Match(tt.f)
			if match != tt.match {
				t.Errorf("New(%#q).Match(%#q): wanted match %v but got %v", tt.pattern, tt.f, tt.match, match)
			}
		}
	}
}

func TestPattern_MatchPrefix(t *testing.T) {
	tests := []test{
		{"**/*.go", "foo/", true, nil},
		{"**/*.go", "foo", true, nil},
		{"**/*.go", "foo/bar/", true, nil},
		{"**/*.go", "foo/bar", true, nil},
		{"*/*.go", "foo", true, nil},
	}

	for _, tc := range tests {
		tc := tc // capture range variable
		t.Run(fmt.Sprintf("%s (%s)", escape(tc.pattern), escape(tc.f)), func(t *testing.T) {
			pat, err := New(tc.pattern)
			if err != nil {
				t.Errorf("unexpected error: %v", err)
				return
			}
			got := pat.MatchPrefix(tc.f)

			if got != tc.match {
				t.Errorf("got %v; want %v", got, tc.match)
			}
		})
	}
}

func TestPattern_GlobFS(t *testing.T) {
	fsys := fstest.MapFS{
		"go.mod":                     &fstest.MapFile{Mode: 0644},
		"go.sum":                     &fstest.MapFile{Mode: 0644},
		"cmd/main.go":                &fstest.MapFile{Mode: 0644},
		"cmd/main_test.go":           &fstest.MapFile{Mode: 0644},
		"internal/tool/tool.go":      &fstest.MapFile{Mode: 0644},
		"internal/tool/tool_test.go": &fstest.MapFile{Mode: 0644},
		"internal/cli/cli.go":        &fstest.MapFile{Mode: 0644},
		"internal/cli/cli_test.go":   &fstest.MapFile{Mode: 0644},
	}

	pat, err := New("**/*_test.go")
	if err != nil {
		t.Fatal(err)
	}

	files, err := pat.GlobFS(fsys, ".")
	if err != nil {
		t.Fatal(err)
	}
	expect := []string{
		"cmd/main_test.go",
		"internal/cli/cli_test.go",
		"internal/tool/tool_test.go",
	}
	if !reflect.DeepEqual(expect, files) {
		t.Errorf("got %v; want %v", files, expect)
	}
}

func TestPattern_String(t *testing.T) {
	tests := []string{
		"main.go",
		"*.go",
		"**/*.go",
		"foo/bar/*",
		"foo/?ar.go",
		"foo/[abc].go",
		"foo/[a-c].go",
		"foo/**/",
		"foo/*/bar.go",
		"foo/\\*bar.go",
	}
	for _, patstr := range tests {
		t.Run(escape(patstr), func(t *testing.T) {
			pat, err := New(patstr)
			if err != nil {
				t.Fatalf("New(%q) failed: %v", patstr, err)
			}
			if pat.String() != patstr {
				t.Fatalf("Pattern.String() = %q, want %q", pat.String(), patstr)
			}
		})
	}
}