// 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 webdav

import (
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"testing"
)

func TestDir(t *testing.T) {
	testCases := []struct {
		dir, name, want string
	}{
		{"/", "", "/"},
		{"/", "/", "/"},
		{"/", ".", "/"},
		{"/", "./a", "/a"},
		{"/", "..", "/"},
		{"/", "..", "/"},
		{"/", "../", "/"},
		{"/", "../.", "/"},
		{"/", "../a", "/a"},
		{"/", "../..", "/"},
		{"/", "../bar/a", "/bar/a"},
		{"/", "../baz/a", "/baz/a"},
		{"/", "...", "/..."},
		{"/", ".../a", "/.../a"},
		{"/", ".../..", "/"},
		{"/", "a", "/a"},
		{"/", "a/./b", "/a/b"},
		{"/", "a/../../b", "/b"},
		{"/", "a/../b", "/b"},
		{"/", "a/b", "/a/b"},
		{"/", "a/b/c/../../d", "/a/d"},
		{"/", "a/b/c/../../../d", "/d"},
		{"/", "a/b/c/../../../../d", "/d"},
		{"/", "a/b/c/d", "/a/b/c/d"},

		{"/foo/bar", "", "/foo/bar"},
		{"/foo/bar", "/", "/foo/bar"},
		{"/foo/bar", ".", "/foo/bar"},
		{"/foo/bar", "./a", "/foo/bar/a"},
		{"/foo/bar", "..", "/foo/bar"},
		{"/foo/bar", "../", "/foo/bar"},
		{"/foo/bar", "../.", "/foo/bar"},
		{"/foo/bar", "../a", "/foo/bar/a"},
		{"/foo/bar", "../..", "/foo/bar"},
		{"/foo/bar", "../bar/a", "/foo/bar/bar/a"},
		{"/foo/bar", "../baz/a", "/foo/bar/baz/a"},
		{"/foo/bar", "...", "/foo/bar/..."},
		{"/foo/bar", ".../a", "/foo/bar/.../a"},
		{"/foo/bar", ".../..", "/foo/bar"},
		{"/foo/bar", "a", "/foo/bar/a"},
		{"/foo/bar", "a/./b", "/foo/bar/a/b"},
		{"/foo/bar", "a/../../b", "/foo/bar/b"},
		{"/foo/bar", "a/../b", "/foo/bar/b"},
		{"/foo/bar", "a/b", "/foo/bar/a/b"},
		{"/foo/bar", "a/b/c/../../d", "/foo/bar/a/d"},
		{"/foo/bar", "a/b/c/../../../d", "/foo/bar/d"},
		{"/foo/bar", "a/b/c/../../../../d", "/foo/bar/d"},
		{"/foo/bar", "a/b/c/d", "/foo/bar/a/b/c/d"},

		{"/foo/bar/", "", "/foo/bar"},
		{"/foo/bar/", "/", "/foo/bar"},
		{"/foo/bar/", ".", "/foo/bar"},
		{"/foo/bar/", "./a", "/foo/bar/a"},
		{"/foo/bar/", "..", "/foo/bar"},

		{"/foo//bar///", "", "/foo/bar"},
		{"/foo//bar///", "/", "/foo/bar"},
		{"/foo//bar///", ".", "/foo/bar"},
		{"/foo//bar///", "./a", "/foo/bar/a"},
		{"/foo//bar///", "..", "/foo/bar"},

		{"/x/y/z", "ab/c\x00d/ef", ""},

		{".", "", "."},
		{".", "/", "."},
		{".", ".", "."},
		{".", "./a", "a"},
		{".", "..", "."},
		{".", "..", "."},
		{".", "../", "."},
		{".", "../.", "."},
		{".", "../a", "a"},
		{".", "../..", "."},
		{".", "../bar/a", "bar/a"},
		{".", "../baz/a", "baz/a"},
		{".", "...", "..."},
		{".", ".../a", ".../a"},
		{".", ".../..", "."},
		{".", "a", "a"},
		{".", "a/./b", "a/b"},
		{".", "a/../../b", "b"},
		{".", "a/../b", "b"},
		{".", "a/b", "a/b"},
		{".", "a/b/c/../../d", "a/d"},
		{".", "a/b/c/../../../d", "d"},
		{".", "a/b/c/../../../../d", "d"},
		{".", "a/b/c/d", "a/b/c/d"},

		{"", "", "."},
		{"", "/", "."},
		{"", ".", "."},
		{"", "./a", "a"},
		{"", "..", "."},
	}

	for _, tc := range testCases {
		d := Dir(filepath.FromSlash(tc.dir))
		if got := filepath.ToSlash(d.resolve(tc.name)); got != tc.want {
			t.Errorf("dir=%q, name=%q: got %q, want %q", tc.dir, tc.name, got, tc.want)
		}
	}
}

func TestWalk(t *testing.T) {
	type walkStep struct {
		name, frag string
		final      bool
	}

	testCases := []struct {
		dir  string
		want []walkStep
	}{
		{"", []walkStep{
			{"", "", true},
		}},
		{"/", []walkStep{
			{"", "", true},
		}},
		{"/a", []walkStep{
			{"", "a", true},
		}},
		{"/a/", []walkStep{
			{"", "a", true},
		}},
		{"/a/b", []walkStep{
			{"", "a", false},
			{"a", "b", true},
		}},
		{"/a/b/", []walkStep{
			{"", "a", false},
			{"a", "b", true},
		}},
		{"/a/b/c", []walkStep{
			{"", "a", false},
			{"a", "b", false},
			{"b", "c", true},
		}},
		// The following test case is the one mentioned explicitly
		// in the method description.
		{"/foo/bar/x", []walkStep{
			{"", "foo", false},
			{"foo", "bar", false},
			{"bar", "x", true},
		}},
	}

	for _, tc := range testCases {
		fs := NewMemFS().(*memFS)

		parts := strings.Split(tc.dir, "/")
		for p := 2; p < len(parts); p++ {
			d := strings.Join(parts[:p], "/")
			if err := fs.Mkdir(d, 0666); err != nil {
				t.Errorf("tc.dir=%q: mkdir: %q: %v", tc.dir, d, err)
			}
		}

		i := 0
		err := fs.walk("test", tc.dir, func(dir *memFSNode, frag string, final bool) error {
			got := walkStep{
				name:  dir.name,
				frag:  frag,
				final: final,
			}
			want := tc.want[i]

			if got != want {
				return fmt.Errorf("got %+v, want %+v", got, want)
			}
			i++
			return nil
		})
		if err != nil {
			t.Errorf("tc.dir=%q: %v", tc.dir, err)
		}
	}
}

func TestMemFile(t *testing.T) {
	testCases := []string{
		"wantData ",
		"wantSize 0",
		"write abc",
		"wantData abc",
		"write de",
		"wantData abcde",
		"wantSize 5",
		"write 5*x",
		"write 4*y+2*z",
		"write 3*st",
		"wantData abcdexxxxxyyyyzzststst",
		"wantSize 22",
		"seek set 4 want 4",
		"write EFG",
		"wantData abcdEFGxxxyyyyzzststst",
		"wantSize 22",
		"seek set 2 want 2",
		"read cdEF",
		"read Gx",
		"seek cur 0 want 8",
		"seek cur 2 want 10",
		"seek cur -1 want 9",
		"write J",
		"wantData abcdEFGxxJyyyyzzststst",
		"wantSize 22",
		"seek cur -4 want 6",
		"write ghijk",
		"wantData abcdEFghijkyyyzzststst",
		"wantSize 22",
		"read yyyz",
		"seek cur 0 want 15",
		"write ",
		"seek cur 0 want 15",
		"read ",
		"seek cur 0 want 15",
		"seek end -3 want 19",
		"write ZZ",
		"wantData abcdEFghijkyyyzzstsZZt",
		"wantSize 22",
		"write 4*A",
		"wantData abcdEFghijkyyyzzstsZZAAAA",
		"wantSize 25",
		"seek end 0 want 25",
		"seek end -5 want 20",
		"read Z+4*A",
		"write 5*B",
		"wantData abcdEFghijkyyyzzstsZZAAAABBBBB",
		"wantSize 30",
		"seek end 10 want 40",
		"write C",
		"wantData abcdEFghijkyyyzzstsZZAAAABBBBB..........C",
		"wantSize 41",
		"seek set 43 want 43",
		"write D",
		"wantData abcdEFghijkyyyzzstsZZAAAABBBBB..........C..D",
		"wantSize 44",
		"seek set 0 want 0",
		"write 5*123456789_",
		"wantData 123456789_123456789_123456789_123456789_123456789_",
		"wantSize 50",
		"seek cur 0 want 50",
		"seek cur -99 want err",
	}

	const filename = "/foo"
	fs := NewMemFS()
	f, err := fs.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
	if err != nil {
		t.Fatalf("OpenFile: %v", err)
	}
	defer f.Close()

	for i, tc := range testCases {
		j := strings.IndexByte(tc, ' ')
		if j < 0 {
			t.Fatalf("test case #%d %q: invalid command", i, tc)
		}
		op, arg := tc[:j], tc[j+1:]

		// Expand an arg like "3*a+2*b" to "aaabb".
		parts := strings.Split(arg, "+")
		for j, part := range parts {
			if k := strings.IndexByte(part, '*'); k >= 0 {
				repeatCount, repeatStr := part[:k], part[k+1:]
				n, err := strconv.Atoi(repeatCount)
				if err != nil {
					t.Fatalf("test case #%d %q: invalid repeat count %q", i, tc, repeatCount)
				}
				parts[j] = strings.Repeat(repeatStr, n)
			}
		}
		arg = strings.Join(parts, "")

		switch op {
		default:
			t.Fatalf("test case #%d %q: invalid operation %q", i, tc, op)

		case "read":
			buf := make([]byte, len(arg))
			if _, err := io.ReadFull(f, buf); err != nil {
				t.Fatalf("test case #%d %q: ReadFull: %v", i, tc, err)
			}
			if got := string(buf); got != arg {
				t.Fatalf("test case #%d %q:\ngot  %q\nwant %q", i, tc, got, arg)
			}

		case "seek":
			parts := strings.Split(arg, " ")
			if len(parts) != 4 {
				t.Fatalf("test case #%d %q: invalid seek", i, tc)
			}

			whence := 0
			switch parts[0] {
			default:
				t.Fatalf("test case #%d %q: invalid seek whence", i, tc)
			case "set":
				whence = os.SEEK_SET
			case "cur":
				whence = os.SEEK_CUR
			case "end":
				whence = os.SEEK_END
			}
			offset, err := strconv.Atoi(parts[1])
			if err != nil {
				t.Fatalf("test case #%d %q: invalid offset %q", i, tc, parts[1])
			}

			if parts[2] != "want" {
				t.Fatalf("test case #%d %q: invalid seek", i, tc)
			}
			if parts[3] == "err" {
				_, err := f.Seek(int64(offset), whence)
				if err == nil {
					t.Fatalf("test case #%d %q: Seek returned nil error, want non-nil", i, tc)
				}
			} else {
				got, err := f.Seek(int64(offset), whence)
				if err != nil {
					t.Fatalf("test case #%d %q: Seek: %v", i, tc, err)
				}
				want, err := strconv.Atoi(parts[3])
				if err != nil {
					t.Fatalf("test case #%d %q: invalid want %q", i, tc, parts[3])
				}
				if got != int64(want) {
					t.Fatalf("test case #%d %q: got %d, want %d", i, tc, got, want)
				}
			}

		case "write":
			n, err := f.Write([]byte(arg))
			if err != nil {
				t.Fatalf("test case #%d %q: write: %v", i, tc, err)
			}
			if n != len(arg) {
				t.Fatalf("test case #%d %q: write returned %d bytes, want %d", i, tc, n, len(arg))
			}

		case "wantData":
			g, err := fs.OpenFile(filename, os.O_RDONLY, 0666)
			if err != nil {
				t.Fatalf("test case #%d %q: OpenFile: %v", i, tc, err)
			}
			gotBytes, err := ioutil.ReadAll(g)
			if err != nil {
				t.Fatalf("test case #%d %q: ReadAll: %v", i, tc, err)
			}
			for i, c := range gotBytes {
				if c == '\x00' {
					gotBytes[i] = '.'
				}
			}
			got := string(gotBytes)
			if got != arg {
				t.Fatalf("test case #%d %q:\ngot  %q\nwant %q", i, tc, got, arg)
			}
			if err := g.Close(); err != nil {
				t.Fatalf("test case #%d %q: Close: %v", i, tc, err)
			}

		case "wantSize":
			n, err := strconv.Atoi(arg)
			if err != nil {
				t.Fatalf("test case #%d %q: invalid size %q", i, tc, arg)
			}
			fi, err := fs.Stat(filename)
			if err != nil {
				t.Fatalf("test case #%d %q: Stat: %v", i, tc, err)
			}
			if got, want := fi.Size(), int64(n); got != want {
				t.Fatalf("test case #%d %q: got %d, want %d", i, tc, got, want)
			}
		}
	}
}