// Copyright 2015 Light Code Labs, LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package browse

import (
	"context"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"runtime"
	"sort"
	"strings"
	"testing"
	"text/template"
	"time"

	"github.com/caddyserver/caddy/caddyhttp/httpserver"
	"github.com/caddyserver/caddy/caddyhttp/staticfiles"
)

const testDirPrefix = "caddy_browse_test"

func TestSort(t *testing.T) {
	// making up []fileInfo with bogus values;
	// to be used to make up our "listing"
	fileInfos := []FileInfo{
		{
			Name:    "fizz",
			Size:    4,
			ModTime: time.Now().AddDate(-1, 1, 0),
		},
		{
			Name:    "buzz",
			Size:    2,
			ModTime: time.Now().AddDate(0, -3, 3),
		},
		{
			Name:    "bazz",
			Size:    1,
			ModTime: time.Now().AddDate(0, -2, -23),
		},
		{
			Name:    "jazz",
			Size:    3,
			ModTime: time.Now(),
		},
	}
	listing := Listing{
		Name:    "foobar",
		Path:    "/fizz/buzz",
		CanGoUp: false,
		Items:   fileInfos,
	}

	// sort by name
	listing.Sort = "name"
	listing.applySort()
	if !sort.IsSorted(byName(listing)) {
		t.Errorf("The listing isn't name sorted: %v", listing.Items)
	}

	// sort by size
	listing.Sort = "size"
	listing.applySort()
	if !sort.IsSorted(bySize(listing)) {
		t.Errorf("The listing isn't size sorted: %v", listing.Items)
	}

	// sort by Time
	listing.Sort = "time"
	listing.applySort()
	if !sort.IsSorted(byTime(listing)) {
		t.Errorf("The listing isn't time sorted: %v", listing.Items)
	}

	// sort by name dir first
	listing.Sort = "namedirfirst"
	listing.applySort()
	if !sort.IsSorted(byNameDirFirst(listing)) {
		t.Errorf("The listing isn't namedirfirst sorted: %v", listing.Items)
	}

	// reverse by name
	listing.Sort = "name"
	listing.Order = "desc"
	listing.applySort()
	if !isReversed(byName(listing)) {
		t.Errorf("The listing isn't reversed by name: %v", listing.Items)
	}

	// reverse by size
	listing.Sort = "size"
	listing.Order = "desc"
	listing.applySort()
	if !isReversed(bySize(listing)) {
		t.Errorf("The listing isn't reversed by size: %v", listing.Items)
	}

	// reverse by time
	listing.Sort = "time"
	listing.Order = "desc"
	listing.applySort()
	if !isReversed(byTime(listing)) {
		t.Errorf("The listing isn't reversed by time: %v", listing.Items)
	}

	// reverse by name dir first
	listing.Sort = "namedirfirst"
	listing.Order = "desc"
	listing.applySort()
	if !isReversed(byNameDirFirst(listing)) {
		t.Errorf("The listing isn't reversed by namedirfirst: %v", listing.Items)
	}
}

func TestBrowseHTTPMethods(t *testing.T) {
	tmpl, err := template.ParseFiles("testdata/photos.tpl")
	if err != nil {
		t.Fatalf("An error occurred while parsing the template: %v", err)
	}

	b := Browse{
		Next: httpserver.HandlerFunc(func(w http.ResponseWriter, r *http.Request) (int, error) {
			return http.StatusTeapot, nil // not t.Fatalf, or we will not see what other methods yield
		}),
		Configs: []Config{
			{
				PathScope: "/photos",
				Fs: staticfiles.FileServer{
					Root: http.Dir("./testdata"),
				},
				Template: tmpl,
			},
		},
	}

	rec := httptest.NewRecorder()
	for method, expected := range map[string]int{
		http.MethodGet:     http.StatusOK,
		http.MethodHead:    http.StatusOK,
		http.MethodOptions: http.StatusNotImplemented,
		"PROPFIND":         http.StatusNotImplemented,
	} {
		req, err := http.NewRequest(method, "/photos/", nil)
		if err != nil {
			t.Fatalf("Test: Could not create HTTP request: %v", err)
		}
		ctx := context.WithValue(req.Context(), httpserver.OriginalURLCtxKey, *req.URL)
		req = req.WithContext(ctx)

		code, _ := b.ServeHTTP(rec, req)
		if code != expected {
			t.Errorf("Wrong status with HTTP Method %s: expected %d, got %d", method, expected, code)
		}
	}
}

func TestBrowseTemplate(t *testing.T) {
	tmpl, err := template.ParseFiles("testdata/photos.tpl")
	if err != nil {
		t.Fatalf("An error occurred while parsing the template: %v", err)
	}

	b := Browse{
		Next: httpserver.HandlerFunc(func(w http.ResponseWriter, r *http.Request) (int, error) {
			t.Fatalf("Next shouldn't be called")
			return 0, nil
		}),
		Configs: []Config{
			{
				PathScope: "/photos",
				Fs: staticfiles.FileServer{
					Root: http.Dir("./testdata"),
					Hide: []string{"photos/hidden.html"},
				},
				Template: tmpl,
			},
		},
	}

	req, err := http.NewRequest("GET", "/photos/", nil)
	if err != nil {
		t.Fatalf("Test: Could not create HTTP request: %v", err)
	}
	ctx := context.WithValue(req.Context(), httpserver.OriginalURLCtxKey, *req.URL)
	req = req.WithContext(ctx)

	rec := httptest.NewRecorder()

	code, _ := b.ServeHTTP(rec, req)
	if code != http.StatusOK {
		t.Fatalf("Wrong status, expected %d, got %d", http.StatusOK, code)
	}

	respBody := rec.Body.String()
	expectedBody := `<!DOCTYPE html>
<html>
<head>
<title>Template</title>
</head>
<body>
<h1>Header</h1>

<h1>/photos/</h1>

<a href="./test1/">test1</a><br>

<a href="./test.html">test.html</a><br>

<a href="./test2.html">test2.html</a><br>

<a href="./test3.html">test3.html</a><br>

</body>
</html>
`

	if respBody != expectedBody {
		t.Fatalf("Expected body: '%v' got: '%v'", expectedBody, respBody)
	}

}

func TestBrowseJson(t *testing.T) {
	b := Browse{
		Next: httpserver.HandlerFunc(func(w http.ResponseWriter, r *http.Request) (int, error) {
			t.Fatalf("Next shouldn't be called: %s", r.URL)
			return 0, nil
		}),
		Configs: []Config{
			{
				PathScope: "/photos/",
				Fs: staticfiles.FileServer{
					Root: http.Dir("./testdata"),
				},
			},
		},
	}

	//Getting the listing from the ./testdata/photos, the listing returned will be used to validate test results
	testDataPath := filepath.Join("./testdata", "photos")
	file, err := os.Open(testDataPath)
	if err != nil {
		if os.IsPermission(err) {
			t.Fatalf("Os Permission Error")
		}
	}
	defer file.Close()

	files, err := file.Readdir(-1)
	if err != nil {
		t.Fatalf("Unable to Read Contents of the directory")
	}
	var fileinfos []FileInfo

	for i, f := range files {
		name := f.Name()

		// Tests fail in CI environment because all file mod times are the same for
		// some reason, making the sorting unpredictable. To hack around this,
		// we ensure here that each file has a different mod time.
		chTime := f.ModTime().UTC().Add(-(time.Duration(i) * time.Second))
		if err := os.Chtimes(filepath.Join(testDataPath, name), chTime, chTime); err != nil {
			t.Fatal(err)
		}

		if f.IsDir() {
			name += "/"
		}

		url := url.URL{Path: "./" + name}

		fileinfos = append(fileinfos, FileInfo{
			IsDir:   f.IsDir(),
			Name:    f.Name(),
			Size:    f.Size(),
			URL:     url.String(),
			ModTime: chTime,
			Mode:    f.Mode(),
		})
	}

	// Test that sort=name returns correct listing.

	listing := Listing{Items: fileinfos} // this listing will be used for validation inside the tests

	tests := []struct {
		QueryURL       string
		SortBy         string
		OrderBy        string
		Limit          int
		shouldErr      bool
		expectedResult []FileInfo
	}{
		//test case 1: testing for default sort and  order and without the limit parameter, default sort is by name and the default order is ascending
		//without the limit query entire listing will be produced
		{"/?sort=name", "", "", -1, false, listing.Items},
		//test case 2: limit is set to 1, orderBy and sortBy is default
		{"/?limit=1&sort=name", "", "", 1, false, listing.Items[:1]},
		//test case 3 : if the listing request is bigger than total size of listing then it should return everything
		{"/?limit=100000000&sort=name", "", "", 100000000, false, listing.Items},
		//test case 4 : testing for negative limit
		{"/?limit=-1&sort=name", "", "", -1, false, listing.Items},
		//test case 5 : testing with limit set to -1 and order set to descending
		{"/?limit=-1&order=desc&sort=name", "", "desc", -1, false, listing.Items},
		//test case 6 : testing with limit set to 2 and order set to descending
		{"/?limit=2&order=desc&sort=name", "", "desc", 2, false, listing.Items},
		//test case 7 : testing with limit set to 3 and order set to descending
		{"/?limit=3&order=desc&sort=name", "", "desc", 3, false, listing.Items},
		//test case 8 : testing with limit set to 3 and order set to ascending
		{"/?limit=3&order=asc&sort=name", "", "asc", 3, false, listing.Items},
		//test case 9 : testing with limit set to 1111111 and order set to ascending
		{"/?limit=1111111&order=asc&sort=name", "", "asc", 1111111, false, listing.Items},
		//test case 10 : testing with limit set to default and order set to ascending and sorting by size
		{"/?order=asc&sort=size&sort=name", "size", "asc", -1, false, listing.Items},
		//test case 11 : testing with limit set to default and order set to ascending and sorting by last modified
		{"/?order=asc&sort=time&sort=name", "time", "asc", -1, false, listing.Items},
		//test case 12 : testing with limit set to 1 and order set to ascending and sorting by last modified
		{"/?order=asc&sort=time&limit=1&sort=name", "time", "asc", 1, false, listing.Items},
		//test case 13 : testing with limit set to -100 and order set to ascending and sorting by last modified
		{"/?order=asc&sort=time&limit=-100&sort=name", "time", "asc", -100, false, listing.Items},
		//test case 14 : testing with limit set to -100 and order set to ascending and sorting by size
		{"/?order=asc&sort=size&limit=-100&sort=name", "size", "asc", -100, false, listing.Items},
	}

	for i, test := range tests {
		var marsh []byte
		req, err := http.NewRequest("GET", "/photos"+test.QueryURL, nil)
		if err != nil && !test.shouldErr {
			t.Errorf("Test %d errored when making request, but it shouldn't have; got '%v'", i, err)
		}
		ctx := context.WithValue(req.Context(), httpserver.OriginalURLCtxKey, *req.URL)
		req = req.WithContext(ctx)

		req.Header.Set("Accept", "application/json")
		rec := httptest.NewRecorder()

		code, err := b.ServeHTTP(rec, req)
		if err == nil && test.shouldErr {
			t.Errorf("Test %d didn't error, but it should have", i)
		} else if err != nil && !test.shouldErr {
			t.Errorf("Test %d errored, but it shouldn't have; got '%v'", i, err)
		}
		if code != http.StatusOK {
			t.Fatalf("In test %d: Wrong status, expected %d, got %d", i, http.StatusOK, code)
		}
		if rec.HeaderMap.Get("Content-Type") != "application/json; charset=utf-8" {
			t.Fatalf("Expected Content type to be application/json; charset=utf-8, but got %s ", rec.HeaderMap.Get("Content-Type"))
		}

		actualJSONResponse := rec.Body.String()
		copyOfListing := listing
		if test.SortBy == "" {
			copyOfListing.Sort = "name"
		} else {
			copyOfListing.Sort = test.SortBy
		}
		if test.OrderBy == "" {
			copyOfListing.Order = "asc"
		} else {
			copyOfListing.Order = test.OrderBy
		}

		copyOfListing.applySort()

		limit := test.Limit
		if limit <= len(copyOfListing.Items) && limit > 0 {
			marsh, err = json.Marshal(copyOfListing.Items[:limit])
		} else { // if the 'limit' query is empty, or has the wrong value, list everything
			marsh, err = json.Marshal(copyOfListing.Items)
		}

		if err != nil {
			t.Fatalf("Unable to Marshal the listing ")
		}
		expectedJSON := string(marsh)

		if actualJSONResponse != expectedJSON {
			t.Errorf("JSON response doesn't match the expected for test number %d with sort=%s, order=%s\nExpected response %s\nActual response = %s\n",
				i+1, test.SortBy, test.OrderBy, expectedJSON, actualJSONResponse)
		}
	}
}

// "sort" package has "IsSorted" function, but no "IsReversed";
func isReversed(data sort.Interface) bool {
	n := data.Len()
	for i := n - 1; i > 0; i-- {
		if !data.Less(i, i-1) {
			return false
		}
	}
	return true
}

func TestBrowseRedirect(t *testing.T) {
	testCases := []struct {
		url        string
		statusCode int
		returnCode int
		location   string
	}{
		{
			"http://www.example.com/photos",
			http.StatusMovedPermanently,
			http.StatusMovedPermanently,
			"http://www.example.com/photos/",
		},
		{
			"/photos",
			http.StatusMovedPermanently,
			http.StatusMovedPermanently,
			"/photos/",
		},
	}

	for i, tc := range testCases {
		b := Browse{
			Next: httpserver.HandlerFunc(func(w http.ResponseWriter, r *http.Request) (int, error) {
				t.Fatalf("Test %d - Next shouldn't be called", i)
				return 0, nil
			}),
			Configs: []Config{
				{
					PathScope: "/photos",
					Fs: staticfiles.FileServer{
						Root: http.Dir("./testdata"),
					},
				},
			},
		}

		req, err := http.NewRequest("GET", tc.url, nil)
		if err != nil {
			t.Fatalf("Test %d - could not create HTTP request: %v", i, err)
		}
		ctx := context.WithValue(req.Context(), httpserver.OriginalURLCtxKey, *req.URL)
		req = req.WithContext(ctx)

		rec := httptest.NewRecorder()

		returnCode, _ := b.ServeHTTP(rec, req)
		if returnCode != tc.returnCode {
			t.Fatalf("Test %d - wrong return code, expected %d, got %d",
				i, tc.returnCode, returnCode)
		}

		if got := rec.Code; got != tc.statusCode {
			t.Errorf("Test %d - wrong status, expected %d, got %d",
				i, tc.statusCode, got)
		}

		if got := rec.Header().Get("Location"); got != tc.location {
			t.Errorf("Test %d - wrong Location header, expected %s, got %s",
				i, tc.location, got)
		}
	}
}

func TestDirSymlink(t *testing.T) {
	if runtime.GOOS == "windows" {
		// Windows support for symlinks is limited, and we had a hard time getting
		// all these tests to pass with the permissions of CI; so just skip them
		fmt.Println("Skipping browse symlink tests on Windows...")
		return
	}

	testCases := []struct {
		source       string
		target       string
		pathScope    string
		url          string
		expectedName string
		expectedURL  string
	}{
		// test case can expect a directory "dir" and a symlink to it called "symlink"

		{"dir", "$TMP/rel_symlink_to_dir", "/", "/",
			"rel_symlink_to_dir", "./rel_symlink_to_dir/"},
		{"$TMP/dir", "$TMP/abs_symlink_to_dir", "/", "/",
			"abs_symlink_to_dir", "./abs_symlink_to_dir/"},

		{"../../dir", "$TMP/sub/dir/rel_symlink_to_dir", "/", "/sub/dir/",
			"rel_symlink_to_dir", "./rel_symlink_to_dir/"},
		{"$TMP/dir", "$TMP/sub/dir/abs_symlink_to_dir", "/", "/sub/dir/",
			"abs_symlink_to_dir", "./abs_symlink_to_dir/"},

		{"../../dir", "$TMP/with/scope/rel_symlink_to_dir", "/with/scope", "/with/scope/",
			"rel_symlink_to_dir", "./rel_symlink_to_dir/"},
		{"$TMP/dir", "$TMP/with/scope/abs_symlink_to_dir", "/with/scope", "/with/scope/",
			"abs_symlink_to_dir", "./abs_symlink_to_dir/"},

		{"../../../../dir", "$TMP/with/scope/sub/dir/rel_symlink_to_dir", "/with/scope", "/with/scope/sub/dir/",
			"rel_symlink_to_dir", "./rel_symlink_to_dir/"},
		{"$TMP/dir", "$TMP/with/scope/sub/dir/abs_symlink_to_dir", "/with/scope", "/with/scope/sub/dir/",
			"abs_symlink_to_dir", "./abs_symlink_to_dir/"},

		{"symlink", "$TMP/rel_symlink_to_symlink", "/", "/",
			"rel_symlink_to_symlink", "./rel_symlink_to_symlink/"},
		{"$TMP/symlink", "$TMP/abs_symlink_to_symlink", "/", "/",
			"abs_symlink_to_symlink", "./abs_symlink_to_symlink/"},

		{"../../symlink", "$TMP/sub/dir/rel_symlink_to_symlink", "/", "/sub/dir/",
			"rel_symlink_to_symlink", "./rel_symlink_to_symlink/"},
		{"$TMP/symlink", "$TMP/sub/dir/abs_symlink_to_symlink", "/", "/sub/dir/",
			"abs_symlink_to_symlink", "./abs_symlink_to_symlink/"},

		{"../../symlink", "$TMP/with/scope/rel_symlink_to_symlink", "/with/scope", "/with/scope/",
			"rel_symlink_to_symlink", "./rel_symlink_to_symlink/"},
		{"$TMP/symlink", "$TMP/with/scope/abs_symlink_to_symlink", "/with/scope", "/with/scope/",
			"abs_symlink_to_symlink", "./abs_symlink_to_symlink/"},

		{"../../../../symlink", "$TMP/with/scope/sub/dir/rel_symlink_to_symlink", "/with/scope", "/with/scope/sub/dir/",
			"rel_symlink_to_symlink", "./rel_symlink_to_symlink/"},
		{"$TMP/symlink", "$TMP/with/scope/sub/dir/abs_symlink_to_symlink", "/with/scope", "/with/scope/sub/dir/",
			"abs_symlink_to_symlink", "./abs_symlink_to_symlink/"},
	}

	for i, tc := range testCases {
		func() {
			tmpdir, err := ioutil.TempDir("", testDirPrefix)
			if err != nil {
				t.Fatalf("failed to create test directory: %v", err)
			}
			defer os.RemoveAll(tmpdir)

			if err := os.MkdirAll(filepath.Join(tmpdir, "dir"), 0755); err != nil {
				t.Fatalf("failed to create test dir 'dir': %v", err)
			}
			if err := os.Symlink("dir", filepath.Join(tmpdir, "symlink")); err != nil {
				t.Fatalf("failed to create test symlink 'symlink': %v", err)
			}

			sourceResolved := strings.Replace(tc.source, "$TMP", tmpdir, -1)
			targetResolved := strings.Replace(tc.target, "$TMP", tmpdir, -1)

			if err := os.MkdirAll(filepath.Dir(sourceResolved), 0755); err != nil {
				t.Fatalf("failed to create source symlink dir: %v", err)
			}
			if err := os.MkdirAll(filepath.Dir(targetResolved), 0755); err != nil {
				t.Fatalf("failed to create target symlink dir: %v", err)
			}
			if err := os.Symlink(sourceResolved, targetResolved); err != nil {
				t.Fatalf("failed to create test symlink: %v", err)
			}

			b := Browse{
				Next: httpserver.HandlerFunc(func(w http.ResponseWriter, r *http.Request) (int, error) {
					t.Fatalf("Test %d - Next shouldn't be called", i)
					return 0, nil
				}),
				Configs: []Config{
					{
						PathScope: tc.pathScope,
						Fs: staticfiles.FileServer{
							Root: http.Dir(tmpdir),
						},
					},
				},
			}

			req, err := http.NewRequest("GET", tc.url, nil)
			req.Header.Add("Accept", "application/json")
			if err != nil {
				t.Fatalf("Test %d - could not create HTTP request: %v", i, err)
			}

			rec := httptest.NewRecorder()

			returnCode, _ := b.ServeHTTP(rec, req)
			if returnCode != http.StatusOK {
				t.Fatalf("Test %d - wrong return code, expected %d, got %d",
					i, http.StatusOK, returnCode)
			}

			type jsonEntry struct {
				Name      string
				IsDir     bool
				IsSymlink bool
				URL       string
			}
			var entries []jsonEntry
			if err := json.Unmarshal(rec.Body.Bytes(), &entries); err != nil {
				t.Fatalf("Test %d - failed to parse json: %v", i, err)
			}

			found := false
			for _, e := range entries {
				if e.Name != tc.expectedName {
					continue
				}
				found = true
				if !e.IsDir {
					t.Errorf("Test %d - expected to be a dir, got %v", i, e.IsDir)
				}
				if !e.IsSymlink {
					t.Errorf("Test %d - expected to be a symlink, got %v", i, e.IsSymlink)
				}
				if e.URL != tc.expectedURL {
					t.Errorf("Test %d - wrong URL, expected %v, got %v", i, tc.expectedURL, e.URL)
				}
			}
			if !found {
				t.Errorf("Test %d - failed, could not find name %v", i, tc.expectedName)
			}
		}()
	}
}