// Copyright 2023 The Hugo Authors. All rights reserved.
//
// 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 page

import (
	"fmt"
	"regexp"
	"strings"
	"sync"
	"testing"
	"time"

	qt "github.com/frankban/quicktest"
)

// testdataPermalinks is used by a couple of tests; the expandsTo content is
// subject to the data in simplePageJSON.
var testdataPermalinks = []struct {
	spec      string
	valid     bool
	expandsTo string
}{
	{":title", true, "spf13-vim-3.0-release-and-new-website"},
	{"/:year-:month-:title", true, "/2012-04-spf13-vim-3.0-release-and-new-website"},
	{"/:year/:yearday/:month/:monthname/:day/:weekday/:weekdayname/", true, "/2012/97/04/April/06/5/Friday/"}, // Dates
	{"/:section/", true, "/blue/"},                                  // Section
	{"/:title/", true, "/spf13-vim-3.0-release-and-new-website/"},   // Title
	{"/:slug/", true, "/the-slug/"},                                 // Slug
	{"/:slugorfilename/", true, "/the-slug/"},                       // Slug or filename
	{"/:filename/", true, "/test-page/"},                            // Filename
	{"/:06-:1-:2-:Monday", true, "/12-4-6-Friday"},                  // Dates with Go formatting
	{"/:2006_01_02_15_04_05.000", true, "/2012_04_06_03_01_59.000"}, // Complicated custom date format
	{"/:sections/", true, "/a/b/c/"},                                // Sections
	{"/:sections[last]/", true, "/c/"},                              // Sections
	{"/:sections[0]/:sections[last]/", true, "/a/c/"},               // Sections

	// Failures
	{"/blog/:fred", false, ""},
	{"/:year//:title", false, ""},
	{"/:TITLE", false, ""},      // case is not normalized
	{"/:2017", false, ""},       // invalid date format
	{"/:2006-01-02", false, ""}, // valid date format but invalid attribute name
}

func urlize(uri string) string {
	// This is just an approximation of the real urlize function.
	return strings.ToLower(strings.ReplaceAll(uri, " ", "-"))
}

func TestPermalinkExpansion(t *testing.T) {
	t.Parallel()

	c := qt.New(t)

	page := newTestPageWithFile("/test-page/index.md")
	page.title = "Spf13 Vim 3.0 Release and new website"
	d, _ := time.Parse("2006-01-02 15:04:05", "2012-04-06 03:01:59")
	page.date = d
	page.section = "blue"
	page.slug = "The Slug"

	for _, item := range testdataPermalinks {
		if !item.valid {
			continue
		}

		specNameCleaner := regexp.MustCompile(`[\:\/\[\]]`)
		name := specNameCleaner.ReplaceAllString(item.spec, "")

		c.Run(name, func(c *qt.C) {
			patterns := map[string]string{
				"posts": item.spec,
			}
			expander, err := NewPermalinkExpander(urlize, patterns)
			c.Assert(err, qt.IsNil)
			expanded, err := expander.Expand("posts", page)
			c.Assert(err, qt.IsNil)
			c.Assert(expanded, qt.Equals, item.expandsTo)
		})

	}
}

func TestPermalinkExpansionMultiSection(t *testing.T) {
	t.Parallel()

	c := qt.New(t)

	page := newTestPage()
	page.title = "Page Title"
	d, _ := time.Parse("2006-01-02", "2012-04-06")
	page.date = d
	page.section = "blue"
	page.slug = "The Slug"

	page_slug_fallback := newTestPageWithFile("/page-filename/index.md")
	page_slug_fallback.title = "Page Title"

	permalinksConfig := map[string]string{
		"posts":   "/:slug",
		"blog":    "/:section/:year",
		"recipes": "/:slugorfilename",
	}
	expander, err := NewPermalinkExpander(urlize, permalinksConfig)
	c.Assert(err, qt.IsNil)

	expanded, err := expander.Expand("posts", page)
	c.Assert(err, qt.IsNil)
	c.Assert(expanded, qt.Equals, "/the-slug")

	expanded, err = expander.Expand("blog", page)
	c.Assert(err, qt.IsNil)
	c.Assert(expanded, qt.Equals, "/blue/2012")

	expanded, err = expander.Expand("posts", page_slug_fallback)
	c.Assert(err, qt.IsNil)
	c.Assert(expanded, qt.Equals, "/page-title")

	expanded, err = expander.Expand("recipes", page_slug_fallback)
	c.Assert(err, qt.IsNil)
	c.Assert(expanded, qt.Equals, "/page-filename")
}

func TestPermalinkExpansionConcurrent(t *testing.T) {
	t.Parallel()

	c := qt.New(t)

	permalinksConfig := map[string]string{
		"posts": "/:slug/",
	}

	expander, err := NewPermalinkExpander(urlize, permalinksConfig)
	c.Assert(err, qt.IsNil)

	var wg sync.WaitGroup

	for i := 1; i < 20; i++ {
		wg.Add(1)
		go func(i int) {
			defer wg.Done()
			page := newTestPage()
			for j := 1; j < 20; j++ {
				page.slug = fmt.Sprintf("slug%d", i+j)
				expanded, err := expander.Expand("posts", page)
				c.Assert(err, qt.IsNil)
				c.Assert(expanded, qt.Equals, fmt.Sprintf("/%s/", page.slug))
			}
		}(i)
	}

	wg.Wait()
}

func TestPermalinkExpansionSliceSyntax(t *testing.T) {
	t.Parallel()

	c := qt.New(t)
	exp, err := NewPermalinkExpander(urlize, nil)
	c.Assert(err, qt.IsNil)
	slice := []string{"a", "b", "c", "d"}
	fn := func(s string) []string {
		return exp.toSliceFunc(s)(slice)
	}

	c.Run("Basic", func(c *qt.C) {
		c.Assert(fn("[1:3]"), qt.DeepEquals, []string{"b", "c"})
		c.Assert(fn("[1:]"), qt.DeepEquals, []string{"b", "c", "d"})
		c.Assert(fn("[:2]"), qt.DeepEquals, []string{"a", "b"})
		c.Assert(fn("[0:2]"), qt.DeepEquals, []string{"a", "b"})
		c.Assert(fn("[:]"), qt.DeepEquals, []string{"a", "b", "c", "d"})
		c.Assert(fn(""), qt.DeepEquals, []string{"a", "b", "c", "d"})
		c.Assert(fn("[last]"), qt.DeepEquals, []string{"d"})
		c.Assert(fn("[:last]"), qt.DeepEquals, []string{"a", "b", "c"})

	})

	c.Run("Out of bounds", func(c *qt.C) {
		c.Assert(fn("[1:5]"), qt.DeepEquals, []string{"b", "c", "d"})
		c.Assert(fn("[-1:5]"), qt.DeepEquals, []string{"a", "b", "c", "d"})
		c.Assert(fn("[5:]"), qt.DeepEquals, []string{})
		c.Assert(fn("[5:]"), qt.DeepEquals, []string{})
		c.Assert(fn("[5:32]"), qt.DeepEquals, []string{})
		c.Assert(exp.toSliceFunc("[:1]")(nil), qt.DeepEquals, []string(nil))
		c.Assert(exp.toSliceFunc("[:1]")([]string{}), qt.DeepEquals, []string(nil))

		// These all return nil
		c.Assert(fn("[]"), qt.IsNil)
		c.Assert(fn("[1:}"), qt.IsNil)
		c.Assert(fn("foo"), qt.IsNil)

	})

}

func BenchmarkPermalinkExpand(b *testing.B) {
	page := newTestPage()
	page.title = "Hugo Rocks"
	d, _ := time.Parse("2006-01-02", "2019-02-28")
	page.date = d

	permalinksConfig := map[string]string{
		"posts": "/:year-:month-:title",
	}
	expander, err := NewPermalinkExpander(urlize, permalinksConfig)
	if err != nil {
		b.Fatal(err)
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		s, err := expander.Expand("posts", page)
		if err != nil {
			b.Fatal(err)
		}
		if s != "/2019-02-hugo-rocks" {
			b.Fatal(s)
		}

	}
}
