// Copyright 2019 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 hugolib

import (
	"fmt"
	"math/rand"
	"path"
	"path/filepath"
	"strconv"
	"strings"
	"testing"

	"github.com/gohugoio/hugo/resources/page"

	qt "github.com/frankban/quicktest"
)

type siteBenchmarkTestcase struct {
	name   string
	create func(t testing.TB) *sitesBuilder
	check  func(s *sitesBuilder)
}

func getBenchmarkSiteDeepContent(b testing.TB) *sitesBuilder {
	pageContent := func(size int) string {
		return getBenchmarkTestDataPageContentForMarkdown(size, false, "", benchmarkMarkdownSnippets)
	}

	sb := newTestSitesBuilder(b).WithConfigFile("toml", `
baseURL = "https://example.com"

[languages]
[languages.en]
weight=1
contentDir="content/en"
[languages.fr]
weight=2
contentDir="content/fr"
[languages.no]
weight=3
contentDir="content/no"
[languages.sv]
weight=4
contentDir="content/sv"
			
`)

	createContent := func(dir, name string) {
		sb.WithContent(filepath.Join("content", dir, name), pageContent(1))
	}

	createBundledFiles := func(dir string) {
		sb.WithContent(filepath.Join("content", dir, "data.json"), `{ "hello": "world" }`)
		for i := 1; i <= 3; i++ {
			sb.WithContent(filepath.Join("content", dir, fmt.Sprintf("page%d.md", i)), pageContent(1))
		}
	}

	for _, lang := range []string{"en", "fr", "no", "sv"} {
		for level := 1; level <= 5; level++ {
			sectionDir := path.Join(lang, strings.Repeat("section/", level))
			createContent(sectionDir, "_index.md")
			createBundledFiles(sectionDir)
			for i := 1; i <= 3; i++ {
				leafBundleDir := path.Join(sectionDir, fmt.Sprintf("bundle%d", i))
				createContent(leafBundleDir, "index.md")
				createBundledFiles(path.Join(leafBundleDir, "assets1"))
				createBundledFiles(path.Join(leafBundleDir, "assets1", "assets2"))
			}
		}
	}

	return sb
}

func getBenchmarkTestDataPageContentForMarkdown(size int, toml bool, category, markdown string) string {
	base := `---
title: "My Page"
%s
---

My page content.
`
	if toml {
		base = `+++
title="My Page"
%s
+++

My page content.
`
	}

	var categoryKey string
	if category != "" {
		categoryKey = fmt.Sprintf("categories: [%s]", category)
		if toml {
			categoryKey = fmt.Sprintf("categories=[%s]", category)
		}
	}
	base = fmt.Sprintf(base, categoryKey)

	return base + strings.Repeat(markdown, size)
}

const benchmarkMarkdownSnippets = `

## Links


This is [an example](http://example.com/ "Title") inline link.

[This link](http://example.net/) has no title attribute.

This is [Relative](/all-is-relative).

See my [About](/about/) page for details. 
`

func getBenchmarkSiteTestCases() []siteBenchmarkTestcase {
	pageContentWithCategory := func(size int, category string) string {
		return getBenchmarkTestDataPageContentForMarkdown(size, false, category, benchmarkMarkdownSnippets)
	}

	pageContent := func(size int) string {
		return getBenchmarkTestDataPageContentForMarkdown(size, false, "", benchmarkMarkdownSnippets)
	}

	config := `
baseURL = "https://example.com"
`

	benchmarks := []siteBenchmarkTestcase{
		{
			"Bundle with image", func(b testing.TB) *sitesBuilder {
				sb := newTestSitesBuilder(b).WithConfigFile("toml", config)
				sb.WithContent("content/blog/mybundle/index.md", pageContent(1))
				sb.WithSunset("content/blog/mybundle/sunset1.jpg")

				return sb
			},
			func(s *sitesBuilder) {
				s.AssertFileContent("public/blog/mybundle/index.html", "/blog/mybundle/sunset1.jpg")
				s.CheckExists("public/blog/mybundle/sunset1.jpg")
			},
		},
		{
			"Bundle with JSON file", func(b testing.TB) *sitesBuilder {
				sb := newTestSitesBuilder(b).WithConfigFile("toml", config)
				sb.WithContent("content/blog/mybundle/index.md", pageContent(1))
				sb.WithContent("content/blog/mybundle/mydata.json", `{ "hello": "world" }`)

				return sb
			},
			func(s *sitesBuilder) {
				s.AssertFileContent("public/blog/mybundle/index.html", "Resources: application/json: /blog/mybundle/mydata.json")
				s.CheckExists("public/blog/mybundle/mydata.json")
			},
		},
		{
			"Tags and categories", func(b testing.TB) *sitesBuilder {
				sb := newTestSitesBuilder(b).WithConfigFile("toml", `
title = "Tags and Cats"
baseURL = "https://example.com"

`)

				const pageTemplate = `
---
title: "Some tags and cats"
categories: ["caGR", "cbGR"]
tags: ["taGR", "tbGR"]
---

Some content.
			
`
				for i := 1; i <= 100; i++ {
					content := strings.Replace(pageTemplate, "GR", strconv.Itoa(i/3), -1)
					sb.WithContent(fmt.Sprintf("content/page%d.md", i), content)
				}

				return sb
			},
			func(s *sitesBuilder) {
				s.AssertFileContent("public/page3/index.html", "/page3/|Permalink: https://example.com/page3/")
				s.AssertFileContent("public/tags/ta3/index.html", "a3")
			},
		},
		{
			"Canonify URLs", func(b testing.TB) *sitesBuilder {
				sb := newTestSitesBuilder(b).WithConfigFile("toml", `
title = "Canon"
baseURL = "https://example.com"
canonifyURLs = true

`)
				for i := 1; i <= 100; i++ {
					sb.WithContent(fmt.Sprintf("content/page%d.md", i), pageContent(i))
				}

				return sb
			},
			func(s *sitesBuilder) {
				s.AssertFileContent("public/page8/index.html", "https://example.com/about/")
			},
		},

		{
			"Deep content tree", func(b testing.TB) *sitesBuilder {
				return getBenchmarkSiteDeepContent(b)
			},
			func(s *sitesBuilder) {
				s.CheckExists("public/blog/mybundle/index.html")
				s.Assert(len(s.H.Sites), qt.Equals, 4)
				s.Assert(len(s.H.Sites[0].RegularPages()), qt.Equals, len(s.H.Sites[1].RegularPages()))
				s.Assert(len(s.H.Sites[0].RegularPages()), qt.Equals, 30)
			},
		},
		{
			"TOML front matter", func(b testing.TB) *sitesBuilder {
				sb := newTestSitesBuilder(b).WithConfigFile("toml", config)
				for i := 1; i <= 200; i++ {
					content := getBenchmarkTestDataPageContentForMarkdown(1, true, "\"a\", \"b\", \"c\"", benchmarkMarkdownSnippets)
					sb.WithContent(fmt.Sprintf("content/p%d.md", i), content)
				}

				return sb
			},
			func(s *sitesBuilder) {
			},
		},
		{
			"Many HTML templates", func(b testing.TB) *sitesBuilder {
				pageTemplateTemplate := `
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>{{ if not .IsPage }}{{ .Title }}{{ else }}{{ printf "Site: %s" site.Title }}{{ end }}</title>
    <style>
     body {
       margin: 3rem;
     }
    </style>
  </head>
  <body>
    <div class="page">{{ .Content }}</div>
    <ul>
    {{ with .Pages }}
    {{ range . }}
    <li><a href="{{ .RelPermalink }}">{{ .LinkTitle }} {{ if not .IsNode }} (Page){{ end }}</a></li>
    {{ end }}
    {{ end }}
    </ul>
  </body>
</html>
`

				sb := newTestSitesBuilder(b).WithConfigFile("toml", `
baseURL = "https://example.com"

[languages]
[languages.en]
weight=1
contentDir="content/en"
[languages.fr]
weight=2
contentDir="content/fr"
[languages.no]
weight=3
contentDir="content/no"
[languages.sv]
weight=4
contentDir="content/sv"
			
`)

				createContent := func(dir, name string) {
					sb.WithContent(filepath.Join("content", dir, name), pageContent(1))
				}

				for _, lang := range []string{"en", "fr", "no", "sv"} {
					sb.WithTemplatesAdded(fmt.Sprintf("_default/single.%s.html", lang), pageTemplateTemplate)
					sb.WithTemplatesAdded(fmt.Sprintf("_default/list.%s.html", lang), pageTemplateTemplate)

					for level := 1; level <= 5; level++ {
						sectionDir := path.Join(lang, strings.Repeat("section/", level))
						createContent(sectionDir, "_index.md")
						for i := 1; i <= 3; i++ {
							leafBundleDir := path.Join(sectionDir, fmt.Sprintf("bundle%d", i))
							createContent(leafBundleDir, "index.md")
						}
					}
				}

				return sb
			},
			func(s *sitesBuilder) {
				s.CheckExists("public/blog/mybundle/index.html")
				s.Assert(len(s.H.Sites), qt.Equals, 4)
				s.Assert(len(s.H.Sites[0].RegularPages()), qt.Equals, len(s.H.Sites[1].RegularPages()))
				s.Assert(len(s.H.Sites[0].RegularPages()), qt.Equals, 15)
			},
		},
		{
			"Page collections", func(b testing.TB) *sitesBuilder {
				pageTemplateTemplate := `
{{ if .IsNode }}
{{ len .Paginator.Pages }}
{{ end }}
{{ len .Sections }}
{{ len .Pages }}
{{ len .RegularPages }}
{{ len .Resources }}
{{ len site.RegularPages }}
{{ len site.Pages }}
{{ with .NextInSection }}Next in section: {{ .RelPermalink }}{{ end }}
{{ with .PrevInSection }}Prev in section: {{ .RelPermalink }}{{ end }}
{{ with .Next }}Next: {{ .RelPermalink }}{{ end }}
{{ with .Prev }}Prev: {{ .RelPermalink }}{{ end }}
`

				sb := newTestSitesBuilder(b).WithConfigFile("toml", `
baseURL = "https://example.com"

[languages]
[languages.en]
weight=1
contentDir="content/en"
[languages.fr]
weight=2
contentDir="content/fr"
[languages.no]
weight=3
contentDir="content/no"
[languages.sv]
weight=4
contentDir="content/sv"
			
`)

				sb.WithTemplates("index.html", pageTemplateTemplate)
				sb.WithTemplates("_default/single.html", pageTemplateTemplate)
				sb.WithTemplates("_default/list.html", pageTemplateTemplate)

				r := rand.New(rand.NewSource(99))

				createContent := func(dir, name string) {
					var content string
					if strings.Contains(name, "_index") {
						content = pageContent(1)
					} else {
						content = pageContentWithCategory(1, fmt.Sprintf("category%d", r.Intn(5)+1))
					}

					sb.WithContent(filepath.Join("content", dir, name), content)
				}

				createBundledFiles := func(dir string) {
					sb.WithContent(filepath.Join("content", dir, "data.json"), `{ "hello": "world" }`)
					for i := 1; i <= 3; i++ {
						sb.WithContent(filepath.Join("content", dir, fmt.Sprintf("page%d.md", i)), pageContent(1))
					}
				}

				for _, lang := range []string{"en", "fr", "no", "sv"} {
					for level := 1; level <= r.Intn(5)+1; level++ {
						sectionDir := path.Join(lang, strings.Repeat("section/", level))
						createContent(sectionDir, "_index.md")
						createBundledFiles(sectionDir)
						for i := 1; i <= r.Intn(20)+1; i++ {
							leafBundleDir := path.Join(sectionDir, fmt.Sprintf("bundle%d", i))
							createContent(leafBundleDir, "index.md")
							createBundledFiles(path.Join(leafBundleDir, "assets1"))
							createBundledFiles(path.Join(leafBundleDir, "assets1", "assets2"))
						}
					}
				}

				return sb
			},
			func(s *sitesBuilder) {
				s.CheckExists("public/blog/mybundle/index.html")
				s.Assert(len(s.H.Sites), qt.Equals, 4)
				s.Assert(len(s.H.Sites[0].RegularPages()), qt.Equals, 26)
			},
		},
		{
			"List terms", func(b testing.TB) *sitesBuilder {
				pageTemplateTemplate := `
<ul>
    {{ range (.GetTerms "categories") }}
        <li><a href="{{ .Permalink }}">{{ .LinkTitle }}</a></li>
   {{ end }}
</ul>
`

				sb := newTestSitesBuilder(b).WithConfigFile("toml", `
baseURL = "https://example.com"
`)

				sb.WithTemplates("_default/single.html", pageTemplateTemplate)
				sb.WithTemplates("_default/list.html", "List")

				r := rand.New(rand.NewSource(99))

				createContent := func(dir, name string) {
					var content string
					if strings.Contains(name, "_index") {
						// Empty
					} else {
						content = pageContentWithCategory(1, fmt.Sprintf("category%d", r.Intn(5)+1))
					}
					sb.WithContent(filepath.Join("content", dir, name), content)
				}

				for level := 1; level <= r.Intn(5)+1; level++ {
					sectionDir := path.Join(strings.Repeat("section/", level))
					createContent(sectionDir, "_index.md")
					for i := 1; i <= r.Intn(33); i++ {
						leafBundleDir := path.Join(sectionDir, fmt.Sprintf("bundle%d", i))
						createContent(leafBundleDir, "index.md")
					}
				}

				return sb
			},
			func(s *sitesBuilder) {
				s.AssertFileContent("public/section/bundle8/index.html", `<a href="https://example.com/categories/category1/">`)
				s.Assert(len(s.H.Sites), qt.Equals, 1)
				s.Assert(len(s.H.Sites[0].RegularPages()), qt.Equals, 35)
			},
		},
	}

	return benchmarks
}

// Run the benchmarks below as tests. Mostly useful when adding new benchmark
// variants.
func TestBenchmarkSite(b *testing.T) {
	benchmarks := getBenchmarkSiteTestCases()
	for _, bm := range benchmarks {
		if bm.name != "Deep content tree" {
			continue
		}
		b.Run(bm.name, func(b *testing.T) {
			s := bm.create(b)

			err := s.BuildE(BuildCfg{})
			if err != nil {
				b.Fatal(err)
			}
			bm.check(s)
		})
	}
}

func TestBenchmarkSiteDeepContentEdit(t *testing.T) {
	b := getBenchmarkSiteDeepContent(t).Running()
	b.Build(BuildCfg{})

	p := b.H.Sites[0].RegularPages()[12]

	b.EditFiles(p.File().Filename(), fmt.Sprintf(`---
title: %s
---

Edited!!`, p.Title()))

	counters := &buildCounters{}

	b.Build(BuildCfg{testCounters: counters})

	// We currently rebuild all the language versions of the same content file.
	// We could probably optimize that case, but it's not trivial.
	b.Assert(int(counters.contentRenderCounter.Load()), qt.Equals, 4)
	b.AssertFileContent("public"+p.RelPermalink()+"index.html", "Edited!!")
}

func BenchmarkSiteNew(b *testing.B) {
	rnd := rand.New(rand.NewSource(32))
	benchmarks := getBenchmarkSiteTestCases()
	for _, edit := range []bool{true, false} {
		for _, bm := range benchmarks {
			name := bm.name
			if edit {
				name = "Edit_" + name
			} else {
				name = "Regular_" + name
			}
			b.Run(name, func(b *testing.B) {
				sites := make([]*sitesBuilder, b.N)
				for i := 0; i < b.N; i++ {
					sites[i] = bm.create(b)
					if edit {
						sites[i].Running()
					}
				}

				b.ResetTimer()
				for i := 0; i < b.N; i++ {
					if edit {
						b.StopTimer()
					}
					s := sites[i]
					err := s.BuildE(BuildCfg{})
					if err != nil {
						b.Fatal(err)
					}
					bm.check(s)

					if edit {
						if edit {
							b.StartTimer()
						}
						// Edit a random page in a random language.
						pages := s.H.Sites[rnd.Intn(len(s.H.Sites))].Pages()
						var p page.Page
						count := 0
						for {
							count++
							if count > 100 {
								panic("infinite loop")
							}
							p = pages[rnd.Intn(len(pages))]
							if p.File() != nil {
								break
							}
						}

						s.EditFiles(p.File().Filename(), fmt.Sprintf(`---
title: %s
---

Edited!!`, p.Title()))

						err := s.BuildE(BuildCfg{})
						if err != nil {
							b.Fatal(err)
						}
					}
				}
			})
		}
	}
}