hugo/hugolib/site.go

// 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"
	"html/template"
	"io"
	"log"
	"mime"
	"net/url"
	"os"
	"path"
	"path/filepath"
	"sort"
	"strconv"
	"strings"
	"time"

	"github.com/gohugoio/hugo/resources"

	"github.com/gohugoio/hugo/identity"

	"github.com/gohugoio/hugo/markup/converter/hooks"

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

	"github.com/gohugoio/hugo/markup/converter"

	"github.com/gohugoio/hugo/hugofs/files"

	"github.com/gohugoio/hugo/common/maps"

	"github.com/pkg/errors"

	"github.com/gohugoio/hugo/common/text"

	"github.com/gohugoio/hugo/common/hugo"
	"github.com/gohugoio/hugo/publisher"
	_errors "github.com/pkg/errors"

	"github.com/gohugoio/hugo/langs"

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

	"github.com/gohugoio/hugo/config"
	"github.com/gohugoio/hugo/lazy"

	"github.com/gohugoio/hugo/media"

	"github.com/fsnotify/fsnotify"
	bp "github.com/gohugoio/hugo/bufferpool"
	"github.com/gohugoio/hugo/deps"
	"github.com/gohugoio/hugo/helpers"
	"github.com/gohugoio/hugo/navigation"
	"github.com/gohugoio/hugo/output"
	"github.com/gohugoio/hugo/related"
	"github.com/gohugoio/hugo/resources/page/pagemeta"
	"github.com/gohugoio/hugo/source"
	"github.com/gohugoio/hugo/tpl"

	"github.com/spf13/afero"
	"github.com/spf13/cast"
	"github.com/spf13/viper"
)

// Site contains all the information relevant for constructing a static
// site.  The basic flow of information is as follows:
//
// 1. A list of Files is parsed and then converted into Pages.
//
// 2. Pages contain sections (based on the file they were generated from),
//    aliases and slugs (included in a pages frontmatter) which are the
//    various targets that will get generated.  There will be canonical
//    listing.  The canonical path can be overruled based on a pattern.
//
// 3. Taxonomies are created via configuration and will present some aspect of
//    the final page and typically a perm url.
//
// 4. All Pages are passed through a template based on their desired
//    layout based on numerous different elements.
//
// 5. The entire collection of files is written to disk.
type Site struct {

	// The owning container. When multiple languages, there will be multiple
	// sites.
	h *HugoSites

	*PageCollections

	taxonomies TaxonomyList

	Sections Taxonomy
	Info     *SiteInfo

	language *langs.Language

	siteCfg siteConfigHolder

	disabledKinds map[string]bool

	enableInlineShortcodes bool

	// Output formats defined in site config per Page Kind, or some defaults
	// if not set.
	// Output formats defined in Page front matter will override these.
	outputFormats map[string]output.Formats

	// All the output formats and media types available for this site.
	// These values will be merged from the Hugo defaults, the site config and,
	// finally, the language settings.
	outputFormatsConfig output.Formats
	mediaTypesConfig    media.Types

	siteConfigConfig SiteConfig

	// How to handle page front matter.
	frontmatterHandler pagemeta.FrontMatterHandler

	// We render each site for all the relevant output formats in serial with
	// this rendering context pointing to the current one.
	rc *siteRenderingContext

	// The output formats that we need to render this site in. This slice
	// will be fixed once set.
	// This will be the union of Site.Pages' outputFormats.
	// This slice will be sorted.
	renderFormats output.Formats

	// Logger etc.
	*deps.Deps `json:"-"`

	// The func used to title case titles.
	titleFunc func(s string) string

	relatedDocsHandler *page.RelatedDocsHandler
	siteRefLinker

	publisher publisher.Publisher

	menus navigation.Menus

	// Shortcut to the home page. Note that this may be nil if
	// home page, for some odd reason, is disabled.
	home *pageState

	// The last modification date of this site.
	lastmod time.Time

	// Lazily loaded site dependencies
	init *siteInit
}

func (s *Site) Taxonomies() TaxonomyList {
	s.init.taxonomies.Do()
	return s.taxonomies
}

type taxonomiesConfig map[string]string

func (t taxonomiesConfig) Values() []viewName {
	var vals []viewName
	for k, v := range t {
		vals = append(vals, viewName{singular: k, plural: v})
	}
	sort.Slice(vals, func(i, j int) bool {
		return vals[i].plural < vals[j].plural
	})

	return vals
}

type siteConfigHolder struct {
	sitemap          config.Sitemap
	taxonomiesConfig taxonomiesConfig
	timeout          time.Duration
	hasCJKLanguage   bool
	enableEmoji      bool
}

// Lazily loaded site dependencies.
type siteInit struct {
	prevNext          *lazy.Init
	prevNextInSection *lazy.Init
	menus             *lazy.Init
	taxonomies        *lazy.Init
}

func (init *siteInit) Reset() {
	init.prevNext.Reset()
	init.prevNextInSection.Reset()
	init.menus.Reset()
	init.taxonomies.Reset()
}

func (s *Site) initInit(init *lazy.Init, pctx pageContext) bool {
	_, err := init.Do()
	if err != nil {
		s.h.FatalError(pctx.wrapError(err))
	}
	return err == nil
}

func (s *Site) prepareInits() {
	s.init = &siteInit{}

	var init lazy.Init

	s.init.prevNext = init.Branch(func() (interface{}, error) {
		regularPages := s.RegularPages()
		for i, p := range regularPages {
			np, ok := p.(nextPrevProvider)
			if !ok {
				continue
			}

			pos := np.getNextPrev()
			if pos == nil {
				continue
			}

			pos.nextPage = nil
			pos.prevPage = nil

			if i > 0 {
				pos.nextPage = regularPages[i-1]
			}

			if i < len(regularPages)-1 {
				pos.prevPage = regularPages[i+1]
			}
		}
		return nil, nil
	})

	s.init.prevNextInSection = init.Branch(func() (interface{}, error) {

		var sections page.Pages
		s.home.treeRef.m.collectSectionsRecursiveIncludingSelf(pageMapQuery{Prefix: s.home.treeRef.key}, func(n *contentNode) {
			sections = append(sections, n.p)
		})

		setNextPrev := func(pas page.Pages) {
			for i, p := range pas {
				np, ok := p.(nextPrevInSectionProvider)
				if !ok {
					continue
				}

				pos := np.getNextPrevInSection()
				if pos == nil {
					continue
				}

				pos.nextPage = nil
				pos.prevPage = nil

				if i > 0 {
					pos.nextPage = pas[i-1]
				}

				if i < len(pas)-1 {
					pos.prevPage = pas[i+1]
				}
			}
		}

		for _, sect := range sections {
			treeRef := sect.(treeRefProvider).getTreeRef()

			var pas page.Pages
			treeRef.m.collectPages(pageMapQuery{Prefix: treeRef.key + cmBranchSeparator}, func(c *contentNode) {
				pas = append(pas, c.p)
			})
			page.SortByDefault(pas)

			setNextPrev(pas)
		}

		// The root section only goes one level down.
		treeRef := s.home.getTreeRef()

		var pas page.Pages
		treeRef.m.collectPages(pageMapQuery{Prefix: treeRef.key + cmBranchSeparator}, func(c *contentNode) {
			pas = append(pas, c.p)
		})
		page.SortByDefault(pas)

		setNextPrev(pas)

		return nil, nil
	})

	s.init.menus = init.Branch(func() (interface{}, error) {
		s.assembleMenus()
		return nil, nil
	})

	s.init.taxonomies = init.Branch(func() (interface{}, error) {
		err := s.pageMap.assembleTaxonomies()
		return nil, err
	})

}

type siteRenderingContext struct {
	output.Format
}

func (s *Site) Menus() navigation.Menus {
	s.init.menus.Do()
	return s.menus
}

func (s *Site) initRenderFormats() {
	formatSet := make(map[string]bool)
	formats := output.Formats{}
	s.pageMap.pageTrees.WalkRenderable(func(s string, n *contentNode) bool {
		for _, f := range n.p.m.configuredOutputFormats {
			if !formatSet[f.Name] {
				formats = append(formats, f)
				formatSet[f.Name] = true
			}
		}
		return false
	})

	// Add the per kind configured output formats
	for _, kind := range allKindsInPages {
		if siteFormats, found := s.outputFormats[kind]; found {
			for _, f := range siteFormats {
				if !formatSet[f.Name] {
					formats = append(formats, f)
					formatSet[f.Name] = true
				}
			}
		}
	}

	sort.Sort(formats)
	s.renderFormats = formats
}

func (s *Site) GetRelatedDocsHandler() *page.RelatedDocsHandler {
	return s.relatedDocsHandler
}

func (s *Site) Language() *langs.Language {
	return s.language
}

func (s *Site) isEnabled(kind string) bool {
	if kind == kindUnknown {
		panic("Unknown kind")
	}
	return !s.disabledKinds[kind]
}

// reset returns a new Site prepared for rebuild.
func (s *Site) reset() *Site {
	return &Site{Deps: s.Deps,
		disabledKinds:          s.disabledKinds,
		titleFunc:              s.titleFunc,
		relatedDocsHandler:     s.relatedDocsHandler.Clone(),
		siteRefLinker:          s.siteRefLinker,
		outputFormats:          s.outputFormats,
		rc:                     s.rc,
		outputFormatsConfig:    s.outputFormatsConfig,
		frontmatterHandler:     s.frontmatterHandler,
		mediaTypesConfig:       s.mediaTypesConfig,
		language:               s.language,
		h:                      s.h,
		publisher:              s.publisher,
		siteConfigConfig:       s.siteConfigConfig,
		enableInlineShortcodes: s.enableInlineShortcodes,
		init:                   s.init,
		PageCollections:        s.PageCollections,
		siteCfg:                s.siteCfg,
	}

}

// newSite creates a new site with the given configuration.
func newSite(cfg deps.DepsCfg) (*Site, error) {
	if cfg.Language == nil {
		cfg.Language = langs.NewDefaultLanguage(cfg.Cfg)
	}

	disabledKinds := make(map[string]bool)
	for _, disabled := range cast.ToStringSlice(cfg.Language.Get("disableKinds")) {
		disabledKinds[disabled] = true
	}

	var (
		mediaTypesConfig    []map[string]interface{}
		outputFormatsConfig []map[string]interface{}

		siteOutputFormatsConfig output.Formats
		siteMediaTypesConfig    media.Types
		err                     error
	)

	// Add language last, if set, so it gets precedence.
	for _, cfg := range []config.Provider{cfg.Cfg, cfg.Language} {
		if cfg.IsSet("mediaTypes") {
			mediaTypesConfig = append(mediaTypesConfig, cfg.GetStringMap("mediaTypes"))
		}
		if cfg.IsSet("outputFormats") {
			outputFormatsConfig = append(outputFormatsConfig, cfg.GetStringMap("outputFormats"))
		}
	}

	siteMediaTypesConfig, err = media.DecodeTypes(mediaTypesConfig...)
	if err != nil {
		return nil, err
	}

	siteOutputFormatsConfig, err = output.DecodeFormats(siteMediaTypesConfig, outputFormatsConfig...)
	if err != nil {
		return nil, err
	}

	rssDisabled := disabledKinds[kindRSS]
	if rssDisabled {
		// Legacy
		tmp := siteOutputFormatsConfig[:0]
		for _, x := range siteOutputFormatsConfig {
			if !strings.EqualFold(x.Name, "rss") {
				tmp = append(tmp, x)
			}
		}
		siteOutputFormatsConfig = tmp
	}

	outputFormats, err := createSiteOutputFormats(siteOutputFormatsConfig, cfg.Language, rssDisabled)
	if err != nil {
		return nil, err
	}

	taxonomies := cfg.Language.GetStringMapString("taxonomies")

	var relatedContentConfig related.Config

	if cfg.Language.IsSet("related") {
		relatedContentConfig, err = related.DecodeConfig(cfg.Language.Get("related"))
		if err != nil {
			return nil, err
		}
	} else {
		relatedContentConfig = related.DefaultConfig
		if _, found := taxonomies["tag"]; found {
			relatedContentConfig.Add(related.IndexConfig{Name: "tags", Weight: 80})
		}
	}

	titleFunc := helpers.GetTitleFunc(cfg.Language.GetString("titleCaseStyle"))

	frontMatterHandler, err := pagemeta.NewFrontmatterHandler(cfg.Logger, cfg.Cfg)
	if err != nil {
		return nil, err
	}

	timeout := 30 * time.Second
	if cfg.Language.IsSet("timeout") {
		v := cfg.Language.Get("timeout")
		if n := cast.ToInt(v); n > 0 {
			timeout = time.Duration(n) * time.Millisecond
		} else {
			d, err := time.ParseDuration(cast.ToString(v))
			if err == nil {
				timeout = d
			}
		}
	}

	siteConfig := siteConfigHolder{
		sitemap:          config.DecodeSitemap(config.Sitemap{Priority: -1, Filename: "sitemap.xml"}, cfg.Language.GetStringMap("sitemap")),
		taxonomiesConfig: taxonomies,
		timeout:          timeout,
		hasCJKLanguage:   cfg.Language.GetBool("hasCJKLanguage"),
		enableEmoji:      cfg.Language.Cfg.GetBool("enableEmoji"),
	}

	s := &Site{

		language:      cfg.Language,
		disabledKinds: disabledKinds,

		outputFormats:       outputFormats,
		outputFormatsConfig: siteOutputFormatsConfig,
		mediaTypesConfig:    siteMediaTypesConfig,

		enableInlineShortcodes: cfg.Language.GetBool("enableInlineShortcodes"),
		siteCfg:                siteConfig,

		titleFunc: titleFunc,

		rc: &siteRenderingContext{output.HTMLFormat},

		frontmatterHandler: frontMatterHandler,
		relatedDocsHandler: page.NewRelatedDocsHandler(relatedContentConfig),
	}

	s.prepareInits()

	return s, nil

}

// NewSite creates a new site with the given dependency configuration.
// The site will have a template system loaded and ready to use.
// Note: This is mainly used in single site tests.
func NewSite(cfg deps.DepsCfg) (*Site, error) {
	s, err := newSite(cfg)
	if err != nil {
		return nil, err
	}

	if err = applyDeps(cfg, s); err != nil {
		return nil, err
	}

	return s, nil
}

// NewSiteDefaultLang creates a new site in the default language.
// The site will have a template system loaded and ready to use.
// Note: This is mainly used in single site tests.
// TODO(bep) test refactor -- remove
func NewSiteDefaultLang(withTemplate ...func(templ tpl.TemplateManager) error) (*Site, error) {
	v := viper.New()
	if err := loadDefaultSettingsFor(v); err != nil {
		return nil, err
	}
	return newSiteForLang(langs.NewDefaultLanguage(v), withTemplate...)
}

// NewEnglishSite creates a new site in English language.
// The site will have a template system loaded and ready to use.
// Note: This is mainly used in single site tests.
// TODO(bep) test refactor -- remove
func NewEnglishSite(withTemplate ...func(templ tpl.TemplateManager) error) (*Site, error) {
	v := viper.New()
	if err := loadDefaultSettingsFor(v); err != nil {
		return nil, err
	}
	return newSiteForLang(langs.NewLanguage("en", v), withTemplate...)
}

// newSiteForLang creates a new site in the given language.
func newSiteForLang(lang *langs.Language, withTemplate ...func(templ tpl.TemplateManager) error) (*Site, error) {
	withTemplates := func(templ tpl.TemplateManager) error {
		for _, wt := range withTemplate {
			if err := wt(templ); err != nil {
				return err
			}
		}
		return nil
	}

	cfg := deps.DepsCfg{WithTemplate: withTemplates, Cfg: lang}

	return NewSiteForCfg(cfg)

}

// NewSiteForCfg creates a new site for the given configuration.
// The site will have a template system loaded and ready to use.
// Note: This is mainly used in single site tests.
func NewSiteForCfg(cfg deps.DepsCfg) (*Site, error) {
	h, err := NewHugoSites(cfg)
	if err != nil {
		return nil, err
	}
	return h.Sites[0], nil

}

type SiteInfo struct {
	Authors page.AuthorList
	Social  SiteSocial

	hugoInfo     hugo.Info
	title        string
	RSSLink      string
	Author       map[string]interface{}
	LanguageCode string
	Copyright    string

	permalinks map[string]string

	LanguagePrefix string
	Languages      langs.Languages

	BuildDrafts bool

	canonifyURLs bool
	relativeURLs bool
	uglyURLs     func(p page.Page) bool

	owner                          *HugoSites
	s                              *Site
	language                       *langs.Language
	defaultContentLanguageInSubdir bool
	sectionPagesMenu               string
}

func (s *SiteInfo) Pages() page.Pages {
	return s.s.Pages()

}

func (s *SiteInfo) RegularPages() page.Pages {
	return s.s.RegularPages()

}

func (s *SiteInfo) AllPages() page.Pages {
	return s.s.AllPages()
}

func (s *SiteInfo) AllRegularPages() page.Pages {
	return s.s.AllRegularPages()
}

func (s *SiteInfo) Permalinks() map[string]string {
	// Remove in 0.61
	helpers.Deprecated(".Site.Permalinks", "", true)
	return s.permalinks
}

func (s *SiteInfo) LastChange() time.Time {
	return s.s.lastmod
}

func (s *SiteInfo) Title() string {
	return s.title
}

func (s *SiteInfo) Site() page.Site {
	return s
}

func (s *SiteInfo) Menus() navigation.Menus {
	return s.s.Menus()
}

// TODO(bep) type
func (s *SiteInfo) Taxonomies() interface{} {
	return s.s.Taxonomies()
}

func (s *SiteInfo) Params() maps.Params {
	return s.s.Language().Params()
}

func (s *SiteInfo) Data() map[string]interface{} {
	return s.s.h.Data()
}

func (s *SiteInfo) Language() *langs.Language {
	return s.language
}

func (s *SiteInfo) Config() SiteConfig {
	return s.s.siteConfigConfig
}

func (s *SiteInfo) Hugo() hugo.Info {
	return s.hugoInfo
}

// Sites is a convenience method to get all the Hugo sites/languages configured.
func (s *SiteInfo) Sites() page.Sites {
	return s.s.h.siteInfos()
}

func (s *SiteInfo) String() string {
	return fmt.Sprintf("Site(%q)", s.title)
}

func (s *SiteInfo) BaseURL() template.URL {
	return template.URL(s.s.PathSpec.BaseURL.String())
}

// ServerPort returns the port part of the BaseURL, 0 if none found.
func (s *SiteInfo) ServerPort() int {
	ps := s.s.PathSpec.BaseURL.URL().Port()
	if ps == "" {
		return 0
	}
	p, err := strconv.Atoi(ps)
	if err != nil {
		return 0
	}
	return p
}

// GoogleAnalytics is kept here for historic reasons.
func (s *SiteInfo) GoogleAnalytics() string {
	return s.Config().Services.GoogleAnalytics.ID

}

// DisqusShortname is kept here for historic reasons.
func (s *SiteInfo) DisqusShortname() string {
	return s.Config().Services.Disqus.Shortname
}

// SiteSocial is a place to put social details on a site level. These are the
// standard keys that themes will expect to have available, but can be
// expanded to any others on a per site basis
// github
// facebook
// facebook_admin
// twitter
// twitter_domain
// pinterest
// instagram
// youtube
// linkedin
type SiteSocial map[string]string

// Param is a convenience method to do lookups in SiteInfo's Params map.
//
// This method is also implemented on Page.
func (s *SiteInfo) Param(key interface{}) (interface{}, error) {
	return resource.Param(s, nil, key)
}

func (s *SiteInfo) IsMultiLingual() bool {
	return len(s.Languages) > 1
}

func (s *SiteInfo) IsServer() bool {
	return s.owner.running
}

type siteRefLinker struct {
	s *Site

	errorLogger *log.Logger
	notFoundURL string
}

func newSiteRefLinker(cfg config.Provider, s *Site) (siteRefLinker, error) {
	logger := s.Log.ERROR

	notFoundURL := cfg.GetString("refLinksNotFoundURL")
	errLevel := cfg.GetString("refLinksErrorLevel")
	if strings.EqualFold(errLevel, "warning") {
		logger = s.Log.WARN
	}
	return siteRefLinker{s: s, errorLogger: logger, notFoundURL: notFoundURL}, nil
}

func (s siteRefLinker) logNotFound(ref, what string, p page.Page, position text.Position) {
	if position.IsValid() {
		s.errorLogger.Printf("[%s] REF_NOT_FOUND: Ref %q: %s: %s", s.s.Lang(), ref, position.String(), what)
	} else if p == nil {
		s.errorLogger.Printf("[%s] REF_NOT_FOUND: Ref %q: %s", s.s.Lang(), ref, what)
	} else {
		s.errorLogger.Printf("[%s] REF_NOT_FOUND: Ref %q from page %q: %s", s.s.Lang(), ref, p.Path(), what)
	}
}

func (s *siteRefLinker) refLink(ref string, source interface{}, relative bool, outputFormat string) (string, error) {
	p, err := unwrapPage(source)
	if err != nil {
		return "", err
	}

	var refURL *url.URL

	ref = filepath.ToSlash(ref)

	refURL, err = url.Parse(ref)

	if err != nil {
		return s.notFoundURL, err
	}

	var target page.Page
	var link string

	if refURL.Path != "" {
		var err error
		target, err = s.s.getPageRef(p, refURL.Path)
		var pos text.Position
		if err != nil || target == nil {
			if p, ok := source.(text.Positioner); ok {
				pos = p.Position()
			}
		}

		if err != nil {
			s.logNotFound(refURL.Path, err.Error(), p, pos)
			return s.notFoundURL, nil
		}

		if target == nil {
			s.logNotFound(refURL.Path, "page not found", p, pos)
			return s.notFoundURL, nil
		}

		var permalinker Permalinker = target

		if outputFormat != "" {
			o := target.OutputFormats().Get(outputFormat)

			if o == nil {
				s.logNotFound(refURL.Path, fmt.Sprintf("output format %q", outputFormat), p, pos)
				return s.notFoundURL, nil
			}
			permalinker = o
		}

		if relative {
			link = permalinker.RelPermalink()
		} else {
			link = permalinker.Permalink()
		}
	}

	if refURL.Fragment != "" {
		_ = target
		link = link + "#" + refURL.Fragment

		if pctx, ok := target.(pageContext); ok {
			if refURL.Path != "" {
				if di, ok := pctx.getContentConverter().(converter.DocumentInfo); ok {
					link = link + di.AnchorSuffix()
				}
			}
		} else if pctx, ok := p.(pageContext); ok {
			if di, ok := pctx.getContentConverter().(converter.DocumentInfo); ok {
				link = link + di.AnchorSuffix()
			}
		}

	}

	return link, nil
}

func (s *Site) running() bool {
	return s.h != nil && s.h.running
}

func (s *Site) multilingual() *Multilingual {
	return s.h.multilingual
}

type whatChanged struct {
	source bool
	files  map[string]bool
}

// RegisterMediaTypes will register the Site's media types in the mime
// package, so it will behave correctly with Hugo's built-in server.
func (s *Site) RegisterMediaTypes() {
	for _, mt := range s.mediaTypesConfig {
		for _, suffix := range mt.Suffixes {
			_ = mime.AddExtensionType(mt.Delimiter+suffix, mt.Type()+"; charset=utf-8")
		}
	}
}

func (s *Site) filterFileEvents(events []fsnotify.Event) []fsnotify.Event {
	var filtered []fsnotify.Event
	seen := make(map[fsnotify.Event]bool)

	for _, ev := range events {
		// Avoid processing the same event twice.
		if seen[ev] {
			continue
		}
		seen[ev] = true

		if s.SourceSpec.IgnoreFile(ev.Name) {
			continue
		}

		// Throw away any directories
		isRegular, err := s.SourceSpec.IsRegularSourceFile(ev.Name)
		if err != nil && os.IsNotExist(err) && (ev.Op&fsnotify.Remove == fsnotify.Remove || ev.Op&fsnotify.Rename == fsnotify.Rename) {
			// Force keep of event
			isRegular = true
		}
		if !isRegular {
			continue
		}

		filtered = append(filtered, ev)
	}

	return filtered
}

func (s *Site) translateFileEvents(events []fsnotify.Event) []fsnotify.Event {
	var filtered []fsnotify.Event

	eventMap := make(map[string][]fsnotify.Event)

	// We often get a Remove etc. followed by a Create, a Create followed by a Write.
	// Remove the superflous events to mage the update logic simpler.
	for _, ev := range events {
		eventMap[ev.Name] = append(eventMap[ev.Name], ev)
	}

	for _, ev := range events {
		mapped := eventMap[ev.Name]

		// Keep one
		found := false
		var kept fsnotify.Event
		for i, ev2 := range mapped {
			if i == 0 {
				kept = ev2
			}

			if ev2.Op&fsnotify.Write == fsnotify.Write {
				kept = ev2
				found = true
			}

			if !found && ev2.Op&fsnotify.Create == fsnotify.Create {
				kept = ev2
			}
		}

		filtered = append(filtered, kept)
	}

	return filtered
}

// reBuild partially rebuilds a site given the filesystem events.
// It returns whetever the content source was changed.
// TODO(bep) clean up/rewrite this method.
func (s *Site) processPartial(config *BuildCfg, init func(config *BuildCfg) error, events []fsnotify.Event) error {
	events = s.filterFileEvents(events)
	events = s.translateFileEvents(events)

	changeIdentities := make(identity.Identities)

	s.Log.DEBUG.Printf("Rebuild for events %q", events)

	h := s.h

	// First we need to determine what changed

	var (
		sourceChanged       = []fsnotify.Event{}
		sourceReallyChanged = []fsnotify.Event{}
		contentFilesChanged []string

		tmplChanged bool
		tmplAdded   bool
		dataChanged bool
		i18nChanged bool

		sourceFilesChanged = make(map[string]bool)

		// prevent spamming the log on changes
		logger = helpers.NewDistinctFeedbackLogger()
	)

	var cachePartitions []string

	for _, ev := range events {
		if assetsFilename := s.BaseFs.Assets.MakePathRelative(ev.Name); assetsFilename != "" {
			cachePartitions = append(cachePartitions, resources.ResourceKeyPartitions(assetsFilename)...)
		}

		id, found := s.eventToIdentity(ev)
		if found {
			changeIdentities[id] = id

			switch id.Type {
			case files.ComponentFolderContent:
				logger.Println("Source changed", ev)
				sourceChanged = append(sourceChanged, ev)
			case files.ComponentFolderLayouts:
				tmplChanged = true
				if !s.Tmpl().HasTemplate(id.Path) {
					tmplAdded = true
				}
				if tmplAdded {
					logger.Println("Template added", ev)
				} else {
					logger.Println("Template changed", ev)
				}

			case files.ComponentFolderData:
				logger.Println("Data changed", ev)
				dataChanged = true
			case files.ComponentFolderI18n:
				logger.Println("i18n changed", ev)
				i18nChanged = true

			}
		}
	}

	changed := &whatChanged{
		source: len(sourceChanged) > 0,
		files:  sourceFilesChanged,
	}

	config.whatChanged = changed

	if err := init(config); err != nil {
		return err
	}

	// These in memory resource caches will be rebuilt on demand.
	for _, s := range s.h.Sites {
		s.ResourceSpec.ResourceCache.DeletePartitions(cachePartitions...)
	}

	if tmplChanged || i18nChanged {
		sites := s.h.Sites
		first := sites[0]

		s.h.init.Reset()

		// TOD(bep) globals clean
		if err := first.Deps.LoadResources(); err != nil {
			return err
		}

		for i := 1; i < len(sites); i++ {
			site := sites[i]
			var err error
			depsCfg := deps.DepsCfg{
				Language:      site.language,
				MediaTypes:    site.mediaTypesConfig,
				OutputFormats: site.outputFormatsConfig,
			}
			site.Deps, err = first.Deps.ForLanguage(depsCfg, func(d *deps.Deps) error {
				d.Site = site.Info
				return nil
			})
			if err != nil {
				return err
			}
		}
	}

	if dataChanged {
		s.h.init.data.Reset()
	}

	for _, ev := range sourceChanged {
		removed := false

		if ev.Op&fsnotify.Remove == fsnotify.Remove {
			removed = true
		}

		// Some editors (Vim) sometimes issue only a Rename operation when writing an existing file
		// Sometimes a rename operation means that file has been renamed other times it means
		// it's been updated
		if ev.Op&fsnotify.Rename == fsnotify.Rename {
			// If the file is still on disk, it's only been updated, if it's not, it's been moved
			if ex, err := afero.Exists(s.Fs.Source, ev.Name); !ex || err != nil {
				removed = true
			}
		}

		if removed && files.IsContentFile(ev.Name) {
			h.removePageByFilename(ev.Name)
		}

		sourceReallyChanged = append(sourceReallyChanged, ev)
		sourceFilesChanged[ev.Name] = true
	}

	if config.ErrRecovery || tmplAdded || dataChanged {
		h.resetPageState()
	} else {
		h.resetPageStateFromEvents(changeIdentities)
	}

	if len(sourceReallyChanged) > 0 || len(contentFilesChanged) > 0 {
		var filenamesChanged []string
		for _, e := range sourceReallyChanged {
			filenamesChanged = append(filenamesChanged, e.Name)
		}
		if len(contentFilesChanged) > 0 {
			filenamesChanged = append(filenamesChanged, contentFilesChanged...)
		}

		filenamesChanged = helpers.UniqueStringsReuse(filenamesChanged)

		if err := s.readAndProcessContent(filenamesChanged...); err != nil {
			return err
		}

	}

	return nil

}

func (s *Site) process(config BuildCfg) (err error) {
	if err = s.initialize(); err != nil {
		err = errors.Wrap(err, "initialize")
		return
	}
	if err = s.readAndProcessContent(); err != nil {
		err = errors.Wrap(err, "readAndProcessContent")
		return
	}
	return err

}

func (s *Site) render(ctx *siteRenderContext) (err error) {

	if err := page.Clear(); err != nil {
		return err
	}

	if ctx.outIdx == 0 {
		// Note that even if disableAliases is set, the aliases themselves are
		// preserved on page. The motivation with this is to be able to generate
		// 301 redirects in a .htacess file and similar using a custom output format.
		if !s.Cfg.GetBool("disableAliases") {
			// Aliases must be rendered before pages.
			// Some sites, Hugo docs included, have faulty alias definitions that point
			// to itself or another real page. These will be overwritten in the next
			// step.
			if err = s.renderAliases(); err != nil {
				return
			}
		}

	}

	if err = s.renderPages(ctx); err != nil {
		return
	}

	if ctx.outIdx == 0 {
		if err = s.renderSitemap(); err != nil {
			return
		}

		if err = s.renderRobotsTXT(); err != nil {
			return
		}

		if err = s.render404(); err != nil {
			return
		}
	}

	if !ctx.renderSingletonPages() {
		return
	}

	if err = s.renderMainLanguageRedirect(); err != nil {
		return
	}

	return
}

func (s *Site) Initialise() (err error) {
	return s.initialize()
}

func (s *Site) initialize() (err error) {
	return s.initializeSiteInfo()
}

// HomeAbsURL is a convenience method giving the absolute URL to the home page.
func (s *SiteInfo) HomeAbsURL() string {
	base := ""
	if s.IsMultiLingual() {
		base = s.Language().Lang
	}
	return s.owner.AbsURL(base, false)
}

// SitemapAbsURL is a convenience method giving the absolute URL to the sitemap.
func (s *SiteInfo) SitemapAbsURL() string {
	p := s.HomeAbsURL()
	if !strings.HasSuffix(p, "/") {
		p += "/"
	}
	p += s.s.siteCfg.sitemap.Filename
	return p
}

func (s *Site) initializeSiteInfo() error {
	var (
		lang      = s.language
		languages langs.Languages
	)

	if s.h != nil && s.h.multilingual != nil {
		languages = s.h.multilingual.Languages
	}

	permalinks := s.Cfg.GetStringMapString("permalinks")

	defaultContentInSubDir := s.Cfg.GetBool("defaultContentLanguageInSubdir")
	defaultContentLanguage := s.Cfg.GetString("defaultContentLanguage")

	languagePrefix := ""
	if s.multilingualEnabled() && (defaultContentInSubDir || lang.Lang != defaultContentLanguage) {
		languagePrefix = "/" + lang.Lang
	}

	var uglyURLs = func(p page.Page) bool {
		return false
	}

	v := s.Cfg.Get("uglyURLs")
	if v != nil {
		switch vv := v.(type) {
		case bool:
			uglyURLs = func(p page.Page) bool {
				return vv
			}
		case string:
			// Is what be get from CLI (--uglyURLs)
			vvv := cast.ToBool(vv)
			uglyURLs = func(p page.Page) bool {
				return vvv
			}
		default:
			m := cast.ToStringMapBool(v)
			uglyURLs = func(p page.Page) bool {
				return m[p.Section()]
			}
		}
	}

	s.Info = &SiteInfo{
		title:                          lang.GetString("title"),
		Author:                         lang.GetStringMap("author"),
		Social:                         lang.GetStringMapString("social"),
		LanguageCode:                   lang.GetString("languageCode"),
		Copyright:                      lang.GetString("copyright"),
		language:                       lang,
		LanguagePrefix:                 languagePrefix,
		Languages:                      languages,
		defaultContentLanguageInSubdir: defaultContentInSubDir,
		sectionPagesMenu:               lang.GetString("sectionPagesMenu"),
		BuildDrafts:                    s.Cfg.GetBool("buildDrafts"),
		canonifyURLs:                   s.Cfg.GetBool("canonifyURLs"),
		relativeURLs:                   s.Cfg.GetBool("relativeURLs"),
		uglyURLs:                       uglyURLs,
		permalinks:                     permalinks,
		owner:                          s.h,
		s:                              s,
		hugoInfo:                       hugo.NewInfo(s.Cfg.GetString("environment")),
	}

	rssOutputFormat, found := s.outputFormats[page.KindHome].GetByName(output.RSSFormat.Name)

	if found {
		s.Info.RSSLink = s.permalink(rssOutputFormat.BaseFilename())
	}

	return nil
}

func (s *Site) eventToIdentity(e fsnotify.Event) (identity.PathIdentity, bool) {
	for _, fs := range s.BaseFs.SourceFilesystems.FileSystems() {
		if p := fs.Path(e.Name); p != "" {
			return identity.NewPathIdentity(fs.Name, filepath.ToSlash(p)), true
		}
	}
	return identity.PathIdentity{}, false
}

func (s *Site) readAndProcessContent(filenames ...string) error {
	sourceSpec := source.NewSourceSpec(s.PathSpec, s.BaseFs.Content.Fs)

	proc := newPagesProcessor(s.h, sourceSpec)

	c := newPagesCollector(sourceSpec, s.h.content, s.Log, s.h.ContentChanges, proc, filenames...)

	if err := c.Collect(); err != nil {
		return err
	}

	s.h.content = newPageMaps(s.h)

	return nil
}

func (s *Site) getMenusFromConfig() navigation.Menus {

	ret := navigation.Menus{}

	if menus := s.language.GetStringMap("menus"); menus != nil {
		for name, menu := range menus {
			m, err := cast.ToSliceE(menu)
			if err != nil {
				s.Log.ERROR.Printf("unable to process menus in site config\n")
				s.Log.ERROR.Println(err)
			} else {
				for _, entry := range m {
					s.Log.DEBUG.Printf("found menu: %q, in site config\n", name)

					menuEntry := navigation.MenuEntry{Menu: name}
					ime, err := maps.ToStringMapE(entry)
					if err != nil {
						s.Log.ERROR.Printf("unable to process menus in site config\n")
						s.Log.ERROR.Println(err)
					}

					menuEntry.MarshallMap(ime)
					// TODO(bep) clean up all of this
					menuEntry.ConfiguredURL = s.Info.createNodeMenuEntryURL(menuEntry.ConfiguredURL)

					if ret[name] == nil {
						ret[name] = navigation.Menu{}
					}
					ret[name] = ret[name].Add(&menuEntry)
				}
			}
		}
		return ret
	}
	return ret
}

func (s *SiteInfo) createNodeMenuEntryURL(in string) string {

	if !strings.HasPrefix(in, "/") {
		return in
	}
	// make it match the nodes
	menuEntryURL := in
	menuEntryURL = helpers.SanitizeURLKeepTrailingSlash(s.s.PathSpec.URLize(menuEntryURL))
	if !s.canonifyURLs {
		menuEntryURL = helpers.AddContextRoot(s.s.PathSpec.BaseURL.String(), menuEntryURL)
	}
	return menuEntryURL
}

func (s *Site) assembleMenus() {
	s.menus = make(navigation.Menus)

	type twoD struct {
		MenuName, EntryName string
	}
	flat := map[twoD]*navigation.MenuEntry{}
	children := map[twoD]navigation.Menu{}

	// add menu entries from config to flat hash
	menuConfig := s.getMenusFromConfig()
	for name, menu := range menuConfig {
		for _, me := range menu {
			flat[twoD{name, me.KeyName()}] = me
		}
	}

	sectionPagesMenu := s.Info.sectionPagesMenu

	if sectionPagesMenu != "" {
		s.pageMap.sections.Walk(func(s string, v interface{}) bool {
			p := v.(*contentNode).p
			if p.IsHome() {
				return false
			}
			// From Hugo 0.22 we have nested sections, but until we get a
			// feel of how that would work in this setting, let us keep
			// this menu for the top level only.
			id := p.Section()
			if _, ok := flat[twoD{sectionPagesMenu, id}]; ok {
				return false
			}

			me := navigation.MenuEntry{Identifier: id,
				Name:   p.LinkTitle(),
				Weight: p.Weight(),
				Page:   p}
			flat[twoD{sectionPagesMenu, me.KeyName()}] = &me

			return false
		})

	}

	// Add menu entries provided by pages
	s.pageMap.pageTrees.WalkRenderable(func(ss string, n *contentNode) bool {
		p := n.p

		for name, me := range p.pageMenus.menus() {
			if _, ok := flat[twoD{name, me.KeyName()}]; ok {
				err := p.wrapError(errors.Errorf("duplicate menu entry with identifier %q in menu %q", me.KeyName(), name))
				s.Log.WARN.Println(err)
				continue
			}
			flat[twoD{name, me.KeyName()}] = me
		}

		return false
	})

	// Create Children Menus First
	for _, e := range flat {
		if e.Parent != "" {
			children[twoD{e.Menu, e.Parent}] = children[twoD{e.Menu, e.Parent}].Add(e)
		}
	}

	// Placing Children in Parents (in flat)
	for p, childmenu := range children {
		_, ok := flat[twoD{p.MenuName, p.EntryName}]
		if !ok {
			// if parent does not exist, create one without a URL
			flat[twoD{p.MenuName, p.EntryName}] = &navigation.MenuEntry{Name: p.EntryName}
		}
		flat[twoD{p.MenuName, p.EntryName}].Children = childmenu
	}

	// Assembling Top Level of Tree
	for menu, e := range flat {
		if e.Parent == "" {
			_, ok := s.menus[menu.MenuName]
			if !ok {
				s.menus[menu.MenuName] = navigation.Menu{}
			}
			s.menus[menu.MenuName] = s.menus[menu.MenuName].Add(e)
		}
	}
}

// get any lanaguagecode to prefix the target file path with.
func (s *Site) getLanguageTargetPathLang(alwaysInSubDir bool) string {
	if s.h.IsMultihost() {
		return s.Language().Lang
	}

	return s.getLanguagePermalinkLang(alwaysInSubDir)
}

// get any lanaguagecode to prefix the relative permalink with.
func (s *Site) getLanguagePermalinkLang(alwaysInSubDir bool) string {

	if !s.Info.IsMultiLingual() || s.h.IsMultihost() {
		return ""
	}

	if alwaysInSubDir {
		return s.Language().Lang
	}

	isDefault := s.Language().Lang == s.multilingual().DefaultLang.Lang

	if !isDefault || s.Info.defaultContentLanguageInSubdir {
		return s.Language().Lang
	}

	return ""
}

func (s *Site) getTaxonomyKey(key string) string {
	if s.PathSpec.DisablePathToLower {
		return s.PathSpec.MakePath(key)
	}
	return strings.ToLower(s.PathSpec.MakePath(key))
}

// Prepare site for a new full build.
func (s *Site) resetBuildState(sourceChanged bool) {
	s.relatedDocsHandler = s.relatedDocsHandler.Clone()
	s.init.Reset()

	if sourceChanged {
		s.PageCollections = newPageCollections(s.pageMap)
		s.pageMap.withEveryBundlePage(func(p *pageState) bool {
			p.pagePages = &pagePages{}
			if p.bucket != nil {
				p.bucket.pagesMapBucketPages = &pagesMapBucketPages{}
			}
			p.parent = nil
			p.Scratcher = maps.NewScratcher()
			return false
		})
	} else {
		s.pageMap.withEveryBundlePage(func(p *pageState) bool {
			p.Scratcher = maps.NewScratcher()
			return false
		})
	}
}

func (s *Site) errorCollator(results <-chan error, errs chan<- error) {
	var errors []error
	for e := range results {
		errors = append(errors, e)
	}

	errs <- s.h.pickOneAndLogTheRest(errors)

	close(errs)
}

// GetPage looks up a page of a given type for the given ref.
// In Hugo <= 0.44 you had to add Page Kind (section, home) etc. as the first
// argument and then either a unix styled path (with or without a leading slash))
// or path elements separated.
// When we now remove the Kind from this API, we need to make the transition as painless
// as possible for existing sites. Most sites will use {{ .Site.GetPage "section" "my/section" }},
// i.e. 2 arguments, so we test for that.
func (s *SiteInfo) GetPage(ref ...string) (page.Page, error) {
	p, err := s.s.getPageOldVersion(ref...)

	if p == nil {
		// The nil struct has meaning in some situations, mostly to avoid breaking
		// existing sites doing $nilpage.IsDescendant($p), which will always return
		// false.
		p = page.NilPage
	}

	return p, err
}

func (s *Site) permalink(link string) string {
	return s.PathSpec.PermalinkForBaseURL(link, s.PathSpec.BaseURL.String())

}

func (s *Site) lookupLayouts(layouts ...string) tpl.Template {
	for _, l := range layouts {
		if templ, found := s.Tmpl().Lookup(l); found {
			return templ
		}
	}

	return nil
}

func (s *Site) renderAndWriteXML(statCounter *uint64, name string, targetPath string, d interface{}, templ tpl.Template) error {
	s.Log.DEBUG.Printf("Render XML for %q to %q", name, targetPath)
	renderBuffer := bp.GetBuffer()
	defer bp.PutBuffer(renderBuffer)

	if err := s.renderForTemplate(name, "", d, renderBuffer, templ); err != nil {
		return err
	}

	var path string
	if s.Info.relativeURLs {
		path = helpers.GetDottedRelativePath(targetPath)
	} else {
		s := s.PathSpec.BaseURL.String()
		if !strings.HasSuffix(s, "/") {
			s += "/"
		}
		path = s
	}

	pd := publisher.Descriptor{
		Src:         renderBuffer,
		TargetPath:  targetPath,
		StatCounter: statCounter,
		// For the minification part of XML,
		// we currently only use the MIME type.
		OutputFormat: output.RSSFormat,
		AbsURLPath:   path,
	}

	return s.publisher.Publish(pd)

}

func (s *Site) renderAndWritePage(statCounter *uint64, name string, targetPath string, p *pageState, templ tpl.Template) error {
	renderBuffer := bp.GetBuffer()
	defer bp.PutBuffer(renderBuffer)

	of := p.outputFormat()

	if err := s.renderForTemplate(p.Kind(), of.Name, p, renderBuffer, templ); err != nil {
		return err
	}

	if renderBuffer.Len() == 0 {
		return nil
	}

	isHTML := of.IsHTML
	isRSS := of.Name == "RSS"

	var path string

	if s.Info.relativeURLs {
		path = helpers.GetDottedRelativePath(targetPath)
	} else if isRSS || s.Info.canonifyURLs {
		url := s.PathSpec.BaseURL.String()
		if !strings.HasSuffix(url, "/") {
			url += "/"
		}
		path = url
	}

	pd := publisher.Descriptor{
		Src:          renderBuffer,
		TargetPath:   targetPath,
		StatCounter:  statCounter,
		OutputFormat: p.outputFormat(),
	}

	if isRSS {
		// Always canonify URLs in RSS
		pd.AbsURLPath = path
	} else if isHTML {
		if s.Info.relativeURLs || s.Info.canonifyURLs {
			pd.AbsURLPath = path
		}

		if s.running() && s.Cfg.GetBool("watch") && !s.Cfg.GetBool("disableLiveReload") {
			pd.LiveReloadPort = s.Cfg.GetInt("liveReloadPort")
		}

		// For performance reasons we only inject the Hugo generator tag on the home page.
		if p.IsHome() {
			pd.AddHugoGeneratorTag = !s.Cfg.GetBool("disableHugoGeneratorInject")
		}

	}

	return s.publisher.Publish(pd)
}

var infoOnMissingLayout = map[string]bool{
	// The 404 layout is very much optional in Hugo, but we do look for it.
	"404": true,
}

// hookRenderer is the canonical implementation of all hooks.ITEMRenderer,
// where ITEM is the thing being hooked.
type hookRenderer struct {
	templateHandler tpl.TemplateHandler
	identity.Provider
	templ tpl.Template
}

func (hr hookRenderer) RenderLink(w io.Writer, ctx hooks.LinkContext) error {
	return hr.templateHandler.Execute(hr.templ, w, ctx)
}

func (hr hookRenderer) RenderHeading(w io.Writer, ctx hooks.HeadingContext) error {
	return hr.templateHandler.Execute(hr.templ, w, ctx)
}

func (s *Site) renderForTemplate(name, outputFormat string, d interface{}, w io.Writer, templ tpl.Template) (err error) {
	if templ == nil {
		s.logMissingLayout(name, "", outputFormat)
		return nil
	}

	if err = s.Tmpl().Execute(templ, w, d); err != nil {
		return _errors.Wrapf(err, "render of %q failed", name)
	}
	return
}

func (s *Site) lookupTemplate(layouts ...string) (tpl.Template, bool) {
	for _, l := range layouts {
		if templ, found := s.Tmpl().Lookup(l); found {
			return templ, true
		}
	}

	return nil, false
}

func (s *Site) publish(statCounter *uint64, path string, r io.Reader) (err error) {
	s.PathSpec.ProcessingStats.Incr(statCounter)

	return helpers.WriteToDisk(filepath.Clean(path), r, s.BaseFs.PublishFs)
}

func (s *Site) kindFromFileInfoOrSections(fi *fileInfo, sections []string) string {
	if fi.TranslationBaseName() == "_index" {
		if fi.Dir() == "" {
			return page.KindHome
		}

		return s.kindFromSections(sections)

	}

	return page.KindPage
}

func (s *Site) kindFromSections(sections []string) string {
	if len(sections) == 0 {
		return page.KindHome
	}

	return s.kindFromSectionPath(path.Join(sections...))

}

func (s *Site) kindFromSectionPath(sectionPath string) string {
	for _, plural := range s.siteCfg.taxonomiesConfig {
		if plural == sectionPath {
			return page.KindTaxonomyTerm
		}

		if strings.HasPrefix(sectionPath, plural) {
			return page.KindTaxonomy
		}

	}

	return page.KindSection
}

func (s *Site) newPage(
	n *contentNode,
	parentbBucket *pagesMapBucket,
	kind, title string,
	sections ...string) *pageState {

	m := map[string]interface{}{}
	if title != "" {
		m["title"] = title
	}

	p, err := newPageFromMeta(
		n,
		parentbBucket,
		m,
		&pageMeta{
			s:        s,
			kind:     kind,
			sections: sections,
		})

	if err != nil {
		panic(err)
	}

	return p
}

func (s *Site) shouldBuild(p page.Page) bool {
	return shouldBuild(s.BuildFuture, s.BuildExpired,
		s.BuildDrafts, p.Draft(), p.PublishDate(), p.ExpiryDate())
}

func shouldBuild(buildFuture bool, buildExpired bool, buildDrafts bool, Draft bool,
	publishDate time.Time, expiryDate time.Time) bool {
	if !(buildDrafts || !Draft) {
		return false
	}
	if !buildFuture && !publishDate.IsZero() && publishDate.After(time.Now()) {
		return false
	}
	if !buildExpired && !expiryDate.IsZero() && expiryDate.Before(time.Now()) {
		return false
	}
	return true
}