initial commit

engine.go

@@ -0,0 +1,252 @@
+package main
+
+import (
+	"errors"
+	"html/template"
+	"regexp"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/blevesearch/bleve"
+	"github.com/blevesearch/bleve/document"
+)
+
+const timeFmt = "2006-01-02 15:04:05"
+
+var titleRe = regexp.MustCompile("[^a-zA-Z0-9+]+")
+
+func now() string {
+	return time.Now().Format(timeFmt)
+}
+
+type Article struct {
+	Title     string `json:"title"`
+	LinkTitle string
+	Search    string        `json:"search"`
+	Index     template.HTML `json:"index"`
+	Text      template.HTML `json:"text"`
+	MD        string        `json:"md"`
+	Created   string        `json:"created"`
+	Updated   string        `json:"updated"`
+	Public    bool          `json:"public"`
+}
+
+type Engine struct {
+	index bleve.Index
+}
+
+func NewEngine(index bleve.Index) *Engine {
+	return &Engine{index}
+}
+
+func (e *Engine) Close() error {
+	return e.index.Close()
+}
+
+func (e *Engine) Index(title, text, user string, public bool) (string, error) {
+	if user == "" {
+		return "", errors.New("engine: user cannot be empty")
+	}
+	title = titleRe.ReplaceAllString(title, "")
+	newTitle := strings.Replace(title, " ", "+", -1)
+	if err := e.Exists(false, newTitle); err == nil {
+		return "", errors.New("engine: article already exists")
+	}
+	art := render(text)
+	art.Title = title
+	art.Created = user + " " + now()
+	art.Public = public
+	e.index.Index(newTitle, art)
+	return newTitle, nil
+}
+
+func (e *Engine) Exists(public bool, title string) error {
+	_, err := e.Get(public, title)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (e *Engine) Delete(title string) error {
+	if title == "Index" {
+		return errors.New("engine: the index page cannot be deleted")
+	}
+	if err := e.Exists(false, title); err != nil {
+		return err
+	}
+	return e.index.Delete(title)
+}
+
+func (e *Engine) Update(title, text, user string, public bool) error {
+	if user == "" {
+		return errors.New("engine: user cannot be empty")
+	}
+	if title == "Index" && !public {
+		return errors.New("engine: page 'Index' must stay public")
+	}
+	if err := e.Exists(false, title); err != nil {
+		return err
+	}
+	art, err := e.Get(false, title)
+	if err != nil {
+		return err
+	}
+	rend := render(text)
+	art.Updated = user + " " + now()
+	art.Search = rend.Search
+	art.Index = rend.Index
+	art.Text = rend.Text
+	art.MD = rend.MD
+	art.Public = public
+	err = e.index.Index(title, art)
+	return err
+}
+
+func (e *Engine) Get(public bool, title string) (Article, error) {
+	var art Article
+	doc, err := e.index.Document(title)
+	if err != nil {
+		return art, err
+	}
+	if doc == nil || doc.Fields == nil {
+		return art, errors.New("engine: article does not esist")
+	}
+	for _, field := range doc.Fields {
+		switch f := field.(type) {
+		case *document.TextField:
+			switch field.Name() {
+			case "title":
+				art.Title = string(f.Value())
+			case "index":
+				art.Index = template.HTML(string(f.Value()))
+			case "text":
+				art.Text = template.HTML(string(f.Value()))
+			case "md":
+				art.MD = string(f.Value())
+			case "created":
+				art.Created = string(f.Value())
+			case "updated":
+				art.Updated = string(f.Value())
+			}
+		case *document.BooleanField:
+			if field.Name() == "public" {
+				p, err := f.Boolean()
+				if err != nil {
+					return art, err
+				}
+				art.Public = p
+			}
+		}
+
+	}
+	art.LinkTitle = title
+	if public && !art.Public {
+		err = errors.New("engine: article does not exist")
+	}
+	return art, err
+}
+
+func (e *Engine) Search(public bool, search string) (string, error) {
+	var (
+		res *bleve.SearchResult
+		err error
+	)
+	if public {
+		req := bleve.NewSearchRequest(bleve.NewConjunctionQuery([]bleve.Query{
+			bleve.NewBoolFieldQuery(true).SetField("public"),
+			bleve.NewQueryStringQuery("title:" + search + " search:" + search),
+		}))
+		req.Highlight = bleve.NewHighlightWithStyle("html")
+		res, err = e.index.Search(req)
+		if err != nil {
+			return "", err
+		}
+	} else {
+		req := bleve.NewSearchRequest(bleve.NewQueryStringQuery("title:" + search + " search:" + search))
+		req.Highlight = bleve.NewHighlightWithStyle("html")
+		res, err = e.index.Search(req)
+		if err != nil {
+			return "", err
+		}
+
+	}
+	if res.Total == 0 {
+		return "<h4>No search results</h4>", nil
+	} else if res.Total > 100 {
+		return "", errors.New("engine: too many search results")
+	}
+	html := ""
+	for _, hit := range res.Hits {
+		art, err := e.Get(false, hit.ID)
+		if err != nil {
+			continue
+		}
+		html += `<h5><a href="/wiki/` + hit.ID + `">` + art.Title + "</a></h5>"
+		for fragField, frags := range hit.Fragments {
+			if fragField == "title" || fragField == "search" {
+				html += `<pre style="white-space: pre-wrap">`
+				for _, f := range frags {
+					html += f
+				}
+				html += "</pre>"
+				break
+			}
+		}
+		html += "<br>"
+	}
+	return html, nil
+}
+
+type Title struct {
+	Title     string
+	LinkTitle string
+}
+
+type Titles []Title
+
+func (t Titles) Len() int           { return len(t) }
+func (t Titles) Swap(i, j int)      { t[i], t[j] = t[j], t[i] }
+func (t Titles) Less(i, j int) bool { return t[i].Title < t[j].Title }
+
+func (e *Engine) GetAll(public bool) (t Titles, err error) {
+	var res *bleve.SearchResult
+	if public {
+		req := bleve.NewSearchRequest(bleve.NewBoolFieldQuery(true).SetField("public"))
+		res, err = e.index.Search(req)
+		if err != nil {
+			return
+		}
+	} else {
+		req := bleve.NewSearchRequest(bleve.NewMatchAllQuery())
+		res, err = e.index.Search(req)
+		if err != nil {
+			return
+		}
+	}
+	t = make(Titles, len(res.Hits)-1)
+	i := 0
+	for _, v := range res.Hits {
+		if v.ID == "Index" {
+			continue
+		}
+		doc, err := e.index.Document(v.ID)
+		if err != nil || doc == nil || doc.Fields == nil {
+			continue
+		}
+		for _, field := range doc.Fields {
+			if field.Name() != "title" {
+				continue
+			}
+			f, ok := field.(*document.TextField)
+			if ok {
+				t[i] = Title{string(f.Value()), v.ID}
+				i++
+				break
+			}
+		}
+	}
+	sort.Sort(t)
+	return
+}