From b068666a99d845a23364ff06c1bf03bcb1aeb325 Mon Sep 17 00:00:00 2001
From: Robert Wang <robertabcd@gmail.com>
Date: Mon, 23 Apr 2018 22:05:26 -0700
Subject: [PATCH] Add template functions for search shortcuts.

---
 pttbbs/search_predicate.go |  7 +++++++
 pttbbs/string.go           | 30 ++++++++++++++++++++++++++++++
 pttweb.go                  | 27 +++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)

diff --git a/pttbbs/search_predicate.go b/pttbbs/search_predicate.go
index d1566cc..3487c64 100644
--- a/pttbbs/search_predicate.go
+++ b/pttbbs/search_predicate.go
@@ -13,6 +13,13 @@ func WithTitle(title string) SearchPredicate {
 	}}
 }
 
+func WithExactTitle(title string) SearchPredicate {
+	return &searchPredicate{&apipb.SearchFilter{
+		Type:       apipb.SearchFilter_TYPE_EXACT_TITLE,
+		StringData: title,
+	}}
+}
+
 func WithAuthor(author string) SearchPredicate {
 	return &searchPredicate{&apipb.SearchFilter{
 		Type:       apipb.SearchFilter_TYPE_AUTHOR,
diff --git a/pttbbs/string.go b/pttbbs/string.go
index 48842b8..c367e16 100644
--- a/pttbbs/string.go
+++ b/pttbbs/string.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"regexp"
 	"strconv"
+	"strings"
 	"time"
 )
 
@@ -16,6 +17,8 @@ var (
 	SignaturePrefixStrings = []string{"※", "==>"}
 
 	ArticlePushPrefixStrings = []string{"推 ", "噓 ", "→ "}
+
+	subjectPrefixStrings = []string{"re:", "fw:", "[轉錄]"}
 )
 
 const (
@@ -26,6 +29,7 @@ const (
 var (
 	validBrdNameRegexp  = regexp.MustCompile(`^[0-9a-zA-Z][0-9a-zA-Z_\.\-]+$`)
 	validFileNameRegexp = regexp.MustCompile(`^[MG]\.\d+\.A(\.[0-9A-F]+)?$`)
+	validUserIDRegexp   = regexp.MustCompile(`^[a-zA-Z][0-9a-zA-Z]{1,11}$`)
 	fileNameTimeRegexp  = regexp.MustCompile(`^[MG]\.(\d+)\.A(\.[0-9A-F]+)?$`)
 )
 
@@ -37,6 +41,10 @@ func IsValidArticleFileName(filename string) bool {
 	return validFileNameRegexp.MatchString(filename)
 }
 
+func IsValidUserID(userID string) bool {
+	return validUserIDRegexp.MatchString(userID)
+}
+
 func ParseArticleFirstLine(line []byte) (tag1, val1, tag2, val2 []byte, ok bool) {
 	m := ArticleFirstLineRegexp.FindSubmatch(line)
 	if m == nil {
@@ -79,3 +87,25 @@ func ParseFileNameTime(filename string) (time.Time, error) {
 	}
 	return time.Unix(int64(unix), 0), nil
 }
+
+func Subject(subject string) string {
+	lower := strings.ToLower(subject)
+	off := 0
+	for _, p := range subjectPrefixStrings {
+		for strings.HasPrefix(lower[off:], p) {
+			off += len(p)
+			off += countPrefixSpaces(lower[off:])
+		}
+		off += countPrefixSpaces(lower[off:])
+	}
+	return subject[off:]
+}
+
+func countPrefixSpaces(s string) int {
+	for i, c := range s {
+		if c != ' ' {
+			return i
+		}
+	}
+	return 0
+}
diff --git a/pttweb.go b/pttweb.go
index 7b21fc9..f3da4b1 100644
--- a/pttweb.go
+++ b/pttweb.go
@@ -293,6 +293,15 @@ func templateFuncMap() template.FuncMap {
 		"route": func(where string, attrs ...string) (*url.URL, error) {
 			return router.Get(where).URLPath(attrs...)
 		},
+		"route_search_author": func(b pttbbs.Board, author string) (*url.URL, error) {
+			if !pttbbs.IsValidUserID(author) {
+				return nil, nil
+			}
+			return bbsSearchURL(b, "author:"+author)
+		},
+		"route_search_thread": func(b pttbbs.Board, title string) (*url.URL, error) {
+			return bbsSearchURL(b, "thread:"+pttbbs.Subject(title))
+		},
 		"static_prefix": func() string {
 			return config.StaticPrefix
 		},
@@ -475,6 +484,17 @@ func handleBbs(c *Context, w http.ResponseWriter) error {
 	return page.ExecutePage(w, (*page.BbsIndex)(bbsindex))
 }
 
+func bbsSearchURL(b pttbbs.Board, query string) (*url.URL, error) {
+	u, err := router.Get("bbssearch").URLPath("brdname", b.BrdName)
+	if err != nil {
+		return nil, err
+	}
+	q := url.Values{}
+	q.Set("q", query)
+	u.RawQuery = q.Encode()
+	return u, nil
+}
+
 func parseKeyValueTerm(term string) (pttbbs.SearchPredicate, bool) {
 	kv := strings.SplitN(term, ":", 2)
 	if len(kv) != 2 {
@@ -495,6 +515,13 @@ func parseKeyValueTerm(term string) (pttbbs.SearchPredicate, bool) {
 }
 
 func parseQuery(query string) ([]pttbbs.SearchPredicate, error) {
+	// Special case, thread takes up all the query.
+	if strings.HasPrefix(query, "thread:") {
+		return []pttbbs.SearchPredicate{
+			pttbbs.WithExactTitle(strings.TrimSpace(strings.TrimPrefix(query, "thread:"))),
+		}, nil
+	}
+
 	segs := strings.Split(query, " ")
 	var titleSegs []string
 	var preds []pttbbs.SearchPredicate