From 3c634fb00a269411c7ffbe1c4949196aa1405d8e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micka=C3=ABl=20Menu?= <mickael.menu@gmail.com>
Date: Sat, 14 May 2022 10:44:39 +0200
Subject: [PATCH] Remove dependency on `libicu` (#213)

---
 CHANGELOG.md                        |  7 ++++++-
 Makefile                            |  4 ++--
 README.md                           |  6 ------
 internal/adapter/sqlite/db.go       |  4 ++++
 internal/adapter/sqlite/note_dao.go |  5 ++---
 internal/util/icu/icu.go            | 19 -----------------
 internal/util/icu/icu_test.go       | 32 -----------------------------
 7 files changed, 14 insertions(+), 63 deletions(-)
 delete mode 100644 internal/util/icu/icu.go
 delete mode 100644 internal/util/icu/icu_test.go

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8ed522f..2763a09 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,12 @@
 
 All notable changes to this project will be documented in this file.
 
-<!--## Unreleased-->
+## Unreleased
+
+### Changed
+
+* Removed the dependency on `libicu`.
+
 
 ## 0.10.0
 
diff --git a/Makefile b/Makefile
index ac6627a..895b399 100644
--- a/Makefile
+++ b/Makefile
@@ -47,11 +47,11 @@ BUILD := `git rev-parse --short HEAD`
 ENV_PREFIX := CGO_ENABLED=1
 # Add necessary env variables for Apple Silicon.
 ifeq ($(shell uname -sm),Darwin arm64)
-	ENV_PREFIX := $(ENV) GOARCH=arm64 CGO_CFLAGS="-I/opt/homebrew/opt/icu4c/include" CGO_LDFLAGS="-L/opt/homebrew/opt/icu4c/lib"
+	ENV_PREFIX := $(ENV) GOARCH=arm64
 endif
 
 # Wrapper around the go binary, to set all the default parameters.
 define go
-	$(ENV_PREFIX) go $(1) -tags "fts5 icu" -ldflags "-X=main.Version=$(VERSION) -X=main.Build=$(BUILD)" $(2)
+	$(ENV_PREFIX) go $(1) -tags "fts5" -ldflags "-X=main.Version=$(VERSION) -X=main.Build=$(BUILD)" $(2)
 endef
 
diff --git a/README.md b/README.md
index 54ec71d..6d3147e 100644
--- a/README.md
+++ b/README.md
@@ -79,20 +79,14 @@ $ cd zk
 
 #### On macOS
 
-`icu4c` is required to build `zk`, which you can install with [Homebrew](https://brew.sh/).
-
 ```
-$ brew install icu4c
 $ make
 $ ./zk -h
 ```
 
 #### On Linux
 
-`libicu-dev` is required to build `zk`, use your favorite package manager to install it.
-
 ```
-$ apt-install libicu-dev
 $ make
 $ ./zk -h
 ```
diff --git a/internal/adapter/sqlite/db.go b/internal/adapter/sqlite/db.go
index 276c596..bc24b0d 100644
--- a/internal/adapter/sqlite/db.go
+++ b/internal/adapter/sqlite/db.go
@@ -3,6 +3,7 @@ package sqlite
 import (
 	"database/sql"
 	"fmt"
+	"regexp"
 
 	sqlite "github.com/mattn/go-sqlite3"
 	"github.com/mickael-menu/zk/internal/core"
@@ -16,6 +17,9 @@ func init() {
 			if err := conn.RegisterFunc("mention_query", buildMentionQuery, true); err != nil {
 				return err
 			}
+			if err := conn.RegisterFunc("regexp", regexp.MatchString, true); err != nil {
+				return err
+			}
 			return nil
 		},
 	})
diff --git a/internal/adapter/sqlite/note_dao.go b/internal/adapter/sqlite/note_dao.go
index 574b324..0ce3c8b 100644
--- a/internal/adapter/sqlite/note_dao.go
+++ b/internal/adapter/sqlite/note_dao.go
@@ -12,7 +12,6 @@ import (
 	"github.com/mickael-menu/zk/internal/util"
 	"github.com/mickael-menu/zk/internal/util/errors"
 	"github.com/mickael-menu/zk/internal/util/fts5"
-	"github.com/mickael-menu/zk/internal/util/icu"
 	"github.com/mickael-menu/zk/internal/util/opt"
 	"github.com/mickael-menu/zk/internal/util/paths"
 	strutil "github.com/mickael-menu/zk/internal/util/strings"
@@ -284,7 +283,7 @@ func (d *NoteDAO) FindIdsByHref(href string, allowPartialHref bool) ([]core.Note
 	// matching a sub-section in the note.
 	href = strings.SplitN(href, "#", 2)[0]
 
-	href = icu.EscapePattern(href)
+	href = regexp.QuoteMeta(href)
 
 	if allowPartialHref {
 		ids, err := d.findIdsByPathRegex("^(.*/)?[^/]*" + href + "[^/]*$")
@@ -298,7 +297,7 @@ func (d *NoteDAO) FindIdsByHref(href string, allowPartialHref bool) ([]core.Note
 		}
 	}
 
-	ids, err := d.findIdsByPathRegex(href + "[^/]*|" + href + "/.+")
+	ids, err := d.findIdsByPathRegex("^(?:" + href + "[^/]*|" + href + "/.+)$")
 	if len(ids) > 0 || err != nil {
 		return ids, err
 	}
diff --git a/internal/util/icu/icu.go b/internal/util/icu/icu.go
deleted file mode 100644
index 6938029..0000000
--- a/internal/util/icu/icu.go
+++ /dev/null
@@ -1,19 +0,0 @@
-package icu
-
-// EscapePattern adds backslash escapes to protect any characters that would
-// match as ICU pattern metacharacters.
-//
-// http://userguide.icu-project.org/strings/regexp
-func EscapePattern(s string) string {
-	out := ""
-
-	for _, c := range s {
-		switch c {
-		case '\\', '.', '^', '$', '(', ')', '[', ']', '{', '}', '|', '*', '+', '?':
-			out += `\`
-		}
-		out += string(c)
-	}
-
-	return out
-}
diff --git a/internal/util/icu/icu_test.go b/internal/util/icu/icu_test.go
deleted file mode 100644
index 685dcab..0000000
--- a/internal/util/icu/icu_test.go
+++ /dev/null
@@ -1,32 +0,0 @@
-package icu
-
-import (
-	"testing"
-
-	"github.com/mickael-menu/zk/internal/util/test/assert"
-)
-
-func TestEscapePAttern(t *testing.T) {
-	tests := map[string]string{
-		`foo bar`: `foo bar`,
-		`\a`:      `\\a`,
-		`.`:       `\.`,
-		`^`:       `\^`,
-		`$`:       `\$`,
-		`(`:       `\(`,
-		`)`:       `\)`,
-		`[`:       `\[`,
-		`]`:       `\]`,
-		`{`:       `\{`,
-		`}`:       `\}`,
-		`|`:       `\|`,
-		`*`:       `\*`,
-		`+`:       `\+`,
-		`?`:       `\?`,
-		`(?:[A-Za-z0-9]+[._]?){1,}[A-Za-z0-9]+\@(?:(?:[A-Za-z0-9]+[-]?){1,}[A-Za-z0-9]+\.){1,}`: `\(\?:\[A-Za-z0-9\]\+\[\._\]\?\)\{1,\}\[A-Za-z0-9\]\+\\@\(\?:\(\?:\[A-Za-z0-9\]\+\[-\]\?\)\{1,\}\[A-Za-z0-9\]\+\\\.\)\{1,\}`,
-	}
-
-	for input, expected := range tests {
-		assert.Equal(t, EscapePattern(input), expected)
-	}
-}