From 1671e097a24cd169f1ad4ea89b0cb3ae105b1e70 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Tue, 17 Jan 2023 17:21:55 +0100
Subject: [PATCH] Add basic Collator::find() method.

---
 src/lib/collator.cc   | 21 +++++++++++++++++++++
 src/lib/collator.h    |  1 +
 test/collator_test.cc | 11 +++++++++++
 3 files changed, 33 insertions(+)

diff --git a/src/lib/collator.cc b/src/lib/collator.cc
index 7bab36fa6..ba504fb6e 100644
--- a/src/lib/collator.cc
+++ b/src/lib/collator.cc
@@ -25,6 +25,7 @@
 #include <unicode/ucol.h>
 #include <unicode/uiter.h>
 #include <unicode/utypes.h>
+#include <unicode/usearch.h>
 #include <unicode/ustring.h>
 #include <boost/scoped_array.hpp>
 #include <cstring>
@@ -79,3 +80,23 @@ Collator::compare (string const& utf8_a, string const& utf8_b) const
 	}
 }
 
+
+bool
+Collator::find(string pattern, string text) const
+{
+	if (_collator) {
+		auto utf16_pattern = utf8_to_utf16(pattern);
+		auto utf16_text = utf8_to_utf16(text);
+		UErrorCode status = U_ZERO_ERROR;
+		auto search = usearch_openFromCollator(utf16_pattern.data(), -1, utf16_text.data(), -1, _collator, nullptr, &status);
+		DCPOMATIC_ASSERT(search);
+		auto const index = usearch_first(search, &status);
+		usearch_close(search);
+		return index != -1;
+	} else {
+		transform(pattern.begin(), pattern.end(), pattern.begin(), ::tolower);
+		transform(text.begin(), text.end(), text.begin(), ::tolower);
+		return pattern.find(text) != string::npos;
+	}
+}
+
diff --git a/src/lib/collator.h b/src/lib/collator.h
index d42278124..1768c43c0 100644
--- a/src/lib/collator.h
+++ b/src/lib/collator.h
@@ -39,6 +39,7 @@ public:
 	Collator& operator=(Collator const&) = delete;
 
 	int compare(std::string const& utf8_a, std::string const& utf8_b) const;
+	bool find(std::string pattern, std::string text) const;
 
 private:
 	UCollator* _collator = nullptr;
diff --git a/test/collator_test.cc b/test/collator_test.cc
index fadc5f063..e88d71b06 100644
--- a/test/collator_test.cc
+++ b/test/collator_test.cc
@@ -30,3 +30,14 @@ BOOST_AUTO_TEST_CASE(collator_compare_works_and_ignores_case)
 	BOOST_CHECK_EQUAL(collator.compare("So often YOU won't even notice", "SO OFTEN you won't even NOTiCE"), 0);
 	BOOST_CHECK_EQUAL(collator.compare("So often YOU won't even notice", "SO OFTEN you won't even see"), -1);
 }
+
+
+
+BOOST_AUTO_TEST_CASE(collator_search_works_and_ignores_case)
+{
+	Collator collator;
+
+	BOOST_CHECK(collator.find("outh", "With filthy mouths, and bad attitudes"));
+	BOOST_CHECK(collator.find("with", "With filthy mouths, and bad attitudes"));
+	BOOST_CHECK(!collator.find("ostrabagalous", "With filthy mouths, and bad attitudes"));
+}
-- 
2.30.2