Use CMake pkg-config .in files in the Makefile

Makefile

@@ -30,6 +30,9 @@ OBJS = $(patsubst $(SRC_DIR)/%.c,$(OBJ_DIR)/%.o,$(SOURCES))
 LIBNAME=libvalkey
 PKGCONFNAME=$(LIB_DIR)/valkey.pc
 
+PKGCONF_TEMPLATE = valkey.pc.in
+SSL_PKGCONF_TEMPLATE = valkey_ssl.pc.in
+
 LIBVALKEY_MAJOR=$(shell grep LIBVALKEY_MAJOR $(INCLUDE_DIR)/valkey.h | awk '{print $$3}')
 LIBVALKEY_MINOR=$(shell grep LIBVALKEY_MINOR $(INCLUDE_DIR)/valkey.h | awk '{print $$3}')
 LIBVALKEY_PATCH=$(shell grep LIBVALKEY_PATCH $(INCLUDE_DIR)/valkey.h | awk '{print $$3}')
@@ -223,34 +226,21 @@ clean:
 
 INSTALL?= cp -pPR
 
-$(PKGCONFNAME): include/valkey/valkey.h
+$(PKGCONFNAME): $(PKGCONF_TEMPLATE)
 	@echo "Generating $@ for pkgconfig..."
-	@echo prefix=$(PREFIX) > $@
-	@echo exec_prefix=\$${prefix} >> $@
-	@echo libdir=$(PREFIX)/$(LIBRARY_PATH) >> $@
-	@echo includedir=$(PREFIX)/include >> $@
-	@echo pkgincludedir=$(PREFIX)/$(INCLUDE_PATH) >> $@
-	@echo >> $@
-	@echo Name: valkey >> $@
-	@echo Description: C client library for Valkey. >> $@
-	@echo Version: $(LIBVALKEY_MAJOR).$(LIBVALKEY_MINOR).$(LIBVALKEY_PATCH) >> $@
-	@echo Libs: -L\$${libdir} -lvalkey >> $@
-	@echo Cflags: -I\$${pkgincludedir} -I\$${includedir} -D_FILE_OFFSET_BITS=64 >> $@
-
-$(SSL_PKGCONFNAME): include/valkey/valkey_ssl.h
+	sed \
+		-e 's|@CMAKE_INSTALL_PREFIX@|$(PREFIX)|g' \
+		-e 's|@CMAKE_INSTALL_LIBDIR@|$(INSTALL_LIBRARY_PATH)|g' \
+		-e 's|@PROJECT_VERSION@|$(LIBVALKEY_SONAME)|g' \
+		$< > $@
+
+$(SSL_PKGCONFNAME): $(SSL_PKGCONF_TEMPLATE)
 	@echo "Generating $@ for pkgconfig..."
-	@echo prefix=$(PREFIX) > $@
-	@echo exec_prefix=\$${prefix} >> $@
-	@echo libdir=$(PREFIX)/$(LIBRARY_PATH) >> $@
-	@echo includedir=$(PREFIX)/include >> $@
-	@echo pkgincludedir=$(PREFIX)/$(INCLUDE_PATH) >> $@
-	@echo >> $@
-	@echo Name: valkey_ssl >> $@
-	@echo Description: SSL Support for valkey. >> $@
-	@echo Version: $(LIBVALKEY_MAJOR).$(LIBVALKEY_MINOR).$(LIBVALKEY_PATCH) >> $@
-	@echo Requires: valkey >> $@
-	@echo Libs: -L\$${libdir} -lvalkey_ssl >> $@
-	@echo Libs.private: -lssl -lcrypto >> $@
+	sed \
+		-e 's|@CMAKE_INSTALL_PREFIX@|$(PREFIX)|g' \
+		-e 's|@CMAKE_INSTALL_LIBDIR@|$(INSTALL_LIBRARY_PATH)|g' \
+		-e 's|@PROJECT_VERSION@|$(LIBVALKEY_SONAME)|g' \
+		$< > $@
 
 install: $(DYLIBNAME) $(STLIBNAME) $(PKGCONFNAME) $(SSL_INSTALL)
 	mkdir -p $(INSTALL_INCLUDE_PATH)/adapters $(INSTALL_LIBRARY_PATH)