begining of usql command line tool

main.cpp

@@ -1,10 +1,129 @@
 #include "parser.h"
 #include "usql.h"
 
+#include "linenoise.h"
+
 // https://dev.to/joaoh82/what-would-sqlite-look-like-if-written-in-rust-part-1-2np4
 
 using namespace std::chrono;
 
+const std::vector<std::string> commands {
+	"select", "create", "load", "table"
+};
+
+std::string get_history_file_dir() {
+	std::string file{"/.usql_history.txt"};
+	const char *t = std::getenv("HOME");
+
+	if (t == nullptr) return "/tmp/" + file;
+	else return std::string{t} + "/" + file;
+}
+
+
+size_t last_token_index( std::string str ) {
+	// remove trailing white space
+	while( !str.empty() && std::isspace( str.back() ) ) str.pop_back() ;
+
+	// locate the last white space
+	return str.find_last_of( "() \t\n" ) ;
+}
+
+
+void completion(const char *buf, linenoiseCompletions *lc) {
+	if (buf != nullptr) {
+		std::string str{buf};
+
+		const auto pos = last_token_index(str);
+		if (pos == std::string::npos)
+			return;     // cannot find what to complete
+
+			std::string token = str.substr(pos+1);
+			std::string begining = str.substr(0, pos+1);
+
+			for (auto t = commands.begin(); t != commands.end(); ++t) {
+				if(t->find(token) == 0) {
+					std::string completion_string = begining + *t;
+					linenoiseAddCompletion(lc, completion_string.c_str());
+				}
+			}
+	}
+}
+
+char *hints(const char *buf, int *color, int *bold) {
+	//     if (!strcasecmp(buf,"hello")) {
+	//         *color = 35;
+	//         *bold = 0;
+	//         return " World";
+	//     }
+	return nullptr;
+}
+
+
+void setup_linenoise() {
+	std::string history_file = get_history_file_dir();
+
+	linenoiseHistorySetMaxLen(500);
+	linenoiseSetCompletionCallback(completion);
+	linenoiseSetHintsCallback(hints);
+	linenoiseSetMultiLine(1);
+	linenoiseHistoryLoad(history_file.c_str());
+}
+
+void linenoise_line_read(char *line) {
+	linenoiseHistoryAdd(line);
+}
+
+void close_linenoise() {
+	std::string history_file = get_history_file_dir();
+
+	linenoiseHistorySave(history_file.c_str());
+}
+
+void repl() {
+	std::string code;
+	std::string input;
+
+	setup_linenoise();
+
+	usql::USql uSql{};
+
+
+	while (true) {
+		char *line = linenoise(">>> ");
+		if (line == nullptr) break;
+
+		linenoise_line_read(line);
+
+		input = std::string(line);
+
+		if (input == "!quit" || input == "!q")
+			break;
+		else if (input == "!export" || input == "!x") {
+			std::cout << "File to export to: ";
+			std::getline(std::cin, input);
+
+			//write_file_contents(input, code);
+		} else if (input != "") {
+			try {
+				time_point<high_resolution_clock> start_time = high_resolution_clock::now();
+				auto result = uSql.execute(input);
+				time_point<high_resolution_clock> end_time = high_resolution_clock::now();
+
+				std::cout << input << std::endl;
+				std::cout << "run time: " << duration_cast<milliseconds>(end_time - start_time).count() << " ms " << std::endl <<std::endl;
+
+				result->print();
+
+				code += input + "\n";
+			} catch (std::exception &e) {
+				std::cerr << e.what() << std::endl;
+			}
+		}
+	}
+
+	close_linenoise();
+}
+
 int main(int argc, char *argv[]) {
 	std::vector<std::string> sql_commands{
 		    "create table a (i integer not null, s varchar(64), f float null)",
@@ -58,5 +177,9 @@ int main(int argc, char *argv[]) {
 		result->print();
 	}
 
+	std::cout << std::endl << std::endl;
+
+	repl();
+
 	return 0;
 }