usql/main.cpp

#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)",
		    "insert into a (i, s) values(1, upper('one'))",
//		    "update table a set s = 'null string aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'",
//		    "update table a set i = null",
		    "insert into a (i, s) values(2, 'two')",
		    "insert into a (i, s) values(3, 'two')",
		    "insert into a (i, s) values(4, lower('FOUR'))",
		    "insert into a (i, s) values(5, 'five')",
		    "insert into a (i, s) values(to_date('20.12.1973', '%d.%m.%Y'), 'six')",
		    "save table a into '/tmp/a.csv'",
		    "select i, s from a where i > 2 order by 1 desc offset 1 limit 1",
		    "select distinct s from a",
//		    "select i, s from a where i = 1",
//		    "select i, s from a where s = 'two'",
//		    "select i, s from a where i <= 3 and s = 'one'",
//		    "select i, s from a where i > 0",
		    "delete from a where i = 4",
//		    "select i, s from a where i > 0",
//		    "update a set f = 9.99 where i = 3",
//		    "select i, s, f from a where i = 3",
//		    "update a set s = 'three', f = f + 0.01 where i = 3",
//		    "select i, s, f from a where i = 3",
//		    "create table data (ticker varchar(8), price float null)",
//		    "load data from '/Users/vaclavt/Library/Mobile Documents/com~apple~CloudDocs/Development/usql/data.csv')",
//		    "select ticker, price from data",
//		    "select i, s, f from a where i < 300",
//		    "create table x as select i, s, f from a where i < 300",
//		    "select i, s, f from x where i < 300",
//		    "drop table x",
//		    "select i, s, f from a where i > 300",
//		    "select i, to_string(i, '%d.%m.%Y'), s, f from a where i > 300",
		    "create table prices (datetime integer, symbol varchar(8), prev_close float, open float, price float, change float, change_prct varchar(16))",
		    "load prices from '/Users/vaclavt/Library/Mobile Documents/com~apple~CloudDocs/Development/usql/prices.csv'",
//		    "insert into prices (datetime, symbol, prev_close, open, price, change, change_prct) values (1626979443, 'MPC', 54.08, 53.82, 53.63, -0.832101, '-0.83 %')",
		    "select to_string(datetime, '%d.%m.%Y %H:%M:%S'), symbol, prev_close, open, price, change, change_prct, datetime from prices where symbol = 'SYF' order by 8 desc limit 10"
	};


	usql::USql uSql{};

	for (auto command : sql_commands) {
		time_point<high_resolution_clock> start_time = high_resolution_clock::now();
		auto result = uSql.execute(command);
		time_point<high_resolution_clock> end_time = high_resolution_clock::now();

		std::cout << command << std::endl;
		std::cout << "run time: " << duration_cast<milliseconds>(end_time - start_time).count() << " ms " << std::endl <<std::endl;

		result->print();
	}

	std::cout << std::endl << std::endl;

	repl();

	return 0;
}