module startup_requests;

import std.stdio;
import std.datetime;
import std.file;
import std.path;
import std.string;

void createServerStartupRequest(string serverIdentifier) {
    File f = File(getRequestFile(serverIdentifier), "w");
    f.writeln(Clock.currTime(UTC()).toISOExtString());
    f.close();
}

bool isStartupRequested(string serverIdentifier) {
    return exists(getRequestFile(serverIdentifier));
}

void removeStartupRequest(string serverIdentifier) {
    string requestFile = getRequestFile(serverIdentifier);
    if (exists(requestFile)) std.file.remove(requestFile);
}

void removeOldStartupRequests() {
    foreach (string requestFile; findAllStartupRequests()) {
        Duration age = getRequestAge(requestFile);
        if (age > hours(1)) {
            std.file.remove(requestFile);
        }
    }
}



private Duration getRequestAge(string requestFile) {
    string text = readText(requestFile).strip();
    SysTime timestamp = SysTime.fromISOExtString(text, UTC());
    return Clock.currTime(UTC()) - timestamp;
}

private string[] findAllStartupRequests() {
    string[] requestFiles;
    foreach (DirEntry entry; dirEntries(getcwd(), SpanMode.shallow, false)) {
        string filename = baseName(entry.name);
        if (startsWith(filename, "request_") && endsWith(filename, ".txt")) {
            requestFiles ~= entry.name;
        }
    }
    return  requestFiles;
}

private string getRequestFile(string identifier) {
    return "request_" ~ identifier ~ ".txt";
}