//ProjectEulerTS/Benchmark.ts
//Matthew Ellison
// Created: 10-18-20
//Modified: 03-29-21
//This runs the benchmark functions for the Java version of the ProjectEuler project
//readline-sync is used to get input from the user in a procedural maner and can be installed with "npm install -g readline-sync"
/*
	Copyright (C) 2021  Matthew Ellison

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/


const readlineSync = require("readline-sync");
import { Problem } from "./Problems/Problem";
import { Stopwatch } from "../../Typescript/typescriptClasses/Stopwatch";
import { ProblemSelection } from "./ProblemSelection";


enum BenchmarkOptions{runSpecific = 1, runAllShort, runAll, exit, size};


export class Benchmark{
	private static tooLong: number[] = [14, 15, 23, 24, 25];
	//The driver function for the benchmark selection
	public static benchmarkMenu(): void{
		let selection: BenchmarkOptions = BenchmarkOptions.size;

		Benchmark.printMenu();
		selection = Benchmark.getMenuSelection();

		switch(selection){
			case BenchmarkOptions.runSpecific: Benchmark.runSpecific(); break;
			case BenchmarkOptions.runAllShort: Benchmark.runAllShort(); break;
			case BenchmarkOptions.runAll: Benchmark.runAll(); break;
			case BenchmarkOptions.exit: break;
			case BenchmarkOptions.size: break;
		}
	}
	//Print the benchmark menu
	private static printMenu(): void{
		console.log("1. Run a specific problem");
		console.log("2. Run all problems that have a reasonably short run time");
		console.log("3. Run all problems");
		console.log("4. Exit the menu");
		console.log();
	}
	//Returns a valid menu option
	private static getMenuSelection(): BenchmarkOptions{
		let selection: number;
		let sel: string = readlineSync.question("");
		while(!Benchmark.isValidMenu(sel)){
			console.log("That is an invalid option!\n");
			Benchmark.printMenu();
			selection = Benchmark.getMenuSelection();
		}
		selection = parseInt(sel);
		return selection;
	}
	//Determines if a value is a valid menu option. Helper for getBenchmarkMenuSelection
	private static isValidMenu(sel: string): boolean{
		let selection: number;
		try{
			selection = parseInt(sel);
		}
		catch(error){
			selection = -1;
		}
		if((selection > 0) && (selection < BenchmarkOptions.size)){
			return true;
		}
		else{
			return false;
		}
	}
	//Determines which problem user wants to run and runs it
	private static runSpecific(): void{
		//Ask which problem the user wants to run
		let problemNumber: number = ProblemSelection.getProblemNumber();
		//Ask how many times to run the problem
		let timesToRun: number = Benchmark.getNumberOfTimesToRun();

		//Get the problem and print its description
		let problem: Problem = ProblemSelection.getProblem(problemNumber);
		console.log("\n" + problemNumber + ". " + problem.getDescription());

		//Run the problem the specific number of times
		let totalTime: number = Benchmark.runProblem(problem, timesToRun);

		//Print the results
		console.log(Benchmark.getBenchmarkResults(problem, totalTime, timesToRun));
	}
	//Runs all problems except a few that are specific because of run length
	private static runAllShort(): void{
		//Ask how many times to run the problems
		let timesToRun: number = Benchmark.getNumberOfTimesToRun();

		//Run through all valid problem numbers, skipping a few that are in the tooLong list
		for(let cnt: number = 1;cnt < ProblemSelection.PROBLEM_NUMBERS.length;++cnt){
			let problemNumber: number = ProblemSelection.PROBLEM_NUMBERS[cnt];

			//If the problem number is contained in the list of problems that take too long skip it
			if(Benchmark.tooLong.includes(problemNumber)){
				continue;
			}

			//Get the problem and print its description
			let problem: Problem = ProblemSelection.getProblem(problemNumber);
			console.log(problemNumber + ". " + problem.getDescription());

			//Run each problem the specified number of times
			let totalTime: number = Benchmark.runProblem(problem, timesToRun);

			//Print the results
			console.log(Benchmark.getBenchmarkResults(problem, totalTime, timesToRun));
		}
	}
	//Runs all problems
	private static runAll(): void{
		//Ask how many times to run the problem
		let timesToRun: number = Benchmark.getNumberOfTimesToRun();

		//Run through all valid problem number, skipping a few that are in the tooLong list
		for(let cnt: number = 1;cnt < ProblemSelection.PROBLEM_NUMBERS.length;++cnt){
			let problemNumber: number = ProblemSelection.PROBLEM_NUMBERS[cnt];

			//Get the problem
			let problem: Problem = ProblemSelection.getProblem(problemNumber);

			//Run each problem the specified number of times
			console.log(problemNumber + ". " + problem.getDescription());
			let totalTime: number = Benchmark.runProblem(problem, timesToRun);

			//Print the results
			console.log(Benchmark.getBenchmarkResults(problem, totalTime, timesToRun));
		}
	}
	//Asks how many times a problem is ksupposed to run and returns the value
	private static getNumberOfTimesToRun(): number{
		let numberOfTimesToRun: number = 1;
		let num: string = readlineSync.question("How many times do you want to run this problem? ");
		try{
			numberOfTimesToRun = parseInt(num);
		}
		catch(error){
			console.log("That is an invalid number!");
			numberOfTimesToRun = Benchmark.getNumberOfTimesToRun();
		}
		return numberOfTimesToRun;
	}
	//Runs the problem the given number of times
	private static runProblem(problem: Problem, timesToRun: number): number{
		let totalTime: number = 0;
		process.stdout.write("Solving");
		for(let cnt: number = 0;cnt < timesToRun;++cnt){
			process.stdout.write('.');
			//Reset the data so you are actually counting the run time an additional time
			problem.reset();
			//Solve the problem
			problem.solve();
			//Get the time dat
			totalTime += problem.getTimer().getNano();
		}
		return totalTime;
	}
	//Prints the benchmark results of a problem
	private static getBenchmarkResults(problem: Problem, totalTime: number, timesRun: number): string{
		//Calculate the average run time of the problem
		totalTime /= timesRun;
		let timeResults: string = Stopwatch.getStr(totalTime);

		//Tally the results
		let results: string = "\n\n" + problem.getResult() + "\nIt took an average of " + timeResults + " to run this problem through " + timesRun + " iterations\n\n";
		return results;
	}
}