const fs = require('fs');
const path = require('path');

let rawInput = fs.readFileSync(path.join(path.dirname(__filename), `input.txt`), {encoding: 'utf-8'})

//took part one 30min 
console.time('Part one');
console.log(partOne(parseInput(rawInput, false)));
console.timeEnd('Part one');
console.log('\n\n')
console.time('Part two');
console.log(partTwo(parseInput(rawInput, true)));
console.timeEnd('Part two');

function parseInput(rawInput, isPartTwo){
    let input = rawInput.split('\r\n');
    
    return input;
}

async function partOne(equations){
    let sum = 0;
    for(let eq of equations){
        let brackets = findBrackets(eq);
        sum += solve(eq, brackets, false)
    }
    return sum;
}

function partTwo(equations){
    let sum = 0;
    for(let eq of equations){
        let brackets = findBrackets(eq);
        sum += solve(eq, brackets, true)
    }
    return sum;
}

function solve(eq, brackets, isPartTwo){
    let hasNested = true;
    while(hasNested){
        eq = solveNestedBetter(eq, brackets, isPartTwo);
        if(!eq.includes("("))
            hasNested = false;
    }
    return solveSimple(eq, isPartTwo);
}

function solveSimple(eq, addBeforeMultiply){
    eq = eq.split(/ +/);
    if(!eq[0])
        eq.shift()

    if(addBeforeMultiply){
        for(let i = eq.length - 2; i >= 0; i -= 2){
            if(eq[i] == '+'){
                eq[i - 1] = Number(eq[i - 1]) + Number(eq[i + 1]);
                eq.splice(i, 2);
            }
        }    
        return eval(eq.join(" "));
    }else{
        let res = eq.shift();
        for(let i = 0; i < eq.length; i += 2)
            res = eval(res + eq[i] + eq[i + 1]);
        return res;
    }
}

//wrote this home :), what it does it loops through the brackets and checks if bracket doesnt have brackets within them then it solves and continues
function solveNestedBetter(eq, brackets, isPartTwo){
    let keys = Object.keys(brackets);
    for(let i = 0; i < keys.length - 1; i++){
        let start = keys[i].split("_")[0]//0 = index, 1 = start or end
        let next = keys[i + 1].split("_")[0];
        if(start == next){
            let eqToSolve = eq.slice(brackets[`${start}_start`], brackets[`${start}_end`])  
            delete brackets[`${start}_start`]
            delete brackets[`${start}_end`]
            let nestedRes = solveSimple(eqToSolve, isPartTwo);
            eq = eq.replace("(" + eqToSolve + ")", nestedRes.toString().padStart(eqToSolve.length + 2, " "));//I pad the number so the equation stays the same length so the brackets indecies are still correct. I dont know if this is more performant than callind findBrackets function again
            i++;
        }
    }
    return eq
}

function findBrackets(eq){
    let chars = eq.split("");
    let brackets = {};
    for(let i = 0; i < chars.length; i++){
        if(chars[i] == "("){
            brackets[`${i}_start`] = i + 1;
        }
        if(chars[i] == ")"){
            for(let j = chars.length; j >= 0; j--){
                let values = Object.values(brackets)
                if(!brackets.hasOwnProperty(`${j}_end`) && brackets.hasOwnProperty(`${j}_start`)){
                    if(!values.includes(i))
                        brackets[`${j}_end`] = i;
                }
            }
        }
    }
    return brackets;
}

//idk what I was doing here lol i was tired and not at home :)
function solveNested(eq, brackets, isPartTwo){
    let start, end;
    for(let key in brackets){
        start = key.split("_")[0]
        end = brackets[`${start - 1}_end`];
        break;
    }
    let eqToSolve = eq.slice(start, end);
    let hasNested = eqToSolve.indexOf("(");

    if(hasNested == -1){
        delete brackets[`${start - 1}_start`]
        delete brackets[`${start - 1}_end`]
        let nestedRes = solveSimple(eqToSolve, isPartTwo);
        return eq.replace("(" + eqToSolve + ")", nestedRes.toString().padStart(eqToSolve.length + 2, " "));
    }else{
        let keys = Object.keys(brackets);
        let start;
        for(let i = 0; i < keys.length; i++){
            start = keys[i].split("_")[0]
            if(start == keys[i + 1].split("_")[0]){
                eqToSolve = eq.slice(brackets[`${start}_start`], brackets[`${start}_end`])  
                break;
            }
        }
        delete brackets[`${start}_start`]
        delete brackets[`${start}_end`]
        let nestedRes = solveSimple(eqToSolve, isPartTwo);
        return eq.replace("(" + eqToSolve + ")", nestedRes.toString().padStart(eqToSolve.length + 2, " "));
    }
}