Hawlucha catch rate

let {calculate, Pokemon, Move} = require("@smogon/calc");

let karateChop = new Move(6, "Karate Chop");
let wingAttack = new Move(6, "Wing Attack");

let karateChopCrit = new Move(6, "Karate Chop", {isCrit: true});
let wingAttackCrit = new Move(6, "Wing Attack", {isCrit: true});

function randomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

function d(x) {
    return Math.floor(x * 4096) / 4096;
}

function r(x) {
    return Math.round(x * 4096) / 4096;
}

function tryHawluchaCatch(hp, maxHp) {
    const catchRate = 100;

    let x = Math.min(255, d(r(d(r(r(3 * maxHp - 2 * hp) * catchRate) / (3 * maxHp)))));
    let y;
    if (x === 0) {
        y = 0;
    } else {
        y = Math.floor(r(65536 / r(Math.pow(r(255 / x), 3 / 16))));
    }

    let chance = Math.pow(y / 65536, 4);

    return Math.random() <= chance;
}

function generateHawlucha(level) {
    let hpIv = randomInt(0, 31);
    let atkIv = randomInt(0, 31);
    let defIv = randomInt(0, 31);

    let nature = randomInt(0, 24);
    let natureName = "Serious";

    switch (nature) {
        case 1: natureName = "Lonely"; break;
        case 2: natureName = "Brave"; break;
        case 3: natureName = "Adamant"; break;
        case 4: natureName = "Naughty"; break;
        case 5: natureName = "Bold"; break;
        case 7: natureName = "Relaxed"; break;
        case 8: natureName = "Impish"; break;
        case 9: natureName = "Lax"; break;
        case 10: natureName = "Timid"; break;
        case 11: natureName = "Hasty"; break;
        case 15: natureName = "Modest"; break;
        case 16: natureName = "Mild"; break;
        case 20: natureName = "Calm"; break;
        case 21: natureName = "Gentle"; break;
    }

    let pokemon = new Pokemon(6, "Hawlucha", {
        ivs: {hp: hpIv, atk: atkIv, def: defIv, spa: 0, spd: 0, spe: 0},
        nature: natureName,
        level: level,
    });

    return {
        maxHp: pokemon.rawStats.hp,
        hp: pokemon.rawStats.hp,
        pokemon: pokemon,
        hasKingsRock: randomInt(0, 19) === 0,
    };
}

function simulateEncounter(useAerialAce, hp, atk, def, level) {

    let ballsLeft = 3;

    let hawlucha = generateHawlucha(level);
    let _hawlucha = hawlucha.pokemon;

    // if (hawlucha.hasKingsRock) {
    //     console.log("Hawlucha has King's Rock.");
    // }

    let _farfetchd = new Pokemon(6, "Farfetch'd", {
        ivs: {hp: hp, atk: atk, def: def, spa: 0, spd: 0, spe: 0},
        evs: {hp: 2, atk: 4, def: 3, spa: 3, spd: 1, spe: 9},
        nature: "Jolly",
        level: 18,
    });

    let farfetchd = {
        maxHp: _farfetchd.rawStats.hp,
        hp: _farfetchd.rawStats.hp,
        pokemon: _farfetchd,
    }

    for (let turn = 1;; ++turn) {
        // console.log("");
        // console.log("Turn " + turn);


        let hawluchaMove = randomInt(0, 3);

        let damageRolls = null;

        let tryBallThrow = !(useAerialAce && hawlucha.maxHp * 0.8 <= hawlucha.hp && farfetchd.maxHp === farfetchd.hp);

        if (tryBallThrow) {
            let catchSuccess = tryHawluchaCatch(hawlucha.hp, hawlucha.maxHp);

            --ballsLeft;

            if (!catchSuccess) {
                // console.log("Failed catch: " + ballsLeft +  " balls left.");

                if (ballsLeft === 0) {
                    return {
                        success: false,
                        turn: turn,
                        result: "out of balls",
                    };
                }
            } else {
                // console.log("Succeeded catch: " + ballsLeft +  " balls left.");

                return {
                    success: true,
                    turn: turn,
                };
            }
        }

        if (level === 19) {
            switch (hawluchaMove) {
                case 0: { // Karate Chop

                    let crit = randomInt(0, 7) === 0;

                    damageRolls = calculate(6, _hawlucha, _farfetchd, crit ? karateChopCrit : karateChop).damage;

                    break;
                }
                case 1:
                case 3: { // Aerial Ace, Wing Attack

                    let crit = randomInt(0, 15) === 0;

                    damageRolls = calculate(6, _hawlucha, _farfetchd, crit ? wingAttackCrit : wingAttack).damage;

                    break;
                }

                case 2: { // Roost
                    // console.log("Hawlucha used Roost.");
                    hawlucha.hp = Math.min(hawlucha.maxHp, hawlucha.hp + Math.floor(hawlucha.maxHp / 2));
                    break;
                }
            }
        } else {
            switch (hawluchaMove) {
                case 0:
                case 2: { // Aerial Ace, Wing Attack

                    let crit = randomInt(0, 15) === 0;

                    damageRolls = calculate(6, _hawlucha, _farfetchd, crit ? wingAttackCrit : wingAttack).damage;

                    break;
                }

                case 1: { // Roost
                    // console.log("Hawlucha used Roost.");
                    hawlucha.hp = Math.min(hawlucha.maxHp, hawlucha.hp + Math.floor(hawlucha.maxHp / 2));
                    break;
                }
                case 3: // Encore, do nothing
                    // console.log("Hawlucha used Encore.");
                    break;
            }
        }

        if (damageRolls !== null) {

            let damage = damageRolls[randomInt(0, 15)];

            // console.log("Farfetch'd took " + damage + " damage.");

            farfetchd.hp -= damage;

            // console.log("Farfetch'd has " + farfetchd.hp + " HP.");

            if (farfetchd.hp <= 0) {
                return {
                    success: false,
                    turn: turn,
                    result: "farfetchd fainted",
                };
            }
        }

        if (!tryBallThrow) {
            // console.log("Farfetch'd used Aerial Ace");

            if (hawlucha.hasKingsRock && damageRolls !== null && randomInt(0, 9) === 0) {
                // console.log("Farfetch'd flinched");
                continue;
            }

            let crit = randomInt(0, 15) === 0;
            damageRolls = calculate(6, _farfetchd, _hawlucha, crit ? wingAttackCrit : wingAttack).damage;
            let damage = damageRolls[randomInt(0, 15)];

            hawlucha.hp -= damage;

            // console.log("Hawlucha has " + hawlucha.hp + " left (damage taken: " + damage + ").");


            if (hawlucha.hp <= 0) {
                // Should almost never happen, can happen with lowest Defense & HP & crit and is at best a 5 / 16 range.

                return {
                    success: false,
                    turn: turn,
                    result: "hawlucha fainted",
                };
            }
        }
    }
}


for (let level = 19; level <= 20; ++level) {

    for (let iv = 0; iv <=1; ++iv) {
        for (let ae = 0; ae <= 1; ++ae) {
            let successCounter = 0;
            let successTurns = 0;

            let ivs = iv === 0 ? 0 : 31;

            for (let i = 0; i < 1000000; ++i) {
                let result = simulateEncounter(!!ae, ivs, ivs, ivs, level);

                if (result.success) {
                    ++successCounter;
                    successTurns += result.turn;
                }
            }

            console.log("");
            console.log("Level: " + level);
            console.log("IVs: " + ivs);
            console.log("Aerial Ace: " + ae.toString());
            console.log((successCounter / 10000).toFixed(2));
            console.log("Turns: " + (successTurns / successCounter).toFixed(2));
        }
    }
}