//list of sponsors that are contained inside eachother
let similarSponsors = [];

for (let i = 0; i < sponsorTimes.length; i++) {
    //see if the start time is located between the start and end time of the other sponsor time.
    for (let j = 0; j < sponsorTimes.length; j++) {
        if (sponsorTimes[j][0] > sponsorTimes[i][0] && sponsorTimes[j][0] < sponsorTimes[i][1]) {
            //sponsor j is contained in sponsor i
            similarSponsors.push([i, j]);
        }
    }
}

let similarSponsorsGroups = [];
//once they have been added to a group, they don't need to be dealt with anymore
let dealtWithSimilarSponsors = [];

//create lists of all the similar groups (if 1 and 2 are similar, and 2 and 3 are similar, the group is 1, 2, 3)
for (let i = 0; i < similarSponsors.length; i++) {
    if (dealtWithSimilarSponsors.includes(i)) {
        //dealt with already
        continue;
    }

    //this is the group of indexes that are similar
    let group = similarSponsors[i];
    for (let j = 0; j < similarSponsors.length; j++) {
        if (group.includes(similarSponsors[j][0]) || group.includes(similarSponsors[j][1])) {
            //this is a similar group
            group.push(similarSponsors[j][0]);
            group.push(similarSponsors[j][1]);
            dealtWithSimilarSponsors.push(j);
        }
    }
    similarSponsorsGroups.push(group);
}

//remove duplicate indexes in group arrays
for (let i = 0; i < similarSponsorsGroups.length; i++) {
    uniqueArray = similarSponsorsGroups[i].filter(function(item, pos, self) {
        return self.indexOf(item) == pos;
    });

    similarSponsorsGroups[i] = uniqueArray;
}

//gets the getWeightedRandomChoice for each group in an array of groups
function getWeightedRandomChoiceForArray(choiceGroups, weights) {
    let finalChoices = [];
    //the indexes either chosen to be added to final indexes or chosen not to be added
    let choicesDealtWith = [];
    //for each choice group, what are the sums of the weights
    let weightSums = [];

    for (let i = 0; i < choiceGroups.length; i++) {
        //find weight sums for this group
        weightSums.push(0);
        for (let j = 0; j < choiceGroups[i].length; j++) {
            //only if it is a positive vote, otherwise it is probably just a sponsor time with slightly wrong time
            if (weights[choiceGroups[i][j]] > 0) {
                weightSums[weightSums.length - 1] += weights[choiceGroups[i][j]];
            }
        }

        //create a random choice for this group
        let randomChoice = getWeightedRandomChoice(choiceGroups[i], weights, 1)
        finalChoices.push(randomChoice.finalChoices);

        for (let j = 0; j < randomChoice.choicesDealtWith.length; j++) {
            choicesDealtWith.push(randomChoice.choicesDealtWith[j])
        }
    }

    return {
        finalChoices: finalChoices,
        choicesDealtWith: choicesDealtWith,
        weightSums: weightSums
    };
}

//gets a weighted random choice from the indexes array based on the weights.
//amountOfChoices speicifies the amount of choices to return, 1 or more.
//choices are unique
function getWeightedRandomChoice(choices, weights, amountOfChoices) {
    if (amountOfChoices > choices.length) {
        //not possible, since all choices must be unique
        return null;
    }

    let finalChoices = [];
    let choicesDealtWith = [];

    let sqrtWeightsList = [];
    //the total of all the weights run through the cutom sqrt function
    let totalSqrtWeights = 0;
    for (let j = 0; j < choices.length; j++) {
        //multiplying by 10 makes around 13 votes the point where it the votes start not mattering as much (10 + 3)
        //The 3 makes -2 the minimum votes before being ignored completely
        //https://www.desmos.com/calculator/ljftxolg9j
        //this can be changed if this system increases in popularity.
        let sqrtVote = Math.sqrt((weights[choices[j]] + 3) * 10);
        sqrtWeightsList.push(sqrtVote)
        totalSqrtWeights += sqrtVote;

        //this index has now been deat with
        choicesDealtWith.push(choices[j]);
    }

    //iterate and find amountOfChoices choices
    let randomNumber = Math.random();
    //this array will keep adding to this variable each time one sqrt vote has been dealt with
    //this is the sum of all the sqrtVotes under this index
    let currentVoteNumber = 0;
    for (let j = 0; j < sqrtWeightsList.length; j++) {
        if (randomNumber > currentVoteNumber / totalSqrtWeights && randomNumber < (currentVoteNumber + sqrtWeightsList[j]) / totalSqrtWeights) {
            //this one was randomly generated
            finalChoices.push(choices[j]);
            //remove that from original array, for next recursion pass if it happens
            choices.splice(j, 1);
            break;
        }

        //add on to the count
        currentVoteNumber += sqrtWeightsList[j];
    }
    
    //add on the other choices as well using recursion
    if (amountOfChoices > 1) {
        let otherChoices = getWeightedRandomChoice(choices, weights, amountOfChoices - 1).finalChoices;
        //add all these choices to the finalChoices array being returned
        for (let i = 0; i < otherChoices.length; i++) {
            finalChoices.push(otherChoices[i]);
        }
    }

    return {
        finalChoices: finalChoices,
        choicesDealtWith: choicesDealtWith
    };
}