SponsorBlock/background.js

chrome.tabs.onUpdated.addListener(function(tabId) {
	chrome.tabs.sendMessage(tabId, {
        message: 'update',
	}, () => void chrome.runtime.lastError ); // Suppress error on Firefox
});

chrome.runtime.onMessage.addListener(function (request, sender, callback) {
	switch(request.message) {
    case "submitTimes":
        submitTimes(request.videoID, callback);
    
        //this allows the callback to be called later by the submitTimes function
        return true; 
    case "addSponsorTime":
        addSponsorTime(request.time, request.videoID, callback);
    
        //this allows the callback to be called later
        return true; 
    case "getSponsorTimes":
        getSponsorTimes(request.videoID, function(sponsorTimes) {
            callback({
                        sponsorTimes: sponsorTimes
            })
        });
    
        //this allows the callback to be called later
        return true;
    case "submitVote":
        submitVote(request.type, request.UUID, callback);
    
        //this allows the callback to be called later
        return true;
    case "alertPrevious":
			chrome.notifications.create("stillThere" + Math.random(), {
        type: "basic",
        title: chrome.i18n.getMessage("wantToSubmit") + request.previousVideoID + "?",
        message: chrome.i18n.getMessage("leftTimes"),
        iconUrl: "./icons/LogoSponsorBlocker256px.png"
			});
	}
});

//add help page on install
chrome.runtime.onInstalled.addListener(function (object) {
    setTimeout(function() {
        chrome.storage.sync.get(["userID"], function(result) {
            const userID = result.userID;

            // If there is no userID, then it is the first install.
            if (!userID){
                //open up the install page
                chrome.tabs.create({url: chrome.extension.getURL("/help/index_en.html")});

                //generate a userID
                const newUserID = generateUserID();
                //save this UUID
                chrome.storage.sync.set({
                    "userID": newUserID
                });
            }
        });
    }, 1500);
});

//gets the sponsor times from memory
function getSponsorTimes(videoID, callback) {
    let sponsorTimes = [];
    let sponsorTimeKey = "sponsorTimes" + videoID;
    chrome.storage.sync.get([sponsorTimeKey], function(result) {
        let sponsorTimesStorage = result[sponsorTimeKey];
        if (sponsorTimesStorage != undefined && sponsorTimesStorage.length > 0) {
            sponsorTimes = sponsorTimesStorage;
        }

        callback(sponsorTimes)
    });
}

function addSponsorTime(time, videoID, callback) {
    getSponsorTimes(videoID, function(sponsorTimes) {
        //add to sponsorTimes
        if (sponsorTimes.length > 0 && sponsorTimes[sponsorTimes.length - 1].length < 2) {
            //it is an end time
            sponsorTimes[sponsorTimes.length - 1][1] = time;
        } else {
            //it is a start time
            let sponsorTimesIndex = sponsorTimes.length;
            sponsorTimes[sponsorTimesIndex] = [];

            sponsorTimes[sponsorTimesIndex][0] = time;
        }

        //save this info
        let sponsorTimeKey = "sponsorTimes" + videoID;
        chrome.storage.sync.set({[sponsorTimeKey]: sponsorTimes}, callback);
    });
}

function submitVote(type, UUID, callback) {
    chrome.storage.sync.get(["userID"], function(result) {
        let userID = result.userID;

        if (userID == undefined || userID === "undefined") {
            //generate one
            userID = generateUserID();
            chrome.storage.sync.set({
                "userID": userID
            });
        }

        //publish this vote
        sendRequestToServer("GET", "/api/voteOnSponsorTime?UUID=" + UUID + "&userID=" + userID + "&type=" + type, function(xmlhttp, error) {
            if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                callback({
                    successType: 1
                });
            } else if (xmlhttp.readyState == 4 && xmlhttp.status == 405) {
                //duplicate vote
                callback({
                    successType: 0,
                    statusCode: xmlhttp.status
                });
            } else if (error) {
                //error while connect
                callback({
                    successType: -1,
                    statusCode: xmlhttp.status
                });
            }
        })
    })
}

function submitTimes(videoID, callback) {
    //get the video times from storage
    let sponsorTimeKey = 'sponsorTimes' + videoID;
    chrome.storage.sync.get([sponsorTimeKey, "userID"], async function(result) {
        let sponsorTimes = result[sponsorTimeKey];
        let userID = result.userID;

        if (sponsorTimes != undefined && sponsorTimes.length > 0) {
            let durationResult = await new Promise((resolve, reject) => {
                chrome.tabs.query({
                    active: true,
                    currentWindow: true
                }, function(tabs) {
                    chrome.tabs.sendMessage(tabs[0].id, {
                        message: "getVideoDuration"
                    }, (response) => resolve(response));
                });
            });

            //check if a sponsor exceeds the duration of the video
            for (let i = 0; i < sponsorTimes.length; i++) {
                if (sponsorTimes[i][1] > durationResult.duration) {
                    sponsorTimes[i][1] = durationResult.duration;
                }
            }

            //submit these times
            for (let i = 0; i < sponsorTimes.length; i++) {
                    //to prevent it from happeneing twice
                    let increasedContributionAmount = false;

                    //submit the sponsorTime
                    sendRequestToServer("GET", "/api/postVideoSponsorTimes?videoID=" + videoID + "&startTime=" + sponsorTimes[i][0] + "&endTime=" + sponsorTimes[i][1]
                    + "&userID=" + userID, function(xmlhttp, error) {
                        if (xmlhttp.readyState == 4 && !error) {
                            callback({
                                statusCode: xmlhttp.status
                            });

                            if (xmlhttp.status == 200) {
                                //add these to the storage log
                                chrome.storage.sync.get(["sponsorTimesContributed"], function(result) {
                                    let currentContributionAmount = 0;
                                    if (result.sponsorTimesContributed != undefined) {
                                        //current contribution amount is known
                                        currentContributionAmount = result.sponsorTimesContributed;
                                    }

                                    //save the amount contributed
                                    if (!increasedContributionAmount) {
                                        increasedContributionAmount = true;
                                        
                                        chrome.storage.sync.set({"sponsorTimesContributed": currentContributionAmount + sponsorTimes.length});
                                    }
                                });
                            }
                        } else if (error) {
                            callback({
                                statusCode: -1
                            });
                        }
                });
            }
        }
    });
}

function sendRequestToServer(type, address, callback) {
    let xmlhttp = new XMLHttpRequest();

    xmlhttp.open(type, serverAddress + address, true);

    if (callback != undefined) {
        xmlhttp.onreadystatechange = function () {
            callback(xmlhttp, false);
        };
  
        xmlhttp.onerror = function(ev) {
            callback(xmlhttp, true);
        };
    }

    //submit this request
    xmlhttp.send();
}

function generateUserID(length = 36) {
        let charset = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        let result = "";
        if (window.crypto && window.crypto.getRandomValues) {
                values = new Uint32Array(length);
                window.crypto.getRandomValues(values);
                for (i = 0; i < length; i++) {
                        result += charset[values[i] % charset.length];
                }
                return result;
        } else {
                for (let i = 0; i < length; i++) {
                    result += charset[Math.floor(Math.random() * charset.length)];
                }
                return result;
        }
}