added get segments by hash prefix

src/routes/getSkipSegmentsByHash.js

@@ -1,125 +1,36 @@
-const config = require('../config.js');
-const { db, privateDB } = require('../databases/databases.js');
+const hashPrefixTester = require('../utils/hashPrefixTester.js');
+const getSegments = require('./getSkipSegments.js').cleanGetSegments;
 
-const getHash = require('../utils/getHash.js');
-const getIP = require('../utils/getIP.js');
-
-/**
- * @typedef {Object} Segment
- * @property {string} videoID YouTube video ID the segment is meant for
- * @property {number[]} segment Tuple of start and end times in seconds
- * @property {string} category Category of content to skip
- * @property {string} UUID Unique identifier for the specific segment
- */
-
-/**
- * @typedef {Object} Row
- * @property {string} videoID
- * @property {number} startTime
- * @property {number} endTime
- * @property {number} votes
- * @property {string} UUID
- * @property {string} category
- * @property {number} shadowHidden
- */
-
-/**
- * Input an array of database records and get only one back, weighed on votes.
- * The logic is taken from getWeightedRandomChoice, just simplified input and output to not work on indices only.
- * 
- * @param {Row[]} rows
- * @returns {?Row}
- */
-function pickWeightedRandomRow(rows) {
-    if (rows.length === 0) {
-        return null;
-    } else if (rows.length === 1) {
-        return rows[0];
-    }
-
-    const sqrtWeightsList = [];
-    let totalSqrtWeights = 0;
-    for (const row of rows) {
-        let sqrtVote = Math.sqrt((row.votes + 3) * 10);
-        sqrtWeightsList.push(sqrtVote);
-        totalSqrtWeights += sqrtVote;
-    }
-
-    const randomNumber = Math.random();
-    let currentVoteNumber = 0;
-    for (let i = 0; i < sqrtWeightsList.length; i++) {
-        if (randomNumber > currentVoteNumber / totalSqrtWeights && randomNumber < (currentVoteNumber + sqrtWeightsList[i]) / totalSqrtWeights) {
-            return rows[i];
-        }
-        currentVoteNumber += sqrtWeightsList[i];
-    }
-}
-/**
- * @param {string} prefix Lowercased hexadecimal hash prefix
- * @param {string} hashedIP Custom hash of the visitor’s IP address
- * @returns {Object.<string, Segment[]>}
- */
-function getSkipSegmentsByHash(prefix, hashedIP) {
-    /** @type Row[] */
-    const rows = db.prepare('SELECT videoID, startTime, endTime, votes, UUID, category, shadowHidden FROM sponsorTimes WHERE votes >= -1 AND hashedVideoID LIKE ? ORDER BY videoID, startTime')
-            .all(prefix + '%');
-    /** @type {string[]} */
-    const onlyForCurrentUser = privateDB.prepare('SELECT videoID FROM sponsorTimes WHERE hashedIP = ?').all(hashedIP).map(row => row.videoID);
-    /** @type {Object.<string, Segment[][]>} */
-    const rowGroupsPerVideo = {};
-
-    let previousVideoID = null;
-    let previousEndTime = null;
-    for (const row of rows) {
-        /** @TODO check if this logic does what is expected. */
-        if (row.shadowHidden === 1 && onlyForCurrentUser.indexOf(row.videoID) === -1) {
-            // The current visitor’s IP did not submit for the current video.
-            // Do not send shadowHidden segments to them.
-            continue;
-        }
-        // Split up the rows per video and group overlapping segments together.
-        if (!(row.videoID in rowGroupsPerVideo)) {
-            rowGroupsPerVideo[row.videoID] = [];
-        }
-        if (previousVideoID === row.videoID && row.startTime <= previousEndTime) {
-            rowGroupsPerVideo[row.videoID][rowGroupsPerVideo[row.videoID].length - 1].push(row);
-            previousEndTime = Math.max(previousEndTime, row.endTime);
-        } else {
-            rowGroupsPerVideo[row.videoID].push([row]);
-            previousVideoID = row.videoID;
-            previousEndTime = row.endTime;
-        }
-    }
-
-    /** @type {Object.<string, Segment[]>} */
-    const output = {};
-    for (const videoID in rowGroupsPerVideo) {
-        const pickedVideosForVideoID = [];
-        for (const group of rowGroupsPerVideo[videoID]) {
-            pickedVideosForVideoID.push(pickWeightedRandomRow(group));
-        }
-        output[videoID] = pickedVideosForVideoID.map(row => ({ videoID: row.videoID, segment: [row.startTime, row.endTime], category: row.category, UUID: row.UUID }));
-    }
-    return output;
-}
-
-const minimumPrefix = config.minimumPrefix || '3';
-const maximumPrefix = config.maximumPrefix || '32'; // Half the hash.
-const prefixChecker = new RegExp('^[\\dA-F]{' + minimumPrefix + ',' + maximumPrefix + '}$', 'i');
+const databases = require('../databases/databases.js');
+const db = databases.db;
 
 module.exports = async function (req, res) {
-    if (!prefixChecker.test(req.params.prefix)) {
-        res.sendStatus(400).end(); // Exit early on faulty prefix
+    let hashPrefix = req.params.prefix;
+    if (!hashPrefixTester(req.params.prefix)) {
+        res.status(400).send("Hash prefix does not match format requirements."); // Exit early on faulty prefix
+        return;
     }
 
-    const segments = getSkipSegmentsByHash(
-        req.params.prefix.toLowerCase(),
-        getHash(getIP(req) + config.globalSalt)
-    );
+    const categories = req.query.categories
+    ? JSON.parse(req.query.categories)
+    : req.query.category
+    ? [req.query.category]
+    : ['sponsor'];
 
-    if (Object.keys(segments).length > 0) {
-        res.send(segments);
-    } else {
-        res.sendStatus(404); // No skipable segments within this prefix
+    // Get all video id's that match hash prefix
+    const videoIds = db.prepare('all', 'SELECT DISTINCT videoId, hashedVideoID from sponsorTimes WHERE hashedVideoID LIKE ?', [hashPrefix+'%']);
+    if (videoIds.length === 0) {
+        res.sendStatus(404);
+        return;
     }
+
+    let segments = videoIds.map((video) => {
+        return {
+            videoID: video.videoID,
+            hash: video.hashedVideoID,
+            segments: getSegments(video.videoID, categories)
+        };
+    });
+
+    res.status(200).json(segments);
 }