MVP for szurubooru plugin

bot/module/abstract.js

@@ -245,6 +245,7 @@ function init(mod, globalConfig) {
         mod.addRecognizedCommand(command, commandMethodName);
     })
     logger.debug("Bound command methods for %s as %s", mod.name, mod.getRecognizedCommands());
+    mod.postInit();
 }
 
 exports.AbstractModule = AbstractModule

bot/module/szurubooru/client.js

@@ -1,3 +1,130 @@
 /**
  * Szurubooru api client
  */
+
+let axios = require('axios');
+let { logger } = require('../../logging');
+
+function getRandomInt(min, max) {
+    min = Math.ceil(min);
+    max = Math.floor(max);
+    return Math.floor(Math.random() * (max - min)) + min; //The maximum is exclusive and the minimum is inclusive
+}
+
+class SzurubooruClient {
+
+    _randomSearchQueryValues = "type:image,animated,video sort:random";
+    _randomSearchUrlTemplate = "%s/posts/?offset=%s&limit=%d&query=%s";
+
+    constructor(url, username, token) {
+        this.url = url;
+        this.baseUrl = url.replace('/api', '');
+        this.username = username;
+        this.token = token;
+        this.updateRandomScope();
+    }
+
+    getRandomSearchUrl(offset, limit, tags = []) {
+        var searchQuery = this._randomSearchQueryValues;
+        if (tags !== null && tags.length > 0) {
+            searchQuery = this._randomSearchQueryValues + tags.join(" ");
+        }
+        return this.url + '/posts/?offset=' + offset + '&limit=' + limit + '&query=' + searchQuery;
+    }
+
+    /**
+     * Determine a sane range of offset values
+     * 
+     * @param {*} limit The content limit of a single page
+     * @param {*} total The number of objects to search through
+     */
+    getValidOffsetRange(limit, total) {
+        let offsetOverflow = total % limit;
+        var offsetCeiling = (Math.round(total / limit));
+        if (offsetOverflow === 0) {
+            offsetCeiling -= 1;
+        }
+        return [0, offsetCeiling];
+    }
+
+
+    /**
+     * Determine a random offset based on the potential random search size
+     *
+     * Because Szurubooru doesn't randomize each sort:random search request, we must
+     * manually calculate a random offset for each request to simulate randomness in the
+     * posts returned.
+     * 
+     * @param {*} self 
+     * @param {*} imageCount 
+     */
+    getRandomSearchParameters(imageCount = null) {
+        let resultLimit = 10;
+        var offsetRange = [0, 1];
+        if (imageCount === null) {
+            offsetRange = this.getValidOffsetRange(resultLimit, this.randomImageCount);
+        } else {    
+            offsetRange = this.getValidOffsetRange(resultLimit, imageCount);
+        }
+        return [resultLimit, getRandomInt(offsetRange[0], offsetRange[1])];
+    }
+
+
+    async updateRandomScope() {
+        let client = this;
+        let target = this.getRandomSearchUrl(0, 1);
+        await this.makeGetRequest(target).then((result) => {
+            client.randomImageCount = result.total;
+        });
+        
+    }
+
+    makeGetRequest(url) {
+        logger.debug("Making get request to %s", url);
+        return axios.get(url, {
+            headers: {
+                "Authorization": "Token " + Buffer.from(this.username + ':' + this.token).toString('base64'),
+                "Accept": "application/json"
+            }
+        }).then((response) => {
+            logger.debug("Recieved: %o", response.data);
+            return response.data;
+        }, (err) => {
+            logger.error("Unexpected client error: %o", err);
+            return null;
+        });
+        return self._handle_response("GET", url, None, response)
+    }
+
+    /**
+     * Return a random post matching the optionally provided tags.
+     * 
+     * @param {*} self 
+     * @param {*} tags 
+     */
+    getRandomPost(tags = []) {
+        let client = this;
+        var resultLimit = 0;
+        var randomSearchOffset = 0;
+        if (tags.length === 0) {
+            let randomSearchParameters = this.getRandomSearchParameters();
+            resultLimit = randomSearchParameters[0];
+            randomSearchOffset = randomSearchParameters[1];
+        }
+        let searchUrl = this.getRandomSearchUrl(randomSearchOffset, resultLimit, tags);
+        return this.makeGetRequest(searchUrl)
+            .then((data) => {
+                if (data !== null) {
+                    let limitSpace = Math.min(resultLimit, data.results.length - 1);
+                    let randomPost = data.results[getRandomInt(0, limitSpace)];
+                    return client.baseUrl + '/' + randomPost.contentUrl;
+                } else {
+                    return null
+                }
+            }, (err) => {
+
+            })
+    }
+}
+
+exports.Client = SzurubooruClient;

bot/module/szurubooru/index.js

@@ -4,6 +4,7 @@
 
 let { AbstractModule } = require('../abstract');
 let { logger } = require('../../logging');
+let szurubooruClient = require('./client');
 
 class SzurubooruModule extends AbstractModule {
     constructor() {
@@ -30,7 +31,16 @@ class SzurubooruModule extends AbstractModule {
 '!szurubooru tags <tag_stub> [<tag_stub>...]' list tags similar to each <tag_stub>
 '!szurubooru upload <url>' upload a remote file to szurubooru`;
         this.needConfig = true;
-        this.defaultCommand = 'help';
+        this.defaultCommand = 'random';
+    }
+
+    postInit() {
+        super.postInit();
+        this.client = new szurubooruClient.Client(
+            this.get("url"),
+            this.get("username"),
+            this.get("token")
+        )
     }
 
     getConfigSensitiveFields() {
@@ -42,7 +52,10 @@ class SzurubooruModule extends AbstractModule {
     */
 
     cmd_random(event, ...args) {
-
+        return this.client.getRandomPost().then((data) => {
+            logger.info("Random post: %o", data);
+            return data;
+        });
     }
 }