From c4605db11bc3d3cd75362b833901ba33e22035f5 Mon Sep 17 00:00:00 2001
From: Demis Bellot <demis.bellot@gmail.com>
Date: Wed, 3 Apr 2024 21:31:07 +0800
Subject: [PATCH] implement FindSimilarQuestions

---
 MyApp.ServiceInterface/QuestionServices.cs | 30 ++++++++++--
 MyApp.ServiceModel/Posts.cs                | 12 +++++
 MyApp/wwwroot/mjs/dtos.mjs                 | 43 +++++++++++++++++-
 MyApp/wwwroot/pages/Questions/Ask.mjs      | 53 ++++++++++++++++++++--
 4 files changed, 130 insertions(+), 8 deletions(-)

diff --git a/MyApp.ServiceInterface/QuestionServices.cs b/MyApp.ServiceInterface/QuestionServices.cs
index dad4f6d..07c715a 100644
--- a/MyApp.ServiceInterface/QuestionServices.cs
+++ b/MyApp.ServiceInterface/QuestionServices.cs
@@ -1,10 +1,10 @@
 using System.Net;
+using System.Text.RegularExpressions;
 using MyApp.Data;
 using ServiceStack;
 using MyApp.ServiceModel;
 using ServiceStack.IO;
 using ServiceStack.OrmLite;
-using ServiceStack.Text;
 
 namespace MyApp.ServiceInterface;
 
@@ -24,12 +24,12 @@ private List<string> ValidateQuestionTags(List<string>? tags)
             throw new ArgumentException("Maximum of 5 tags allowed", nameof(tags));
         return validTags;
     }
-    
+
     public async Task<object> Get(GetAllAnswers request)
     {
         var question = await questions.GetQuestionAsync(request.Id);
         var modelNames = question.Question?.Answers.Where(x => !string.IsNullOrEmpty(x.Model)).Select(x => x.Model).ToList();
-        var humanAnswers = question.Question?.Answers.Where(x => string.IsNullOrEmpty(x.Model)).Select(x => x.Id.SplitOnFirst("-")[1]).ToList();
+        var humanAnswers = question.Question?.Answers.Where(x => string.IsNullOrEmpty(x.Model)).Select(x => x.Id.LeftPart("-")).ToList();
         modelNames?.AddRange(humanAnswers ?? []);
         var answers = question
             .GetAnswerFiles()
@@ -41,6 +41,30 @@ public async Task<object> Get(GetAllAnswers request)
         };
     }
     
+    static Regex AlphaNumericRegex = new("[^a-zA-Z0-9]", RegexOptions.Compiled);
+    static Regex SingleWhiteSpaceRegex = new( @"\s+", RegexOptions.Multiline | RegexOptions.Compiled);
+
+    public async Task<object> Any(FindSimilarQuestions request)
+    {
+        var searchPhrase = AlphaNumericRegex.Replace(request.Text, " ");
+        searchPhrase = SingleWhiteSpaceRegex.Replace(searchPhrase, " ").Trim();
+        if (searchPhrase.Length < 15)
+            throw new ArgumentException("Search text must be at least 20 characters", nameof(request.Text));
+
+        using var dbSearch = HostContext.AppHost.GetDbConnection(Databases.Search);
+        var q = dbSearch.From<PostFts>()
+            .Where("Body match {0} AND instr(RefId,'-') == 0", searchPhrase)
+            .OrderBy("rank")
+            .Limit(10);
+        
+        var results = await dbSearch.SelectAsync(q);
+        var posts = await Db.PopulatePostsAsync(results);
+
+        return new FindSimilarQuestionsResponse
+        {
+            Results = posts
+        };
+    }
 
     public async Task<object> Any(AskQuestion request)
     {
diff --git a/MyApp.ServiceModel/Posts.cs b/MyApp.ServiceModel/Posts.cs
index 29f8bc3..80c414c 100644
--- a/MyApp.ServiceModel/Posts.cs
+++ b/MyApp.ServiceModel/Posts.cs
@@ -293,6 +293,18 @@ public class GetQuestionFile : IGet, IReturn<string>
     public int Id { get; set; }
 }
 
+public class FindSimilarQuestions : IGet, IReturn<FindSimilarQuestionsResponse>
+{
+    [ValidateNotEmpty, ValidateMinimumLength(20)]
+    public string Text { get; set; }
+}
+
+public class FindSimilarQuestionsResponse
+{
+    public List<Post> Results { get; set; }
+    public ResponseStatus? ResponseStatus { get; set; }
+}
+
 [ValidateIsAuthenticated]
 public class AskQuestion : IPost, IReturn<AskQuestionResponse>
 {
diff --git a/MyApp/wwwroot/mjs/dtos.mjs b/MyApp/wwwroot/mjs/dtos.mjs
index 4495357..bf860ed 100644
--- a/MyApp/wwwroot/mjs/dtos.mjs
+++ b/MyApp/wwwroot/mjs/dtos.mjs
@@ -1,5 +1,5 @@
 /* Options:
-Date: 2024-03-29 23:35:25
+Date: 2024-04-03 11:09:35
 Version: 8.22
 Tip: To override a DTO option, remove "//" prefix before updating
 BaseUrl: https://localhost:5001
@@ -374,6 +374,14 @@ export class CalculateLeaderboardResponse {
     /** @type {ModelWinRate[]} */
     modelWinRate;
 }
+export class FindSimilarQuestionsResponse {
+    /** @param {{results?:Post[],responseStatus?:ResponseStatus}} [init] */
+    constructor(init) { Object.assign(this, init) }
+    /** @type {Post[]} */
+    results;
+    /** @type {?ResponseStatus} */
+    responseStatus;
+}
 export class AskQuestionResponse {
     /** @param {{id?:number,slug?:string,redirectTo?:string,responseStatus?:ResponseStatus}} [init] */
     constructor(init) { Object.assign(this, init) }
@@ -601,6 +609,15 @@ export class CalculateLeaderBoard {
     getMethod() { return 'GET' }
     createResponse() { return new CalculateLeaderboardResponse() }
 }
+export class FindSimilarQuestions {
+    /** @param {{text?:string}} [init] */
+    constructor(init) { Object.assign(this, init) }
+    /** @type {string} */
+    text;
+    getTypeName() { return 'FindSimilarQuestions' }
+    getMethod() { return 'GET' }
+    createResponse() { return new FindSimilarQuestionsResponse() }
+}
 export class AskQuestion {
     /** @param {{title?:string,body?:string,tags?:string[],refId?:string}} [init] */
     constructor(init) { Object.assign(this, init) }
@@ -712,6 +729,17 @@ export class CreateWorkerAnswer {
     getMethod() { return 'POST' }
     createResponse() { return new IdResponse() }
 }
+export class RankAnswers {
+    /** @param {{postId?:number,votes?:{ [index: string]: number; }}} [init] */
+    constructor(init) { Object.assign(this, init) }
+    /** @type {number} */
+    postId;
+    /** @type {{ [index: string]: number; }} */
+    votes;
+    getTypeName() { return 'RankAnswers' }
+    getMethod() { return 'POST' }
+    createResponse() { return new IdResponse() }
+}
 export class CreateComment {
     /** @param {{id?:string,body?:string}} [init] */
     constructor(init) { Object.assign(this, init) }
@@ -791,6 +819,19 @@ export class PostVote {
     getMethod() { return 'POST' }
     createResponse() { }
 }
+export class CreateAvatar {
+    /** @param {{userName?:string,textColor?:string,bgColor?:string}} [init] */
+    constructor(init) { Object.assign(this, init) }
+    /** @type {string} */
+    userName;
+    /** @type {?string} */
+    textColor;
+    /** @type {?string} */
+    bgColor;
+    getTypeName() { return 'CreateAvatar' }
+    getMethod() { return 'GET' }
+    createResponse() { return '' }
+}
 export class RenderComponent {
     /** @param {{ifQuestionModified?:number,regenerateMeta?:number,question?:QuestionAndAnswers,home?:RenderHome}} [init] */
     constructor(init) { Object.assign(this, init) }
diff --git a/MyApp/wwwroot/pages/Questions/Ask.mjs b/MyApp/wwwroot/pages/Questions/Ask.mjs
index 1b743d3..98bff6b 100644
--- a/MyApp/wwwroot/pages/Questions/Ask.mjs
+++ b/MyApp/wwwroot/pages/Questions/Ask.mjs
@@ -1,13 +1,31 @@
 import { ref, watchEffect, nextTick, onMounted } from "vue"
 import { queryString } from "@servicestack/client"
 import { useClient, useUtils } from "@servicestack/vue"
-import { AskQuestion, PreviewMarkdown } from "dtos.mjs"
+import { AskQuestion, PreviewMarkdown, FindSimilarQuestions } from "dtos.mjs"
 
 export default {
     template:`
         <AutoForm ref="autoform" type="AskQuestion" v-model="request" header-class="" submit-label="Create Question" 
             :configureField="configureField" @success="onSuccess">
             <template #heading></template>
+            <template #footer>
+                <div v-if="similarQuestions.length" class="px-6">
+                    <div class="px-4 pb-2 bg-gray-50 dark:bg-gray-900 rounded-md">
+                        <div class="flex justify-between items-center">
+                            <h3 class="my-4 select-none text-xl font-semibold flex items-center cursor-pointer" @click="expandSimilar=!expandSimilar">
+                                <svg :class="['w-4 h-4 inline-block mr-1 transition-all',!expandSimilar ? '-rotate-90' : '']" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path fill="currentColor" d="M11.178 19.569a.998.998 0 0 0 1.644 0l9-13A.999.999 0 0 0 21 5H3a1.002 1.002 0 0 0-.822 1.569z"/></svg>
+                                Similar Questions
+                            </h3>
+                            <span class="text-sm text-gray-500">has this been asked before?</span>
+                        </div>
+                        <div v-if="expandSimilar" class="pl-4">
+                            <div v-for="q in similarQuestions" :key="q.id" class="pb-2">
+                                <a :href="'/questions/' + q.id + '/' + q.slug" target="_blank" class="text-indigo-600 dark:text-indigo-300 hover:text-indigo-800">{{ q.title }}</a>
+                            </div>
+                        </div>
+                    </div>
+                </div> 
+            </template>
         </AutoForm>
         <div v-if="request.body" class="pb-40">
             <h3 class="my-4 text-xl font-semibold">Preview</h3>
@@ -20,7 +38,9 @@ export default {
         
         const client = useClient()
         const autoform = ref()
-        const request = ref(new AskQuestion())
+        const savedJson = localStorage.getItem('ask')
+        const saved = savedJson ? JSON.parse(savedJson) : {}
+        const request = ref(new AskQuestion(saved))
         const qs = queryString(location.search)
         if (qs.title) request.value.title = qs.title
         if (qs.body) request.value.body = qs.body
@@ -28,6 +48,8 @@ export default {
         if (qs.refId || qs.refid) request.value.refId = qs.refId || qs.refid
         const previewHtml = ref('')
         let allTags = localStorage.getItem('data:tags.txt')?.split('\n') || []
+        const expandSimilar = ref(true)
+        const similarQuestions = ref([])
 
         const { createDebounce } = useUtils()
         let lastBody = ''
@@ -47,8 +69,30 @@ export default {
         watchEffect(async () => {
             debounceApi(request.value.body)
         })
+
+        watchEffect(async () => {
+            if ((request.value.title ?? '').trim().length > 19) {
+                findSimilarQuestions(request.value.title)
+            }
+        })
+
+        let lastJson = ''        
+        watchEffect(async () => {
+            const json = JSON.stringify(request.value)
+            if (json === lastJson) return
+            localStorage.setItem('ask', json)
+            lastJson = json
+        })
+
+        async function findSimilarQuestions(text) {
+            const api = await client.api(new FindSimilarQuestions({ text }))
+            if (api.succeeded) {
+                similarQuestions.value = api.response.results || []
+            }
+        }
         
         function onSuccess(r) {
+            localStorage.removeItem('ask')
             if (r.redirectTo) {
                 location.href = r.redirectTo
             }
@@ -56,7 +100,8 @@ export default {
         
         onMounted(async () => {
             if (allTags.length === 0) {
-                const txt = await (await fetch('/data/tags.txt')).text()
+                let txt = await (await fetch('/data/tags.txt')).text()
+                txt = txt.replace(/\r\n/g,'\n')
                 localStorage.setItem('data:tags.txt', txt)
                 allTags = txt.split('\n')
             }
@@ -69,6 +114,6 @@ export default {
             }
         }
         
-        return { request, previewHtml, autoform, configureField, onSuccess }
+        return { request, previewHtml, autoform, expandSimilar, similarQuestions, configureField, onSuccess }
     }
 }