Init commit

.gitignore

+data/config.json
+
+.ionide
+src/Bot/obj
+src/Bot/bin
\ No newline at end of file

README.md

+# WikiMathBot
+
+This is a bot originally made for keeping track of whenever the newest exercise came out for the subject `MA0301`
+
+In order to make the bot functional, it needs a configuration file at `src/Bot/config.json` that looks like this:
+
+```json
+{
+  "BotToken": "<secret discord bot token>",
+  "Class": "ma0301",
+  "Year": "2021v",
+  "SecondsBetweenUpdate": 3600.0
+}
+```
+
+The class and year variables are part of the url to the page:
+
+`https://wiki.math.ntnu.no/<class>/<year>/start`
+
+The project can be run by executing `dotnet run` from within the `src/Bot` directory

WikiMathBot.sln

+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.26124.0
+MinimumVisualStudioVersion = 15.0.26124.0
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{7D95551A-EDA1-409F-B788-06331223141D}"
+EndProject
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "Bot", "src\Bot\Bot.fsproj", "{43083459-0352-497A-9514-2E17FCE3E783}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|Any CPU = Release|Any CPU
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{43083459-0352-497A-9514-2E17FCE3E783}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Debug|x64.Build.0 = Debug|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Debug|x86.Build.0 = Debug|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Release|Any CPU.Build.0 = Release|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Release|x64.ActiveCfg = Release|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Release|x64.Build.0 = Release|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Release|x86.ActiveCfg = Release|Any CPU
+		{43083459-0352-497A-9514-2E17FCE3E783}.Release|x86.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{43083459-0352-497A-9514-2E17FCE3E783} = {7D95551A-EDA1-409F-B788-06331223141D}
+	EndGlobalSection
+EndGlobal

src/Bot/Bot.fsproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <ServerGarbageCollection>true</ServerGarbageCollection>
+  </PropertyGroup>
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="Config.fs" />
+    <Compile Include="Channels.fs" />
+    <Compile Include="WikiMathParser.fs" />
+    <Compile Include="BotCommands.fs" />
+    <Compile Include="WebsiteCheckLoop.fs" />
+    <Compile Include="Program.fs" />
+  </ItemGroup>
+  <ItemGroup>
+    <Content Include="../../data/channels.dat" />
+    <Content Include="../../data/config.json">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Discord.Net" Version="1.0.2" />
+    <PackageReference Include="DSharpPlus" Version="3.2.3" />
+    <PackageReference Include="DSharpPlus.CommandsNext" Version="3.2.3" />
+    <PackageReference Include="FSharp.Data" Version="4.0.1" />
+    <PackageReference Include="Microsoft.Extensions.Configuration" Version="2.1.1" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="2.1.1" />
+  </ItemGroup>
+</Project>
\ No newline at end of file

src/Bot/BotCommands.fs

+namespace Bot
+
+module BotCommands = 
+
+  open System.Threading.Tasks
+  open DSharpPlus.CommandsNext
+  open DSharpPlus.CommandsNext.Attributes
+
+  open Channels
+  
+  type BotCommands() =
+    [<Command("hi")>]
+    member public self.hi(ctx:CommandContext) = 
+      async { ctx.RespondAsync "Hi there" |> ignore } |> Async.StartAsTask :> Task       
+  
+    [<Command("echo")>]
+    member public self.echo(ctx:CommandContext) (message:string) =
+      async { ctx.RespondAsync message |> ignore } |> Async.StartAsTask :> Task 
+  
+    [<Command("toggle")>]
+    member public self.toggle(ctx:CommandContext) =
+      async { 
+        toggleChannel ctx.Channel.Id
+        |> fun channelGotAdded ->
+           match channelGotAdded with
+           | true  -> ctx.RespondAsync "This is now my channel :)"   |> ignore
+           | false -> ctx.RespondAsync "This is now your channel (:" |> ignore
+      } |> Async.StartAsTask :> Task 
\ No newline at end of file

src/Bot/Channels.fs

+namespace Bot
+
+module Channels =
+
+  open FSharp.Data
+  open System.IO
+
+  let private filepath = __SOURCE_DIRECTORY__ + "/../../data/channels.dat"
+
+  let mutable channels = 
+    File.ReadLines(filepath)
+      |> Seq.map (fun line -> line.ToString().AsInteger64())
+      |> Seq.map (uint64)
+      |> set
+
+  let private updateChannels newChannels =
+    newChannels
+    |> Seq.map (fun i -> i.ToString())
+    |> Seq.toList
+    |> fun lines -> File.WriteAllLines(filepath, lines)
+    channels <- newChannels
+
+  let private removeChannel (channelId:uint64) =
+    channels.Remove(channelId)
+    |> updateChannels
+
+  let private addChannel (channelId:uint64) =
+    channels.Add(channelId)
+    |> updateChannels
+  
+  let toggleChannel (channelId:uint64) =
+    match channelId with
+    | channelId when channels.Contains(channelId) -> 
+      removeChannel channelId
+      false
+
+    | channelId -> 
+      addChannel channelId
+      true
+  
+    
\ No newline at end of file

src/Bot/Config.fs

+namespace Bot
+
+module Config = 
+
+  open System.IO
+  open Microsoft.Extensions.Configuration
+
+  let private getConfig =
+    let builder = new ConfigurationBuilder()
+    do builder.SetBasePath( Directory.GetCurrentDirectory() + "/../../data" ) |> ignore
+    do builder.AddJsonFile("config.json") |> ignore
+    builder.Build()
+
+  let config = getConfig
\ No newline at end of file

src/Bot/Program.fs

+namespace Bot
+
+module core = 
+
+  open System
+  open DSharpPlus
+  open DSharpPlus.CommandsNext
+  open System.Threading.Tasks
+
+  open Config
+  open WebsiteCheckLoop
+  open BotCommands
+  open WikiMathParser
+
+  let getDiscordConfig =
+    let conf = new DiscordConfiguration()
+    conf.set_Token config.["BotToken"]
+    conf.set_TokenType TokenType.Bot
+    conf.set_UseInternalLogHandler true
+    conf.set_LogLevel LogLevel.Debug
+    conf
+
+  let getCommandsConfig =
+    let conf = new CommandsNextConfiguration()
+    conf.set_StringPrefix "!"
+    conf
+
+  let client =  new DiscordClient(getDiscordConfig)
+  let commands = client.UseCommandsNext(getCommandsConfig)
+
+  let mainTask =
+    let mutable previousResults = getStatus
+
+    async {
+      client.add_MessageCreated(fun e -> async { Console.WriteLine e.Message.Content } |> Async.StartAsTask :> _)
+      commands.RegisterCommands<BotCommands>()
+      client.ConnectAsync() |> Async.AwaitTask |> Async.RunSynchronously
+      do! scrapePeriodically (scrapeFun client previousResults
+                        >> fun results -> previousResults <- results)
+      do! Async.AwaitTask(Task.Delay(-1))
+    }
+
+  [<EntryPoint>]
+  let main argv =
+    Async.RunSynchronously(mainTask)
+    0
\ No newline at end of file

src/Bot/WebsiteCheckLoop.fs

+namespace Bot
+
+module WebsiteCheckLoop =
+
+  open System
+  open DSharpPlus
+  open Channels
+
+  let private log message = 
+    printfn "[%A] [Info] %s" DateTime.Now message
+
+  let private sendToChannelWith (client:DiscordClient) message id = 
+    log <| sprintf "Sending message to channel: %A" id
+    id
+    |> client.GetChannelAsync
+    |> Async.AwaitTask
+    |> Async.RunSynchronously
+    |> fun channel -> 
+          client.SendMessageAsync(channel, message)
+          |> Async.AwaitTask
+          |> Async.RunSynchronously
+    |> ignore
+  
+  let private formatMessage message link =
+    message + "\n" + link
+
+  let scrapeFun client (previousListOfResults:List<string * string>) (listOfResults:List<string * string>) =
+    log "Scraping website"
+
+    match previousListOfResults, listOfResults with
+    | (previousListOfResults, listOfResults) when previousListOfResults = listOfResults ->
+
+      channels
+      |> Seq.iter (fun id -> sendToChannelWith client (formatMessage <|| Seq.head listOfResults) id)
+
+      Seq.head listOfResults
+      ||> formatMessage
+      |> fun s -> s.Split("\n")
+      |> Seq.map (fun s -> "\t" + s)
+      |> Seq.fold (fun a b -> a + "\n" + b) ""
+      |> sprintf "Found following update: \n%s" 
+      |> log
+
+    | (_, _) ->
+      log "No new content found"
+
+    listOfResults
\ No newline at end of file

src/Bot/WikiMathParser.fs

+namespace Bot
+
+module WikiMathParser =
+
+  open System
+  open FSharp.Data
+  open Config
+
+  let private page = HtmlDocument.Load(sprintf "https://wiki.math.ntnu.no/%s/%s/start" config.["Class"] config.["Year"])
+
+  let private findPDFLink (node:HtmlNode) = 
+    node.CssSelect(".mf_pdf") 
+    |> fun l -> match l with
+                | l when Seq.length l = 0 -> "" 
+                | l -> HtmlNode.attributeValue "href" (Seq.head l)
+                       |> (+) "https://wiki.math.ntnu.no"
+  
+  let getStatus = 
+    (page.CssSelect ".level2 > ul > .level1")
+    |> Seq.map (fun (x:HtmlNode) -> (x.InnerText().TrimStart(), findPDFLink x ))
+    |> Seq.filter (fun (x:string, _) -> x.Contains("Problem Set"))
+    |> Seq.toList
+
+
+  let private timer = new Timers.Timer( config.["SecondsBetweenUpdate"].AsFloat() * 1000.0)
+  let private waitAPeriod = Async.AwaitEvent (timer.Elapsed) |> Async.Ignore
+
+  let scrapePeriodically (callback: List<String * String> -> unit ) = 
+    timer.Start()
+    async {
+      while true do
+        Async.RunSynchronously waitAPeriod
+        getStatus
+        |> callback
+    }