fsharp_imap_scanner.fs

open System
open MailKit.Net.Imap
open MailKit
open MimeKit

type FolderInfo = {
    name : string
    size : uint64
    }

    
module actions

open model
open MailKit.Net.Imap
open MailKit



let calcFolderSize (folder: IMailFolder) : uint64 =
    printfn "%s" folder.FullName
    let summaries = 
        try
            folder.Open(FolderAccess.ReadOnly) |> ignore
            folder.Fetch(0,-1,MessageSummaryItems.Full)
            |> Seq.cast<IMessageSummary>  
            |> Seq.toList
        with 
        | _ as ex -> 
            printfn "Error fetching folder %s: %s" folder.FullName ex.Message 
            []

    summaries
    |>  List.map<IMessageSummary,uint64> (fun summary ->
            let size= summary.Size |> Option.ofNullable    
            match size with
            | None -> 
                printfn "No size in Folder %s Mail %s" folder.FullName summary.NormalizedSubject
                0UL
            | Some size -> uint64 size ) 
    |> List.sum


let printFolderInfo totalSize folderInfo : unit =
    let percent = (folderInfo.size * 100UL) / totalSize
    printfn "%s: Size %d %d" folderInfo.name (folderInfo.size / 1024UL) percent   
    

let buildFolderInfo (folder: IMailFolder) : FolderInfo = 
    {name=folder.FullName; size= calcFolderSize folder}
   

let getAllFoldersInfos (client: ImapClient): FolderInfo seq =
    let folders = client.GetFolders(client.PersonalNamespaces.[0])
    folders 
    |> Seq.cast<IMailFolder> 
    |> Seq.map (fun folder -> buildFolderInfo folder )


let analyzeFolders (client: ImapClient) =
    let folders = 
        getAllFoldersInfos client 
        |> Seq.sortByDescending(fun folder -> folder.size) 
        |> Seq.cache
    
    let totalSize = folders  |> Seq.sumBy (fun folder -> folder.size)
    
    folders |> Seq.iter (fun folder -> printFolderInfo totalSize folder)



[<EntryPoint>]
let main argv =
    let client = new ImapClient ()
    client.Connect ("mail.yourserver.de", 993, true);
    client.Authenticate ("username", "password");
    
    analyzeFolders client

    0 // return an integer exit code