phoenix_live_view_dropzone

module Upload exposing (Upload, UploadExport, UploadId, UploadStatus(..), UploadTarget, createUpload, export, updateUploadProgress)

import File exposing (File)
import Http exposing (Progress(..))
import Task exposing (Task)
import Time exposing (Posix)


type alias UploadId =
    String


type UploadStatus
    = InProgress
    | Done
    | Error


type alias UploadExport =
    { id : UploadId
    , name : String
    , progress : Int
    , sent : Int
    , size : Int
    , status : String
    }


type alias Upload =
    { file : File
    , id : UploadId
    , name : String
    , progress : Int
    , sent : Int
    , size : Int
    , status : UploadStatus
    }


type alias UploadTarget =
    { id : UploadId
    , url : String
    }


createUpload : (Upload -> msg) -> File -> Cmd msg
createUpload msg file =
    let
        idFromTime : Posix -> UploadId
        idFromTime posix =
            Time.posixToMillis posix |> String.fromInt

        generateId : Posix -> Task x UploadId
        generateId =
            Task.succeed << idFromTime

        setIdInUpload : UploadId -> Task x Upload
        setIdInUpload =
            Task.succeed << makeUpload file
    in
    Time.now |> Task.andThen generateId |> Task.andThen setIdInUpload |> Task.perform msg


export : Upload -> UploadExport
export upload =
    let
        status : String
        status =
            case upload.status of
                InProgress ->
                    "InProgress"

                Done ->
                    "Done"

                Error ->
                    "Error"
    in
    { id = upload.id, name = upload.name, progress = upload.progress, sent = upload.sent, size = upload.size, status = status }


makeUpload : File -> String -> Upload
makeUpload file id =
    let
        name : String
        name =
            File.name file

        size : Int
        size =
            File.size file
    in
    { file = file, id = id, name = name, progress = 0, sent = 0, size = size, status = InProgress }


updateUploadProgress : Upload -> Progress -> Upload
updateUploadProgress upload progress =
    case progress of
        Sending data ->
            let
                percentage : Int
                percentage =
                    ceiling ((toFloat data.sent / toFloat upload.size) * 100)
            in
            { upload | progress = percentage, sent = data.sent }

        _ ->
            upload