' Copyright (C) 2022  Andy
' This program is free software: you can redistribute it and/or modify
' it under the terms of the GNU General Public License as published by
' the Free Software Foundation, either version 3 of the License, or
' (at your option) any later version.
'
' This program is distributed in the hope that it will be useful,
' but WITHOUT ANY WARRANTY
Imports PersonalUtilities.Functions.XML
Imports PersonalUtilities.Functions.RegularExpressions
Imports PersonalUtilities.Tools.WebDocuments.JSON
Imports System.Net
Imports SCrawler.API.Imgur.Declarations
Imports SCrawler.API.Base
Namespace API.Imgur
    Namespace Declarations
        Friend Module Imgur_Declarations
            Friend ReadOnly PostRegex As RParams = RParams.DMS("/([\w\d]+?)(|\.[\w]{0,4})\Z", 1)
        End Module
    End Namespace
    Friend NotInheritable Class Envir
        Private Sub New()
        End Sub
        Friend Shared Function GetGallery(ByVal URL As String, Optional ByVal e As ErrorsDescriber = Nothing) As List(Of String)
            Try
                If Not Settings.ImgurClientID.IsEmptyString And Not URL.IsEmptyString Then
                    Dim __url$ = RegexReplace(URL, PostRegex)
                    If Not __url.IsEmptyString Then
                        __url = $"https://api.imgur.com/post/v1/albums/{__url}?client_id={Settings.ImgurClientID.Value}&include=media"
                        Using w As New WebClient
                            Dim r$ = w.DownloadString(__url)
                            If Not r.IsEmptyString Then
                                Using j As EContainer = JsonDocument.Parse(r).XmlIfNothing
                                    If j.Contains("media") Then
                                        Dim UrlsList As New List(Of String)
                                        Dim tmpUrl$
                                        For Each m As EContainer In j("media")
                                            tmpUrl = m.Value("url")
                                            If Not tmpUrl.IsEmptyString Then UrlsList.ListAddValue(tmpUrl, Base.LNC)
                                        Next
                                        Return UrlsList
                                    End If
                                End Using
                            End If
                        End Using
                    End If
                End If
                Return Nothing
            Catch ex As Exception
                Return DownloadingException(ex, $"[API.Imgur.Envir.GetGallery({URL})]", Nothing, e)
            End Try
        End Function
        Friend Shared Function GetImage(ByVal URL As String, Optional ByVal e As ErrorsDescriber = Nothing) As String
            Try
                If Not Settings.ImgurClientID.IsEmptyString And Not URL.IsEmptyString Then
                    Dim __url$ = RegexReplace(URL, PostRegex)
                    If Not __url.IsEmptyString Then
                        __url = $"https://api.imgur.com/3/image/{__url}?client_id={Settings.ImgurClientID.Value}&include=media"
                        Using w As New WebClient
                            Dim r$ = w.DownloadString(__url)
                            If Not r.IsEmptyString Then Return JsonDocument.Parse(r).XmlIfNothing.Value({"data"}, "link")
                        End Using
                    End If
                End If
                Return String.Empty
            Catch ex As Exception
                Return DownloadingException(ex, $"[API.Imgur.Envir.GetImage({URL})]", String.Empty, e)
            End Try
        End Function
        Friend Shared Function GetVideoInfo(ByVal URL As String) As IEnumerable(Of UserMedia)
            Try
                If Not URL.IsEmptyString AndAlso URL.ToLower.Contains("imgur") AndAlso Not Settings.ImgurClientID.IsEmptyString Then
                    Dim img$ = GetImage(URL, EDP.ReturnValue)
                    If Not img.IsEmptyString Then
                        Return {New UserMedia(img)}
                    Else
                        Return GetGallery(URL, EDP.ReturnValue).ListIfNothing.Select(Function(u) New UserMedia(u))
                    End If
                End If
                Return Nothing
            Catch ex As Exception
                Return ErrorsDescriber.Execute(EDP.ShowMainMsg + EDP.SendInLog, ex, "Imgur standalone downloader: fetch media error")
            End Try
        End Function
        Private Shared Function DownloadingException(ByVal ex As Exception, ByVal Message As String,
                                                     ByVal NullArg As Object, ByVal e As ErrorsDescriber) As Object
            If TypeOf ex Is WebException Then
                Dim obj As HttpWebResponse = TryCast(DirectCast(ex, WebException).Response, HttpWebResponse)
                If Not obj Is Nothing Then
                    If obj.StatusCode = HttpStatusCode.NotFound Then
                        Return NullArg
                    ElseIf obj.StatusCode = HttpStatusCode.Unauthorized Then
                        MyMainLOG = "Imgur credentials expired"
                        Return NullArg
                    End If
                End If
            End If
            If Not e.Exists Then e = New ErrorsDescriber(EDP.ReturnValue + EDP.SendInLog)
            Return ErrorsDescriber.Execute(e, ex, Message, NullArg)
        End Function
    End Class
End Namespace