# Load configuration from config.json
function Load-Config {
    try {
        $configPath = "$PSScriptRoot\config.json"
        if (Test-Path $configPath) {
            $script:config = Get-Content $configPath -Raw | ConvertFrom-Json
            return $true
        } else {
            return $false
        }
    } catch {
        $script:txtStatus.Text += "Error loading configuration: $($_.Exception.Message)`n"
        return $false
    }
}

# Save configuration to config.json
function Save-Config {
    param (
        [string]$SiteUrl,
        [string]$ProductionLibrary,
        [string]$TempLibrary
    )
    try {
        $configPath = "$PSScriptRoot\config.json"
        $configData = @{
            SiteUrl = $SiteUrl
            ProductionLibrary = $ProductionLibrary
            TempLibrary = $TempLibrary
        }
        $configJson = ConvertTo-Json -InputObject $configData -Compress
        $configJson | Out-File $configPath
        $script:txtStatus.Text += "Configuration saved successfully.`n"
    } catch {
        $script:txtStatus.Text += "Error saving configuration: $($_.Exception.Message)`n"
    }
}

function Get-FolderBrowser {
    param (
        [string]$ParentFolderUrl = ""
    )
    try {
        # Get site ID first
        $siteUrl = $script:txtSiteUrl.Text.TrimEnd('/')
        
        # Get site directly using the URL
        $encodedUrl = [System.Web.HttpUtility]::UrlEncode($siteUrl)
        $site = Invoke-MgGraphRequest -Method GET -Uri "https://graph.microsoft.com/v1.0/sites/sutterhill.sharepoint.com:/sites/tax" -ErrorAction Stop
        
        if (-not $site) {
            throw "Site not found at $siteUrl"
        }

        $script:txtStatus.Text += "Found site: $($site.webUrl)`n"

        # Get drive (document library)
        $drives = Get-MgSiteDrive -SiteId $site.id
        # Handle "Shared Documents" special case
        $libraryName = if ($script:txtProdLib.Text -eq "Shared Documents") { 
            "Documents" 
        } else { 
            $script:txtProdLib.Text 
        }
        $drive = $drives | Where-Object { $_.Name -eq $libraryName }
        
        if (-not $drive) {
            $script:txtStatus.Text += "Available libraries: $($drives.Name -join ', ')`n"
            throw "Library not found: $libraryName"
        }

        # Get root folder first
        # Get root folder first
        if ($ParentFolderUrl) {
            # Get the folder ID first
            # Construct the correct URI for the folder
            # Remove the /sites/tax/Shared Documents/ part from the folder path
            $relativePath = $ParentFolderUrl.Replace("/sites/tax/Shared Documents/", "").TrimStart("/")
            
            # URL encode the relative path, but replace + with %20 for spaces
            $encodedPath = [System.Web.HttpUtility]::UrlEncode($relativePath).Replace("+", "%20")
            
            $folderUri = "https://graph.microsoft.com/v1.0/drives/$($drive.Id)/root:/$encodedPath"
            $script:txtStatus.Text += "Folder URI: $folderUri`n"
            try {
                $folderItem = Invoke-MgGraphRequest -Method GET -Uri $folderUri -ErrorAction Stop
            } catch {
                throw "Folder not found: $($_.Exception.Message)"
            }
            $root = $folderItem
        }
        else {
            $root = Get-MgDriveRoot -DriveId $drive.Id
        }
        
        # Get folders using the root item's ID
        $folders = Get-MgDriveItemChild -DriveId $drive.Id -DriveItemId $root.Id | Where-Object { $_.Folder }

        # Create custom objects for the grid view
        $folderObjects = $folders | ForEach-Object {
            [PSCustomObject]@{
                Name = $_.Name
                ServerRelativeUrl = "/sites/tax/Shared Documents/$($_.Name)"
                IsFolder = $true # Add a property to indicate it's a folder
            }
        }

        # Add ".." entry to go up a level if not at the root
        if ($ParentFolderUrl) {
            $parentUrl = Split-Path -Path $ParentFolderUrl -Parent
            $folderObjects = @([PSCustomObject]@{
                Name = ".."
                ServerRelativeUrl = $parentUrl
                IsFolder = $true
            }) + $folderObjects
        }

        # Create a form and listbox for folder selection
        $form = New-Object System.Windows.Forms.Form
        $form.Text = "Select Folder"
        $form.Size = New-Object System.Drawing.Size(400, 400)
        $listBox = New-Object System.Windows.Forms.ListBox
        $listBox.Size = New-Object System.Drawing.Size(360, 320)
        $listBox.Location = New-Object System.Drawing.Point(10, 10)
        $okButton = New-Object System.Windows.Forms.Button
        $okButton.Location = New-Object System.Drawing.Point(150, 340)
        $okButton.Size = New-Object System.Drawing.Size(75, 23)
        $okButton.Text = "OK"
        $cancelButton = New-Object System.Windows.Forms.Button
        $cancelButton.Location = New-Object System.Drawing.Point(230, 340)
        $cancelButton.Size = New-Object System.Drawing.Size(75, 23)
        $cancelButton.Text = "Cancel"
        $selectFolderButton = New-Object System.Windows.Forms.Button
        $selectFolderButton.Location = New-Object System.Drawing.Point(70, 340)
        $selectFolderButton.Size = New-Object System.Drawing.Size(75, 23)
        $selectFolderButton.Text = "Select Folder"
        $form.Controls.Add($listBox) | Out-Null
        $form.Controls.Add($okButton) | Out-Null
        $form.Controls.Add($cancelButton) | Out-Null
        $form.Controls.Add($selectFolderButton) | Out-Null
        $form.FormBorderStyle = 'FixedDialog'
        $form.StartPosition = 'CenterScreen'
        $form.Add_Shown({$Form.Activate()})
        # Populate listbox
        foreach ($folder in $folderObjects) {
            $listBox.Items.Add($folder.Name) | Out-Null
        }

        # Handle OK button click
        $okButton.Add_Click({
            $form.Tag = $listBox.SelectedItem
            $form.Close()
        })

         # Handle Select Folder button click
        $selectFolderButton.Add_Click({
            $form.Tag = $listBox.SelectedItem + "|SELECT" # Add a flag to indicate folder selection
            $form.Close()
        })

        # Handle Cancel button click
        $cancelButton.Add_Click({
            $form.Tag = $null
            $form.Close()
        })

        # Show the Form as a Dialog
        [void]$form.ShowDialog()

        # Get the selected folder
        $selected = $folderObjects | Where-Object {$_.Name -eq $form.Tag.Split('|')[0]}

         # Check if the "Select Folder" button was clicked
        if ($form.Tag -like "*|SELECT") {
            return $selected # Return the selected folder
        }
        # If a folder is selected, browse into it
        elseif ($selected -and $selected.IsFolder -eq $true -and $selected.Name -ne "..") {
            return Get-FolderBrowser -ParentFolderUrl $selected.ServerRelativeUrl
        }
        elseif ($selected -and $selected.Name -eq "..") {
            return Get-FolderBrowser -ParentFolderUrl $selected.ServerRelativeUrl
        }
        elseif ($selected) {
            return $selected
        }
        else {
            return $null
        }
    }
    catch {
        $script:txtStatus.Text += "Folder Error: $($_.Exception.Message)`n"
        return $null
    }
}

function Connect-SharePoint {
    return Connect-Graph
}

function List-XlsFiles {
    try {
        $script:txtStatus.Text += "Connecting to SharePoint...`n"
        if (-not (Connect-SharePoint)) {
            throw "Failed to connect to SharePoint"
        }
        
        $script:txtStatus.Text += "Getting site...`n"
        $site = Invoke-MgGraphRequest -Method GET -Uri "https://graph.microsoft.com/v1.0/sites/sutterhill.sharepoint.com:/sites/tax" -ErrorAction Stop
        
        $script:txtStatus.Text += "Getting document library...`n"
        $drives = Get-MgSiteDrive -SiteId $site.id
        $libraryName = if ($script:txtProdLib.Text -eq "Shared Documents") { 
            "Documents" 
        } else { 
            $script:txtProdLib.Text 
        }
        $drive = $drives | Where-Object { $_.Name -eq $libraryName }
        
        if (-not $drive) {
            throw "Library not found: $libraryName. Available libraries: $($drives.Name -join ', ')"
        }

        $script:txtStatus.Text += "Getting root folder...`n"
        $root = Get-MgDriveRoot -DriveId $drive.Id
        
        $fileList = @()
        $folderPath = $script:txtFolder.Text

        $script:txtStatus.Text += "Searching for XLS files...`n"
        
        # If a specific folder is selected, search only in that folder
        if (-not [string]::IsNullOrWhiteSpace($folderPath)) {
            $script:txtStatus.Text += "Searching in folder: $folderPath`n"
            # Get the folder ID first
            # Construct the correct URI for the folder
            # Remove the /sites/tax/Shared Documents/ part from the folder path
            $relativePath = $folderPath.Replace("/sites/tax/Shared Documents/", "").TrimStart("/")
            
            # URL encode the relative path, but replace + with %20 for spaces
            $encodedPath = [System.Web.HttpUtility]::UrlEncode($relativePath).Replace("+", "%20")
            
            $folderUri = "https://graph.microsoft.com/v1.0/drives/$($drive.Id)/root:/$encodedPath"
            $script:txtStatus.Text += "Folder URI: $folderUri`n"
            try {
                $folderItem = Invoke-MgGraphRequest -Method GET -Uri $folderUri -ErrorAction Stop
            } catch {
                throw "Folder not found: $($_.Exception.Message)"
            }
            $items = Get-MgDriveItemChild -DriveId $drive.Id -DriveItemId $folderItem.id
        } else {
            $script:txtStatus.Text += "Searching in root folder`n"
            $items = Get-MgDriveItemChild -DriveId $drive.Id -DriveItemId $root.Id
        }

        foreach ($item in $items) {
            $script:txtStatus.Text += "Checking file: $($item.Name)`n"
            if ($item.Name -like "*.xls" -and $item.Name -notlike "*.xlsx") {
                $fileList += [PSCustomObject]@{
                    OriginalPath = $item.WebUrl
                    OriginalFileName = $item.Name
                    TempPath = "$($script:txtTempLib.Text)/$($item.Name)"
                }
                $script:txtStatus.Text += "Found XLS file: $($item.Name)`n"
            }
        }

        if ($fileList.Count -gt 0) {
            $script:txtStatus.Text += "Saving file list...`n"
            $fileList | ConvertTo-Json | Out-File "$env:TEMP\FileList.json"
            $script:txtStatus.Text += "Found $($fileList.Count) XLS files`n"
        } else {
            $script:txtStatus.Text += "No XLS files found`n"
        }
    }
    catch {
        $script:txtStatus.Text += "Error listing files: $($_.Exception.Message)`n"
    }
}