$configPath = Join-Path $PSScriptRoot "config.json"

function Load-Config {
    if (Test-Path $configPath) {
        try {
            $script:config = Get-Content $configPath | ConvertFrom-Json
            $script:txtSiteUrl.Text = $config.SiteUrl
            return $true
        }
        catch {
            Write-Error "Invalid config file: $_"
            return $false
        }
    }
    return $false
}

function Save-Config {
    param(
        [string]$SiteUrl,
        [string]$ProductionLibrary,
        [string]$TempLibrary
    )
    
    $config = @{
        SiteUrl = $SiteUrl
        ProductionLibrary = $ProductionLibrary
        TempLibrary = $TempLibrary
    }
    
    $config | ConvertTo-Json | Set-Content $configPath
}

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
            $encodedPath = [System.Web.HttpUtility]::UrlEncode($relativePath)
            
            $folderUri = "https://graph.microsoft.com/v1.0/drives/$($drive.Id)/root:/$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"
    }
}

function Convert-Files {
    if (-not (Connect-SharePoint)) {
    }
    
    $excel = New-Object -ComObject Excel.Application
    $excel.Visible = $false
    
    try {
        Get-PnPFile -Url "/sites/yoursite/$($script:txtTempLib.Text)/FileList.json" -Path $env:TEMP -Filename "FileList.json"
        $files = Get-Content "$env:TEMP\FileList.json" | ConvertFrom-Json
        
        foreach ($file in $files) {
            try {
                $workbook = $excel.Workbooks.Open((Convert-PnPFile -Url $file.OriginalPath -Path $env:TEMP -Filename $file.OriginalFileName))
                $newName = [System.IO.Path]::ChangeExtension($file.OriginalFileName, ".xlsx")
                $workbook.SaveAs([System.IO.Path]::Combine($env:TEMP, $newName), 51) # 51 = xlsx
                Add-PnPFile -Folder "Documents" -Path "$env:TEMP\$newName"
                $script:txtStatus.Text += "Converted $($file.OriginalFileName) to XLSX`n"
            }
            finally {
                $workbook.Close()
            }
        }
    }
    finally {
        $excel.Quit()
    }
}

function Move-Files {
    if (-not (Connect-SharePoint)) {
    }
    
    $files = Get-Content "$env:TEMP\FileList.json" | ConvertFrom-Json
    
    foreach ($file in $files) {
        Move-PnPFile -SourceUrl $file.OriginalPath -TargetUrl $file.TempPath -Force
        $xlsxPath = [System.IO.Path]::ChangeExtension($file.OriginalPath, ".xlsx")
        Move-PnPFile -SourceUrl "$($script:txtProdLib.Text)/$xlsxPath" -TargetUrl $xlsxPath -Force
        $script:txtStatus.Text += "Moved $($file.OriginalFileName) and its XLSX version`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
            $encodedPath = [System.Web.HttpUtility]::UrlEncode($relativePath)
            
            $folderUri = "https://graph.microsoft.com/v1.0/drives/$($drive.Id)/root:/$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
        }

        # Show the Out-GridView
        $selected = $folderObjects | Out-GridView -Title "Select Folder" -PassThru

        # If a folder is selected, browse into it
        if ($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
        }
        else {
            return $selected
        }
    }
    catch {
        $script:txtStatus.Text += "Folder Error: $($_.Exception.Message)`n"
        return $null
    }
}