using namespace System.Text

# folder location where the .epub lives
$root = ''

# the title of the .epub (no extension)
$bookTitle = ''

# unzip the .epub
dir $root |
    ? {
        $_.Extension -eq '.epub' -and $_.BaseName -eq $bookTitle
    } |
    % {
        $dest = "$root\$($_.BaseName)"

        if (-not (Test-Path $dest)) {
            Expand-Archive -Path $_.FullName -DestinationPath $dest
        }
    }

# title of the folder of extracted .zip contents file (without extension)

# this tells you where
$container = [xml](Get-Content "$root\$bookTitle\META-INF\container.xml")

$contentFilePath = $container.container.rootfiles.rootfile.'full-path'.Replace('/', '\')

# fetch the folder location of all of the chapters
$contentDir = "$root\$bookTitle\$contentFilePath"
$contentSubdir = (Get-ChildItem $contentDir)[0].Directory.FullName

$content = [xml](Get-Content $contentDir)

# this has the "spine" of the .epub and dictates what order the contents go in
$spine = $content.package.spine.itemref.idref

# this manifest contains all of the parts and  which files they refer to
$manifest = $content.package.manifest

# StringBuilder to collect all of the text into one
$sb = [StringBuilder]::new()

# for every part in the spine, pull out the text and append it to the StringBuilder object
$spine |
    ForEach-Object {
        $id = $_
        # $id

        $manifest.item |
            Where-Object {
                $_.id -eq $id
            } |
            ForEach-Object {
                $partFilePath = "$contentSubdir\$($_.href)"
                # Write-Host -ForegroundColor Yellow $partFilePath
                # (cat $partFilePath)
                [void] $sb.AppendLine((Get-Content $partFilePath))
            }

        }

# write the combined text into one html file
$outFile = "$contentSubdir\combined.html"
$sb.ToString() > $outFile

# make a shortcut for the combined file
$WshShell = New-Object -comObject WScript.Shell
$Shortcut = $WshShell.CreateShortcut("$root\$bookTitle.lnk")
$Shortcut.TargetPath = "$outFile"
$Shortcut.Save()