#Requires -Version 5.1
<#
    JbTecWiz Support Centre -- generated fix script

    Fault : HTTP 500.19 -- the configuration file cannot be read
    Fix   : Install the module the config references
    Source: https://jbtecwiz.com/support/srv-iis-500-19

    Run as     : Elevated PowerShell on the web server
    Expect     : 20 minutes
    Risk       : low
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    0x8007000d, and the error page names a section such as <rewrite> or
    <aspNetCore>.

    HOW TO UNDO IT
    Uninstall the module -- the site returns to its previous broken state.

    This script walks the fix one step at a time and asks before each
    one. Steps with no command are things you do yourself -- it prints
    those and waits. Run with -DryRun to print without executing.

    --------------------------------------------------------------------
    NO WARRANTY - USE AT YOUR OWN RISK

    This script is provided by JbTecWiz as-is and with no warranty of any
    kind, express or implied. You run it entirely at your own risk.

    JbTecWiz accepts no liability for any loss or damage arising from its
    use, including but not limited to data loss, downtime, or configuration
    changes that turn out to be wrong for your system.

    You are responsible for reading this script before running it, for
    satisfying yourself that it suits the machine in front of you, and for
    having a working backup first. Some steps cannot be undone.
    --------------------------------------------------------------------
#>

[CmdletBinding()]
param(
    # Print every step and command without running anything.
    [switch]$DryRun,
    # Do not ask before each step. Read the script first if you use this.
    [switch]$Unattended
)

$ErrorActionPreference = 'Stop'
$script:Failed = 0

function Write-Rule { param([string]$Text)
    Write-Host ''
    Write-Host ('-' * 70) -ForegroundColor DarkGray
    if ($Text) { Write-Host $Text -ForegroundColor Cyan }
}

function Show-Prose { param([string]$Text, [string]$Colour = "Gray")
    if (-not $Text) { return }
    $words = $Text -split "\s+"; $line = "  "
    foreach ($w in $words) {
        if (($line.Length + $w.Length) -gt 74) { Write-Host $line -ForegroundColor $Colour; $line = "  " }
        $line += "$w "
    }
    if ($line.Trim()) { Write-Host $line -ForegroundColor $Colour }
}

function Invoke-Step {
    param(
        [int]$Number, [string]$Do, [string]$Why,
        [scriptblock]$Command, [switch]$Manual, [string]$Shell = "powershell"
    )
    Write-Rule "  Step $Number of 4"
    Show-Prose $Do "White"
    if ($Why) { Write-Host ""; Show-Prose $Why "DarkGray" }

    if ($Manual) {
        Write-Host ''
        Write-Host '  -> Do this yourself, then press Enter to carry on.' -ForegroundColor Yellow
        if (-not $Unattended -and -not $DryRun) { [void](Read-Host) }
        return
    }

    Write-Host ''
    foreach ($l in ($Command.ToString().Trim() -split "`n")) {
        Write-Host ("    " + $l.Trim()) -ForegroundColor Green
    }
    Write-Host ''

    if ($DryRun) { Write-Host "  (dry run -- not executed)" -ForegroundColor DarkGray; return }
    if (-not $Unattended) {
        $a = Read-Host "  Run this step? [Y]es / [S]kip / [Q]uit"
        if ($a -match "^[Qq]") { Write-Host "  Stopped at your request."; exit 0 }
        if ($a -match "^[Ss]") { Write-Host "  Skipped." -ForegroundColor DarkGray; return }
    }
    try { & $Command }
    catch {
        $script:Failed++
        Write-Host ("  Step $Number failed: " + $_.Exception.Message) -ForegroundColor Red
        Show-Prose "The rest of the fix may depend on this. Read the write-up before carrying on." "Red"
        if (-not $Unattended) {
            $c = Read-Host "  Carry on anyway? [y/N]"
            if ($c -notmatch "^[Yy]") { exit 1 }
        }
    }
}

Write-Rule
Write-Host '  HTTP 500.19 -- the configuration file cannot be read' -ForegroundColor White
Write-Host '  Install the module the config references' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: low   Reversible   20 minutes'
Write-Host ''
Show-Prose 'No warranty. Use at your own risk - JbTecWiz accepts no liability. Read it before you run it, and have a backup.' 'DarkYellow'
Write-Rule

if (-not $Unattended -and -not $DryRun) {
    $go = Read-Host '  Ready? [y/N]'
    if ($go -notmatch "^[Yy]") { Write-Host "  Nothing was changed."; exit 0 }
}

Invoke-Step -Number 1 -Do 'Read the section name from the error page. It tells you which module is missing.' -Manual

Invoke-Step -Number 2 -Do 'For <rewrite>: install the URL Rewrite module from Microsoft.' -Why 'A web.config that uses a rewrite rule is invalid on a server without the module, and IIS reports that as a config read failure rather than a missing feature.' -Manual

Invoke-Step -Number 3 -Do 'For <aspNetCore>: install the matching .NET Hosting Bundle, then restart IIS.' -Command {
    cmd.exe /c 'net stop was /y & net start w3svc'
}

Invoke-Step -Number 4 -Do 'List what is installed to confirm.' -Command {
    Get-WebGlobalModule | Select-Object Name | Sort-Object Name
}

Write-Rule "  Confirm it worked"
Show-Prose 'The site returns a page.' 'White'
Write-Host ''
if (-not $DryRun) {
    Invoke-WebRequest http://localhost/ -UseBasicParsing | Select-Object StatusCode
}

Write-Rule
if ($script:Failed -gt 0) {
    Write-Host ("  Finished with " + $script:Failed + " failed step(s).") -ForegroundColor Yellow
    Show-Prose 'Read the full write-up at https://jbtecwiz.com/support/srv-iis-500-19' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Uninstall the module -- the site returns to its previous broken state.' 'DarkGray'
Write-Rule