<#
.SYNOPSIS
SharePoint Production Toolkit - Scriptates a full SharePoint farm inventory including:SharePoint Production Toolkit - Script 15 - Farm Inventory Report
- Farm name and version
- Servers in the farm
- Server roles and status
- Service instances across the farm

Supports migration planning, governance reviews, and environment validation.

.PARAMETER WebAppUrl
Context only (not required for farm-level scan, kept for toolkit consistency)

.PARAMETER OutputCsv
Full path to output CSV

.PARAMETER NoPrompt
Skips confirmation prompt
#>

[CmdletBinding()]
param(
    [Parameter(Mandatory = $true)]
    [string]$OutputCsv,

    [string]$WebAppUrl,

    [switch]$NoPrompt
)

Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"

Write-Host ""
Write-Host "SCRIPT 15 - FARM INVENTORY REPORT" -ForegroundColor Cyan
Write-Host "READ-ONLY. NO CHANGES ARE MADE." -ForegroundColor Green
Write-Host ""

# ------------------------------------------------------------
# Load SharePoint Snap-in
# ------------------------------------------------------------
try {
    if (-not (Get-PSSnapin "Microsoft.SharePoint.PowerShell" -ErrorAction SilentlyContinue)) {
        Add-PSSnapin "Microsoft.SharePoint.PowerShell"
    }
}
catch {
    throw "Run in SharePoint Management Shell. Error: $($_.Exception.Message)"
}

# ------------------------------------------------------------
# Output Setup
# ------------------------------------------------------------
$outDir = Split-Path -Path $OutputCsv -Parent
if ([string]::IsNullOrWhiteSpace($outDir)) {
    throw "Provide full output path. Example: C:\Temp\FarmInventory.csv"
}

if (-not (Test-Path $outDir)) {
    New-Item -Path $outDir -ItemType Directory -Force | Out-Null
}

$timestamp   = (Get-Date).ToString("yyyyMMdd_HHmmss")
$baseName    = [System.IO.Path]::GetFileNameWithoutExtension($OutputCsv)
$summaryPath = Join-Path $outDir ("{0}_{1}_Summary_ByRisk.csv" -f $baseName, $timestamp)
$logPath     = Join-Path $outDir ("{0}_{1}_RunLog.txt" -f $baseName, $timestamp)
$errorPath   = Join-Path $outDir ("{0}_{1}_Errors.csv" -f $baseName, $timestamp)

# ------------------------------------------------------------
# Logging Helpers
# ------------------------------------------------------------
$errors = New-Object System.Collections.Generic.List[object]
$log    = New-Object System.Collections.Generic.List[string]

function Log {
    param($msg)
    $line = "[{0}] {1}" -f (Get-Date -Format "yyyy-MM-dd HH:mm:ss"), $msg
    $log.Add($line) | Out-Null
    Write-Host $line
}

function Add-Error {
    param($scope, $msg)
    $errors.Add([pscustomobject]@{
        Timestamp = Get-Date
        Scope     = $scope
        Message   = $msg
    }) | Out-Null
}

if (-not $NoPrompt) {
    Write-Host "This script inventories the SharePoint farm." -ForegroundColor Yellow
    if ((Read-Host "Type YES to continue") -ne "YES") { return }
}

# ------------------------------------------------------------
# Risk Model
# ------------------------------------------------------------
function Get-RiskLevel {
    param($ServerStatus, $ServiceStatus)

    if ($ServerStatus -ne "Online") { return "High" }
    if ($ServiceStatus -eq "Disabled") { return "Medium" }
    return "Low"
}

function Get-Score {
    param($risk)
    switch ($risk) {
        "High"   { return 30 }
        "Medium" { return 60 }
        "Low"    { return 90 }
        default  { return 50 }
    }
}

function Get-Recommendation {
    param($risk)

    switch ($risk) {
        "High"   { return "Server or service not healthy. Investigate before migration." }
        "Medium" { return "Review service configuration and validate expected state." }
        "Low"    { return "Farm configuration healthy. Suitable for migration readiness baseline." }
    }
}

# ------------------------------------------------------------
# Main Execution
# ------------------------------------------------------------
$results = New-Object System.Collections.Generic.List[object]

try {
    $farm = Get-SPFarm
    Log "Collected farm information."
}
catch {
    Add-Error "Farm" $_.Exception.Message
    throw
}

# Servers
try {
    $servers = Get-SPServer
    Log ("Found {0} servers in farm." -f $servers.Count)
}
catch {
    Add-Error "Servers" $_.Exception.Message
    throw
}

# Service Instances
try {
    $services = Get-SPServiceInstance -All
    Log ("Collected service instances.")
}
catch {
    Add-Error "Services" $_.Exception.Message
    throw
}

foreach ($server in $servers) {
    try {
        $serverName  = $server.Name
        $serverRole  = [string]$server.Role
        $serverState = [string]$server.Status

        $serverServices = $services | Where-Object { $_.Server.Name -eq $serverName }

        foreach ($svc in $serverServices) {

            $serviceName  = $svc.TypeName
            $serviceState = [string]$svc.Status

            $risk = Get-RiskLevel -ServerStatus $serverState -ServiceStatus $serviceState

            $results.Add([pscustomobject]@{
                FarmName           = $farm.Name
                BuildVersion       = $farm.BuildVersion
                ServerName         = $serverName
                ServerRole         = $serverRole
                ServerStatus       = $serverState
                ServiceName        = $serviceName
                ServiceStatus      = $serviceState
                RiskLevel          = $risk
                Score              = Get-Score $risk
                Category           = "FarmInventory"
                ActionRecommendation = Get-Recommendation $risk
            }) | Out-Null
        }
    }
    catch {
        Add-Error $server.Name $_.Exception.Message
    }
}

# ------------------------------------------------------------
# Export Detail
# ------------------------------------------------------------
$results | Export-Csv -Path $OutputCsv -NoTypeInformation -Encoding UTF8

# ------------------------------------------------------------
# Export Summary
# ------------------------------------------------------------
$results |
    Group-Object RiskLevel |
    ForEach-Object {
        [pscustomobject]@{
            RiskLevel = $_.Name
            Count     = $_.Count
        }
    } |
    Export-Csv -Path $summaryPath -NoTypeInformation -Encoding UTF8

# ------------------------------------------------------------
# Export Logs / Errors
# ------------------------------------------------------------
$log | Set-Content $logPath

if ($errors.Count -gt 0) {
    $errors | Export-Csv -Path $errorPath -NoTypeInformation -Encoding UTF8
    Write-Host ("ERROR REPORT: {0}" -f $errorPath) -ForegroundColor Yellow
}

Write-Host ""
Write-Host ("DETAIL REPORT:  {0}" -f $OutputCsv) -ForegroundColor Green
Write-Host ("SUMMARY REPORT: {0}" -f $summaryPath) -ForegroundColor Green
Write-Host ("RUN LOG:        {0}" -f $logPath) -ForegroundColor Green
Write-Host ""
Write-Host "Complete." -ForegroundColor Green

.DESCRIPTION
READ-ONLY.