<#
.SYNOPSIS
    Installs the Veeam Backup for Microsoft 365 collector as a SYSTEM scheduled task.

.DESCRIPTION
    - Copies Send-Vb365BackupStatus.ps1 to Program Files (only admins can modify it, which
      matters because it runs as SYSTEM).
    - Writes the config to ProgramData\BackupDashboard and restricts that folder to SYSTEM and
      Administrators, since it contains the API key.
    - Registers a scheduled task that runs every IntervalMinutes, under Windows PowerShell 5.1
      (powershell.exe) unless -PwshPath points at PowerShell 7.
    Safe to re-run to change settings or update the script. Can sit alongside the other collectors.

    Dashboard company per job: -OrganizationTenants maps Microsoft 365 organization names to
    companies; jobs of unmapped organizations use -Tenant, or the organization's name if no -Tenant.

.EXAMPLE
    .\Install-Vb365Collector.ps1 -ApiUrl https://backups.example.com -Tenant "Acme Corp"
    One client per VB365 server. Prompts for the API key.
.EXAMPLE
    .\Install-Vb365Collector.ps1 -ApiUrl https://backups.example.com -OrganizationTenants @{
        'acme.onmicrosoft.com' = 'Acme Corp'; 'bluewater.onmicrosoft.com' = 'Bluewater Dental' }
    A shared VB365 server protecting several organizations.
#>
#Requires -RunAsAdministrator
[CmdletBinding()]
param(
    [Parameter(Mandatory)][string]$ApiUrl,
    [string]$Tenant,
    [hashtable]$OrganizationTenants = @{},
    [string]$SourceSystem = 'Veeam Backup for M365',
    [ValidateRange(5, 1440)][int]$IntervalMinutes = 60,
    [ValidateRange(1, 720)][int]$LookbackHours = 48,
    [string]$InstallDir = (Join-Path $env:ProgramFiles 'BackupDashboard'),
    # Run under PowerShell 7 instead of Windows PowerShell, e.g. 'C:\Program Files\PowerShell\7\pwsh.exe'
    [string]$PwshPath
)

$ErrorActionPreference = 'Stop'
$Shell = Join-Path $env:SystemRoot 'System32\WindowsPowerShell\v1.0\powershell.exe'
if ($PwshPath) {
    if (-not (Test-Path $PwshPath)) { throw "PowerShell 7 not found at '$PwshPath'." }
    $Shell = $PwshPath
}

# Check VB365 is here before changing anything
$moduleFile = Join-Path $env:ProgramFiles 'Veeam\Backup365\Veeam.Archiver.PowerShell\Veeam.Archiver.PowerShell.psd1'
if (-not (Get-Module -ListAvailable -Name Veeam.Archiver.PowerShell) -and -not (Test-Path $moduleFile)) {
    throw 'The Veeam Backup for Microsoft 365 PowerShell module (Veeam.Archiver.PowerShell) is not installed on this server.'
}
if (-not $Tenant -and $OrganizationTenants.Count -eq 0) {
    Write-Warning 'No -Tenant or -OrganizationTenants: jobs will be listed under their Microsoft 365 organization name.'
}

# Shared installer code: in the repo it's in ..\common, so copy the whole collectors folder
$sharedModule = @(
    (Join-Path $PSScriptRoot 'BackupDashboard.Collector.psm1'),
    (Join-Path (Join-Path (Join-Path $PSScriptRoot '..') 'common') 'BackupDashboard.Collector.psm1')
) | Where-Object { Test-Path $_ } | Select-Object -First 1
if (-not $sharedModule) {
    throw "BackupDashboard.Collector.psm1 not found. Copy the whole collectors folder, including common."
}
Import-Module $sharedModule -Force

$settings = [ordered]@{
    SourceSystem        = $SourceSystem
    LookbackHours       = $LookbackHours
    OrganizationTenants = $OrganizationTenants
}
if ($Tenant) { $settings.Tenant = $Tenant }
Install-CollectorTask -Name 'vb365' -ScriptPath (Join-Path $PSScriptRoot 'Send-Vb365BackupStatus.ps1') `
    -TaskName 'Backup Dashboard - VB365 collector' `
    -TaskDescription 'Sends Veeam Backup for Microsoft 365 results to the Backup Dashboard' `
    -Shell $Shell -ApiUrl $ApiUrl -IntervalMinutes $IntervalMinutes -InstallDir $InstallDir -Settings $settings