<#
.SYNOPSIS
    Runs the collector test suite (Pester): the shared module, each collector against its mock,
    and the installers.

.DESCRIPTION
    Needs PowerShell 7.2+ and Pester 5.5+:
        Install-Module Pester -MinimumVersion 5.5 -Scope CurrentUser

    Each collector runs in its own process, by default under the same PowerShell running the
    tests. On Windows, use -CollectorShell to run them under Windows PowerShell 5.1 instead, as
    the MARS, WSB and VB365 servers do.

    Exits non-zero if any test fails, so it can gate a commit or CI job.

.EXAMPLE
    ./collectors/tests/Invoke-CollectorTests.ps1
.EXAMPLE
    ./collectors/tests/Invoke-CollectorTests.ps1 -CollectorShell powershell.exe
.EXAMPLE
    ./collectors/tests/Invoke-CollectorTests.ps1 -Path ./collectors/tests/Wsb.Tests.ps1
#>
#Requires -Version 7.2
[CmdletBinding()]
param(
    # powershell.exe / pwsh / a full path: the shell the collectors and installers run under
    [string]$CollectorShell,
    # Test files or folders to run; defaults to every *.Tests.ps1 here
    [string[]]$Path = @($PSScriptRoot),
    [ValidateSet('None', 'Normal', 'Detailed', 'Diagnostic')][string]$Output = 'Detailed'
)

$ErrorActionPreference = 'Stop'

$pester = Get-Module -ListAvailable -Name Pester | Where-Object Version -GE '5.5' |
    Sort-Object Version -Descending | Select-Object -First 1
if (-not $pester) {
    throw 'Pester 5.5 or newer is needed: Install-Module Pester -MinimumVersion 5.5 -Scope CurrentUser'
}
Import-Module $pester

if ($CollectorShell) {
    $resolved = Get-Command $CollectorShell -ErrorAction SilentlyContinue
    if (-not $resolved) { throw "Shell not found: $CollectorShell" }
    $env:COLLECTOR_TEST_SHELL = $resolved.Source
}
$shellName = if ($env:COLLECTOR_TEST_SHELL) { $env:COLLECTOR_TEST_SHELL } else { "this PowerShell ($($PSVersionTable.PSVersion))" }
Write-Host "Collectors run under: $shellName"

# All temp folders for this run, removed at the end
$env:COLLECTOR_TEST_TEMP = Join-Path ([IO.Path]::GetTempPath()) ("backup-dashboard-tests-" + [guid]::NewGuid().ToString('N').Substring(0, 8))
try {
    $config = New-PesterConfiguration
    $config.Run.Path = $Path
    $config.Run.PassThru = $true
    $config.Output.Verbosity = $Output
    $result = Invoke-Pester -Configuration $config
} finally {
    Remove-Item -Recurse -Force $env:COLLECTOR_TEST_TEMP -ErrorAction SilentlyContinue
    Remove-Item env:COLLECTOR_TEST_TEMP
}
exit $(if ($result.Result -eq 'Passed') { 0 } else { 1 })