#Requires -Version 5.1
<#
.SYNOPSIS
    Service loop wrapper -- runs Process-MailRules.ps1 at a configurable interval.

.DESCRIPTION
    Designed to be launched by NSSM as a Windows service. Runs Process-MailRules.ps1
    in an infinite loop, sleeping ServiceIntervalMinutes between runs.
    Handles graceful shutdown via Ctrl+C / console close events.

.PARAMETER ConfigPath
    Path to config directory (default: ..\config relative to script)

.EXAMPLE
    .\Run-ServiceLoop.ps1
    .\Run-ServiceLoop.ps1 -ConfigPath "C:\work\mail-organizer\config"
#>

param(
    [string]$ConfigPath = (Join-Path $PSScriptRoot "..\config")
)

# --- Load Logger ---
Import-Module (Join-Path $PSScriptRoot "Logger.psm1") -Force

$logDir = Join-Path (Split-Path $ConfigPath -Parent) "logs"
Initialize-Logger -LogDirectory $logDir -Level "Info"

# --- Read interval from settings ---
$settingsFile = Join-Path $ConfigPath "settings.json"
if (-not (Test-Path $settingsFile)) {
    Write-Log "Settings not found: $settingsFile" -Level Error
    exit 1
}

$settings = Get-Content $settingsFile -Raw | ConvertFrom-Json
$intervalMinutes = if ($settings.ServiceIntervalMinutes) { $settings.ServiceIntervalMinutes } else { 5 }

# --- Graceful shutdown flag ---
$script:Running = $true

$cancelHandler = {
    $script:Running = $false
    Write-Log "Shutdown signal received, stopping after current run..." -Level Warn
}

# Register Ctrl+C / console close handler
try {
    [Console]::TreatControlCAsInput = $false
    $null = Register-EngineEvent -SourceIdentifier PowerShell.Exiting -Action $cancelHandler -ErrorAction SilentlyContinue
} catch {
    # Ignore if not supported in this host
}
trap {
    $script:Running = $false
    Write-Log "Service loop terminated by signal" -Level Warn
    break
}

# --- Main loop ---
$processScript = Join-Path $PSScriptRoot "Process-MailRules.ps1"

if (-not (Test-Path $processScript)) {
    Write-Log "Process-MailRules.ps1 not found: $processScript" -Level Error
    exit 1
}

Write-Log "Service loop started (interval: $intervalMinutes min)"

while ($script:Running) {
    Write-Log "Running Process-MailRules.ps1..."

    try {
        & $processScript -ConfigPath $ConfigPath
        Write-Log "Process-MailRules.ps1 completed successfully"
    }
    catch {
        Write-Log "Process-MailRules.ps1 failed: $_" -Level Error
    }

    if (-not $script:Running) { break }

    Write-Log "Waiting $intervalMinutes minute(s) until next run..."

    # Sleep in 1-second intervals for responsive shutdown
    $sleepSeconds = $intervalMinutes * 60
    for ($i = 0; $i -lt $sleepSeconds; $i++) {
        if (-not $script:Running) { break }
        Start-Sleep -Seconds 1
    }
}

Write-Log "Service loop stopped"