[CmdletBinding(SupportsShouldProcess = $true)]
param(
    [Parameter(Mandatory = $true)][string]$PythonPath,
    [Parameter(Mandatory = $true)][string]$BackupDirectory,
    [string]$ProjectRoot,
    [string]$Container = 'ys-mysql-dev',
    [string]$Database = 'payroll',
    [switch]$Apply
)
$ErrorActionPreference = 'Stop'
if (-not $ProjectRoot) {
    $ProjectRoot = Split-Path (Split-Path $PSScriptRoot -Parent) -Parent
}
$project = [IO.Path]::GetFullPath($ProjectRoot)
$python = [IO.Path]::GetFullPath($PythonPath)
$backups = [IO.Path]::GetFullPath($BackupDirectory)
$script = Join-Path $project 'scripts\payroll_backup.py'
if (-not (Test-Path -LiteralPath $python -PathType Leaf) -or -not (Test-Path -LiteralPath $script -PathType Leaf)) {
    throw 'Python 或备份程序不存在。'
}
if ($Container -notmatch '^[A-Za-z0-9_.-]+$' -or $Database -notmatch '^[A-Za-z][A-Za-z0-9_]{0,63}$') { throw '容器或数据库标识无效。' }
if (@($python, $script, $backups) | Where-Object { $_.Contains('"') }) { throw '路径不能含双引号。' }
$taskPath = '\PayrollManagementSystem-Backup\'
$common = ' --directory "' + $backups + '" --container ' + $Container + ' --database ' + $Database
$definitions = @(
    @{ Name = 'DailyFull'; Action = 'full'; Time = '02:30' },
    @{ Name = 'ChangedIncremental'; Action = 'incremental'; Time = '00:10' },
    @{ Name = 'BackupCheck'; Action = 'check'; Time = '07:30' }
)
foreach ($definition in $definitions) {
    $arguments = '"' + $script + '" ' + $definition.Action + $common
    [pscustomobject]@{ TaskPath = $taskPath; Name = $definition.Name; Python = $python; Arguments = $arguments; Enabled = [bool]$Apply }
    if (-not $Apply) { continue }
    $existing = Get-ScheduledTask -TaskPath $taskPath -TaskName $definition.Name -ErrorAction SilentlyContinue
    if ($existing -and (@($existing.Actions).Count -ne 1 -or $existing.Actions[0].Execute -ne $python -or $existing.Actions[0].Arguments -ne $arguments)) {
        throw '同名任务已有不同动作，拒绝覆盖。'
    }
    if ($PSCmdlet.ShouldProcess($definition.Name, '注册当前用户本地开发备份任务')) {
        $scheduler = New-Object -ComObject 'Schedule.Service'
        $scheduler.Connect()
        try { $null = $scheduler.GetFolder($taskPath) }
        catch { $null = $scheduler.GetFolder('\').CreateFolder('PayrollManagementSystem-Backup') }
        $action = New-ScheduledTaskAction -Execute $python -Argument $arguments -WorkingDirectory $project
        $trigger = if ($definition.Action -eq 'incremental') {
            New-ScheduledTaskTrigger -Once -At ((Get-Date).Date.AddMinutes(10)) -RepetitionInterval (New-TimeSpan -Minutes 15)
        } else { New-ScheduledTaskTrigger -Daily -At $definition.Time }
        $principal = New-ScheduledTaskPrincipal -UserId ([Security.Principal.WindowsIdentity]::GetCurrent().Name) -LogonType Interactive -RunLevel Limited
        $settings = New-ScheduledTaskSettingsSet -StartWhenAvailable -MultipleInstances IgnoreNew -RestartCount 2 -RestartInterval (New-TimeSpan -Minutes 5)
        Register-ScheduledTask -TaskPath $taskPath -TaskName $definition.Name -Action $action -Trigger $trigger -Principal $principal -Settings $settings -Force | Out-Null
    }
}