# DeployCenter - Load and validate partitioning profiles
# PSD1 profiles are data files; they contain no executable code.

function Get-DeployCenterPartitionProfileNames {
    [CmdletBinding()]
    param([Parameter(Mandatory=$true)][string]$ProfilesRoot)

    if (-not (Test-Path -LiteralPath $ProfilesRoot -PathType Container)) { return @() }
    $names = @()
    foreach ($file in (Get-ChildItem -LiteralPath $ProfilesRoot -Filter '*.psd1' -File -ErrorAction SilentlyContinue)) {
        if ($file.BaseName -match '^[A-Za-z0-9_-]+$') { $names += $file.BaseName }
    }
    return @($names | Sort-Object -Unique)
}

function Import-DeployCenterPartitionProfile {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)][string]$ProfilesRoot,
        [Parameter(Mandatory=$true)][string]$ProfileName
    )

    if ($ProfileName -notmatch '^[A-Za-z0-9_-]+$') { throw "Invalid profile name: $ProfileName" }
    $path = Join-Path $ProfilesRoot ($ProfileName + '.psd1')
    if (-not (Test-Path -LiteralPath $path -PathType Leaf)) { throw "Profile not found: $ProfileName" }

    $profile = Import-PowerShellDataFile -LiteralPath $path
    foreach ($key in @('Id','Name','Description','Firmware','PartitionStyle','Partitions')) {
        if (-not $profile.ContainsKey($key)) { throw "The profile '$ProfileName' does not contain key '$key'." }
    }
    if ([string]$profile.Id -ne $ProfileName) { throw "Profile ID '$ProfileName' does not match the file name." }
    if (@($profile.Partitions).Count -lt 2) { throw 'The profile must define at least two partitions.' }
    if (@($profile.Partitions | Where-Object { [string]$_.Role -eq 'Windows' }).Count -ne 1) {
        throw 'The profile must define exactly one Windows partition.'
    }
    $userInputPartitions = @($profile.Partitions | Where-Object { [string]$_.Size.Policy -eq 'UserInputGB' })
    $remainderPartitions = @($profile.Partitions | Where-Object { [string]$_.Size.Policy -eq 'RemainderAfterInputs' })
    $remainingPartitions = @($profile.Partitions | Where-Object { [string]$_.Size.Policy -eq 'Remaining' })
    if ($userInputPartitions.Count -gt 0) {
        if ($remainderPartitions.Count -ne 1 -or $remainingPartitions.Count -gt 0) {
            throw "Profile '$ProfileName' must associate user inputs with exactly one remaining-space partition."
        }
    } elseif ($remainingPartitions.Count -ne 1 -or [string]$profile.Partitions[-1].Size.Policy -ne 'Remaining') {
        throw "Profile '$ProfileName' must place exactly one remaining-space partition last."
    }
    foreach ($partition in $profile.Partitions) {
        foreach ($key in @('Name','Role','FileSystem','Size')) {
            if (-not $partition.ContainsKey($key)) { throw "A profile partition '$ProfileName' does not contain key '$key'." }
        }
        if (-not $partition.Size.ContainsKey('Policy')) { throw "The size of a profile partition '$ProfileName' does not define Policy." }
        switch ([string]$partition.Size.Policy) {
            'FixedMB' {
                if ([int]$partition.Size.Value -le 0) { throw "A fixed size in profile '$ProfileName' must be greater than zero." }
            }
            'ImageSizePlusFreeSpace' {
                if ([int]$partition.Size.FreeSpaceMB -lt 250) { throw 'The WinRE free-space allowance must be at least 250 MB.' }
                if ([int]$partition.Size.PreviewMB -le 0) { throw "Profile '$ProfileName' must define a PreviewMB reserve to estimate available capacity." }
            }
            'ConfiguredMB' {
                if ([string]::IsNullOrWhiteSpace([string]$partition.Size.ConfigKey) -or
                    [int]$partition.Size.Value -le 0 -or [int]$partition.Size.PreviewMB -le 0) {
                    throw "The configured size of partition '$($partition.Name)' in profile '$ProfileName' must define ConfigKey and strictly positive sizes."
                }
            }
            'UserInputGB' {
                if ([int]$partition.Size.MinimumGB -le 0 -or [int]$partition.Size.DefaultPercent -le 0 -or [int]$partition.Size.DefaultPercent -ge 100) {
                    throw 'The user-size input must define MinimumGB and a DefaultPercent from 1 to 99.'
                }
                if ([string]::IsNullOrWhiteSpace([string]$partition.Size.Label)) { throw "The profile user-size input '$ProfileName' must define Label." }
            }
            'RemainderAfterInputs' {
                if ([double]$partition.Size.MinimumGB -lt 0 -or [string]::IsNullOrWhiteSpace([string]$partition.Size.Label)) {
                    throw "The remaining-space partition in profile '$ProfileName' must define a non-negative MinimumGB and a Label."
                }
            }
            'Remaining' { }
            default { throw "Unknown size policy in profile '$ProfileName': $($partition.Size.Policy)" }
        }
    }

    return $profile
}

function Get-DeployCenterPartitionSizingCapacity {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)][System.Collections.IDictionary]$Profile,
        [Parameter(Mandatory=$true)][long]$DiskSizeBytes
    )

    $reservedMB = 0.0
    foreach ($partition in $Profile.Partitions) {
        switch ([string]$partition.Size.Policy) {
            { $_ -in @('FixedMB','ConfiguredMB') } { $reservedMB += [double]$partition.Size.Value }
            default {
                if ($partition.Size.ContainsKey('PreviewMB')) { $reservedMB += [double]$partition.Size.PreviewMB }
            }
        }
    }

    $capacityBytes = $DiskSizeBytes - [long][math]::Ceiling($reservedMB * 1MB)
    if ($capacityBytes -le 0) { throw "The disk is too small for the profile reserves '$($Profile.Name)'." }
    return [pscustomobject]@{
        UsableBytes = [long]$capacityBytes
        UsableGB = [math]::Round(($capacityBytes / 1GB), 1)
        ReservedMB = [math]::Ceiling($reservedMB)
    }
}

function New-DeployCenterPartitionSizingState {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)][System.Collections.IDictionary]$Profile,
        [Parameter(Mandatory=$true)]$DiskInfo,
        [Parameter(Mandatory=$true)][System.Collections.IDictionary]$Selection
    )
    return [pscustomobject]@{
        ProfileId = [string]$Profile.Id
        DiskIndex = [int]$DiskInfo.Index
        Inputs = $Selection.Inputs
        RemainderRole = [string]$Selection.RemainderRole
        RemainderGB = [double]$Selection.RemainderGB
        AvailableGB = [double]$Selection.AvailableGB
    }
}

Export-ModuleMember -Function Get-DeployCenterPartitionProfileNames, Import-DeployCenterPartitionProfile, Get-DeployCenterPartitionSizingCapacity, New-DeployCenterPartitionSizingState