<#
.SYNOPSIS
    Launches a visible, offline acdream Atmospheric Rendering preview.

.DESCRIPTION
    Builds acdream unless -SkipBuild is supplied, creates a timestamped
    disposable settings/profile directory under artifacts, selects the built-in
    Atmospheric shader pack, and starts the real AcDream.App executable.

    The preview deliberately removes inherited live-session credentials for the
    child process. It never reads or rewrites the user's normal acdream settings.

.PARAMETER Preset
    Atmospheric quality preset. Defaults to High.

.PARAMETER Resolution
    Window resolution written to the disposable settings profile.

.PARAMETER EnableAudio
    Explicitly enable OpenAL for this preview. Audio is disabled by default so
    graphics inspection does not depend on the system audio device/driver.

.PARAMETER NoAudio
    Legacy explicit spelling for the safe default. Retained so existing
    invocations remain valid; do not combine it with -EnableAudio.

.PARAMETER SkipBuild
    Launch the existing Release binary without rebuilding it.

.EXAMPLE
    .\tools\launch-atmospheric-preview.ps1 -Preset High

.EXAMPLE
    .\tools\launch-atmospheric-preview.ps1 -Preset High -EnableAudio
#>
[CmdletBinding()]
param(
    [ValidateSet('Low', 'Medium', 'High', 'Auto')]
    [string]$Preset = 'High',
    [ValidatePattern('^[1-9][0-9]*x[1-9][0-9]*$')]
    [string]$Resolution = '1920x1080',
    [switch]$EnableAudio,
    [switch]$NoAudio,
    [switch]$SkipBuild
)

Set-StrictMode -Version Latest
$ErrorActionPreference = 'Stop'
$repo = Split-Path -Parent $PSScriptRoot
$exe = Join-Path $repo 'src\AcDream.App\bin\Release\net10.0\AcDream.App.exe'
$datDirectory = Join-Path $env:USERPROFILE "Documents\Asheron's Call"
$audioEnabled = [bool]$EnableAudio

if ($EnableAudio -and $NoAudio) {
    throw '-EnableAudio and -NoAudio are mutually exclusive.'
}

if (-not $SkipBuild) {
    Write-Host '[atmospheric-preview] building acdream Release'
    & dotnet build (Join-Path $repo 'AcDream.slnx') -c Release --nologo -v q
    if ($LASTEXITCODE -ne 0) {
        throw "acdream Release build failed with exit code $LASTEXITCODE."
    }
}
if (-not (Test-Path -LiteralPath $exe)) {
    throw "acdream executable not found at '$exe'. Build it first or omit -SkipBuild."
}
if (-not (Test-Path -LiteralPath $datDirectory)) {
    throw "AC DAT directory not found at '$datDirectory'."
}

$stamp = Get-Date -Format 'yyyyMMdd-HHmmss-fff'
$root = Join-Path $repo "artifacts\atmospheric-rendering\visible-$($Preset.ToLowerInvariant())-$stamp"
$config = Join-Path $root 'state\config'
$data = Join-Path $root 'state\data'
$cache = Join-Path $root 'state\cache'
if (Test-Path -LiteralPath $root) {
    throw "Preview artifact directory already exists: '$root'."
}
New-Item -ItemType Directory -Path $config, $data, $cache | Out-Null

$settings = [ordered]@{
    display = [ordered]@{
        resolution = $Resolution
        fullscreen = $false
        vsync = $true
        renderPack = [ordered]@{
            packId = 'acdream.atmospheric'
            packVersion = '1.0.0'
            presetId = $Preset.ToLowerInvariant()
            settingOverrides = [ordered]@{}
        }
    }
    version = 3
}
$settingsPath = Join-Path $config 'settings.json'
$settings | ConvertTo-Json -Depth 8 |
    Set-Content -Encoding utf8 -LiteralPath $settingsPath

$requiredEnvironmentNames = @(
    'ACDREAM_CONFIG_DIR',
    'ACDREAM_DATA_DIR',
    'ACDREAM_CACHE_DIR',
    'ACDREAM_DAT_DIR',
    'ACDREAM_RETAIL_UI',
    'ACDREAM_NO_AUDIO'
)
$environmentNames = @(
    @([Environment]::GetEnvironmentVariables('Process').Keys) |
        ForEach-Object { [string]$_ } |
        Where-Object { $_.StartsWith('ACDREAM_', [StringComparison]::OrdinalIgnoreCase) }
    $requiredEnvironmentNames
) | Sort-Object -Unique
$prior = @{}
foreach ($name in $environmentNames) {
    $prior[$name] = [Environment]::GetEnvironmentVariable($name, 'Process')
}

$stdoutLog = Join-Path $root 'client.stdout.log'
$stderrLog = Join-Path $root 'client.stderr.log'
$launchPath = Join-Path $root 'launch.json'
$binary = Get-Item -LiteralPath $exe
$binaryVersion = [Diagnostics.FileVersionInfo]::GetVersionInfo($exe).ProductVersion
$launch = [ordered]@{
    schemaVersion = 2
    status = 'prepared'
    processId = $null
    executable = $exe
    executableSha256 = (Get-FileHash -Algorithm SHA256 -LiteralPath $exe).Hash.ToLowerInvariant()
    executableProductVersion = $binaryVersion
    executableLastWriteUtc = $binary.LastWriteTimeUtc.ToString('O')
    preset = $Preset.ToLowerInvariant()
    resolution = $Resolution
    audio = [ordered]@{
        enabled = $audioEnabled
        mode = if ($audioEnabled) { 'enabled-explicit' } else { 'disabled-default' }
    }
    stateRoot = Join-Path $root 'state'
    settings = $settingsPath
    stdoutLog = $stdoutLog
    stderrLog = $stderrLog
    preparedUtc = [DateTimeOffset]::UtcNow.ToString('O')
    launchedUtc = $null
    startupError = $null
}
$launch | ConvertTo-Json -Depth 6 |
    Set-Content -Encoding utf8 -LiteralPath $launchPath

$process = $null
try {
    # The preview is a clean product launch, not an extension of whichever
    # connected/automation/diagnostic gate happened to run in this shell.
    # Clear every inherited ACDREAM_* value transactionally, then publish only
    # the explicit preview inputs below. Prior values are restored without ever
    # being serialized into the artifact.
    foreach ($name in $environmentNames) {
        [Environment]::SetEnvironmentVariable($name, $null, 'Process')
    }
    $env:ACDREAM_CONFIG_DIR = $config
    $env:ACDREAM_DATA_DIR = $data
    $env:ACDREAM_CACHE_DIR = $cache
    $env:ACDREAM_DAT_DIR = $datDirectory
    $env:ACDREAM_RETAIL_UI = '1'
    $env:ACDREAM_NO_AUDIO = if ($audioEnabled) { $null } else { '1' }

    try {
        $process = Start-Process -FilePath $exe -PassThru `
            -RedirectStandardOutput $stdoutLog `
            -RedirectStandardError $stderrLog
    }
    catch {
        $launch.status = 'start-failed'
        $launch.startupError = $_.Exception.Message
        $launch | ConvertTo-Json -Depth 6 |
            Set-Content -Encoding utf8 -LiteralPath $launchPath
        throw
    }
}
finally {
    foreach ($name in $environmentNames) {
        [Environment]::SetEnvironmentVariable($name, $prior[$name], 'Process')
    }
}

$launch.status = 'started'
$launch.processId = $process.Id
$launch.launchedUtc = [DateTimeOffset]::UtcNow.ToString('O')
$launch | ConvertTo-Json -Depth 6 |
    Set-Content -Encoding utf8 -LiteralPath $launchPath

Write-Host "[atmospheric-preview] launched acdream process $($process.Id)"
Write-Host "[atmospheric-preview] preset: $Preset; resolution: $Resolution"
Write-Host "[atmospheric-preview] audio: $($launch.audio.mode)"
Write-Host "[atmospheric-preview] disposable state: $root"
Write-Host "[atmospheric-preview] logs: $stdoutLog and $stderrLog"
Write-Host '[atmospheric-preview] close the acdream window normally when finished'