<#
.SYNOPSIS
    symlink_models.ps1 -- place in the "Sven Co-op" root folder alongside tags.json.

.DESCRIPTION
    Creates a relative symlink for every model:
      svencoop_addon\models\player\<id>\<id>.mdl  ->  ..\..\..\..\ svencoop\models\player\helmet\helmet.mdl

    Sources (pick one, or default to tags.json):
      default          -- model IDs from tags.json, grouped by category
      -Server PATH     -- scan any svencoop_addon\models\player\ directory for .mdl files
      -FromFile FILE   -- read one model ID per line from a text file

    Dump server model IDs to a file (run on the server):
      Get-ChildItem -Path "C:\path\to\svencoop_addon\models\player" -Recurse -Filter "*.mdl" |
        Where-Object { $_.DirectoryName -ne "...\player" } |
        ForEach-Object { $_.BaseName } | Sort-Object -Unique | Set-Content server_models.txt

.NOTES
    Requires PowerShell 5.1+ and either:
      - Developer Mode enabled  (Settings > For developers)
      - Running as Administrator
#>
[CmdletBinding()]
param(
    [switch]$DryRun,
    [string]$Server,
    [string]$FromFile
)

Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"

# --- Paths ---
$scriptDir     = $PSScriptRoot
$helmetAbs     = Join-Path $scriptDir "svencoop\models\player\helmet\helmet.mdl"
$addonRoot     = Join-Path $scriptDir "svencoop_addon\models\player"
$symlinkTarget = "..\..\..\..\svencoop\models\player\helmet\helmet.mdl"

# --- Pre-flight ---
if (-not (Test-Path $helmetAbs)) {
    Write-Error "helmet.mdl not found: $helmetAbs`nRun from the Sven Co-op root folder."
    exit 1
}

$isAdmin = ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole(
    [Security.Principal.WindowsBuiltInRole]::Administrator
)
if (-not $isAdmin) {
    $devMode = $false
    try {
        $dm = Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock" -ErrorAction SilentlyContinue
        $devMode = $dm.AllowDevelopmentWithoutDevLicense -eq 1
    } catch {}
    if (-not $devMode) {
        Write-Warning @"
Symlink creation may fail. To fix, either:
  - Enable Developer Mode  (Settings > For developers > Developer Mode)
  - Re-run this script as Administrator
"@
    }
}

# --- Shared: symlink one model ID ---
function Invoke-Symlink {
    param([string]$ModelId)

    $modelDir = Join-Path $addonRoot $ModelId
    $mdlPath  = Join-Path $modelDir "$ModelId.mdl"

    if (-not (Test-Path $modelDir -PathType Container)) {
        if (-not $DryRun) { New-Item -ItemType Directory -Path $modelDir -Force | Out-Null }
    }

    $item = Get-Item $mdlPath -ErrorAction SilentlyContinue

    if ($item -and $item.LinkType) {
        if ($item.Target -eq $symlinkTarget) { return "skipped" }
        if (-not $DryRun) { Remove-Item $mdlPath -Force }
        Write-Host "  replace : $ModelId"
        $result = "replaced"
    } elseif ($item) {
        if (-not $DryRun) { Remove-Item $mdlPath -Force }
        Write-Host "  replace : $ModelId  (was real file)"
        $result = "replaced"
    } else {
        Write-Host "  create  : $ModelId"
        $result = "created"
    }

    if (-not $DryRun) {
        try {
            New-Item -ItemType SymbolicLink -Path $mdlPath -Target $symlinkTarget | Out-Null
        } catch {
            Write-Host "  ERROR   : $ModelId -- $_"
            return "error"
        }
    }
    return $result
}

function Write-Summary {
    param([hashtable]$Counts)
    $total  = $Counts.created + $Counts.replaced
    $prefix = if ($DryRun) { "[DRY RUN] " } else { "" }
    $verb   = if ($DryRun) { "would be written" } else { "written" }
    $errors = if ($Counts.error) { ", $($Counts.error) errors" } else { "" }
    Write-Host "`n${prefix}$total symlinks $verb ($($Counts.created) new, $($Counts.replaced) replaced), $($Counts.skipped) already correct${errors}"
}

$counts = @{ created = 0; replaced = 0; skipped = 0; error = 0 }

# --- -Server: scan a player/ directory ---
if ($Server) {
    if (-not (Test-Path $Server -PathType Container)) {
        Write-Error "Server path not found: $Server"
        exit 1
    }
    $modelIds = Get-ChildItem -Path $Server -Recurse -Filter "*.mdl" |
        Where-Object { $_.DirectoryName -ne $Server } |
        ForEach-Object { $_.BaseName } |
        Sort-Object -Unique
    Write-Host "`n[server] -- $($modelIds.Count) models found in $Server`n"
    foreach ($id in $modelIds) { $counts[(Invoke-Symlink $id)]++ }
    Write-Summary $counts
    return
}

# --- -FromFile: read model IDs from a text file ---
if ($FromFile) {
    if (-not (Test-Path $FromFile)) {
        Write-Error "File not found: $FromFile"
        exit 1
    }
    $modelIds = Get-Content $FromFile | Where-Object { $_.Trim() -ne "" } | ForEach-Object { $_.Trim() }
    Write-Host "`n[from file] -- $($modelIds.Count) models in $FromFile`n"
    foreach ($id in $modelIds) { $counts[(Invoke-Symlink $id)]++ }
    Write-Summary $counts
    return
}

# --- Default: tags.json ---
$tagsPath = Join-Path $scriptDir "tags.json"
if (-not (Test-Path $tagsPath)) {
    Write-Error "tags.json not found next to script ($tagsPath)"
    exit 1
}

$tags = Get-Content $tagsPath -Raw -Encoding UTF8 | ConvertFrom-Json
foreach ($category in $tags.PSObject.Properties) {
    Write-Host "`n[$($category.Name)] -- $($category.Value.Count) models"
    foreach ($id in $category.Value) { $counts[(Invoke-Symlink $id)]++ }
}
Write-Summary $counts