# ============================================================
# Plom Mods Installer
# Installs Fabric + mods for Minecraft 26.1.2
# https://mods.plom.one
# ============================================================

$ErrorActionPreference = "Stop"
$MC_VERSION = "26.1.2"
$FABRIC_INSTALLER_VERSION = "1.1.1"
$RAM_MAX_GB = 12

Write-Host ""
Write-Host "=================================" -ForegroundColor Cyan
Write-Host "   Plom Mods Installer" -ForegroundColor Cyan
Write-Host "   Minecraft $MC_VERSION + Fabric" -ForegroundColor Cyan
Write-Host "=================================" -ForegroundColor Cyan
Write-Host ""

# ── Step 1: Find .minecraft ───────────────────────────────────────────────────
$mcDir = "$env:APPDATA\.minecraft"
if (-not (Test-Path $mcDir)) {
    Write-Host "ERROR: .minecraft folder not found at $mcDir" -ForegroundColor Red
    Write-Host "Please open the Minecraft Launcher and log in first, then re-run." -ForegroundColor Yellow
    exit 1
}
Write-Host "[1/4] .minecraft: $mcDir" -ForegroundColor Green

# ── Step 2: Find Java ─────────────────────────────────────────────────────────
Write-Host "[2/4] Finding Java..." -ForegroundColor Yellow

$javaExe = $null

# Prefer Minecraft's own bundled JRE (always present if you've launched the game)
$runtimeDir = "$mcDir\runtime"
if (Test-Path $runtimeDir) {
    $javaExe = Get-ChildItem -Path $runtimeDir -Filter "java.exe" -Recurse -ErrorAction SilentlyContinue |
        Sort-Object -Property FullName -Descending |
        Select-Object -First 1 -ExpandProperty FullName
}

# Fall back to whatever java is on PATH
if (-not $javaExe) {
    $systemJava = Get-Command java -ErrorAction SilentlyContinue
    if ($systemJava) { $javaExe = $systemJava.Source }
}

if (-not $javaExe) {
    Write-Host "ERROR: Java not found." -ForegroundColor Red
    Write-Host "Please launch Minecraft $MC_VERSION at least once so it installs its bundled Java." -ForegroundColor Yellow
    exit 1
}
Write-Host "[2/4] Java: $javaExe" -ForegroundColor Green

# ── Step 3: Install Fabric ────────────────────────────────────────────────────
Write-Host "[3/4] Installing Fabric..." -ForegroundColor Yellow

# Fabric installer (and mod file replacement) will fail if the game is running
while (@(Get-Process -Name "javaw", "Minecraft", "MinecraftLauncher" -ErrorAction SilentlyContinue).Count -gt 0) {
    Write-Host ""
    Write-Host "      Minecraft is currently running!" -ForegroundColor Red
    Write-Host "      Please close the game and the Minecraft Launcher, then press Enter to continue." -ForegroundColor Yellow
    Read-Host "      Press Enter when Minecraft is closed"
}

# Get latest Fabric loader version for this MC version
$loaderData = Invoke-RestMethod "https://meta.fabricmc.net/v2/versions/loader/$MC_VERSION"
$loaderVersion = $loaderData[0].loader.version
Write-Host "      Loader: $loaderVersion"

# Skip if this exact Fabric version is already installed
$fabricVersionDir = "$mcDir\versions\fabric-loader-$loaderVersion-$MC_VERSION"
if (Test-Path $fabricVersionDir) {
    Write-Host "      Already installed, skipping." -ForegroundColor Cyan
} else {
    # Download Fabric installer
    $installerUrl = "https://maven.fabricmc.net/net/fabricmc/fabric-installer/$FABRIC_INSTALLER_VERSION/fabric-installer-$FABRIC_INSTALLER_VERSION.jar"
    $installerJar = "$env:TEMP\fabric-installer-$FABRIC_INSTALLER_VERSION.jar"
    Write-Host "      Downloading Fabric installer $FABRIC_INSTALLER_VERSION..."
    Invoke-WebRequest $installerUrl -OutFile $installerJar -UseBasicParsing

    # Run the installer (CLI mode - no GUI since we pass flags)
    Write-Host "      Running installer (may take a moment if downloading game files)..."
    & $javaExe -jar $installerJar client -mcversion $MC_VERSION -loader $loaderVersion -dir $mcDir
    if ($LASTEXITCODE -ne 0) {
        Write-Host "      Warning: installer exited with code $LASTEXITCODE" -ForegroundColor Yellow
    }
}

# Patch the launcher profile to use more RAM
$profilesPath = "$mcDir\launcher_profiles.json"
if (Test-Path $profilesPath) {
    $profiles = Get-Content $profilesPath -Raw | ConvertFrom-Json
    $profileKey = $profiles.profiles.PSObject.Properties.Name |
        Where-Object { $_ -like "*fabric-loader*$MC_VERSION*" } |
        Select-Object -First 1

    if ($profileKey) {
        $current = $profiles.profiles.$profileKey.javaArgs
        $updated = $current -replace '-Xmx\d+[GgMm]', "-Xmx${RAM_MAX_GB}G"
        if ($updated -notmatch '-Xmx') { $updated = "-Xmx${RAM_MAX_GB}G $updated" }
        $profiles.profiles.$profileKey.javaArgs = $updated
        # Write without BOM — the Fabric installer's JSON parser rejects files that start with a BOM
        $utf8NoBom = New-Object System.Text.UTF8Encoding $false
        [System.IO.File]::WriteAllText($profilesPath, ($profiles | ConvertTo-Json -Depth 20), $utf8NoBom)
        Write-Host "      RAM: set to ${RAM_MAX_GB}GB (was: $current)"
    } else {
        Write-Host "      Could not find Fabric launcher profile to patch RAM." -ForegroundColor Yellow
    }
}

Write-Host "[3/4] Fabric ready." -ForegroundColor Green

# ── Step 4: Download Mods ─────────────────────────────────────────────────────
Write-Host "[4/4] Downloading mods..." -ForegroundColor Yellow

$modsDir = "$mcDir\mods"
if (-not (Test-Path $modsDir)) {
    New-Item -ItemType Directory -Path $modsDir | Out-Null
}

# Modrinth project slugs / IDs
$mods = @(
    "appleskin",    # Shows food saturation info
    "chat-heads",   # Player heads next to chat messages
    "cloth-config", # Config library required by many mods
    "fabric-api",   # Required by almost everything
    "iris",         # Shader support
    "lithium",      # Performance - game logic optimizations
    "modmenu",      # In-game mod list and config UI
    "sodium",       # Performance - better rendering
    "fxxUqruK"      # Voxy - long-distance rendering
)

$gvParam = [uri]::EscapeDataString('["' + $MC_VERSION + '"]')
$ldParam  = [uri]::EscapeDataString('["fabric"]')

# Resolve mod metadata from Modrinth first so we can show what will be installed
Write-Host "      Resolving mods..." -ForegroundColor Yellow

# Batch-fetch project titles (one call for all mods)
$projectTitles = @{}
try {
    $idsParam = [uri]::EscapeDataString(($mods | ConvertTo-Json -Compress))
    $projects = Invoke-RestMethod "https://api.modrinth.com/v2/projects?ids=$idsParam"
    $projects | ForEach-Object { $projectTitles[$_.id] = $_.title; $projectTitles[$_.slug] = $_.title }
} catch {}

$modQueue = @()
foreach ($modId in $mods) {
    try {
        $apiUrl = "https://api.modrinth.com/v2/project/$modId/version?game_versions=$gvParam&loaders=$ldParam"
        $versions = Invoke-RestMethod $apiUrl
        if (-not $versions -or $versions.Count -eq 0) {
            Write-Host "      [SKIP] No Fabric/$MC_VERSION release found for: $modId" -ForegroundColor Yellow
            continue
        }
        $file = $versions[0].files | Where-Object { $_.primary } | Select-Object -First 1
        if (-not $file) { $file = $versions[0].files[0] }
        $displayName = if ($projectTitles[$modId]) { $projectTitles[$modId] } else { $modId }
        $modQueue += [PSCustomObject]@{ Name = $displayName; File = $file }
    } catch {
        Write-Host "      [FAIL] $modId`: $_" -ForegroundColor Red
    }
}

Write-Host ""
Write-Host "      Will install $($modQueue.Count) mod(s):" -ForegroundColor Cyan
$modQueue | ForEach-Object { Write-Host "        - $($_.Name)" }
Write-Host ""

# Prompt before clearing existing mods
$oldJars = @(Get-ChildItem -Path $modsDir -Filter "*.jar" -ErrorAction SilentlyContinue)
if ($oldJars.Count -gt 0) {
    Write-Host "      Found $($oldJars.Count) existing mod(s) in mods folder:" -ForegroundColor Yellow
    $oldJars | ForEach-Object { Write-Host "        - $($_.Name)" }
    Write-Host ""
    $choice = Read-Host "      Delete existing mods before installing? [Y/n]"
    if ($choice -eq "" -or $choice -match "^[Yy]") {
        Write-Host "      Removing old mod file(s)..."
        $oldJars | Remove-Item -Force
    } else {
        Write-Host "      Keeping existing mods (new mods will be added alongside them)." -ForegroundColor Cyan
    }
    Write-Host ""
}

# Download
$installedMods = @()
foreach ($mod in $modQueue) {
    try {
        Invoke-WebRequest $mod.File.url -OutFile "$modsDir\$($mod.File.filename)" -UseBasicParsing
        $installedMods += $mod.Name
    } catch {
        Write-Host "      [FAIL] $($mod.Name)`: $_" -ForegroundColor Red
    }
}

Write-Host "[4/4] Mods downloaded." -ForegroundColor Green

# ── Done ──────────────────────────────────────────────────────────────────────
Write-Host ""
Write-Host "All done!" -ForegroundColor Green
Write-Host ""
Write-Host "Installed mods:" -ForegroundColor White
$installedMods | ForEach-Object { Write-Host "  - $_" -ForegroundColor Cyan }
Write-Host ""
Write-Host "Open the Minecraft Launcher and select the Fabric profile to play:" -ForegroundColor White
Write-Host "  fabric-loader-$loaderVersion-$MC_VERSION" -ForegroundColor Cyan
Write-Host ""