[CmdletBinding()]
param(
    [int]$Port = 8091,
    [int]$Context = 131072,
    [switch]$InstallOnly,
    [switch]$NoBrowser,
    [switch]$HiddenServer
)

$ErrorActionPreference = 'Stop'
$ProgressPreference = 'Continue'
$Package = $PSScriptRoot
$ModelDir = Join-Path $Package 'llama-model'
$BaseModel = Join-Path $ModelDir 'anru-gemma4-12b-base-Q5_K_M.gguf'
$LoraModel = Join-Path $ModelDir 'anru-final-lora-Q8_0.gguf'
$ChatTemplate = Join-Path $ModelDir 'chat_template.prompt30k.jinja'
$UiConfig = Join-Path $ModelDir 'ui-config.json'
$RuntimeManifest = Join-Path $Package 'llama-runtime-state.json'
$ModelVerification = Join-Path $ModelDir 'model-verification.json'

function Get-LlamaServer {
    $Candidates = @(Get-ChildItem -LiteralPath $Package -Directory -Filter 'llama-runtime*' -ErrorAction SilentlyContinue |
        Sort-Object @{ Expression = { if ($_.Name -eq 'llama-runtime') { 0 } else { 1 } } }, Name)
    foreach ($Directory in $Candidates) {
        $Found = Get-ChildItem -LiteralPath $Directory.FullName -Recurse -File -Filter 'llama-server.exe' -ErrorAction SilentlyContinue |
            Select-Object -First 1
        if ($Found) { return $Found.FullName }
    }
    return $null
}

function Install-LlamaRuntime {
    [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
    Write-Host '[bootstrap] llama.cpp runtime is missing; resolving the latest official Windows release...'
    $Headers = @{ 'User-Agent' = 'Anru-Llama-Bootstrap' }
    $Release = Invoke-RestMethod -Uri 'https://api.github.com/repos/ggml-org/llama.cpp/releases/latest' `
        -Headers $Headers -TimeoutSec 60

    $GpuName = ''
    $Nvidia = Get-Command 'nvidia-smi.exe' -ErrorAction SilentlyContinue
    if ($Nvidia) {
        $GpuName = (& $Nvidia.Source --query-gpu=name --format=csv,noheader 2>$null | Select-Object -First 1).Trim()
    }

    $Assets = @()
    if ($GpuName) {
        $CudaFlavor = if ($GpuName -match '(?i)RTX\s*50\d\d|Blackwell') { '13.3' } else { '12.4' }
        $Main = $Release.assets | Where-Object { $_.name -match "^llama-.*-bin-win-cuda-$([regex]::Escape($CudaFlavor))-x64\.zip$" } | Select-Object -First 1
        $Cuda = $Release.assets | Where-Object { $_.name -eq "cudart-llama-bin-win-cuda-$CudaFlavor-x64.zip" } | Select-Object -First 1
        if (-not $Main -or -not $Cuda) { throw "No matching CUDA $CudaFlavor Windows assets in release $($Release.tag_name)" }
        $Assets = @($Main, $Cuda)
        Write-Host "[bootstrap] detected $GpuName; installing CUDA $CudaFlavor build $($Release.tag_name)."
    } else {
        $Main = $Release.assets | Where-Object { $_.name -match '^llama-.*-bin-win-cpu-x64\.zip$' } | Select-Object -First 1
        if (-not $Main) { throw "No Windows CPU asset in release $($Release.tag_name)" }
        $Assets = @($Main)
        Write-Host "[bootstrap] NVIDIA GPU not detected; installing CPU build $($Release.tag_name)."
    }

    $TempRoot = Join-Path ([IO.Path]::GetTempPath()) ("AnruLlamaBootstrap-" + [guid]::NewGuid().ToString('N'))
    $RuntimeDir = Join-Path $Package 'llama-runtime'
    if (Test-Path -LiteralPath $RuntimeDir) {
        $RuntimeDir = Join-Path $Package ("llama-runtime-" + $Release.tag_name)
    }
    New-Item -ItemType Directory -Path $TempRoot, $RuntimeDir -Force | Out-Null
    try {
        $Index = 0
        $InstalledAssets = @()
        foreach ($Asset in $Assets) {
            $Index++
            $Zip = Join-Path $TempRoot $Asset.name
            $Extract = Join-Path $TempRoot ("extract-$Index")
            Write-Host "[bootstrap] downloading $($Asset.name) ($([math]::Round($Asset.size / 1MB, 1)) MiB)..."
            Invoke-WebRequest -Uri $Asset.browser_download_url -Headers $Headers -OutFile $Zip -UseBasicParsing -TimeoutSec 1800
            if ($Asset.digest -and $Asset.digest -match '^sha256:(.+)$') {
                $Actual = (Get-FileHash -Algorithm SHA256 -LiteralPath $Zip).Hash
                if ($Actual -ne $Matches[1].ToUpperInvariant()) { throw "Download checksum mismatch: $($Asset.name)" }
            }
            Expand-Archive -LiteralPath $Zip -DestinationPath $Extract -Force
            foreach ($File in Get-ChildItem -LiteralPath $Extract -Recurse -File) {
                Copy-Item -LiteralPath $File.FullName -Destination (Join-Path $RuntimeDir $File.Name) -Force
            }
            $InstalledAssets += [ordered]@{ name = $Asset.name; bytes = [long]$Asset.size; digest = $Asset.digest }
        }
        $Server = Get-ChildItem -LiteralPath $RuntimeDir -Recurse -File -Filter 'llama-server.exe' | Select-Object -First 1
        if (-not $Server) { throw 'Downloaded runtime does not contain llama-server.exe' }
        [ordered]@{
            state = 'installed'
            release = [string]$Release.tag_name
            gpu = $GpuName
            installed_at = (Get-Date).ToUniversalTime().ToString('o')
            runtime = $RuntimeDir
            server = $Server.FullName
            assets = $InstalledAssets
        } | ConvertTo-Json -Depth 8 | Set-Content -LiteralPath $RuntimeManifest -Encoding UTF8
        Write-Host "[bootstrap] runtime installed at $RuntimeDir"
    } finally {
        $ResolvedTemp = [IO.Path]::GetFullPath($TempRoot)
        $SystemTemp = [IO.Path]::GetFullPath([IO.Path]::GetTempPath())
        if ($ResolvedTemp.StartsWith($SystemTemp, [StringComparison]::OrdinalIgnoreCase) -and
            (Test-Path -LiteralPath $ResolvedTemp)) {
            Remove-Item -LiteralPath $ResolvedTemp -Recurse -Force -ErrorAction SilentlyContinue
        }
    }
}

$Server = Get-LlamaServer
if (-not $Server) {
    Install-LlamaRuntime
    $Server = Get-LlamaServer
}
if (-not $Server) { throw 'llama-server.exe is still missing after installation' }

if ($InstallOnly) {
    [ordered]@{ state = 'installed'; server = $Server } | ConvertTo-Json
    exit 0
}

foreach ($Required in @($BaseModel, $LoraModel, $ChatTemplate, $UiConfig)) {
    if (-not (Test-Path -LiteralPath $Required -PathType Leaf)) { throw "Missing packaged Llama artifact: $Required" }
}
if ((Get-Item -LiteralPath $BaseModel).Length -ne 8547249568) { throw 'Packaged Q5 model size mismatch' }
if ((Get-Item -LiteralPath $LoraModel).Length -ne 51682496) { throw 'Packaged Q8 LoRA size mismatch' }

$NeedModelHash = $true
if (Test-Path -LiteralPath $ModelVerification) {
    try {
        $Verified = Get-Content -LiteralPath $ModelVerification -Raw | ConvertFrom-Json
        $NeedModelHash = -not ($Verified.state -eq 'passed' -and
            $Verified.base_sha256 -eq '057C364366301EE285E9026ECF417AAE36F4447D5D9CBBC3591447A9FC77A752' -and
            $Verified.lora_sha256 -eq '3A5060E1CC0C8D4609052EF04A5A60770A64D566E2544B65F6D28F2BA6542037')
    } catch { $NeedModelHash = $true }
}
if ($NeedModelHash) {
    Write-Host '[bootstrap] verifying packaged GGUF model checksums (first launch only)...'
    $BaseHash = (Get-FileHash -Algorithm SHA256 -LiteralPath $BaseModel).Hash
    $LoraHash = (Get-FileHash -Algorithm SHA256 -LiteralPath $LoraModel).Hash
    if ($BaseHash -ne '057C364366301EE285E9026ECF417AAE36F4447D5D9CBBC3591447A9FC77A752') { throw 'Q5 model checksum mismatch' }
    if ($LoraHash -ne '3A5060E1CC0C8D4609052EF04A5A60770A64D566E2544B65F6D28F2BA6542037') { throw 'Q8 LoRA checksum mismatch' }
    [ordered]@{ state = 'passed'; base_sha256 = $BaseHash; lora_sha256 = $LoraHash; verified_at = (Get-Date).ToUniversalTime().ToString('o') } |
        ConvertTo-Json | Set-Content -LiteralPath $ModelVerification -Encoding UTF8
}

$Listener = Get-NetTCPConnection -State Listen -LocalPort $Port -ErrorAction SilentlyContinue | Select-Object -First 1
if ($Listener) {
    $Owner = Get-CimInstance Win32_Process -Filter "ProcessId=$($Listener.OwningProcess)"
    $KnownRuntime = $Owner.Name -eq 'llama-server.exe'
    $KnownNative = $Owner.Name -eq 'python.exe' -and $Owner.CommandLine -like '*anru-gemma4-12b-native-multimodal-release*serve.py*'
    if ($KnownRuntime -or $KnownNative) {
        Write-Host "[bootstrap] stopping the previous local model service on port $Port (PID $($Listener.OwningProcess))..."
        Stop-Process -Id $Listener.OwningProcess -Force
        Wait-Process -Id $Listener.OwningProcess -Timeout 30 -ErrorAction SilentlyContinue
        Start-Sleep -Seconds 2
    } else {
        throw "Port $Port is occupied by $($Owner.Name) (PID $($Listener.OwningProcess))"
    }
}

$Alias = 'anru-gemma4-12b-q5-lora045-prompt30k'
$RuntimeDir = Split-Path -Parent $Server
$BaseForRuntime = '..\llama-model\anru-gemma4-12b-base-Q5_K_M.gguf'
$LoraForRuntime = '..\llama-model\anru-final-lora-Q8_0.gguf'
$TemplateForRuntime = '..\llama-model\chat_template.prompt30k.jinja'
$UiForRuntime = '..\llama-model\ui-config.json'
$Arguments = @(
    '-m', $BaseForRuntime,
    '--lora-scaled', ('{0}:0.45' -f $LoraForRuntime),
    '--chat-template-file', $TemplateForRuntime,
    '--ui-config-file', $UiForRuntime,
    '-ngl', '99',
    '-c', "$Context",
    '-fa', 'on',
    '-ctk', 'q8_0',
    '-ctv', 'q8_0',
    '-b', '1024',
    '-ub', '256',
    '-np', '1',
    '--host', '127.0.0.1',
    '--port', "$Port",
    '--metrics',
    '--jinja',
    '--webui',
    '--alias', $Alias
)

$Stdout = Join-Path $Package 'llama-server.stdout.log'
$Stderr = Join-Path $Package 'llama-server.stderr.log'
Write-Host "[bootstrap] starting llama-server with $Context-token context and LoRA scale 0.45..."
if ($HiddenServer) {
    $Process = Start-Process -FilePath $Server -ArgumentList $Arguments -WorkingDirectory $RuntimeDir `
        -WindowStyle Hidden -RedirectStandardOutput $Stdout -RedirectStandardError $Stderr -PassThru
} else {
    $Process = Start-Process -FilePath $Server -ArgumentList $Arguments -WorkingDirectory $RuntimeDir `
        -WindowStyle Normal -PassThru
}

$Health = $null
$Deadline = (Get-Date).AddMinutes(10)
do {
    Start-Sleep -Seconds 2
    try { $Health = Invoke-RestMethod -Uri "http://127.0.0.1:$Port/health" -TimeoutSec 3 } catch { $Health = $null }
    if ($Process.HasExited -and $Health.status -ne 'ok') {
        $Tail = if (Test-Path -LiteralPath $Stderr) { (Get-Content -LiteralPath $Stderr -Tail 120) -join "`n" } else { '' }
        throw "llama-server exited during startup (code $($Process.ExitCode))`n$Tail"
    }
} until (($Health.status -eq 'ok') -or ((Get-Date) -ge $Deadline))
if ($Health.status -ne 'ok') { throw 'llama-server readiness timeout' }

$State = [ordered]@{
    state = 'healthy'
    pid = $Process.Id
    endpoint = "http://127.0.0.1:$Port"
    model = $Alias
    context_tokens = $Context
    lora_scale = 0.45
    prompt = 'embedded 30k constitution in chat_template.prompt30k.jinja'
    prompt_sha256 = '5591AC2C99FDC6C8E21D1D3B87625BB368204548BEC7B63C3FD6598CF23639BF'
    runtime = $Server
    started_at = (Get-Date).ToUniversalTime().ToString('o')
}
$State | ConvertTo-Json -Depth 6 | Set-Content -LiteralPath (Join-Path $Package 'llama-service-state.json') -Encoding UTF8
Write-Host "[bootstrap] ready: http://127.0.0.1:$Port"
if (-not $NoBrowser) { Start-Process "http://127.0.0.1:$Port" }
$State | ConvertTo-Json -Depth 6