# scripts/download-ollama.ps1
# Downloads the portable Ollama Windows binary into resources/ollama/.
# Usage: powershell -ExecutionPolicy Bypass -File scripts/download-ollama.ps1
#
# Note: Ollama only ships an NSIS installer officially. We use the
# ollama-windows-amd64.zip release asset on GitHub instead.

$ErrorActionPreference = "Stop"

$OLLAMA_VERSION = if ($env:OLLAMA_VERSION) { $env:OLLAMA_VERSION } else { "v0.5.7" }
$OLLAMA_URL = "https://github.com/ollama/ollama/releases/download/$OLLAMA_VERSION/ollama-windows-amd64.zip"
$DEST_DIR = Join-Path $PSScriptRoot "..\resources\ollama"
$TEMP_ZIP = Join-Path $env:TEMP "ollama-$OLLAMA_VERSION-windows-amd64.zip"
$TEMP_DIR = Join-Path $env:TEMP "ollama-extract"

Write-Host "=== Ollama $OLLAMA_VERSION (Windows amd64) ===" -ForegroundColor Cyan

if (Test-Path (Join-Path $DEST_DIR "ollama.exe")) {
    Write-Host "Ollama already present: $DEST_DIR\ollama.exe" -ForegroundColor Green
    exit 0
}

if (Test-Path $TEMP_ZIP) { Remove-Item -Force $TEMP_ZIP }

Write-Host "Downloading: $OLLAMA_URL"
# curl.exe (Win10+ native) handles GitHub redirects, progress output, large files
# better than Invoke-WebRequest. -L follow redirects, --fail error on HTTP >=400,
# --retry 3, --max-time 1800 (30min), --progress-bar human readable.
$curlExe = "$env:SystemRoot\System32\curl.exe"
if (-not (Test-Path $curlExe)) { $curlExe = "curl.exe" }
& $curlExe -L --fail --retry 3 --max-time 1800 --progress-bar `
    -o $TEMP_ZIP $OLLAMA_URL
if ($LASTEXITCODE -ne 0) {
    Write-Host "curl download failed with exit code $LASTEXITCODE" -ForegroundColor Red
    Write-Host ""
    Write-Host "=== Manual install ===" -ForegroundColor Yellow
    Write-Host "Download ollama-windows-amd64.zip from:"
    Write-Host "  https://github.com/ollama/ollama/releases"
    Write-Host "and extract its contents into:"
    Write-Host "  $DEST_DIR"
    exit 1
}

$fileSize = (Get-Item $TEMP_ZIP).Length
if ($fileSize -lt 1000000) {
    Write-Host ("Downloaded file too small ({0} bytes)." -f $fileSize) -ForegroundColor Red
    exit 1
}

$sizeMB = [math]::Round($fileSize / 1MB, 1)
Write-Host ("Download complete ({0} MB)" -f $sizeMB)
Write-Host "Extracting..."

if (Test-Path $TEMP_DIR) { Remove-Item -Recurse -Force $TEMP_DIR }
Expand-Archive -Path $TEMP_ZIP -DestinationPath $TEMP_DIR -Force

New-Item -ItemType Directory -Force -Path $DEST_DIR | Out-Null

# zip layout: ollama.exe + lib/ (runners + DLLs).
# Prune GPU runners (CUDA v11/v12, ROCm) to keep installer under NSIS 2GB limit.
# CPU runners (cpu_avx2, cpu_avx) are sufficient for initial bundle; users needing GPU
# can install Ollama separately or via future builds.
Get-ChildItem -Path $TEMP_DIR -Force | ForEach-Object {
    Copy-Item $_.FullName -Destination $DEST_DIR -Recurse -Force
    Write-Host ("  copied: {0}" -f $_.Name) -ForegroundColor Green
}

# Remove heavy GPU runners to stay below NSIS size limits
$runnersDir = Join-Path $DEST_DIR "lib\ollama\runners"
if (Test-Path $runnersDir) {
    Get-ChildItem $runnersDir -Directory | Where-Object { $_.Name -like "cuda*" -or $_.Name -like "rocm*" } | ForEach-Object {
        Remove-Item -Recurse -Force $_.FullName
        Write-Host ("  pruned GPU runner: {0}" -f $_.Name) -ForegroundColor Yellow
    }
}

Remove-Item -Recurse -Force $TEMP_DIR -ErrorAction SilentlyContinue
Remove-Item -Force $TEMP_ZIP -ErrorAction SilentlyContinue

if (Test-Path (Join-Path $DEST_DIR "ollama.exe")) {
    $ollamaSize = (Get-Item (Join-Path $DEST_DIR "ollama.exe")).Length
    $ollamaMB = [math]::Round($ollamaSize / 1MB, 1)
    Write-Host ""
    Write-Host ("Ollama installed: {0} ({1} MB)" -f $DEST_DIR, $ollamaMB) -ForegroundColor Green
} else {
    Write-Host "ollama.exe not found after extraction. Inspect the zip layout." -ForegroundColor Red
    exit 1
}