param(
    [switch]$Force,
    [string]$InstallDir = "$env:APPDATA\pngquant",
    [switch]$NoModifyPath
)

$ErrorActionPreference = "Stop"
$DownloadUrl = "https://pngquant.org/pngquant-windows.zip"

function Test-PngquantInstalled {
    try {
        $result = Get-Command pngquant -ErrorAction Stop
        Write-Host "pngquant 已安装: $($result.Source)" -ForegroundColor Green
        return $true
    } catch {
        Write-Host "pngquant 未安装" -ForegroundColor Yellow
        return $false
    }
}

function Test-ScoopInstalled {
    try {
        $result = Get-Command scoop -ErrorAction Stop
        Write-Host "scoop 已安装: $($result.Source)" -ForegroundColor Green
        return $true
    } catch {
        return $false
    }
}

function Install-ViaScoop {
    Write-Host "正在使用 scoop 安装 pngquant..." -ForegroundColor Cyan
    try {
        scoop install pngquant
        Write-Host "pngquant 安装成功" -ForegroundColor Green
        return $true
    } catch {
        Write-Host "scoop 安装 pngquant 失败: $_" -ForegroundColor Red
        return $false
    }
}

function Install-Manual {
    Write-Host "正在从 $DownloadUrl 下载 pngquant..." -ForegroundColor Cyan

    $zipPath = "$env:TEMP\pngquant-windows.zip"
    $extractTemp = "$env:TEMP\pngquant_extract"

    try {
        # Download
        $wc = New-Object System.Net.WebClient
        $wc.DownloadFile($DownloadUrl, $zipPath)

        # Clean up previous temp extract
        if (Test-Path $extractTemp) {
            Remove-Item $extractTemp -Recurse -Force
        }

        # Extract
        Expand-Archive -Path $zipPath -DestinationPath $extractTemp

        # Create install dir
        if (-not (Test-Path $InstallDir)) {
            New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
        }

        # Copy exe files to install dir
        $exeFiles = Get-ChildItem -Path $extractTemp -Filter "*.exe" -Recurse
        foreach ($exe in $exeFiles) {
            Copy-Item -Path $exe.FullName -Destination $InstallDir -Force
            Write-Host "  已安装: $($exe.Name)" -ForegroundColor Green
        }

        # Cleanup
        Remove-Item $zipPath -Force -ErrorAction SilentlyContinue
        Remove-Item $extractTemp -Recurse -Force -ErrorAction SilentlyContinue

        # Add to PATH
        if (-not $NoModifyPath) {
            Add-ToPath $InstallDir
        }

        return $true
    } catch {
        Write-Host "手动安装失败: $_" -ForegroundColor Red
        return $false
    }
}

function Add-ToPath($LiteralPath) {
    $RegistryPath = 'registry::HKEY_CURRENT_USER\Environment'
    $CurrentDirs = (Get-Item -LiteralPath $RegistryPath).GetValue(
        'Path', '', 'DoNotExpandEnvironmentNames'
    ) -split ';' -ne ''

    if ($LiteralPath -in $CurrentDirs) {
        Write-Host "安装目录已在 PATH 中: $LiteralPath" -ForegroundColor Green
        return
    }

    $NewPath = (,$LiteralPath + $CurrentDirs) -join ';'
    Set-ItemProperty -Type ExpandString -LiteralPath $RegistryPath Path $NewPath

    # 通知系统环境变量已更新
    $DummyName = 'pngquant-install-' + [guid]::NewGuid().ToString()
    [Environment]::SetEnvironmentVariable($DummyName, 'dummy', 'User')
    [Environment]::SetEnvironmentVariable($DummyName, [NullString]::value, 'User')

    Write-Host "已将 $LiteralPath 添加到用户 PATH" -ForegroundColor Green
}

# ============================================================
Write-Host "========================================" -ForegroundColor Cyan
Write-Host "  pngquant 安装脚本" -ForegroundColor Cyan
Write-Host "========================================" -ForegroundColor Cyan
Write-Host ""

if (Test-PngquantInstalled) {
    if (-not $Force) {
        Write-Host ""
        Write-Host "pngquant 已经安装，无需重复安装。" -ForegroundColor Green
        Write-Host "如需强制重新安装，请使用 -Force 参数。" -ForegroundColor Yellow
        exit 0
    }
    Write-Host "使用 -Force 参数强制重新安装..." -ForegroundColor Yellow
}

Write-Host ""

if (Test-ScoopInstalled) {
    Write-Host "检测到 scoop，使用 scoop 安装..." -ForegroundColor Cyan
    if (Install-ViaScoop) {
        Write-Host ""
        pngquant --version
        exit 0
    }
    Write-Host "scoop 安装失败，回退到手动安装方式..." -ForegroundColor Yellow
} else {
    Write-Host "未检测到 scoop，使用手动安装方式..." -ForegroundColor Cyan
}

Write-Host "安装目录: $InstallDir" -ForegroundColor Cyan
Write-Host ""

if (Install-Manual) {
    Write-Host ""
    Write-Host "========================================" -ForegroundColor Green
    Write-Host "  pngquant 安装完成！" -ForegroundColor Green
    Write-Host "========================================" -ForegroundColor Green
    Write-Host "安装路径: $InstallDir" -ForegroundColor Cyan

    try {
        $env:Path = "$InstallDir;$env:Path"
        Write-Host ""
        Write-Host "验证安装:" -ForegroundColor Cyan
        pngquant --version
    } catch {
        Write-Host ""
        Write-Host "安装文件已就绪，请重启终端后运行 pngquant --version 验证。" -ForegroundColor Yellow
    }
} else {
    Write-Host ""
    Write-Host "pngquant 安装失败。" -ForegroundColor Red
    Write-Host "请尝试手动下载: $DownloadUrl" -ForegroundColor Yellow
    exit 1
}