# Installs lsh, the LogiShell command line, for this user on Windows:
#   irm https://cli.lsh.dev/install.ps1 | iex
#
#   $env:LSH_VERSION       a release to install (0.2.0); default: the latest
#   $env:LSH_INSTALL_DIR   where lsh.exe goes; default: %LOCALAPPDATA%\Programs\lsh
#   $env:LSH_DL            where releases live; default: https://cli.lsh.dev/cli
#
# No administrator rights, PATH is not changed silently: the script prints the command that
# adds the directory. Layout of the release server: harness/cli/dist/README.md.

& {
    Set-StrictMode -Version 3.0
    $ErrorActionPreference = 'Stop'
    $ProgressPreference = 'SilentlyContinue'

    function Fail([string]$Message, [string]$Hint) {
        Write-Host "error: $Message" -ForegroundColor Red
        if ($Hint) { Write-Host "  hint: $Hint" -ForegroundColor DarkGray }
        throw "lsh install: $Message"
    }

    # TLS 1.2 for Windows PowerShell 5.1 (PowerShell 7 already has it).
    try {
        [Net.ServicePointManager]::SecurityProtocol = [Net.ServicePointManager]::SecurityProtocol -bor [Net.SecurityProtocolType]::Tls12
    } catch { }

    $base = if ($env:LSH_DL) { $env:LSH_DL.TrimEnd('/') } else { 'https://cli.lsh.dev/cli' }
    $dir = if ($env:LSH_INSTALL_DIR) { $env:LSH_INSTALL_DIR } else { Join-Path $env:LOCALAPPDATA 'Programs\lsh' }
    $version = if ($env:LSH_VERSION) { $env:LSH_VERSION.TrimStart('v') } else { '' }

    # The architecture of the OS, not of this process (a 32 bit or emulated shell lies).
    $arch = $env:PROCESSOR_ARCHITEW6432
    if (-not $arch) { $arch = $env:PROCESSOR_ARCHITECTURE }
    switch ($arch) {
        'AMD64' { $target = 'x86_64-pc-windows-msvc' }
        'ARM64' {
            # No native ARM64 build yet: the x64 build runs under the emulation of Windows 11.
            $target = 'x86_64-pc-windows-msvc'
            Write-Host '! no native ARM64 build yet, installing the x64 build (runs under emulation)' -ForegroundColor Yellow
        }
        default { Fail "no lsh build for Windows on $arch" 'builds: https://lsh.dev/dl' }
    }
    $name = "lsh-$target.exe"

    if ($version) {
        $url = "$base/v$version/$name"
        try {
            $sumText = [string](Invoke-RestMethod -UseBasicParsing -Uri "$base/v$version/lsh-$target.sha256")
        } catch {
            Fail "no lsh $version for $target at $base/v$version/" 'see the releases at https://lsh.dev/dl'
        }
        $sum = ($sumText.Trim() -split '\s+')[0].ToLowerInvariant()
    } else {
        try {
            $manifest = Invoke-RestMethod -UseBasicParsing -Uri "$base/latest.json"
        } catch {
            Fail "could not read $base/latest.json: $($_.Exception.Message)" 'check the network, or set $env:LSH_DL to a mirror'
        }
        $version = ([string]$manifest.version).TrimStart('v')
        if (-not $version) { Fail "$base/latest.json names no version" 'report it at https://lsh.dev/gh' }
        $asset = $manifest.assets.PSObject.Properties[$target]
        if (-not $asset) { Fail "lsh $version has no build for $target" 'see the builds at https://lsh.dev/dl' }
        $url = [string]$asset.Value.url
        $sum = ([string]$asset.Value.sha256).ToLowerInvariant()
    }
    if ($sum -notmatch '^[0-9a-f]{64}$') { Fail "no valid sha256 for $name" 'report it at https://lsh.dev/gh' }

    Write-Host "installing lsh $version for $target"
    try {
        New-Item -ItemType Directory -Force -Path $dir | Out-Null
    } catch {
        Fail "cannot create $dir" 'pick another directory: $env:LSH_INSTALL_DIR = "<dir>"'
    }
    $tmp = Join-Path $dir ".lsh-install-$PID.exe"
    $exe = Join-Path $dir 'lsh.exe'
    try {
        try {
            Invoke-WebRequest -UseBasicParsing -Uri $url -OutFile $tmp
        } catch {
            Fail "download of $url failed: $($_.Exception.Message)" 'check the network and run the installer again'
        }
        $got = (Get-FileHash -Algorithm SHA256 -Path $tmp).Hash.ToLowerInvariant()
        if ($got -ne $sum) {
            Fail "checksum mismatch for ${name}: expected $sum, got $got" 'nothing was installed; run the installer again'
        }
        try {
            Move-Item -Force -Path $tmp -Destination $exe
        } catch {
            Fail "cannot write $exe (is lsh running?)" 'stop the daemon (lsh daemon stop) and run the installer again'
        }
    } finally {
        if (Test-Path $tmp) { Remove-Item -Force $tmp -ErrorAction SilentlyContinue }
    }

    # Marks as code points: `irm | iex` in Windows PowerShell 5.1 may not decode the script as UTF-8.
    $check = [char]0x2713
    $arrow = [char]0x2192
    Write-Host "$check lsh $version installed to $exe" -ForegroundColor Green
    try { & $exe version } catch { }

    $userPath = [Environment]::GetEnvironmentVariable('Path', 'User')
    $onPath = @($env:Path -split ';') + @("$userPath" -split ';') | Where-Object { $_.TrimEnd('\') -ieq $dir.TrimEnd('\') }
    if ($onPath) {
        $cmd = 'lsh'
    } else {
        $cmd = "& '$exe'"
        Write-Host "! $dir is not on your PATH; to add it for your user run:" -ForegroundColor Yellow
        Write-Host "    [Environment]::SetEnvironmentVariable('Path', [Environment]::GetEnvironmentVariable('Path', 'User') + ';$dir', 'User')"
        Write-Host '  then open a new terminal.'
    }
    Write-Host "$arrow next: $cmd onboard" -ForegroundColor Cyan
}