# Detect or generate ED25519 SSH key. Print public key only. Never print the private key.

param(
    [string]$Email,
    [string]$KeyPath,
    [switch]$ForceGenerate,
    [switch]$NoGenerate,
    [switch]$Quiet
)

$ErrorActionPreference = 'Stop'
. (Join-Path $PSScriptRoot 'common.ps1')

$gitProfile = Get-GitSkillsProfile

if ([string]::IsNullOrWhiteSpace($Email)) {
    if ($gitProfile) { $Email = [string]$gitProfile.userEmail }
}
if ([string]::IsNullOrWhiteSpace($Email)) {
    $Email = [string](Get-GitSkillsDefaults).userEmail
}

if ([string]::IsNullOrWhiteSpace($KeyPath)) {
    if ($gitProfile -and $gitProfile.sshKeyPath) {
        $KeyPath = [string]$gitProfile.sshKeyPath
    } else {
        $KeyPath = Join-Path $env:USERPROFILE '.ssh\id_ed25519'
    }
}

if (Test-Path -LiteralPath $KeyPath -PathType Container) {
    $KeyPath = Join-Path $KeyPath 'id_ed25519'
}

$pubPath = $KeyPath + '.pub'
$sshDir = Split-Path -Parent $KeyPath
if (-not (Test-Path -LiteralPath $sshDir)) {
    New-Item -ItemType Directory -Path $sshDir -Force | Out-Null
}

$status = 'exists'
if ($NoGenerate -and -not (Test-Path -LiteralPath $KeyPath)) {
    Write-StatusLine -Key 'status' -Value 'failed'
    Write-StatusLine -Key 'reason' -Value 'ssh_key_missing'
    Write-StatusLine -Key 'key_path' -Value $KeyPath
    exit 1
}

if ($ForceGenerate -or -not (Test-Path -LiteralPath $KeyPath)) {
    if ((Test-Path -LiteralPath $KeyPath) -and $ForceGenerate) {
        Write-StatusLine -Key 'status' -Value 'failed'
        Write-StatusLine -Key 'reason' -Value 'refusing_to_overwrite_ssh_key'
        Write-StatusLine -Key 'key_path' -Value $KeyPath
        exit 1
    }

    $sshKeygen = Get-Command ssh-keygen -ErrorAction SilentlyContinue
    if ($null -eq $sshKeygen) {
        Write-StatusLine -Key 'status' -Value 'failed'
        Write-StatusLine -Key 'reason' -Value 'ssh_keygen_missing'
        exit 1
    }

    Invoke-GitSkillsNative -FilePath ssh-keygen -ArgumentList @('-t', 'ed25519', '-C', $Email, '-f', $KeyPath, '-N', '""') | Out-Null
    if ($LASTEXITCODE -ne 0) {
        Write-StatusLine -Key 'status' -Value 'failed'
        Write-StatusLine -Key 'reason' -Value 'ssh_keygen_failed'
        exit 1
    }
    $status = 'created'
}

if (-not (Test-Path -LiteralPath $pubPath)) {
    Write-StatusLine -Key 'status' -Value 'failed'
    Write-StatusLine -Key 'reason' -Value 'public_key_missing'
    Write-StatusLine -Key 'key_path' -Value $KeyPath
    exit 1
}

$agent = 'unavailable'
$added = 'skipped'
$svc = Get-Service -Name ssh-agent -ErrorAction SilentlyContinue
if ($null -ne $svc) {
    try {
        if ($svc.StartType -eq 'Disabled') {
            Set-Service -Name ssh-agent -StartupType Manual
        }
        if ((Get-Service -Name ssh-agent).Status -ne 'Running') {
            Start-Service -Name ssh-agent
        }
        $agent = 'running'
        Invoke-GitSkillsNative -FilePath ssh-add -ArgumentList @($KeyPath) | Out-Null
        if ($LASTEXITCODE -eq 0) {
            $added = 'yes'
        } else {
            $added = 'failed'
        }
    }
    catch {
        $agent = 'error'
        $added = 'failed'
    }
}

$publicKey = (Get-Content -LiteralPath $pubPath -Raw -Encoding UTF8).Trim()

Write-StatusLine -Key 'status' -Value $status
Write-StatusLine -Key 'key_path' -Value $KeyPath
Write-StatusLine -Key 'public_key_path' -Value $pubPath
Write-StatusLine -Key 'ssh_agent' -Value $agent
Write-StatusLine -Key 'ssh_add' -Value $added
if (-not $Quiet) {
    Write-Output ('public_key=' + $publicKey)
}