#!/usr/bin/env nu
# Verify all prerequisites for Hetzner + NixOS deployment

def check_command [cmd: string, name: string] {
    let result = (which $cmd 2>&1)
    if ($result | is-empty) {
        print $"❌ ($name) - NOT INSTALLED"
        print $"   Install with: brew install $cmd"
        return {name: $name, installed: false, version: ""}
    } else {
        let version = (try { ^$cmd --version | lines | first } catch { "unknown" })
        print $"✅ ($name) - OK"
        return {name: $name, installed: true, version: $version}
    }
}

def check_env_var [var: string] {
    let value = (try { $env | get $var } catch { "" })
    if ($value | is-empty) {
        print $"❌ ($var) - NOT SET"
        return {name: $var, set: false}
    } else {
        print $"✅ ($var) - SET"
        return {name: $var, set: true}
    }
}

def check_file [path: string, name: string] {
    if ($path | path exists) {
        print $"✅ ($name) - EXISTS"
        return {name: $name, exists: true}
    } else {
        print $"❌ ($name) - MISSING"
        return {name: $name, exists: false}
    }
}

def main [] {
    print "╔════════════════════════════════════════════════════════╗"
    print "║   LibreCloud Hetzner + NixOS - Prerequisites Check     ║"
    print "╚════════════════════════════════════════════════════════╝"
    print ""

    # Check tools
    print "📦 Required Tools:"
    mut tools_ok = true

    let tools = [
        {cmd: "nushell", name: "Nushell 0.110+"},
        {cmd: "nickel", name: "Nickel"},
        {cmd: "nix", name: "Nix"},
        {cmd: "nixos-anywhere", name: "nixos-anywhere"},
        {cmd: "hcloud", name: "Hetzner Cloud CLI"},
        {cmd: "jq", name: "jq (JSON processor)"},
        {cmd: "curl", name: "curl"},
        {cmd: "ssh", name: "OpenSSH"},
    ]

    for tool in $tools {
        let result = (check_command $tool.cmd $tool.name)
        if not $result.installed {
            $tools_ok = false
        }
    }
    print ""

    # Check environment variables
    print "🔐 Hetzner Configuration:"
    let hcloud_token_set = (check_env_var "HCLOUD_TOKEN")
    if not $hcloud_token_set.set {
        print "   ⚠️  To set: export HCLOUD_TOKEN='your-token-here'"
        print "   Get token: https://console.hetzner.cloud/tokens"
        $tools_ok = false
    }
    print ""

    # Check SSH key in Hetzner
    print "🔑 SSH Key in Hetzner:"
    if $hcloud_token_set.set {
        let ssh_key_exists = (try {
            ^hcloud ssh-key list --output json | from json | where name == "provisioning-key" | length } catch { 0 })
        if $ssh_key_exists > 0 {
            print "✅ provisioning-key - EXISTS in Hetzner"
        } else {
            print "❌ provisioning-key - NOT FOUND in Hetzner"
            print "   Create with:"
            print "   hcloud ssh-key create --name provisioning-key --public-key-from-file ~/.ssh/id_rsa.pub"
            $tools_ok = false
        }
    } else {
        print "⏭️  Skipping (HCLOUD_TOKEN not set)"
    }
    print ""

    # Check local SSH key
    print "🔑 Local SSH Key:"
    let ssh_key_path = $"($env.HOME)/.ssh/id_rsa.pub"
    if ($ssh_key_path | path exists) {
        print "✅ SSH public key - EXISTS"
    } else {
        print "❌ SSH public key - NOT FOUND at ($ssh_key_path)"
        print "   Generate with: ssh-keygen -t rsa -b 4096"
        $tools_ok = false
    }
    print ""

    # Check project files
    print "📁 Project Files:"
    let project_files = [
        {path: "provisioning/scripts/deploy-librecloud-hetzner.nu", name: "Deploy script"},
        {path: "provisioning/scripts/generate-flakes.nu", name: "Flake generator"},
        {path: "workspaces/librecloud_hetzner/infra/main/servers.ncl", name: "Server config"},
    ]

    for file in $project_files {
        let result = (check_file $file.path $file.name)
        if not $result.exists {
            $tools_ok = false
        }
    }
    print ""

    # Summary
    print "╔════════════════════════════════════════════════════════╗"
    if $tools_ok {
        print "║ ✅ ALL PREREQUISITES MET - Ready to Deploy!            ║"
        print "╚════════════════════════════════════════════════════════╝"
        print ""
        print "Next steps:"
        print "1. Generate flakes:"
        print "   nu provisioning/scripts/deploy-librecloud-hetzner.nu --generate-only"
        print ""
        print "2. Dry-run deployment:"
        print "   nu provisioning/scripts/deploy-librecloud-hetzner.nu --dry-run"
        print ""
        print "3. Deploy to Hetzner (30-40 minutes):"
        print "   nu provisioning/scripts/deploy-librecloud-hetzner.nu"
    } else {
        print "║ ❌ MISSING PREREQUISITES - See above for details        ║"
        print "╚════════════════════════════════════════════════════════╝"
    }
}

main