#!/usr/bin/env nu
# Derived variables for private_ingress bundle rendering.
# Reads the component JSON, outputs Tera context vars as JSON.

def slug_from_host [host: string]: nothing -> string {
    $host | str replace --all "." "-"
}

def resolve_cluster_ip [upstream: string, cp_host: string]: nothing -> string {
    # upstream is a K8s FQDN: <svc>.<ns>.svc.<domain> — extract svc+ns and resolve ClusterIP via SSH
    let parts = ($upstream | split row ".")
    if ($parts | length) < 2 { return $upstream }
    let svc = ($parts | first)
    let ns  = ($parts | get 1)
    let r = (do { ^ssh $cp_host $"kubectl get svc ($svc) -n ($ns) -o jsonpath='{.spec.clusterIP}'" } | complete)
    if $r.exit_code != 0 or ($r.stdout | is-empty) {
        error make { msg: $"Could not resolve ClusterIP for ($svc).($ns): ($r.stderr | str trim)" }
    }
    $r.stdout | str trim | str replace "'" "" | str replace "'" ""
}

def sozu_cluster_block [route: record, cp_host: string]: nothing -> string {
    let slug      = (slug_from_host $route.host)
    let cert_path = $"/etc/sozu/tls/($route.host)/tls.crt"
    let key_path  = $"/etc/sozu/tls/($route.host)/tls.key"
    let clusterip = (resolve_cluster_ip $route.upstream $cp_host)
    [
        $"[clusters.($slug)]",
        "protocol = \"http\"",
        "",
        $"[[clusters.($slug).frontends]]",
        "address           = \"0.0.0.0:8443\"",
        $"hostname          = \"($route.host)\"",
        $"certificate       = \"($cert_path)\"",
        $"certificate_chain = \"($cert_path)\"",
        $"key               = \"($key_path)\"",
        "",
        $"[[clusters.($slug).backends]]",
        $"backend_id = \"($slug)-0\"",
        $"address    = \"($clusterip):($route.port)\"",
    ] | str join "\n"
}

def secret_volume_entry [route: record]: nothing -> string {
    let slug        = (slug_from_host $route.host)
    let secret_name = $"private-ingress-tls-($slug)"
    [
        $"- name: tls-($slug)",
        "  secret:",
        $"    secretName: ($secret_name)",
        "    items:",
        "      - key: tls.crt",
        "        path: tls.crt",
        "      - key: tls.key",
        "        path: tls.key",
    ] | str join "\n"
}

def secret_mount_entry [route: record]: nothing -> string {
    let slug = (slug_from_host $route.host)
    [
        $"- name: tls-($slug)",
        $"  mountPath: /etc/sozu/tls/($route.host)",
        "  readOnly: true",
    ] | str join "\n"
}

def certificate_entry [route: record, cluster_issuer: string, namespace: string]: nothing -> string {
    let slug        = (slug_from_host $route.host)
    let secret_name = $"private-ingress-tls-($slug)"
    $"---
apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: ($secret_name)
  namespace: ($namespace)
  labels:
    app.kubernetes.io/name: private-ingress
    app.kubernetes.io/managed-by: provisioning
spec:
  secretName: ($secret_name)
  duration: 2160h
  renewBefore: 720h
  dnsNames:
    - ($route.host)
  issuerRef:
    name: ($cluster_issuer)
    kind: ClusterIssuer
    group: cert-manager.io"
}

def main [component_json: string]: nothing -> nothing {
    let d = ($component_json | from json)

    let ns             = ($d.namespace?      | default "ingress-private")
    let name           = ($d.name?           | default "private-ingress")
    let image          = ($d.image?          | default "ghcr.io/sozu-proxy/sozu:1.0.3")
    let cluster_issuer = ($d.cluster_issuer? | default "letsencrypt-prod-librecloud")
    let routes         = ($d.routes?         | default [])
    let private_lb_ip  = ($d.private_lb_ip?  | default "")

    let cp_host = ($d.cp_host? | default "libre-wuji-cp-0")

    let cluster_blocks = (
        $routes
        | each { |r| sozu_cluster_block $r $cp_host }
        | str join "\n\n"
    )

    let sozu_config = [
        "[config]",
        "log_level      = \"info\"",
        "log_target     = \"stdout\"",
        "worker_count   = 2",
        "command_socket = \"/var/run/sozu/sozu.sock\"",
        "",
        "[[listeners]]",
        "protocol       = \"https\"",
        "address        = \"0.0.0.0:8443\"",
        "",
        # HTTP listener removed — sozu v2 answer_301 requires a file path, not URL template.
        # Port 80 on the LB Service remains open (connections get TCP reset) until
        # a proper redirect file/mechanism is configured.
        "",
        $cluster_blocks,
    ] | str join "\n"

    let tls_volumes = (
        $routes
        | each { |r| secret_volume_entry $r }
        | str join "\n"
    )

    let tls_mounts = (
        $routes
        | each { |r| secret_mount_entry $r }
        | str join "\n"
    )

    let certificates_yaml = (
        $routes
        | each { |r| certificate_entry $r $cluster_issuer $ns }
        | str join "\n"
    )

    {
        sozu_config:       $sozu_config,
        tls_volumes:       $tls_volumes,
        tls_mounts:        $tls_mounts,
        certificates_yaml: $certificates_yaml,
        private_lb_ip:     $private_lb_ip,
        namespace:         $ns,
        name:              $name,
        image:             $image,
        cluster_issuer:    $cluster_issuer,
    }
    | to json --raw
    | print
}