#!/usr/bin/env nu
# provisioning gateway — reconcile a Cilium Gateway's HTTPS listeners against
# live ground truth (HTTPRoutes + Certificates), so a wiped/drifted Gateway
# (e.g. a taskserv re-apply that clobbers spec.listeners) can be restored with
# one command instead of manual archaeology across every app's HTTPRoute.
#
# Ground truth, not the .ncl declarations: every app's listener_name/hostname
# convention already lives in its own HTTPRoute (parentRefs[].sectionName) and
# Certificate (spec.secretName) — reading those directly is exact, where
# re-deriving names from component .ncl fields would have to guess a naming
# convention that isn't actually uniform across components (verified by hand
# 2026-07-06: e.g. odoo-jesusperez's listener is "https-jesusperez", not
# "https-odoo-jesusperez").
#
# Requires kubectl configured against the target cluster (VPN, or run on a
# control-plane node) — this is live reconciliation, not a local render.

# Args as a list literal, not rest params — nu's parser checks bare rest
# tokens against this command's own flag signature, so a literal "-A" or
# "--all-namespaces" meant for kubectl gets rejected as an unknown flag on
# kubectl_json itself. A list<string> argument sidesteps that entirely.
def kubectl_json [args: list<string>]: nothing -> any {
    let r = (^kubectl ...$args -o json | complete)
    if $r.exit_code != 0 {
        error make --unspanned { msg: $"kubectl ($args | str join ' ') failed: ($r.stderr | str trim)" }
    }
    $r.stdout | from json
}

# Every HTTPS listener a Gateway should have, derived from HTTPRoutes that
# attach to it (sectionName starting with "https-") plus the Certificate that
# covers each route's hostname.
def expected-listeners [gw_name: string, gw_ns: string]: nothing -> table {
    let httproutes = (kubectl_json [get httproute --all-namespaces] | get items)
    let certs      = (kubectl_json [get certificate --all-namespaces] | get items)

    $httproutes
    | each {|hr|
        let ns = $hr.metadata.namespace
        $hr.spec.parentRefs? | default []
        | where {|p| (
            ($p.name? | default "") == $gw_name
            and ($p.namespace? | default "kube-system") == $gw_ns
            and ($p.sectionName? | default "" | str starts-with "https-")
        ) }
        | each {|p|
            let hostname = ($hr.spec.hostnames? | default [] | get -o 0 | default "")
            let cert = (
                $certs
                | where {|c| (
                    $c.metadata.namespace == $ns
                    and ($c.spec.dnsNames? | default [] | any {|d| $d == $hostname })
                ) }
                | get -o 0
            )
            if ($cert | is-empty) {
                {
                    listener: $p.sectionName, hostname: $hostname,
                    route_ns: $ns, route: $hr.metadata.name,
                    secret: null, secret_ns: null, cert_ready: false,
                    status: "no Certificate found for this hostname",
                }
            } else {
                let ready = (
                    $cert.status?.conditions? | default []
                    | where {|c| $c.type == "Ready" } | get -o 0.status | default "False"
                ) == "True"
                {
                    listener: $p.sectionName, hostname: $hostname,
                    route_ns: $ns, route: $hr.metadata.name,
                    secret: $cert.spec.secretName, secret_ns: $cert.metadata.namespace,
                    cert_ready: $ready,
                    status: (if $ready { "ok" } else { "Certificate not Ready" }),
                }
            }
        }
    }
    | flatten
}

def live-listeners [gw_name: string, gw_ns: string]: nothing -> table {
    kubectl_json [get gateway $gw_name -n $gw_ns]
    | get spec.listeners
    | where {|l| $l.name != "http" }
    | each {|l| {
        name:   $l.name,
        hostname: ($l.hostname? | default ""),
        secret: ($l.tls?.certificateRefs?.0.name? | default ""),
        secret_ns: ($l.tls?.certificateRefs?.0.namespace? | default ""),
    } }
}

# Diff a Gateway's live spec.listeners against what its HTTPRoutes+Certificates
# say should exist. With --apply, adds any missing listener via the same
# additive JSON-patch every component's own install script already uses
# (catalog/lib/gateway-tls.sh:_lib_gateway_patch_https) — never touches or
# removes an existing listener, so re-running this is always safe.
export def "gateway build-listeners" [
    --gateway (-g): string      # Gateway name (default: libre-wuji)
    --gateway-ns: string        # Gateway namespace (default: kube-system)
    --dry-run
    --apply
]: nothing -> table {
    let gw_name = ($gateway | default "libre-wuji")
    let gw_ns   = ($gateway_ns | default "kube-system")

    let expected = (expected-listeners $gw_name $gw_ns)
    let live     = (live-listeners $gw_name $gw_ns)

    let missing = ($expected | where {|e| not ($live | any {|l| $l.name == $e.listener }) })
    let orphans = ($live | where {|l| not ($expected | any {|e| $e.listener == $l.name }) })

    if $apply and not $dry_run {
        for m in $missing {
            if ($m.secret | is-empty) {
                print $"  [skip] ($m.listener) — ($m.status), cannot patch without a secret"
                continue
            }
            let patch = (
                [{
                    op: "add", path: "/spec/listeners/-",
                    value: {
                        name: $m.listener, port: 443, protocol: "HTTPS", hostname: $m.hostname,
                        tls: { mode: "Terminate", certificateRefs: [{ group: "", kind: "Secret", name: $m.secret, namespace: $m.secret_ns }] },
                        allowedRoutes: { namespaces: { from: "All" } },
                    },
                }] | to json
            )
            let r = (^kubectl patch gateway $gw_name -n $gw_ns --type=json -p $patch | complete)
            if $r.exit_code == 0 {
                print $"  [ok] ($m.listener) -> ($m.hostname) \(($m.secret_ns)/($m.secret)\)"
            } else {
                print $"  [error] ($m.listener): ($r.stderr | str trim)"
            }
        }
    }

    if ($orphans | is-not-empty) {
        print $"⚠ ($orphans | length) listener\(s\) live with no matching HTTPRoute — not touched, review manually:"
        print ($orphans | select name hostname)
    }

    if ($missing | is-empty) {
        print $"✓ Gateway ($gw_ns)/($gw_name) — all ($expected | length) expected HTTPS listener\(s\) present."
    } else if not $apply {
        print $"($missing | length) missing listener\(s\) — pass --apply to add:"
    }

    $missing
}

def print_help []: nothing -> nothing {
    print "Gateway HTTPS Listener Reconciliation"
    print "======================================"
    print ""
    print "Usage: provisioning gateway <subcommand> [flags]"
    print ""
    print "Subcommands:"
    print "  build-listeners (bl)  [--gateway NAME] [--gateway-ns NS] [--dry-run] [--apply]"
    print "                        Diff a Gateway's live HTTPS listeners against what its"
    print "                        HTTPRoutes + Certificates say should exist. --apply adds"
    print "                        any missing listener (additive JSON-patch, never removes)."
    print ""
    print "  help                  Show this help"
    print ""
    print "Defaults: --gateway libre-wuji --gateway-ns kube-system"
    print ""
    print "Requires kubectl configured against the target cluster (VPN, or run from a"
    print "control-plane node) — this reads and patches live cluster state, it does not"
    print "render locally like `dns build-private`."
}

def "main build-listeners" [
    --gateway (-g): string
    --gateway-ns: string
    --dry-run
    --apply
]: nothing -> table {
    gateway build-listeners --gateway $gateway --gateway-ns $gateway_ns --dry-run=$dry_run --apply=$apply
}

def "main bl" [
    --gateway (-g): string
    --gateway-ns: string
    --dry-run
    --apply
]: nothing -> table {
    gateway build-listeners --gateway $gateway --gateway-ns $gateway_ns --dry-run=$dry_run --apply=$apply
}

def main [...args: string]: nothing -> nothing {
    let first = ($args | get -o 0 | default "")
    match $first {
        "" | "help" | "h" | "-h" | "--help" => { print_help }
        _ => {
            print $"Unknown subcommand: ($first)"
            print ""
            print_help
        }
    }
}