#!/usr/bin/env bash
set -e

script=$(basename "$0")
version="1.1.0"

help() {
    echo
    echo "$script v$version"
    echo
    echo 'Description: List PostgreSQL databases in Kubernetes cluster.'
    echo "Syntax: $script <pod>"
    echo "Example: $script postgres"
    echo 'Options:'
    echo "  help  Show $script manual."
    echo
}

if [[ "$1" == 'help' ]]; then
    help
    exit 0
fi

pod="$1"

[[ -z "$pod" ]] && { echo 'Error: Parameter pod is empty'; exit 1; }

echo "Search for pod matching name '$pod'"
matches=$(kubectl get pods --no-headers -o custom-columns=':metadata.name' | grep -F "$pod" || true)
match_count=$(echo "$matches" | grep -c . || true)

if [[ "$match_count" -eq 0 ]]; then
    echo "Error: No pod found matching '$pod'"
    exit 1
elif [[ "$match_count" -gt 1 ]]; then
    echo "Error: Multiple pods found matching '$pod':"
    echo "$matches"
    exit 1
fi

pod_id="$matches"

echo "Found pod: $pod_id"
kubectl_exec="kubectl exec $pod_id -- /bin/bash -c"

$kubectl_exec "psql -h \"\$PGHOST\" -U \"\$PGUSER\" -d postgres -tAc \"SELECT datname FROM pg_database WHERE datistemplate = false AND datname NOT IN ('postgres', 'template0', 'template1');\""