#!/usr/bin/env bash

# Ensure the helper image is built locally. If missing, build from the
# Dockerfile adjacent to this script (same `contws` directory).

script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
IMAGE_NAME="inftools-cn:latest"

if ! docker image inspect "$IMAGE_NAME" >/dev/null 2>&1; then
  echo "Docker image $IMAGE_NAME not found. Building from $script_dir/Dockerfile..."
  docker build -t "$IMAGE_NAME" -f "$script_dir/Dockerfile" "$script_dir" || {
    echo "Failed to build Docker image $IMAGE_NAME" >&2
    exit 1
  }
fi

# Check if the Docker network 'student-net' exists, if not, create it
if ! docker network inspect student-net >/dev/null 2>&1; then
  echo "Docker network 'student-net' not found. Creating it..."
  docker network create student-net || {
    echo "Failed to create Docker network 'student-net'" >&2
    exit 1
  }
fi

# docker ps | grep mycluster | wc -l
# 2

if docker ps | grep -q mycluster; then
  echo "Cluster already exists. Skipping creation."
  docker run --rm -it \
    --network student-net \
    -v /var/run/docker.sock:/var/run/docker.sock \
    -v mykube:/root/.kube \
    $IMAGE_NAME bash
  exit 0
fi

# create cluster
#
# Capture k3d output and extract the load-balancer node name.
# Example line in output: "INFO[0005] Starting node 'k3d-mycluster-serverlb'"
#
tmpfile=$(mktemp)
# Stream docker output live to terminal and save it to a temp file for parsing
docker run --rm \
  --network student-net \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v mykube:/root/.kube \
  $IMAGE_NAME k3d cluster create mycluster --network student-net 2>&1 | tee "$tmpfile"

# Read captured output into a variable for parsing
output=$(cat "$tmpfile")
rm -f "$tmpfile"

# Prefer the node name that contains 'serverlb' (most likely the LB),
# otherwise fall back to the last "Starting node '..." match.
# First try to find a line that includes 'serverlb'.
LB_NODE=$(printf "%s" "$output" | grep "Starting node" | grep -E "serverlb" | sed -n "s/.*Starting node '\\([^']*\\)'.*/\\1/p" | head -n1 || true)

if [ -z "$LB_NODE" ]; then
  # Fallback: take the last Starting node match (in case serverlb isn't present)
  LB_NODE=$(printf "%s" "$output" | sed -n "s/.*Starting node '\\([^']*\\)'.*/\\1/p" | tail -n1)
fi

if [ -n "$LB_NODE" ]; then
  echo "Load balancer node: $LB_NODE"
  export LB_NODE
else
  echo "Warning: could not parse load balancer node from k3d output" >&2
fi

# edit kubeconfig to use load-balancer node IP
# server: https://0.0.0.0:40115
# needs to be changed to be sed -i 's/:34791/:6443/g' ~/.kube/config
# 0.0.0.0:40115 -> <LB_NODE_IP>:6443
docker run --rm \
  --network student-net \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -v mykube:/root/.kube \
  $IMAGE_NAME sed -i "s/0.0.0.0:[0-9]*/${LB_NODE}:6443/g" /root/.kube/config