#!/usr/bin/env bash

COMPOSE_JOB_NETWORK_RUNNING_IN_CONTAINER=false
COMPOSE_JOB_NETWORK_CURRENT_CONTAINER=""
COMPOSE_JOB_NETWORK_NAME=""
COMPOSE_JOB_NETWORK_CONNECTED=false

compose_job_network_initialize() {
  COMPOSE_JOB_NETWORK_RUNNING_IN_CONTAINER=false
  COMPOSE_JOB_NETWORK_CURRENT_CONTAINER=""
  COMPOSE_JOB_NETWORK_NAME=""
  COMPOSE_JOB_NETWORK_CONNECTED=false

  if [[ ! -f /.dockerenv ]]; then
    return 0
  fi
  if [[ -z "${HOSTNAME:-}" ]]; then
    return 1
  fi

  COMPOSE_JOB_NETWORK_RUNNING_IN_CONTAINER=true
  COMPOSE_JOB_NETWORK_CURRENT_CONTAINER="$HOSTNAME"
}

# Emits the identifier of the container this job is executing in, or an empty string when the job
# runs directly on a host. This is the single topology signal: harnesses that provision their own
# containers instead of a Compose project (the TLS integration suite) consume it through the
# environment rather than re-deriving the topology, so there is exactly one detector.
compose_job_network_job_container() {
  if [[ "$COMPOSE_JOB_NETWORK_RUNNING_IN_CONTAINER" != "true" ]]; then
    return 0
  fi
  printf '%s' "$COMPOSE_JOB_NETWORK_CURRENT_CONTAINER"
}

compose_job_network_connect() {
  if [[ "$COMPOSE_JOB_NETWORK_RUNNING_IN_CONTAINER" != "true" ]]; then
    return 1
  fi
  if (($# == 0)); then
    return 1
  fi
  local service="$1"
  shift
  if [[ -z "$service" || $# -eq 0 ]]; then
    return 1
  fi

  local service_container_output
  if ! service_container_output="$("$@" ps -q "$service" 2>/dev/null)"; then
    return 1
  fi

  local service_containers=()
  while IFS= read -r container_id; do
    if [[ -n "$container_id" ]]; then
      service_containers+=("$container_id")
    fi
  done <<<"$service_container_output"
  if ((${#service_containers[@]} != 1)); then
    return 1
  fi

  local service_network_output
  if ! service_network_output="$(
    docker inspect \
      --format '{{range $networkName, $_ := .NetworkSettings.Networks}}{{println $networkName}}{{end}}' \
      "${service_containers[0]}" 2>/dev/null
  )"; then
    return 1
  fi

  local service_networks=()
  while IFS= read -r network_name; do
    if [[ -n "$network_name" ]]; then
      service_networks+=("$network_name")
    fi
  done <<<"$service_network_output"
  if ((${#service_networks[@]} != 1)); then
    return 1
  fi
  COMPOSE_JOB_NETWORK_NAME="${service_networks[0]}"

  local current_network_output
  if ! current_network_output="$(
    docker inspect \
      --format '{{range $networkName, $_ := .NetworkSettings.Networks}}{{println $networkName}}{{end}}' \
      "$COMPOSE_JOB_NETWORK_CURRENT_CONTAINER" 2>/dev/null
  )"; then
    return 1
  fi

  while IFS= read -r network_name; do
    if [[ "$network_name" == "$COMPOSE_JOB_NETWORK_NAME" ]]; then
      COMPOSE_JOB_NETWORK_CONNECTED=true
      return 0
    fi
  done <<<"$current_network_output"

  COMPOSE_JOB_NETWORK_CONNECTED=true
  if ! docker network connect \
    "$COMPOSE_JOB_NETWORK_NAME" \
    "$COMPOSE_JOB_NETWORK_CURRENT_CONTAINER" >/dev/null 2>&1; then
    docker network disconnect \
      "$COMPOSE_JOB_NETWORK_NAME" \
      "$COMPOSE_JOB_NETWORK_CURRENT_CONTAINER" >/dev/null 2>&1 || true
    COMPOSE_JOB_NETWORK_CONNECTED=false
    return 1
  fi
}

compose_job_network_disconnect() {
  if [[ "$COMPOSE_JOB_NETWORK_CONNECTED" != "true" ]]; then
    return 0
  fi

  if ! docker network disconnect \
    "$COMPOSE_JOB_NETWORK_NAME" \
    "$COMPOSE_JOB_NETWORK_CURRENT_CONTAINER" >/dev/null 2>&1; then
    return 1
  fi
  COMPOSE_JOB_NETWORK_CONNECTED=false
}