#!/usr/bin/env bash
# -*- indent-tabs-mode: nil; tab-width: 4; sh-indentation: 4; -*-

set -euo pipefail

### GLOBALS ###
NAMESPACE=""
ACTION="install"

### HELP & LOGGING ###
print_help() {
  cat <<EOF
Usage: $(basename "$0") [OPTIONS]

Deploy or remove an OpenTelemetry Collector and Jaeger backend for llm-d
distributed tracing. Both are deployed into the same namespace so that
llm-d components can export traces to http://otel-collector:4317.

If the OpenTelemetry Operator CRD is detected, the collector is deployed
as an OpenTelemetryCollector CR. Otherwise a standalone Deployment is used.

Options:
  -n, --namespace NAME   Target namespace (required)
  -u, --uninstall        Remove OTel Collector and Jaeger
  -h, --help             Show this help and exit

Examples:
  $(basename "$0") -n my-namespace    # Install in 'my-namespace'
  $(basename "$0") -u -n my-namespace # Uninstall from 'my-namespace'
EOF
}

# ANSI colour helpers
COLOR_RESET=$'\e[0m'
COLOR_GREEN=$'\e[32m'
COLOR_RED=$'\e[31m'
COLOR_BLUE=$'\e[34m'

log_info()    { echo "${COLOR_BLUE}[INFO]  $*${COLOR_RESET}"; }
log_success() { echo "${COLOR_GREEN}[OK]    $*${COLOR_RESET}"; }
log_error()   { echo "${COLOR_RED}[ERROR] $*${COLOR_RESET}" >&2; }
fail()        { echo "${COLOR_RED}[ERROR] $*${COLOR_RESET}" >&2; exit 1; }

### ARG PARSING ###
parse_args() {
  while [[ $# -gt 0 ]]; do
    case "$1" in
      -n|--namespace) NAMESPACE="$2"; shift 2 ;;
      -u|--uninstall) ACTION="uninstall"; shift ;;
      -h|--help)      print_help; exit 0 ;;
      *)              fail "Unknown option: $1" ;;
    esac
  done
}

require_namespace() {
  if [[ -z "$NAMESPACE" ]]; then
    fail "Namespace is required. Use -n <namespace> to specify the target namespace."
  fi
}

### DETECTION ###
otel_operator_available() {
  kubectl get crd opentelemetrycollectors.opentelemetry.io &>/dev/null
}

### ACTIONS ###
install() {
  log_info "Deploying OTel Collector + Jaeger into namespace '${NAMESPACE}'..."

  SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
  TRACING_DIR="${SCRIPT_DIR}/../tracing"
  JAEGER_MANIFEST="${TRACING_DIR}/jaeger-all-in-one.yaml"

  if [[ ! -f "$JAEGER_MANIFEST" ]]; then
    fail "Jaeger manifest not found at: ${JAEGER_MANIFEST}"
  fi

  # Create namespace if needed
  if ! kubectl get namespace "${NAMESPACE}" &>/dev/null; then
    log_info "Creating namespace '${NAMESPACE}'..."
    kubectl create namespace "${NAMESPACE}"
  fi

  # Deploy Jaeger
  log_info "Deploying Jaeger all-in-one..."
  kubectl apply -n "${NAMESPACE}" -f "${JAEGER_MANIFEST}"

  # Deploy OTel Collector (operator CR or standalone)
  STANDALONE_MANIFEST="${TRACING_DIR}/otel-collector.yaml"
  if otel_operator_available; then
    COLLECTOR_MANIFEST="${TRACING_DIR}/otel-collector-operator.yaml"
    if [[ -f "$COLLECTOR_MANIFEST" ]]; then
      log_info "OpenTelemetry Operator detected -- deploying collector as OpenTelemetryCollector CR..."
      kubectl apply -n "${NAMESPACE}" -f "${COLLECTOR_MANIFEST}"
    elif [[ -f "$STANDALONE_MANIFEST" ]]; then
      log_info "OpenTelemetry Operator detected but operator manifest not found -- falling back to standalone collector..."
      kubectl apply -n "${NAMESPACE}" -f "${STANDALONE_MANIFEST}"
    else
      fail "No OTel Collector manifest found in: ${TRACING_DIR}"
    fi
  else
    if [[ ! -f "$STANDALONE_MANIFEST" ]]; then
      fail "OTel Collector standalone manifest not found at: ${STANDALONE_MANIFEST}"
    fi
    log_info "OpenTelemetry Operator not found -- deploying standalone collector..."
    kubectl apply -n "${NAMESPACE}" -f "${STANDALONE_MANIFEST}"
  fi

  log_success "OTel Collector + Jaeger deployed successfully."
  echo ""
  log_info "Access the Jaeger UI with:"
  echo "  kubectl port-forward -n ${NAMESPACE} svc/jaeger-collector 16686:16686"
  echo "  Then open http://localhost:16686"
  echo ""
  log_info "Components should export OTLP traces to:"
  echo "  http://otel-collector.${NAMESPACE}.svc.cluster.local:4317"
  echo "  (or simply http://otel-collector:4317 from the same namespace)"
}

uninstall() {
  log_info "Removing OTel Collector + Jaeger from namespace '${NAMESPACE}'..."

  SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
  TRACING_DIR="${SCRIPT_DIR}/../tracing"

  # Remove OTel Collector (try both variants)
  if otel_operator_available; then
    OPERATOR_MANIFEST="${TRACING_DIR}/otel-collector-operator.yaml"
    if [[ -f "$OPERATOR_MANIFEST" ]]; then
      kubectl delete -n "${NAMESPACE}" -f "${OPERATOR_MANIFEST}" --ignore-not-found
    fi
  fi

  STANDALONE_MANIFEST="${TRACING_DIR}/otel-collector.yaml"
  if [[ -f "$STANDALONE_MANIFEST" ]]; then
    kubectl delete -n "${NAMESPACE}" -f "${STANDALONE_MANIFEST}" --ignore-not-found
  fi

  # Remove Jaeger
  JAEGER_MANIFEST="${TRACING_DIR}/jaeger-all-in-one.yaml"
  if [[ -f "$JAEGER_MANIFEST" ]]; then
    kubectl delete -n "${NAMESPACE}" -f "${JAEGER_MANIFEST}" --ignore-not-found
  else
    kubectl delete deployment jaeger -n "${NAMESPACE}" --ignore-not-found
    kubectl delete service jaeger-collector -n "${NAMESPACE}" --ignore-not-found
  fi

  log_success "OTel Collector + Jaeger removed from namespace '${NAMESPACE}'."
}

### MAIN ###
main() {
  parse_args "$@"

  command -v kubectl &>/dev/null || fail "kubectl is required but not found in PATH"

  require_namespace

  if [[ "$ACTION" == "install" ]]; then
    install
  elif [[ "$ACTION" == "uninstall" ]]; then
    uninstall
  fi
}

main "$@"