#!/bin/bash
# Run a step-load (staircase) test across a collection of endpoints.
# Usage:
#   ./scripts/stepload.sh <base-url> <endpoints-json> [start-rps] [step-rps] [step-duration] [steps]
# Example:
#   ./scripts/stepload.sh https://api.example.com \
#     '[{"name":"login","method":"POST","path":"/login"},{"name":"list","path":"/items","weight":3}]' \
#     25 25 2m 6
#   -> starts at 25 rps, +25 rps every 2 minutes, 6 steps (ending at 150 rps)
set -euo pipefail

BASE=${1:?usage: stepload.sh <base-url> <endpoints-json> [start-rps] [step-rps] [step-duration] [steps]}
EPS=${2:?endpoints-json required - see script header for format}
START=${3:-50}
STEP=${4:-50}
DUR=${5:-2m}
STEPS=${6:-5}
NAME="stepload-$(date +%s)"
PROM_RW="http://prometheus.monitoring.svc:9090/api/v1/write"

kubectl -n loadtest apply -f - <<EOF
apiVersion: batch/v1
kind: Job
metadata:
  name: $NAME
spec:
  parallelism: 1
  ttlSecondsAfterFinished: 1800
  template:
    spec:
      restartPolicy: Never
      containers:
        - name: k6
          image: grafana/k6:1.4.0
          command: ["k6", "run", "/scripts/step.js", "-o", "experimental-prometheus-rw"]
          env:
            - {name: BASE_URL, value: "$BASE"}
            - {name: ENDPOINTS_JSON, value: '$EPS'}
            - {name: START_RPS, value: "$START"}
            - {name: STEP_RPS, value: "$STEP"}
            - {name: STEP_DURATION, value: "$DUR"}
            - {name: STEPS, value: "$STEPS"}
            - {name: K6_PROMETHEUS_RW_SERVER_URL, value: "$PROM_RW"}
            - {name: K6_PROMETHEUS_RW_TREND_STATS, value: "avg,p(50),p(95),p(99),min,max"}
          resources:
            requests: {cpu: 200m, memory: 256Mi}
            limits: {memory: 512Mi}
          volumeMounts:
            - {name: scripts, mountPath: /scripts}
      volumes:
        - name: scripts
          configMap: {name: k6-step-script}
EOF

MAX=$(( START + (STEPS - 1) * STEP ))
echo "Staircase '$NAME': $STEPS steps, $START -> $MAX rps (+$STEP each), $DUR holds"
echo "Total duration: $STEPS x $DUR (plus 5s ramps per step)"
echo ""
echo "Watch live:  Grafana -> the 'k6 Step Load' dashboard (or kubectl -n loadtest logs -f job/$NAME)"
echo "Logs:        kubectl -n loadtest logs -f job/$NAME"
echo "Stop early:  kubectl -n loadtest delete job $NAME"