#!/usr/bin/env bash
# HA Failover Test — Decision D3
#
# Deliberately kills the primary PostgreSQL pod and asserts that:
#   1. Gitea remains accessible during failover
#   2. pgpool recovers to Running state
#   3. All postgresql-ha pods return to Running
#
# Must be run against a live cluster. Exits 0 on full pass.
# Run: bash tests/test_ha_failover.sh [GITEA_URL]
#
# GITEA_URL defaults to http://localhost:3000 — override for your ingress:
#   bash tests/test_ha_failover.sh https://git.example.com

set -uo pipefail

GITEA_URL="${1:-http://localhost:32166}"
NAMESPACE="default"
KUBECTL="k3s kubectl"
FAILOVER_TIMEOUT=60   # seconds to wait for repmgr promotion
RECOVERY_TIMEOUT=120  # seconds to wait for all pods Running again
PASS=0
FAIL=0

ok()   { echo "[OK]   $*"; ((PASS++)) || true; }
fail() { echo "[FAIL] $*"; ((FAIL++)) || true; }
info() { echo "[INFO] $*"; }

# ── Pre-flight ────────────────────────────────────────────────────────────────
info "Target cluster: $($KUBECTL config current-context 2>/dev/null || echo 'default')"
info "Gitea URL: ${GITEA_URL}"
info "Namespace: ${NAMESPACE}"
echo ""

# Confirm a postgresql node pod exists (component=postgresql excludes pgpool)
PRIMARY_POD=$($KUBECTL get pods -n "${NAMESPACE}" \
  -l app.kubernetes.io/name=postgresql-ha,app.kubernetes.io/component=postgresql \
  -o jsonpath='{.items[0].metadata.name}' 2>/dev/null)
if [[ -z "$PRIMARY_POD" ]]; then
  fail "No postgresql-ha postgresql pods found — is Gitea deployed?"
  exit 1
fi
info "PostgreSQL pod to kill: ${PRIMARY_POD}"

# ── Baseline: Gitea accessible before failover ────────────────────────────────
info "Checking Gitea baseline..."
HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" --max-time 10 "${GITEA_URL}" 2>/dev/null || echo "000")
if [[ "$HTTP_CODE" =~ ^[23] ]]; then
  ok "Gitea accessible before failover (HTTP ${HTTP_CODE})"
else
  fail "Gitea not accessible before failover (HTTP ${HTTP_CODE}) — aborting test"
  exit 1
fi

# ── Trigger failover: kill primary pod ───────────────────────────────────────
info "Deleting primary pod ${PRIMARY_POD} to trigger failover..."
$KUBECTL delete pod -n "${NAMESPACE}" "${PRIMARY_POD}" --grace-period=0
FAILOVER_START=$(date +%s)

# ── Wait for repmgr promotion ─────────────────────────────────────────────────
info "Waiting up to ${FAILOVER_TIMEOUT}s for a replica to be promoted..."
PROMOTED=false
while (( $(date +%s) - FAILOVER_START < FAILOVER_TIMEOUT )); do
  RUNNING=$($KUBECTL get pods -n "${NAMESPACE}" -l app.kubernetes.io/name=postgresql-ha 2>/dev/null \
    | grep " Running " | wc -l)
  if [[ "$RUNNING" -ge 1 ]]; then
    PROMOTED=true
    ELAPSED=$(( $(date +%s) - FAILOVER_START ))
    info "Replica promoted in ${ELAPSED}s"
    break
  fi
  sleep 3
done

if $PROMOTED; then
  ok "PostgreSQL replica promoted within ${FAILOVER_TIMEOUT}s"
else
  fail "No replica promoted within ${FAILOVER_TIMEOUT}s"
fi

# ── Gitea accessible after failover ──────────────────────────────────────────
info "Checking Gitea accessibility after failover..."
GITEA_OK=false
for i in $(seq 1 10); do
  HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" --max-time 5 "${GITEA_URL}" 2>/dev/null || echo "000")
  if [[ "$HTTP_CODE" =~ ^[23] ]]; then
    GITEA_OK=true
    break
  fi
  sleep 1
done

if $GITEA_OK; then
  ok "Gitea accessible after failover (HTTP ${HTTP_CODE})"
else
  fail "Gitea not accessible within 10s of failover (last HTTP ${HTTP_CODE})"
fi

# ── pgpool Running after failover ─────────────────────────────────────────────
info "Checking pgpool state..."
PGPOOL_OK=false
for i in $(seq 1 20); do
  PGPOOL_STATE=$($KUBECTL get pods -n "${NAMESPACE}" -l app.kubernetes.io/component=pgpool 2>/dev/null \
    | grep -v "^NAME" | awk '{print $3}' | head -1)
  if [[ "$PGPOOL_STATE" == "Running" ]]; then
    PGPOOL_OK=true
    break
  fi
  sleep 3
done

if $PGPOOL_OK; then
  ok "pgpool pod Running after failover"
else
  fail "pgpool not Running after failover (state: ${PGPOOL_STATE:-not found}) — missing pgpool-password?"
fi

# ── All postgresql-ha pods recover ───────────────────────────────────────────
info "Waiting up to ${RECOVERY_TIMEOUT}s for all postgresql-ha pods to return to Running..."
ALL_OK=false
RECOVERY_START=$(date +%s)
while (( $(date +%s) - RECOVERY_START < RECOVERY_TIMEOUT )); do
  TOTAL=$($KUBECTL get pods -n "${NAMESPACE}" -l app.kubernetes.io/name=postgresql-ha 2>/dev/null \
    | grep -v "^NAME" | wc -l)
  RUNNING=$($KUBECTL get pods -n "${NAMESPACE}" -l app.kubernetes.io/name=postgresql-ha 2>/dev/null \
    | grep " Running " | wc -l)
  if [[ "$TOTAL" -gt 0 && "$TOTAL" -eq "$RUNNING" ]]; then
    ALL_OK=true
    ELAPSED=$(( $(date +%s) - RECOVERY_START ))
    info "All ${TOTAL} postgresql-ha pods Running after ${ELAPSED}s"
    break
  fi
  sleep 5
done

if $ALL_OK; then
  ok "All postgresql-ha pods recovered to Running"
else
  fail "Not all postgresql-ha pods recovered within ${RECOVERY_TIMEOUT}s"
  $KUBECTL get pods -n "${NAMESPACE}" -l app.kubernetes.io/name=postgresql-ha 2>/dev/null || true
fi

# ── Summary ───────────────────────────────────────────────────────────────────
echo ""
echo "Results: ${PASS} passed, ${FAIL} failed"
echo ""
if [[ "$FAIL" -gt 0 ]]; then
  echo "FAILOVER TEST FAILED — review output above"
  exit 1
else
  echo "FAILOVER TEST PASSED — cluster is HA-verified (D3 satisfied)"
  exit 0
fi