#!/usr/bin/env bash
set -euo pipefail

# --------------------------------------------------
# Config
# --------------------------------------------------
BACKUP_DATE="$(date +%Y-%m-%d)"
TMP_DIR="/tmp/backup-${BACKUP_DATE}"

K8S_STORAGE="/k8s_storage"
S3_BASE="s3://mist-backups/${BACKUP_DATE}"

POSTGRES_NAMESPACE="default"
POSTGRES_POD_LABEL="app=postgres"
POSTGRES_USER="postgres"
POSTGRES_DB="stripe_invoice"

mkdir -p "$TMP_DIR/postgres"

echo "=== Backup date: $BACKUP_DATE ==="

# --------------------------------------------------
# 1. Discover schemas (for documentation)
# --------------------------------------------------
echo "=== Discovering Postgres schemas ==="

POSTGRES_POD="$(kubectl get pods -n "$POSTGRES_NAMESPACE" \
  -l "$POSTGRES_POD_LABEL" \
  -o jsonpath='{.items[0].metadata.name}')"

SCHEMAS="$(kubectl exec -n "$POSTGRES_NAMESPACE" "$POSTGRES_POD" -- \
  psql -U "$POSTGRES_USER" -d "$POSTGRES_DB" -Atc \
  "SELECT schema_name FROM information_schema.schemata
   WHERE schema_name NOT IN ('pg_catalog', 'information_schema')
   ORDER BY schema_name;")"

# Write README
{
  echo "Database: ${POSTGRES_DB}"
  echo "Schemas:"
  for s in $SCHEMAS; do
    echo "- $s"
  done
  echo
  echo "Backup date: ${BACKUP_DATE}"
  echo "Host: mist"
} > "$TMP_DIR/postgres/README.txt"

echo "✓ Schemas documented"

# --------------------------------------------------
# 2. Postgres logical backup (FULL DB)
# --------------------------------------------------
echo "=== Dumping Postgres database ==="

kubectl exec -n "$POSTGRES_NAMESPACE" "$POSTGRES_POD" -- \
  pg_dump -U "$POSTGRES_USER" "$POSTGRES_DB" \
  | gzip > "$TMP_DIR/postgres/stripe_invoice.sql.gz"

echo "✓ Postgres dump complete"

# --------------------------------------------------
# 3. Filesystem backup (best-effort)
# --------------------------------------------------
echo "=== Archiving /k8s_storage ==="

tar \
  --ignore-failed-read \
  --warning=no-file-changed \
  -czf "$TMP_DIR/k8s_storage.tar.gz" \
  -C "$K8S_STORAGE" .

echo "✓ Filesystem archive complete"

# --------------------------------------------------
# 4. Upload to S3
# --------------------------------------------------
echo "=== Uploading to S3 ==="

aws s3 cp "$TMP_DIR/k8s_storage.tar.gz" \
  "${S3_BASE}/k8s_storage.tar.gz"

aws s3 cp "$TMP_DIR/postgres/stripe_invoice.sql.gz" \
  "${S3_BASE}/postgres/stripe_invoice.sql.gz"

aws s3 cp "$TMP_DIR/postgres/README.txt" \
  "${S3_BASE}/postgres/README.txt"

echo "✓ Upload complete"

# --------------------------------------------------
# 5. Cleanup
# --------------------------------------------------
rm -rf "$TMP_DIR"

echo "=== Backup finished successfully ==="