#!/bin/bash
set -euo pipefail

PLUGIN_DIR="$(cd "$(dirname "$0")/.." && pwd)"
SCRIPT="$PLUGIN_DIR/scripts/da-integration/alt_mysql_restore_payload.sh"
TMP_DIR="$(mktemp -d)"
trap 'rm -rf "$TMP_DIR"' EXIT

fail() {
  echo "FAIL: $*" >&2
  exit 1
}

sha256_of() {
  if command -v sha256sum >/dev/null 2>&1; then
    sha256sum "$1" | awk '{print $1}'
  else
    shasum -a 256 "$1" | awk '{print $1}'
  fi
}

# --- Fake alt-mariadb client binaries + credentials, isolated from the real system ---
# The stub tracks a simple "existing databases" state file so CREATE/DROP
# DATABASE during the test actually affects what a later existence check sees.
mkdir -p "$TMP_DIR/mariadb/bin"
cat > "$TMP_DIR/mariadb/bin/mariadb" <<'STUB'
#!/bin/bash
STATE_FILE="${FAKE_DB_STATE_FILE:?FAKE_DB_STATE_FILE must be set}"

sql=""
mode=""
for arg in "$@"; do
  case "$arg" in
    -e) mode="sql" ;;
    -Nse) mode="sql" ;;
    --database=*|--user=*|--socket=*|--host=*|--port=*|--protocol=*) ;;
    *)
      if [ "$mode" = "sql" ]; then
        sql="$arg"
        mode=""
      fi
      ;;
  esac
done

if [ -n "$sql" ]; then
  case "$sql" in
    *"SELECT 1 FROM information_schema.SCHEMATA"*)
      name="$(printf '%s' "$sql" | sed -n "s/.*SCHEMA_NAME='\([^']*\)'.*/\1/p")"
      grep -qx "$name" "$STATE_FILE" 2>/dev/null && echo 1
      ;;
    *"DROP DATABASE"*)
      name="$(printf '%s' "$sql" | sed -n 's/.*DATABASE[^`]*`\([A-Za-z0-9_]*\)`.*/\1/p')"
      if [ -n "$name" ]; then
        grep -vx "$name" "$STATE_FILE" > "$STATE_FILE.tmp" 2>/dev/null || true
        mv -f "$STATE_FILE.tmp" "$STATE_FILE"
      fi
      ;;
    *"CREATE DATABASE"*)
      name="$(printf '%s' "$sql" | sed -n 's/.*DATABASE[^`]*`\([A-Za-z0-9_]*\)`.*/\1/p')"
      [ -n "$name" ] && echo "$name" >> "$STATE_FILE"
      ;;
  esac
  exit 0
fi

# No -e/-Nse: reading an import from stdin
cat >/dev/null
if [ "${FAKE_MYSQL_IMPORT_FAIL:-0}" = "1" ]; then
  echo "fake mariadb: simulated import failure" >&2
  exit 1
fi
exit 0
STUB
chmod 755 "$TMP_DIR/mariadb/bin/mariadb"

cat > "$TMP_DIR/mariadb/bin/mariadb-dump" <<'STUB'
#!/bin/bash
echo "-- fake rollback dump"
echo "SELECT 1;"
exit 0
STUB
chmod 755 "$TMP_DIR/mariadb/bin/mariadb-dump"

cat > "$TMP_DIR/alt-mysql.conf" <<EOF
host=
passwd=secret
port=4407
socket=$TMP_DIR/data/mariadb.sock
user=da_admin
EOF

cat > "$TMP_DIR/settings.conf" <<EOF
MYSQL_PLUGIN_CREDENTIALS_FILE=$TMP_DIR/alt-mysql.conf
MYSQL_PLUGIN_CLIENT_BIN_DIR=$TMP_DIR/mariadb/bin
EOF

# --- Build a valid manifest + payload files ---
build_payload() {
  local payload_dir="$1" db_name="$2"
  mkdir -p "$payload_dir/databases" "$payload_dir/grants" "$payload_dir/metadata"
  printf 'CREATE TABLE t (id INT);\n' > "$payload_dir/databases/${db_name}.sql"
  gzip -9 -f "$payload_dir/databases/${db_name}.sql"
  printf '%s\n' '-- users' | gzip -9 > "$payload_dir/grants/users.sql.gz"
  printf '%s\n' '-- grants' | gzip -9 > "$payload_dir/grants/grants.sql.gz"
  local sha
  sha="$(sha256_of "$payload_dir/databases/${db_name}.sql.gz")"
  cat > "$payload_dir/manifest.json" <<JSON
{
  "format": "da-alt-mysql-v1",
  "created_at": "2026-01-01T00:00:00Z",
  "da_user": "demo",
  "databases": [
    { "name": "${db_name}", "file": "databases/${db_name}.sql.gz", "sha256": "${sha}" }
  ]
}
JSON
}

run_restore() {
  local db_state
  db_state="$(mktemp)"
  printf '%s\n' "${FAKE_EXISTING_DBS:-}" | tr ',' '\n' | sed '/^$/d' > "$db_state"

  DA_ALT_MYSQL_SETTINGS_FILE="$TMP_DIR/settings.conf" \
  DA_ALT_MYSQL_RESTORE_LOG="$TMP_DIR/restore.log" \
  FAKE_DB_STATE_FILE="$db_state" \
  bash "$SCRIPT" "$@"
}

# --- Scenario 1: checksum mismatch must be rejected before any restore happens ---
PAYLOAD1="$TMP_DIR/payload1"
build_payload "$PAYLOAD1" "demo_app"
echo 'CORRUPTED CONTENT' > "$PAYLOAD1/databases/demo_app.sql.gz"

OUTPUT1="$(run_restore --user demo --payload "$PAYLOAD1" --overwrite allow 2>&1)" && fail "checksum mismatch must cause a non-zero exit, output: $OUTPUT1"
echo "$OUTPUT1" | grep -qi "checksum mismatch" \
  || fail "expected a checksum mismatch error, got: $OUTPUT1"
[ ! -f "$TMP_DIR/restore.log" ] || ! grep -qi "restoring user definitions" "$TMP_DIR/restore.log" \
  || fail "restore must not proceed past checksum verification on mismatch"

# --- Scenario 2: overwrite=deny must refuse to touch an existing database ---
PAYLOAD2="$TMP_DIR/payload2"
build_payload "$PAYLOAD2" "demo_existing"

OUTPUT2="$(FAKE_EXISTING_DBS="demo_existing" run_restore --user demo --payload "$PAYLOAD2" --overwrite deny 2>&1)" && fail "overwrite=deny must reject an existing database, output: $OUTPUT2"
echo "$OUTPUT2" | grep -qi "overwrite is denied" \
  || fail "expected an overwrite-denied error, got: $OUTPUT2"

# --- Scenario 3: happy path - valid checksum, no conflict, overwrite=allow ---
PAYLOAD3="$TMP_DIR/payload3"
build_payload "$PAYLOAD3" "demo_new"

run_restore --user demo --payload "$PAYLOAD3" --overwrite allow >/dev/null 2>&1 \
  || fail "a valid payload with no conflicts and overwrite=allow should succeed"
grep -qi "restore payload completed" "$TMP_DIR/restore.log" \
  || fail "expected the restore to log completion"

echo "alt_mysql_restore_payload_test: OK"