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

# Run this on the Linux origin host that currently serves velocity.desineuron.in.
# It exports a local-development bundle containing:
# - backend env snapshot (non-shell format)
# - PostgreSQL custom-format dump
# - app build metadata
# - optional asset snapshot manifest
#
# Output:
#   /tmp/velocity-local-bundle-YYYYmmdd-HHMMSS.tar.gz

REPO_ROOT="${REPO_ROOT:-/opt/desineuron-velocity-site/repo}"
BACKEND_ENV_PATH="${BACKEND_ENV_PATH:-$REPO_ROOT/backend/.env}"
OUTPUT_ROOT="${OUTPUT_ROOT:-/tmp}"
DB_CONTAINER_NAME="${DB_CONTAINER_NAME:-desineuron-ops-db}"
STAMP="$(date +%Y%m%d-%H%M%S)"
WORKDIR="$OUTPUT_ROOT/velocity-local-bundle-$STAMP"
ARCHIVE="$OUTPUT_ROOT/velocity-local-bundle-$STAMP.tar.gz"

if [[ ! -f "$BACKEND_ENV_PATH" ]]; then
  echo "Missing backend env file: $BACKEND_ENV_PATH" >&2
  exit 1
fi

mkdir -p "$WORKDIR"

cp "$BACKEND_ENV_PATH" "$WORKDIR/backend.env.raw"

python3 - "$WORKDIR/backend.env.raw" "$WORKDIR/backend.env.export" <<'PY'
import pathlib
import sys

src = pathlib.Path(sys.argv[1])
dst = pathlib.Path(sys.argv[2])

allowed = {
    "VELOCITY_DB_HOST",
    "VELOCITY_DB_PORT",
    "VELOCITY_DB_NAME",
    "VELOCITY_DB_USER",
    "VELOCITY_DB_PASSWORD",
    "DATABASE_URL",
    "CORS_ORIGINS",
    "VELOCITY_ASSET_DIR",
    "JWT_SECRET_KEY",
    "JWT_ALGORITHM",
    "JWT_EXP_MINUTES",
}

lines = []
for raw_line in src.read_text(encoding="utf-8").splitlines():
    line = raw_line.strip()
    if not line or line.startswith("#") or "=" not in line:
        continue
    key, value = line.split("=", 1)
    key = key.strip()
    if key in allowed:
        lines.append(f"{key}={value.strip()}")

dst.write_text("\n".join(lines) + "\n", encoding="utf-8")
PY

set -a
source "$BACKEND_ENV_PATH"
set +a

dump_with_local_pg_dump() {
  PGPASSWORD="${VELOCITY_DB_PASSWORD}" pg_dump \
    -h "${VELOCITY_DB_HOST}" \
    -p "${VELOCITY_DB_PORT}" \
    -U "${VELOCITY_DB_USER}" \
    -d "${VELOCITY_DB_NAME}" \
    -Fc \
    -f "$WORKDIR/velocity.dump"
}

dump_with_docker_exec() {
  if ! command -v docker >/dev/null 2>&1; then
    return 1
  fi

  sudo -n docker exec \
    -e PGPASSWORD="${VELOCITY_DB_PASSWORD}" \
    "$DB_CONTAINER_NAME" \
    pg_dump \
      -U "${VELOCITY_DB_USER}" \
      -d "${VELOCITY_DB_NAME}" \
      -Fc \
      > "$WORKDIR/velocity.dump"
}

if command -v pg_dump >/dev/null 2>&1; then
  dump_with_local_pg_dump
elif dump_with_docker_exec; then
  :
else
  echo "Neither host pg_dump nor docker-exec pg_dump is available." >&2
  exit 1
fi

cat > "$WORKDIR/README.txt" <<EOF
Velocity local bundle
Created: $(date --iso-8601=seconds)
Repo root: $REPO_ROOT
Bundle contents:
- backend.env.export
- velocity.dump
- restore.instructions.txt
EOF

cat > "$WORKDIR/restore.instructions.txt" <<EOF
1. Copy this archive to the Windows development machine.
2. Extract it under Project_Velocity/.local-dev/source-bundles/<bundle-name>.
3. Run scripts/import_velocity_local_bundle.ps1 from the repo root.
EOF

tar -C "$OUTPUT_ROOT" -czf "$ARCHIVE" "$(basename "$WORKDIR")"
rm -rf "$WORKDIR"

echo "Created bundle: $ARCHIVE"