#!/usr/bin/env bash
# Pipekit deployment — idempotent. Re-run after any code update.
#
# What it does:
#   1. Creates the 'pipekit' system user and group (if absent)
#   2. Adds the invoking user to the 'pipekit' group
#   3. Sets ownership of /opt/pipekit to pipekit:pipekit (group-writable)
#   4. Creates Python venv (as pipekit) and installs requirements
#   5. Installs /usr/local/bin/pipekit launcher
#   6. Creates /etc/pipekit/secrets.env (mode 0640, group pipekit)
#   7. Runs 'pipekit init' to create/upgrade the SQLite schema
#   8. Registers JDBC driver rows for every jar shipped with jrunner
#   9. Installs and enables the systemd unit (does not start it)
#
# Usage:
#   ./deploy.sh          # re-execs itself with sudo if needed
#
# After deploy:
#   sudo pipekit secrets set KEY VALUE   # add connection passwords
#   sudo systemctl start pipekit

set -euo pipefail

REPO_DIR="${PIPEKIT_REPO:-$(cd "$(dirname "$0")" && pwd)}"
VENV_DIR="$REPO_DIR/.venv"
LAUNCHER="/usr/local/bin/pipekit"
CONFIG_DIR="/etc/pipekit"
SECRETS_FILE="$CONFIG_DIR/secrets.env"
SERVICE_NAME="pipekit"
UNIT_SRC="$REPO_DIR/systemd/pipekit.service"
UNIT_DST="/etc/systemd/system/pipekit.service"

# Capture the invoking user before re-execing as root
INVOKING_USER="${SUDO_USER:-${USER:-}}"

# Re-exec as root if needed
if [ "$EUID" -ne 0 ]; then
    exec sudo -E "$0" "$@"
fi

step() { echo ""; echo "── $* ──"; }

echo "== pipekit deploy =="
echo "repo:    $REPO_DIR"
echo "venv:    $VENV_DIR"
echo "secrets: $SECRETS_FILE"
echo "user:    $SERVICE_NAME (invoking user: ${INVOKING_USER:-unknown})"

# ── Prerequisites ─────────────────────────────────────────────────────────────
step "Checking prerequisites"
command -v python3 >/dev/null || { echo "ERROR: python3 not on PATH"; exit 1; }
echo "  python3: $(python3 --version)"
command -v jrunner >/dev/null || { echo "ERROR: jrunner not on PATH — install /opt/jrunner first"; exit 1; }
echo "  jrunner: $(command -v jrunner)"

# ── 1. System user ────────────────────────────────────────────────────────────
step "System user"
if ! id -u "$SERVICE_NAME" >/dev/null 2>&1; then
    echo "  Creating system user: $SERVICE_NAME"
    useradd --system --no-create-home --home-dir /nonexistent \
            --shell /usr/sbin/nologin "$SERVICE_NAME"
    echo "  Done."
else
    echo "  User '$SERVICE_NAME' already exists (uid=$(id -u "$SERVICE_NAME"))."
fi

# ── 2. Add invoking user to pipekit group ─────────────────────────────────────
step "Group membership"
if [ -n "$INVOKING_USER" ] && [ "$INVOKING_USER" != "$SERVICE_NAME" ]; then
    if id -nG "$INVOKING_USER" | grep -qw "$SERVICE_NAME"; then
        echo "  $INVOKING_USER is already in the '$SERVICE_NAME' group."
    else
        echo "  Adding $INVOKING_USER to the '$SERVICE_NAME' group."
        usermod -aG "$SERVICE_NAME" "$INVOKING_USER"
        echo "  Done. Log out and back in for this to take effect."
    fi
else
    echo "  Skipping — could not determine invoking user."
fi

# ── 3. Ownership ──────────────────────────────────────────────────────────────
step "File ownership and permissions"
echo "  Setting $REPO_DIR → $SERVICE_NAME:$SERVICE_NAME (group-writable)"
chown -R "$SERVICE_NAME:$SERVICE_NAME" "$REPO_DIR"
chmod -R g+w "$REPO_DIR"
echo "  Done."

# ── 4. Venv + deps ────────────────────────────────────────────────────────────
step "Python venv"
if [ -d "$VENV_DIR" ] && [ "$(stat -c '%U' "$VENV_DIR")" != "$SERVICE_NAME" ]; then
    echo "  Venv exists but is not owned by $SERVICE_NAME — recreating."
    rm -rf "$VENV_DIR"
fi

if [ ! -d "$VENV_DIR" ]; then
    echo "  Creating venv at $VENV_DIR"
    sudo -u "$SERVICE_NAME" HOME=/nonexistent python3 -m venv "$VENV_DIR"
else
    echo "  Venv already exists at $VENV_DIR."
fi

echo "  Upgrading pip"
sudo -u "$SERVICE_NAME" HOME=/nonexistent \
    "$VENV_DIR/bin/pip" install --quiet --no-cache-dir --upgrade pip

echo "  Installing requirements"
sudo -u "$SERVICE_NAME" HOME=/nonexistent \
    "$VENV_DIR/bin/pip" install --quiet --no-cache-dir -r "$REPO_DIR/requirements.txt"
echo "  Done."

# ── 5. Launcher ───────────────────────────────────────────────────────────────
step "Launcher"
chmod +x "$REPO_DIR/bin/pipekit"
ln -sf "$REPO_DIR/bin/pipekit" "$LAUNCHER"
echo "  $LAUNCHER -> $REPO_DIR/bin/pipekit"

# ── 6. Secrets file ───────────────────────────────────────────────────────────
step "Secrets file"
install -d -m 0755 "$CONFIG_DIR"
if [ ! -f "$SECRETS_FILE" ]; then
    echo "  Creating $SECRETS_FILE (mode 0640, group $SERVICE_NAME)"
    install -m 0640 /dev/null "$SECRETS_FILE"
    chown "root:$SERVICE_NAME" "$SECRETS_FILE"
    cat > "$SECRETS_FILE" <<'EOF'
# pipekit secrets — loaded by the systemd unit as EnvironmentFile.
# Connection passwords are stored as $KEY references in the DB.
# Add entries with:  sudo pipekit secrets set KEY VALUE
EOF
else
    echo "  $SECRETS_FILE already exists — keeping contents."
    chown "root:$SERVICE_NAME" "$SECRETS_FILE"
    chmod 0640 "$SECRETS_FILE"
    echo "  Permissions ensured: 0640 group $SERVICE_NAME."
fi

# ── 7. Schema init ────────────────────────────────────────────────────────────
step "Database schema"
echo "  Running pipekit init"
sudo -u "$SERVICE_NAME" HOME=/nonexistent "$LAUNCHER" init
echo "  Done."

# ── 8. Driver registration ────────────────────────────────────────────────────
step "JDBC driver registration"
JR_LIB="$(dirname "$(readlink -f "$(command -v jrunner)")")/../lib"
echo "  jrunner lib dir: $JR_LIB"
register_jar() {
    local kind="$1" pattern="$2"
    local jar
    jar="$(find "$JR_LIB" -maxdepth 1 -name "$pattern" 2>/dev/null | head -1)"
    if [ -n "$jar" ]; then
        echo "  Registering $kind: $(basename "$jar")"
        sudo -u "$SERVICE_NAME" HOME=/nonexistent "$LAUNCHER" drivers register "$kind" --jar "$jar"
    else
        echo "  No $pattern found in $JR_LIB — skipping $kind"
    fi
}
register_jar db2   "jt400-*.jar"
register_jar pg    "postgresql-*.jar"
register_jar mssql "mssql-jdbc-*.jar"

# ── 9. Systemd unit ───────────────────────────────────────────────────────────
step "Systemd unit"
if [ ! -f "$UNIT_SRC" ]; then
    echo "  WARNING: $UNIT_SRC not found — skipping"
else
    echo "  Installing $UNIT_DST"
    cp "$UNIT_SRC" "$UNIT_DST"
    echo "  Running systemctl daemon-reload"
    systemctl daemon-reload
    echo "  Enabling $SERVICE_NAME service"
    systemctl enable "$SERVICE_NAME"
    echo "  Done."
fi

echo ""
echo "════════════════════════════════════"
echo "  pipekit deployed successfully."
echo "════════════════════════════════════"
echo ""
echo "Next steps:"
echo "  1. Add connection passwords:"
echo "       sudo pipekit secrets set DB2PW <value>"
echo "       sudo pipekit secrets set PGPW  <value>"
echo "  2. Start the service:"
echo "       sudo systemctl start pipekit"
echo "  3. Check it:"
echo "       sudo systemctl status pipekit"
echo "       journalctl -u pipekit -f"
if [ -n "$INVOKING_USER" ]; then
    if ! id -nG "$INVOKING_USER" 2>/dev/null | grep -qw "$SERVICE_NAME"; then
        echo ""
        echo "  NOTE: $INVOKING_USER was added to the '$SERVICE_NAME' group."
        echo "        Log out and back in for write access to take effect."
    fi
fi