#!/usr/bin/env bash
# Pipekit deployment — idempotent. Re-run after any code update.
#
# What it does:
#   1. Creates the 'pipekit' system user (if absent)
#   2. Chowns /opt/pipekit to pipekit:pipekit
#   3. Creates Python venv (as pipekit) and installs requirements
#   4. Installs /usr/local/bin/pipekit launcher
#   5. Creates /etc/pipekit/secrets.env (mode 0640, group pipekit)
#   6. Runs 'pipekit init' to create/upgrade the SQLite schema
#   7. Registers JDBC driver rows for every jar shipped with jrunner
#   8. 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"

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

echo "== pipekit deploy =="
echo "repo:    $REPO_DIR"
echo "venv:    $VENV_DIR"
echo "secrets: $SECRETS_FILE"
echo ""

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

# ── 1. System user ────────────────────────────────────────────────────────────
if ! id -u "$SERVICE_NAME" >/dev/null 2>&1; then
    echo "Creating system user: $SERVICE_NAME"
    useradd --system --no-create-home --shell /usr/sbin/nologin "$SERVICE_NAME"
else
    echo "User $SERVICE_NAME already exists."
fi

# ── 2. Ownership ──────────────────────────────────────────────────────────────
echo "Setting ownership of $REPO_DIR to $SERVICE_NAME:$SERVICE_NAME"
chown -R "$SERVICE_NAME:$SERVICE_NAME" "$REPO_DIR"

# ── 3. Venv + deps ────────────────────────────────────────────────────────────
if [ -d "$VENV_DIR" ] && [ "$(stat -c '%U' "$VENV_DIR")" != "$SERVICE_NAME" ]; then
    echo "Removing root-owned venv and recreating as $SERVICE_NAME"
    rm -rf "$VENV_DIR"
fi

if [ ! -d "$VENV_DIR" ]; then
    echo "Creating venv at $VENV_DIR"
    sudo -u "$SERVICE_NAME" python3 -m venv "$VENV_DIR"
fi

echo "Installing Python dependencies"
sudo -u "$SERVICE_NAME" "$VENV_DIR/bin/pip" install --quiet --upgrade pip
sudo -u "$SERVICE_NAME" "$VENV_DIR/bin/pip" install --quiet -r "$REPO_DIR/requirements.txt"
echo "Dependencies installed."

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

# ── 5. Secrets file ───────────────────────────────────────────────────────────
install -d -m 0755 "$CONFIG_DIR"
if [ ! -f "$SECRETS_FILE" ]; then
    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
    echo "Created $SECRETS_FILE"
else
    # Ensure correct permissions even if file pre-existed
    chown "root:$SERVICE_NAME" "$SECRETS_FILE"
    chmod 0640 "$SECRETS_FILE"
    echo "Keeping existing $SECRETS_FILE"
fi

# ── 6. Schema init ────────────────────────────────────────────────────────────
sudo -u "$SERVICE_NAME" "$LAUNCHER" init
echo "Schema initialised."

# ── 7. Driver registration ────────────────────────────────────────────────────
JR_LIB="$(dirname "$(readlink -f "$(command -v jrunner)")")/../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 "$jar" ]; then
        sudo -u "$SERVICE_NAME" "$LAUNCHER" drivers register "$kind" --jar "$jar"
    else
        echo "  (no $pattern in $JR_LIB — skipping $kind)"
    fi
}
register_jar db2   "jt400-*.jar"
register_jar pg    "postgresql-*.jar"
register_jar mssql "mssql-jdbc-*.jar"

# ── 8. Systemd unit ───────────────────────────────────────────────────────────
if [ ! -f "$UNIT_SRC" ]; then
    echo "WARNING: $UNIT_SRC not found — skipping systemd install"
else
    cp "$UNIT_SRC" "$UNIT_DST"
    systemctl daemon-reload
    systemctl enable "$SERVICE_NAME"
    echo "Systemd unit installed and enabled."
fi

echo ""
echo "pipekit deployed."
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"