#!/bin/bash
#
# Install svn-git-server as a systemd service (daemon).
#
# The daemon handles bidirectional sync: SVN->Git polling AND Git->SVN push.
#
# Usage:
#   sudo ./deploy/install.sh --install-dir /opt/svn-git-server --user gitea
#
# Options:
#   --install-dir DIR   Path where the code is installed (required)
#   --user USER         System user to run the service as (default: gitea)
#   --config FILE       Config file path (default: <install-dir>/config.yml)
#   --venv DIR          Virtualenv path (default: <install-dir>/.venv)
#   --uninstall          Remove service instead of installing
#

set -euo pipefail

INSTALL_DIR=""
SERVICE_USER="gitea"
CONFIG_FILE=""
VENV_DIR=""
UNINSTALL=false

# ── Parse args ──────────────────────────────────────────────
while [[ $# -gt 0 ]]; do
    case "$1" in
        --install-dir)  INSTALL_DIR="$2"; shift 2 ;;
        --user)         SERVICE_USER="$2"; shift 2 ;;
        --config)       CONFIG_FILE="$2"; shift 2 ;;
        --venv)         VENV_DIR="$2"; shift 2 ;;
        --uninstall)    UNINSTALL=true; shift ;;
        -h|--help)
            grep -E '^#( |$)' "$0" | sed 's/^# \?//'
            exit 0
            ;;
        *)
            echo "Unknown option: $1" >&2
            exit 1
            ;;
    esac
done

if [[ "$UNINSTALL" == true ]]; then
    echo "Removing svn-mirror service..."
    systemctl disable --now svn-mirror.service 2>/dev/null || true
    rm -f /etc/systemd/system/svn-mirror.service
    systemctl daemon-reload
    echo "Done. Service removed."
    exit 0
fi

if [[ -z "$INSTALL_DIR" ]]; then
    echo "Error: --install-dir is required" >&2
    echo "Usage: sudo $0 --install-dir /opt/svn-git-server --user gitea" >&2
    exit 1
fi

# Resolve to absolute path
INSTALL_DIR="$(cd "$INSTALL_DIR" 2>/dev/null && pwd)" || {
    echo "Error: install-dir '$INSTALL_DIR' does not exist" >&2
    exit 1
}

CONFIG_FILE="${CONFIG_FILE:-$INSTALL_DIR/config.yml}"
VENV_DIR="${VENV_DIR:-$INSTALL_DIR/.venv}"

echo "=== svn-mirror install ==="
echo "  Install dir: $INSTALL_DIR"
echo "  User:        $SERVICE_USER"
echo "  Config:      $CONFIG_FILE"
echo "  Venv:        $VENV_DIR"
echo ""

# ── Checks ──────────────────────────────────────────────────
if [[ "$EUID" -ne 0 ]]; then
    echo "Error: must run as root (use sudo)" >&2
    exit 1
fi

if ! id "$SERVICE_USER" &>/dev/null; then
    echo "Error: user '$SERVICE_USER' does not exist" >&2
    exit 1
fi

if [[ ! -f "$CONFIG_FILE" ]]; then
    echo "Warning: config file '$CONFIG_FILE' not found"
    echo "         You can create it later before starting the service."
fi

if [[ ! -d "$VENV_DIR" ]]; then
    echo "Creating virtualenv at $VENV_DIR ..."
    python3 -m venv "$VENV_DIR"
    chown -R "$SERVICE_USER":"$SERVICE_USER" "$VENV_DIR"
    sudo -u "$SERVICE_USER" "$VENV_DIR/bin/pip" install --quiet --upgrade pip
    sudo -u "$SERVICE_USER" "$VENV_DIR/bin/pip" install --quiet -r "$INSTALL_DIR/requirements.txt"
    echo "  Virtualenv created."
else
    echo "Virtualenv already exists at $VENV_DIR"
fi

# Make sure the install dir is owned by the service user
chown -R "$SERVICE_USER":"$SERVICE_USER" "$INSTALL_DIR"

# ── Generate systemd unit ───────────────────────────────────
SERVICE_UNIT="/etc/systemd/system/svn-mirror.service"

cat > "$SERVICE_UNIT" <<EOF
# Generated by svn-git-server deploy/install.sh
# Do not edit by hand — re-run install.sh to change settings.
[Unit]
Description=gitea-svn-mirror daemon (bidirectional SVN<->Git sync)
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
User=$SERVICE_USER
Group=$SERVICE_USER
WorkingDirectory=$INSTALL_DIR
ExecStart=$VENV_DIR/bin/python -m svn_mirror daemon --config $CONFIG_FILE
Restart=always
RestartSec=10
StandardOutput=journal
StandardError=journal

# Ensure UTF-8 locale for SVN with non-ASCII filenames
Environment=LC_ALL=en_US.UTF-8
Environment=LANG=en_US.UTF-8

[Install]
WantedBy=multi-user.target
EOF

echo "Created service file:"
echo "  $SERVICE_UNIT"

# ── Reload and enable ───────────────────────────────────────
systemctl daemon-reload

systemctl enable svn-mirror.service

echo ""
echo "Service enabled. Start it with:"
echo "  systemctl start svn-mirror"
echo ""
echo "Check logs with:"
echo "  journalctl -u svn-mirror -f"
echo ""
echo "Status:"
echo "  systemctl status svn-mirror"