#!/usr/bin/env bash
# install.sh — install Busbar Designer on Debian / Ubuntu.
#
# Runs inside an LXC, VM, or bare-metal host. Idempotent (safe to re-run).
#
# Required env:
#   REPO_URL    Git URL of the busbar-designer repo
#               (e.g. https://gitea.local/me/busbar-designer.git)
#
# Optional env:
#   BRANCH         git branch to track     (default: main)
#   INSTALL_DIR    install location        (default: /opt/busbar-designer)
#   SVC_USER       systemd service user    (default: busbar)
#   PORT           HTTP port               (default: 5000)
#   GIT_SSL_NO_VERIFY=1   skip TLS verify for self-signed Gitea certs

set -euo pipefail

REPO_URL="${REPO_URL:-}"
BRANCH="${BRANCH:-main}"
INSTALL_DIR="${INSTALL_DIR:-/opt/busbar-designer}"
SVC_USER="${SVC_USER:-busbar}"
PORT="${PORT:-5000}"

# ---- helpers ---------------------------------------------------------------
GREEN='\033[0;32m'; YELLOW='\033[1;33m'; RED='\033[0;31m'; NC='\033[0m'
log()  { echo -e "${GREEN}▸${NC} $*"; }
warn() { echo -e "${YELLOW}!${NC} $*"; }
die()  { echo -e "${RED}✗ $*${NC}" >&2; exit 1; }

[[ $EUID -eq 0 ]] || die "Run as root (or via sudo)."
[[ -n "$REPO_URL" ]] || die "REPO_URL is required (export REPO_URL=https://gitea.local/me/busbar-designer.git)"

if [[ "${GIT_SSL_NO_VERIFY:-0}" == "1" ]]; then
    warn "GIT_SSL_NO_VERIFY=1 — skipping TLS verification for git."
    export GIT_SSL_NO_VERIFY=true
fi

# ---- system packages -------------------------------------------------------
log "Installing system packages..."
export DEBIAN_FRONTEND=noninteractive
apt-get update -qq
apt-get install -y -qq \
    git ca-certificates curl \
    python3 python3-venv python3-pip \
    libgl1 libglu1-mesa libxrender1 libxext6 libsm6 libgomp1

# ---- service user ----------------------------------------------------------
if ! id "$SVC_USER" >/dev/null 2>&1; then
    log "Creating service user '$SVC_USER'..."
    useradd --system --create-home --shell /usr/sbin/nologin "$SVC_USER"
else
    log "Service user '$SVC_USER' already exists."
fi

# ---- source tree -----------------------------------------------------------
mkdir -p "$(dirname "$INSTALL_DIR")"

if [[ -d "$INSTALL_DIR/.git" ]]; then
    log "Updating existing checkout at $INSTALL_DIR..."
    chown -R "$SVC_USER:$SVC_USER" "$INSTALL_DIR"
    sudo -u "$SVC_USER" git -C "$INSTALL_DIR" remote set-url origin "$REPO_URL"
    sudo -u "$SVC_USER" git -C "$INSTALL_DIR" fetch --depth 1 origin "$BRANCH"
    sudo -u "$SVC_USER" git -C "$INSTALL_DIR" reset --hard "origin/$BRANCH"
else
    log "Cloning $REPO_URL (branch $BRANCH) into $INSTALL_DIR..."
    rm -rf "$INSTALL_DIR"
    git clone --depth 1 --branch "$BRANCH" "$REPO_URL" "$INSTALL_DIR"
    chown -R "$SVC_USER:$SVC_USER" "$INSTALL_DIR"
fi

# ---- virtualenv + python deps ---------------------------------------------
if [[ ! -x "$INSTALL_DIR/.venv/bin/python" ]]; then
    log "Creating Python venv..."
    sudo -u "$SVC_USER" python3 -m venv "$INSTALL_DIR/.venv"
fi

log "Installing Python dependencies (build123d pulls OpenCASCADE — may take a few minutes)..."
sudo -u "$SVC_USER" "$INSTALL_DIR/.venv/bin/pip" install --quiet --upgrade pip
sudo -u "$SVC_USER" "$INSTALL_DIR/.venv/bin/pip" install --quiet \
    -r "$INSTALL_DIR/requirements.txt" gunicorn

# ---- data dir (for SQLite) -------------------------------------------------
sudo -u "$SVC_USER" mkdir -p "$INSTALL_DIR/data"

# ---- systemd unit ----------------------------------------------------------
log "Installing systemd unit..."
UNIT_SRC="$INSTALL_DIR/deploy/busbar-designer.service"
UNIT_DST="/etc/systemd/system/busbar-designer.service"
[[ -f "$UNIT_SRC" ]] || die "deploy/busbar-designer.service missing in the repo."

# Substitute paths / user / port into the unit.
sed -e "s|/opt/busbar-designer|$INSTALL_DIR|g" \
    -e "s|User=busbar|User=$SVC_USER|g" \
    -e "s|Group=busbar|Group=$SVC_USER|g" \
    -e "s|--bind=0.0.0.0:5000|--bind=0.0.0.0:$PORT|g" \
    -e "s|Environment=PORT=5000|Environment=PORT=$PORT|g" \
    "$UNIT_SRC" > "$UNIT_DST"

systemctl daemon-reload
systemctl enable --now busbar-designer
sleep 2

if ! systemctl is-active --quiet busbar-designer; then
    warn "Service is not active. Last 30 log lines:"
    journalctl -u busbar-designer -n 30 --no-pager
    die "Service failed to start."
fi

IP_ADDR=$(hostname -I 2>/dev/null | awk '{print $1}')
[[ -n "$IP_ADDR" ]] || IP_ADDR="$(hostname)"

echo
log "================================================================"
log "  ✓ Busbar Designer installed."
log ""
log "  URL:     http://$IP_ADDR:$PORT"
log "  Logs:    journalctl -u busbar-designer -f"
log "  Update:  sudo bash $INSTALL_DIR/deploy/update.sh"
log "  Backup:  cp $INSTALL_DIR/data/busbar.db ..."
log "================================================================"