#!/usr/bin/env bash

# What makes a Fedora machine able to run rootless compose services. Server
# role only -- ./install never runs this on a desktop. Idempotent throughout:
# every step checks the machine before touching it, so a re-run on a machine
# that already has all of this changes nothing and says so.

set -euo pipefail

log() { echo -e "\033[1;34m[INFO]\033[0m $*"; }

PANAMA_PATH="${PANAMA_PATH:-$HOME/.local/share/Panama}"

# ── Linger ───────────────────────────────────────────────────────────────────
# Without it every user unit -- which is every service -- stops at logout and
# starts only at login, which on a server means "runs while somebody is SSHed
# in". Linger is what makes the user session a real init.
if loginctl show-user "$USER" 2>/dev/null | grep -q '^Linger=yes'; then
  log "Linger already enabled for $USER"
else
  log "Enabling linger for $USER"
  sudo loginctl enable-linger "$USER"
fi

# ── Unprivileged ports from 80 ───────────────────────────────────────────────
# Rootless containers cannot bind 80/443 while the kernel reserves everything
# below 1024 for root. Lowering the floor to 80 is what lets the reverse proxy
# be a rootless container like everything else. A file in /etc/sysctl.d so it
# survives reboots; sysctl --system so it applies now.
SYSCTL_FILE=/etc/sysctl.d/99-rootless-ports.conf
SYSCTL_WANT='net.ipv4.ip_unprivileged_port_start=80'
if [[ -r "$SYSCTL_FILE" ]] && grep -qx "$SYSCTL_WANT" "$SYSCTL_FILE"; then
  log "Unprivileged ports already start at 80 ($SYSCTL_FILE)"
else
  log "Allowing unprivileged binds from port 80"
  printf '%s\n' "$SYSCTL_WANT" | sudo tee "$SYSCTL_FILE" >/dev/null
  sudo sysctl --system >/dev/null
fi

# ── Firewall ─────────────────────────────────────────────────────────────────
# 80 and 443 because everything is reverse-proxied; 81 for the proxy's own
# admin portal. Deliberately nothing else: a service needing another port open
# documents that in its own folder and it is opened by hand, because a list of
# per-service firewall holes maintained by an installer is a list nobody
# audits.
#
# "Open" means reachable, not literally listed by --list-ports. A machine can
# already reach 80 through a rich rule admitting one CDN's address set, or
# through an enabled service. On such a machine `--add-port` is not the no-op
# it looks like: it replaces a deliberate, narrow grant with a blanket one,
# and does it during a routine `panama update` that asked nobody anything.
# So each port is checked for existing coverage and left alone when it has
# some. Panama opens what is shut; it does not widen what is already open.
#
# The bias is deliberate. Only a rule that positively reads as covering the
# port counts, and anything unrecognised falls through to opening it, because
# a fresh server that silently ends up unreachable is the worse failure --
# see the firewalld comment in setup/packages/server-packages. For the same
# reason only `accept` rules count: a rich rule that drops a port is not
# coverage, it is the opposite, and treating it as coverage would leave the
# reverse proxy unreachable on a machine nobody thought to check.
#
# A machine that manages its own firewall opts out once:
#
#   echo manual > ~/.local/state/panama/firewall
#
# after which Panama never touches firewalld on it again. A file rather than
# an environment variable because `panama update` runs unattended and asks
# nothing; a decision that lives only as long as somebody exports a variable
# is a decision that quietly lapses on the next run.
STATE_DIR="${XDG_STATE_HOME:-$HOME/.local/state}/panama"
FIREWALL_DECISION="$STATE_DIR/firewall"

# Every port an enabled permanent service already grants, one <port>/<proto>
# per line. Read back out of firewalld rather than from a hardcoded http=80
# table, so a machine's own service definition counts for exactly as much as
# a shipped one.
service_ports() {
  local service ports
  for service in $(sudo firewall-cmd --permanent --list-services 2>/dev/null || true); do
    ports="$(sudo firewall-cmd --permanent --info-service="$service" 2>/dev/null \
      | sed -n 's/^[[:space:]]*ports:[[:space:]]*//p')" || true
    [[ -n "$ports" ]] || continue
    printf '%s\n' $ports
  done
}

# Does an accepting rich rule already admit this tcp port? Ranges count, so a
# rule granting 8000-8100 covers 8080.
rich_rule_covers() {
  local port="$1" rule value low high
  while IFS= read -r rule; do
    [[ "$rule" == *accept* ]]              || continue
    [[ "$rule" == *'protocol="tcp"'* ]]    || continue
    value="${rule#*port port=\"}"
    [[ "$value" != "$rule" ]]              || continue
    value="${value%%\"*}"
    if [[ "$value" == *-* ]]; then
      low="${value%%-*}"; high="${value##*-}"
      [[ "$low" =~ ^[0-9]+$ && "$high" =~ ^[0-9]+$ ]] || continue
      (( port >= low && port <= high )) && return 0
    else
      [[ "$value" == "$port" ]] && return 0
    fi
  done < <(sudo firewall-cmd --permanent --list-rich-rules 2>/dev/null || true)
  return 1
}

if [[ "$(cat "$FIREWALL_DECISION" 2>/dev/null || true)" == manual ]]; then
  log "Firewall left to this machine ($FIREWALL_DECISION says manual)"
elif systemctl is-active firewalld >/dev/null 2>&1; then
  granted_ports="$(service_ports)"
  reload_needed=0
  for port in 80 443 81; do
    if sudo firewall-cmd --permanent --query-port="${port}/tcp" >/dev/null 2>&1; then
      log "Port ${port}/tcp already open"
    elif grep -qxF "${port}/tcp" <<<"$granted_ports"; then
      log "Port ${port}/tcp already granted by an enabled service; leaving it alone"
    elif rich_rule_covers "$port"; then
      log "Port ${port}/tcp already granted by a rich rule; leaving it alone"
    else
      log "Opening port ${port}/tcp"
      sudo firewall-cmd --permanent --add-port="${port}/tcp" >/dev/null
      reload_needed=1
    fi
  done
  (( reload_needed )) && sudo firewall-cmd --reload >/dev/null
else
  log "firewalld is not active; no ports to open"
fi

# ── The shared container network ─────────────────────────────────────────────
# Every compose file expects nginx-bridge as an external network: the reverse
# proxy reaches each service by container name across it, and no service needs
# a published port of its own. External means compose will not create it, so
# somebody has to -- this is that somebody.
if podman network exists nginx-bridge 2>/dev/null; then
  log "podman network nginx-bridge already exists"
else
  log "Creating podman network nginx-bridge"
  podman network create nginx-bridge >/dev/null
fi

# ── Nightly image updates ────────────────────────────────────────────────────
# server/scripts/update-containers, on a midnight timer. Linked rather than
# copied so a pull updates the machinery with everything else; see the script
# header for why this replaced watchtower.
UNIT_SRC="$PANAMA_PATH/server/systemd"
UNIT_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/systemd/user"
mkdir -p "$UNIT_DIR" "$HOME/Server/logs"
for unit in podman-update.service podman-update.timer; do
  src="$UNIT_SRC/$unit"
  dst="$UNIT_DIR/$unit"
  [[ -e "$src" ]] || { log "Missing $src; skipping the update timer"; continue; }
  if [[ -L "$dst" ]]; then
    rm "$dst"
  elif [[ -e "$dst" ]]; then
    mv "$dst" "$dst.pre-panama"
    log "Kept the existing $unit as $unit.pre-panama"
  fi
  ln -s "$src" "$dst"
  log "Linked $unit"
done
systemctl --user daemon-reload
if systemctl --user is-enabled podman-update.timer >/dev/null 2>&1; then
  log "podman-update.timer already enabled"
else
  log "Enabling podman-update.timer (nightly image updates)"
  systemctl --user enable --now podman-update.timer
fi