#!/usr/bin/env bash
# EG4 LifePower4 → Home Assistant monitoring — reproducible installer.
#
# Installs the eg4-battery daemon onto /usr/local/bin (uv handles deps via the
# script's PEP-723 inline metadata), drops in the udev rule + systemd unit,
# and seeds the config template. Idempotent: safe to re-run.
#
# Assumptions:
#   - Debian-family Linux with systemd
#   - `uv` on $PATH (https://docs.astral.sh/uv/)
#   - User has sudo
#
# After install, finish by editing:
#   ~/.config/eg4-battery/eg4-battery.yaml   — bus.port, MQTT creds, pack addresses
# then:
#   ./install.sh --dry-run                    — end-to-end smoke test (no HW needed)
#   sudo systemctl enable --now eg4-battery.service
#   journalctl -u eg4-battery.service -f

set -euo pipefail

BASE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
DRY_RUN=0
for arg in "$@"; do
    [ "$arg" = "--dry-run" ] && DRY_RUN=1
done

msg() { printf '\n\033[1;36m== %s ==\033[0m\n' "$*"; }

# --- 1. dependency check ---------------------------------------------------
msg "Checking prerequisites"
command -v uv >/dev/null || { echo "uv not found — install from https://docs.astral.sh/uv/"; exit 1; }

# --- 2. entry point --------------------------------------------------------
msg "Installing /usr/local/bin/eg4-battery"
sudo install -m 755 "${BASE}/bin/eg4-battery" /usr/local/bin/eg4-battery

# --- 3. udev rule ----------------------------------------------------------
msg "Installing udev rule (FTDI/CH340/CP210x → dialout)"
sudo install -m 644 "${BASE}/etc/udev/rules.d/99-eg4-rs485.rules" /etc/udev/rules.d/99-eg4-rs485.rules
sudo udevadm control --reload-rules
sudo udevadm trigger --subsystem-match=tty

# --- 4. systemd unit -------------------------------------------------------
msg "Installing systemd unit"
sudo install -m 644 "${BASE}/etc/systemd/system/eg4-battery.service" /etc/systemd/system/eg4-battery.service
sudo systemctl daemon-reload

# --- 5. user config (only if not already present) --------------------------
msg "Installing config template"
mkdir -p "${HOME}/.config/eg4-battery"
dest="${HOME}/.config/eg4-battery/eg4-battery.yaml"
if [ -e "$dest" ]; then
    echo "  $dest already exists — not overwriting"
else
    install -m 600 "${BASE}/config/eg4-battery.yaml.example" "$dest"
    echo "  wrote $dest (mode 600) — edit bus.port, MQTT creds, pack addresses"
fi

# --- 6. smoke test ---------------------------------------------------------
if [ "$DRY_RUN" = "1" ]; then
    msg "Dry-run: running one mock-bus cycle (no MQTT publish)"
    /usr/local/bin/eg4-battery -C "$dest" --dry-run
    echo
    echo "(above output is what would be published to MQTT under real run)"
fi

# --- 7. enable -------------------------------------------------------------
if grep -q '<MQTT_PASSWORD>' "$dest" 2>/dev/null; then
    cat <<EOF

Credentials in $dest still contain a placeholder.
Edit the file, verify with: eg4-battery -C $dest --dry-run
Then enable the daemon:

    sudo systemctl enable --now eg4-battery.service
    journalctl -u eg4-battery.service -f

EOF
else
    msg "Enabling eg4-battery.service"
    sudo systemctl enable --now eg4-battery.service
    sleep 3
    systemctl --no-pager status eg4-battery.service | head -15
fi

msg "Done"
echo "Next steps:"
echo "  - While batteries are still in the mail:  ./install.sh --dry-run"
echo "  - Once one pack is wired:                 edit ~/.config/eg4-battery/eg4-battery.yaml,"
echo "                                              set bus.transport: serial + address: 1 only,"
echo "                                              validate per ../NOTES.md"
echo "  - Full three-pack bring-up:               uncomment addresses 2 and 3"