#!/bin/bash
# install.sh — generate and install sky-cam systemd units from sky-cam.conf.
#
# Usage:
#   ./install.sh           # installs to ~/.config/systemd/user (no root needed)
#   ./install.sh --system  # installs to /etc/systemd/system    (needs sudo)
#
# Run this once after editing sky-cam.conf, and again whenever sky-cam.conf
# changes (e.g. SCRIPT_DIR moves).  No other file needs editing.

set -euo pipefail

HERE="$(dirname "$(realpath "$0")")"
source "$HERE/sky-cam.conf"

# ── Install target ────────────────────────────────────────────────────────────
SYSTEM_MODE=false
[ "${1:-}" = "--system" ] && SYSTEM_MODE=true

if $SYSTEM_MODE; then
    UNIT_DIR="/etc/systemd/system"
    SC="sudo systemctl"
else
    UNIT_DIR="$HOME/.config/systemd/user"
    SC="systemctl --user"
fi

mkdir -p "$UNIT_DIR"
echo "Installing systemd units to $UNIT_DIR ..."

# ── Helper: write a oneshot service unit ─────────────────────────────────────
write_service() {
    local unit="$1" description="$2" script="$3" extra="${4:-}"
    cat > "$UNIT_DIR/${unit}.service" <<EOF
[Unit]
Description=Sky-Cam ($CAM_NAME) — $description
${extra}OnFailure=sky-cam-notify-failure@%n.service

[Service]
Type=oneshot
ExecStart=$SCRIPT_DIR/$script
StandardOutput=journal
StandardError=journal
EOF
    echo "  wrote ${unit}.service"
}

# ── Helper: write a timer unit ───────────────────────────────────────────────
write_timer() {
    local unit="$1" description="$2" calendar="$3"
    cat > "$UNIT_DIR/${unit}.timer" <<EOF
[Unit]
Description=Sky-Cam ($CAM_NAME) — $description

[Timer]
OnCalendar=$calendar
Persistent=true

[Install]
WantedBy=timers.target
EOF
    echo "  wrote ${unit}.timer"
}

# ── Failure notification template ────────────────────────────────────────────
cat > "$UNIT_DIR/sky-cam-notify-failure@.service" <<EOF
[Unit]
Description=Sky-Cam notify on failure for %i

[Service]
Type=oneshot
ExecStart=$SCRIPT_DIR/notify.sh "sky-cam job failed: %i" "systemd unit %i failed — check: journalctl -u %i"
EOF
echo "  wrote sky-cam-notify-failure@.service"

# ── Three daily jobs ──────────────────────────────────────────────────────────
# Sunrise video → Mattermost (run after sunrise window ends)
write_service "sky-cam-sunrise" \
    "daily sunrise video → Mattermost" \
    "sunrise_video.10s.sh" \
    "After=network-online.target\nWants=network-online.target\n"
write_timer "sky-cam-sunrise" "daily sunrise video" "*-*-* 09:00:00"

# Four Seasons daily clip (auto-triggers montage + year-end on last days)
write_service "sky-cam-4seasons" \
    "Four Seasons daily clip" \
    "4-seasons.sh" \
    "After=network-online.target\nWants=network-online.target\n"
write_timer "sky-cam-4seasons" "Four Seasons daily clip" "*-*-* 01:00:00"

# Full-day timelapse with 10-day retention
write_service "sky-cam-fullday" \
    "full-day timelapse" \
    "fullday-video.sh"
write_timer "sky-cam-fullday" "full-day timelapse" "*-*-* 02:00:00"

# ── Reload and enable ─────────────────────────────────────────────────────────
echo ""
$SC daemon-reload

for timer in sky-cam-sunrise sky-cam-4seasons sky-cam-fullday; do
    $SC enable --now "${timer}.timer" \
        && echo "  enabled + started ${timer}.timer" \
        || echo "  WARNING: could not enable ${timer}.timer"
done

echo ""
echo "Done. Check status with:"
if $SYSTEM_MODE; then
    echo "  sudo systemctl list-timers 'sky-cam-*'"
    echo "  sudo journalctl -u sky-cam-4seasons.service -f"
else
    echo "  systemctl --user list-timers 'sky-cam-*'"
    echo "  journalctl --user -u sky-cam-4seasons.service -f"
fi