#!/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, cameras added, schedules changed).
# 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 — $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 — $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"

# ── Sunrise video — SUNRISE_CAM only ─────────────────────────────────────────
# OnSuccess= triggers the upload service only when video creation succeeds.
cat > "$UNIT_DIR/sky-cam-sunrise.service" <<EOF
[Unit]
Description=Sky-Cam — $SUNRISE_CAM: daily sunrise video
After=network-online.target
Wants=network-online.target
OnFailure=sky-cam-notify-failure@%n.service
OnSuccess=sky-cam-sunrise-upload.service

[Service]
Type=oneshot
ExecStart=$SCRIPT_DIR/daily_sunrise_video.sh
StandardOutput=journal
StandardError=journal
EOF
echo "  wrote sky-cam-sunrise.service"

cat > "$UNIT_DIR/sky-cam-sunrise-upload.service" <<EOF
[Unit]
Description=Sky-Cam — $SUNRISE_CAM: upload daily sunrise to Mattermost
After=network-online.target
Wants=network-online.target
OnFailure=sky-cam-notify-failure@%n.service

[Service]
Type=oneshot
ExecStart=$SCRIPT_DIR/sunrise2mm.py
StandardOutput=journal
StandardError=journal
EOF
echo "  wrote sky-cam-sunrise-upload.service"

write_timer "sky-cam-sunrise" "$SUNRISE_CAM: daily sunrise video" "$SCHEDULE_SUNRISE"

timers=(sky-cam-sunrise)

# ── Per-camera Four Seasons and full-day jobs ─────────────────────────────────
# Reads CAMERAS, SCHEDULE_SEASONS_<cam>, SCHEDULE_FULLDAY_<cam> from sky-cam.conf.
# Scripts receive the camera name as $1 so they know which camera to process.
for cam in "${CAMERAS[@]}"; do
    sched_seasons_var="SCHEDULE_SEASONS_${cam}"
    sched_fullday_var="SCHEDULE_FULLDAY_${cam}"

    if [ -n "${!sched_seasons_var:-}" ]; then
        write_service "sky-cam-seasons-${cam}" \
            "${cam}: Four Seasons daily clip" \
            "4-seasons.sh ${cam}" \
            "After=network-online.target\nWants=network-online.target\n"
        write_timer "sky-cam-seasons-${cam}" "${cam}: Four Seasons daily clip" \
            "${!sched_seasons_var}"
        timers+=("sky-cam-seasons-${cam}")
    else
        echo "  WARNING: SCHEDULE_SEASONS_${cam} not set — skipping seasons timer for ${cam}"
    fi

    if [ -n "${!sched_fullday_var:-}" ]; then
        write_service "sky-cam-fullday-${cam}" \
            "${cam}: full-day timelapse" \
            "fullday-video.sh ${cam}"
        write_timer "sky-cam-fullday-${cam}" "${cam}: full-day timelapse" \
            "${!sched_fullday_var}"
        timers+=("sky-cam-fullday-${cam}")
    else
        echo "  WARNING: SCHEDULE_FULLDAY_${cam} not set — skipping fullday timer for ${cam}"
    fi
done

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

for timer in "${timers[@]}"; 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 $SYSTEM_MODE; then
    echo "  sudo systemctl list-timers 'sky-cam-*'"
    echo "  sudo journalctl -u sky-cam-seasons-${CAMERAS[0]}.service -f"
else
    echo "  systemctl --user list-timers 'sky-cam-*'"
    echo "  journalctl --user -u sky-cam-seasons-${CAMERAS[0]}.service -f"
fi