#!/bin/bash
# capture.sh <cam-name> — continuous JPEG frame capture from a camera's RTSP
# stream.  Replaces MotionEye or any NVR for sky-cam's timelapse pipeline.
# Pure ffmpeg — no NVR software required.
#
# Run as a long-running systemd service (Type=simple), one per camera.
# install.sh generates sky-cam-capture-<cam>.service automatically when
# CAM_RTSP_<cam> is set in sky-cam.conf.
#
# Writes: BASE_DIR/<cam>/YYYY-MM-DD/HH-MM-SS.jpg
# Restarts ffmpeg at midnight so images land in the correct date directory.
# On camera disconnect, waits 30 s then reconnects automatically.

set -euo pipefail

SCRIPT_DIR="$(dirname "$(realpath "$0")")"
source "$SCRIPT_DIR/sky-cam.conf"
source "$SCRIPT_DIR/.env" 2>/dev/null || true
export TZ="$TIMEZONE"

CAM="${1:-}"
if [ -z "$CAM" ]; then
    echo "Usage: $0 <camera-name>"
    exit 1
fi

rtsp_var="CAM_RTSP_${CAM}"
RTSP_URL="${!rtsp_var:-}"
if [ -z "$RTSP_URL" ]; then
    echo "ERROR: CAM_RTSP_${CAM} not set in .env"
    exit 1
fi

interval_var="CAPTURE_INTERVAL_${CAM}"
INTERVAL="${!interval_var:-${CAPTURE_INTERVAL:-10}}"
echo "Starting capture: cam=$CAM  interval=${INTERVAL}s"

while true; do
    today=$(date +%Y-%m-%d)
    dir="$BASE_DIR/$CAM/$today"
    mkdir -p "$dir"

    # Run until midnight + 5 s so the new day's directory is ready on restart
    midnight=$(date -d "tomorrow 00:00:00" +%s)
    now=$(date +%s)
    duration=$(( midnight - now + 5 ))

    echo "[$(date '+%Y-%m-%d %H:%M:%S')] Capturing → $dir  (rollover in ${duration}s)"

    # -strftime 1 expands %H-%M-%S in the output path using the frame timestamp
    ffmpeg -loglevel warning \
        -rtsp_transport tcp \
        -i "$RTSP_URL" \
        -t "$duration" \
        -vf "fps=1/${INTERVAL}" \
        -f image2 \
        -strftime 1 \
        -q:v 2 \
        "${dir}/%H-%M-%S.jpg" || true

    # If ffmpeg exited before midnight the camera dropped — wait then retry
    if [ "$(date +%s)" -lt "$midnight" ]; then
        echo "[$(date '+%Y-%m-%d %H:%M:%S')] [$CAM] stream lost — retrying in 30s"
        sleep 30
    else
        sleep 2  # brief pause at midnight before day rollover restart
    fi
done