#!/bin/bash

BASE_DIR="/files"
CURRENT_DIR="$BASE_DIR/current"

mkdir -p "$CURRENT_DIR"

# Store last SHA256 checksums and last update timestamps for each camera
declare -A LAST_SHA
declare -A LAST_UPDATE

# How long to wait before deleting stale images (in seconds)
STALE_TIMEOUT=$((15 * 60))

echo "[Watcher] Starting to monitor subfolders in $BASE_DIR ..."

while true; do
    NOW=$(date +%s)

    for CAM_DIR in "$BASE_DIR"/msvcam*; do
        [ -d "$CAM_DIR" ] || continue

        CAM_NAME=$(basename "$CAM_DIR")
        OUT_FILE="$CURRENT_DIR/${CAM_NAME}.avif"

        # Find the newest image
        NEWEST_FILE=$(find "$CAM_DIR" -type f \
          \( -iname "*.jpg" -o -iname "*.jpeg" -o -iname "*.png" -o -iname "*.bmp" -o -iname "*.tif" -o -iname "*.tiff" \) \
          -printf "%T@ %p\n" 2>/dev/null | sort -n | tail -1 | awk '{print $2}')

        if [ -n "$NEWEST_FILE" ]; then
            # Calculate SHA256 of the newest image
            SHA=$(sha256sum "$NEWEST_FILE" | awk '{print $1}')

            # Check if this file has already been converted
            if [ "${LAST_SHA[$CAM_NAME]}" != "$SHA" ]; then
                echo "[Watcher] New or changed file detected for $CAM_NAME: $NEWEST_FILE"

                if avifenc "$NEWEST_FILE" "$OUT_FILE"; then
                    sync
                    LAST_SHA[$CAM_NAME]="$SHA"
                    LAST_UPDATE[$CAM_NAME]=$NOW
                    echo "[Watcher] Conversion successful: $OUT_FILE"
                else
                    echo "[Watcher][ERROR] Conversion failed for $NEWEST_FILE"
                fi
            else
                echo "[Watcher] No change detected for $CAM_NAME, skipping conversion."
            fi
        fi

        # Check for staleness
        if [ -n "${LAST_UPDATE[$CAM_NAME]}" ]; then
            ELAPSED=$((NOW - LAST_UPDATE[$CAM_NAME]))
            if [ $ELAPSED -ge $STALE_TIMEOUT ]; then
                if [ -f "$OUT_FILE" ]; then
                    echo "[Watcher] No new image for $CAM_NAME in $((STALE_TIMEOUT/60)) minutes. Removing $OUT_FILE"
                    rm -f "$OUT_FILE"
                fi
            fi
        fi
    done

    # Sleep before next check
    SLEEP_INTERVAL="${SLEEP_INTERVAL:-5}"
    sleep "$SLEEP_INTERVAL"
done