#!/bin/bash
set -x #echo on
SOURCE_VIDEO="$1"
START_TIME="$2"
END_TIME="$3"

# Get total number of frames for progress tracking
TOTAL_FRAMES=$(ffprobe -v error -select_streams v:0 -count_packets -show_entries stream=nb_read_packets -of csv=p=0 "$SOURCE_VIDEO")
if [ -z "$TOTAL_FRAMES" ]; then
    echo "Error: Unable to retrieve the total number of frames."
    exit 1
fi

# Initialize variables for tracking progress
frames_processed=0
start_frame=""
end_frame=""
start_diff=999999
end_diff=999999

# Function to display progress and information dynamically
display_progress() {
    local progress=$(( frames_processed * 100 / TOTAL_FRAMES ))
    echo -ne "\rProcessed frames: $frames_processed / $TOTAL_FRAMES ($progress%) | Closest start frame: $start_frame | Closest end frame: $end_frame"
}
# Process frames
ffprobe -show_frames -select_streams v:0 \
        -print_format csv "$SOURCE_VIDEO" 2>&1 |
grep -n frame,video,1 |
awk 'BEGIN { FS="," } { print $1 " " $5 }' |
sed 's/:frame//g' |
awk -v start="$START_TIME" -v end="$END_TIME" '
BEGIN {
    start_frame="";
    end_frame="";
    start_diff=999999;
    end_diff=999999;
    between_frames="";
}
{
    split($2, time, ".");
    current = time[1];

    if (current > end) {
        exit;
    }

    if (start_frame == "" && current >= start) {
        start_frame = $1;
        start_diff = current - start;
    } else if (current >= start && (current - start) < start_diff) {
        start_frame = $1;
        start_diff = current - start;
    }

    if (current <= end && (end - current) < end_diff) {
        end_frame = $1;
        end_diff = end - current;
    }

    if (current >= start && current <= end) {
        between_frames = between_frames $1 ",";
    }
}
END {
    print "\nProcessing completed."
    print "Closest keyframe to start time: " start_frame;
    print "Closest keyframe to end time: " end_frame;
    print "All keyframes between start and end:";
    print substr(between_frames, 1, length(between_frames)-1);
}'