#!/bin/env bash



while getopts ":d:f:S:s:i:n:g:hv" opt; do
  case $opt in
    d)
      declare -r  location="$OPTARG"
      ;;
    f)
      declare -r filename="$OPTARG"
      ;;
    S)
      declare -r sub="$OPTARG"
      ;;
    s)
      declare -r startFrame="$OPTARG"
      ;;
    i)
      declare -r intervalScreenshots="$OPTARG"
      ;;
    n)
      declare -r numberScreenshots="$OPTARG"
      ;;
    g)
      declare -r videoHeight="$OPTARG"
      ;;
    h)
      declare -r help="TRUE"
      ;;
    v)
      declare -r verbose="TRUE"
      ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2
      exit 1
      ;;
    :)
      echo "Option -$OPTARG requires an argument." >&2
      exit 1
      ;;
  esac
done

# Quit if we missed -s or -n. Or if -h is used.
if [[ -z "$startFrame" ]] || [[ -z "$numberScreenshots" ]] || [[ -n "$help" ]]  ; then
  printf 'You must at the minimum set -s and -n.
  -d <set a chosen directory>
  -f <the video file>
  -S <sub options: lang|auto|no>
  -s <the start frame>
  -i <set an optional frame interval>
  -n <the number of screenshots you want>
  -g <the desired display resolution>
  -h <help>
  -v <set verbose to true>\n\n'

  exit 1
# If user tries to use -d and -f together. This is redundent. Preventing the creation stupid questions later.
elif [[ -d "$location" ]] && [[ -f "$filename" ]]   ; then
  printf '
  Cannot set -d and -f at the same time
  Please use -d for multiple files only
  Please only use full path with -f \n\n'

  exit 1

fi

# Subtitle Selection

if [[ -S 'no' ]] ;
then
declare langcom='sid'
declare lang=no

elif [[ -z "$sub" ]] ;
then
declare langcom='sid'
declare lang='auto'
else
declare langcom='slang'
declare lang="$sub"
fi

# Automatic directory finding if -d isn't set.
if [[ -z "$location" ]] ; then
  declare -r dir="."
else
  declare -r dir="$location"
fi
for f in "$dir"/*.*

do
# Loop for file. Sets to either f in $dir or $filename.
if [[ -z "$filename" ]] ;
then
declare file="$f"

elif [[ -f "$filename" ]] ; then
declare file="$filename"
else
echo "No Files Found"

exit

fi
# Creates a directiry for image placement
 declare base="$(basename "$file" | cut -d "." -f1)"
mkdir "$base"
# Start mpv

mpv --pause --quiet --no-osc --no-audio --osd-level=0  --no-border --vo=opengl --framedrop=no --"$langcom"="$lang" --scaler-lut-size=8 --scale=spline36 --cscale=spline36 --opengl-fbo-format=rgb16 --linear-scaling --geometry="$videoHeight" --screenshot-template=%F-%ws --screenshot-format=png --screenshot-png-compression=5 --screenshot-directory="$base" "$file" --input-ipc-server=/tmp/mpvsocket  > /dev/null 2>&1 &


# Information grabbing

 sleep 1

 declare -r lastFrame="$(echo '{ "command": ["get_property", "estimated-frame-count"]}' | socat - /tmp/mpvsocket | cut -d":" -f2 | cut -d , -f1)"

 sleep 1

 declare -r fpsVideo="$(echo '{ "command": ["get_property", "estimated-vf-fps"]}' | socat - /tmp/mpvsocket | cut -d":" -f2 | cut -d , -f1)"


 sleep 1

# Declare interval for each screenshot
if [[ -z "$intervalScreenshots" ]] ; then
  declare diffFrame="$(awk "BEGIN {printf $lastFrame - $startFrame}")"
  declare intervalFrame="$(awk "BEGIN {printf $diffFrame / $numberScreenshots}")"

else
  declare -r intervalFrame="$intervalScreenshots"

fi

# Looping to take screenshots
declare currentFrame="$startFrame"
for i in $(seq 1 "$numberScreenshots") ; do

   declare currentTime="$(awk "BEGIN {printf $currentFrame / $fpsVideo}")"

  if [[ -n "$verbose" ]] ; then
    printf 'File: %s\n' "$base"
    printf 'Current time: %.2f\n' "$currentTime"
    printf 'Last frame: %s\n' "$lastFrame"
    printf 'FPS: %s\n' "$fpsVideo"
    printf 'Interval: %s\n' "$intervalFrame"
    printf 'Screenshot: %02d\n\n\n' "$i"

 fi
  # Debug line



   echo '{ "command": ["set_property", "pause", true] }'    | socat - /tmp/mpvsocket

   sleep 1

   echo '{ "command": ["seek", '$currentTime', "absolute"] }' | socat - /tmp/mpvsocket

   sleep 1

   echo '{ "command": ["screenshot", "window"] }' | socat - /tmp/mpvsocket

   sleep 1



currentFrame="$(awk "BEGIN {printf $currentFrame+$intervalFrame}")"



done

echo '{ "command": ["quit"] }'  | socat - /tmp/mpvsocket

done