#!/bin/env bash

set -e

LONG_ARGUMENTS=(
    "output:"
    "debug"
    "help"
)
SHORT_ARGUMENTS=(
    "o:"
    "d"
    "h"
)
OPTS=$(getopt \
           --longoptions "$(printf "%s," "${LONG_ARGUMENTS[@]}")" \
           --options "$(printf "%s," "${SHORT_ARGUMENTS[@]}")" \
           --name "$(basename "${0}")" \
           -- "${@}"
    )

eval set -- "${OPTS}"

### Utility functions ###
print_help() {
    echo "$(basename "${0}") [FLAGS...] FOLDER

<description>

Parameters:
-d    --debug        Enable debug output
-h    --help         This very help
"
}

err() {
    echo "${@}" >&2
}

create_demuxer_file() {
    local demuxer_file="$(mktemp)"
    local entry_template=<<EOF
file '${FILE_PATH}'
duration ${DURATION_SECOND}
EOF
    local last_entry_template=<<EOF
file '${FILE_PATH}'
duration ${DURATION_SECOND}
file '${FILE_PATH}'
EOF
    local last_img=""
    for img_to_demux in "${INPUT_FOLDER}"/*.jpeg "${INPUT_FOLDER}"/*.jpg "${INPUT_FOLDER}"/*.png
    do
        last_img="${img_to_demux}"
        local random_duration=$((${RANDOM}%${MAX_PHOTO_DURATION_SECONDS}))
        echo <<EOF >> "${demuxer_file}"
file '${img_to_demux}'
duration ${random_duration}
EOF
    done

    echo "file '${last_img}'" >> "${demuxer_file}"
}
########################


### Config ###
VIDEO_TITLE="output"
MAX_PHOTO_DURATION_SECONDS=10
##############


while [[ $# -gt 0 ]]; do
    case "${1}" in
        --debug)
            set -x
            shift 1
            ;;
        -d)
            set -x
            shift 1
            ;;
        --help)
            print_help
            exit 0
            ;;
        -h)
            print_help
            exit 0
            ;;
        --)
            shift 1
            break
            ;;
    esac
done

INPUT_FOLDER="${1}"
shift 1