#!/usr/bin/env zsh
#
# Copyright (C) 2024-2026 Maria Lisina
# SPDX-License-Identifier: Apache-2.0
#
# Telegram Media Re-encoder

if (( __env != 1 ))
then
    exec /usr/bin/env -i PATH="${PATH}" __env=1 "${0}" ${@} 2> /dev/null
fi

set -e

version="3.4"

if [[ -n "${1}" ]]
then
    while getopts hl:r:f:ap:c:d opts
    do
        case "${opts}" in
            (h)
                help=1
            ;;
            (l)
                loglevel=${OPTARG}
            ;;
            (r)
                fps=${OPTARG}
            ;;
            (f)
                filters="${OPTARG}"
            ;;
            (a)
                noaudio=1
            ;;
            (p)
                preset=${OPTARG}
            ;;
            (c)
                crf=${OPTARG}
            ;;
            (d)
                delete=1
            ;;
            (*)
                echo "Unrecognized options" \
                    "\nSee '${0} -h'"
                exit 1
            ;;
        esac
    done

    shift $((OPTIND - 1))
else
    help=1
fi

if (( help == 1 ))
then
    echo "Telegram Media Re-encoder v${version}" \
        "\n\nUsage: ${0} [options] [file]" \
        "\n\nOptions:" \
        "\n  -h\t\tShow help information" \
        "\n  -l <lvl>\tLog level, default: info" \
        "\n  -r <num>\tSet custom frame rate" \
        "\n  -f <str>\tSet custom filters" \
        "\n  -a\t\tRemove audio stream" \
        "\n  -p <pst>\tPreset, default: medium" \
        "\n  -c <num>\tConstant Rate Factor, default: 23" \
        "\n  -d\t\tDelete original file"
    exit 0
fi

for zmod in zsh/files
do
    if ! zmodload ${zmod}
    then
        failed+=(${zmod})
    fi
done

if [[ -n "${failed}" ]]
then
    echo "Failed to load Z Shell modules: ${failed}" \
        "\nUpdate your Z Shell or get a version with all required modules"
    exit 1
fi

for req in ffmpeg
do
    if ! command -v ${req} > /dev/null
    then
        missing+=(${req})
    fi
done

if [[ -n "${missing}" ]]
then
    echo "Missing dependencies: ${missing}" \
        "\nFor more information follow: https://command-not-found.com/"
    exit 1
fi

if [[ -z "${loglevel}" ]]
then
    loglevel=info
fi

if [[ -z "${fps}" ]]
then
    fps=source_fps
fi

if [[ -z "${filters}" ]]
then
    filters="pad=ceil(iw/2)*2:ceil(ih/2)*2"
fi

if (( noaudio == 1 ))
then
    acodec=(an)
else
    acodec=(acodec aac)
fi

if [[ -z "${preset}" ]]
then
    preset=medium
fi

if [[ -z "${crf}" ]]
then
    crf=23
fi

if [[ -z "${1}" ]]
then
    echo "No input file specified" \
        "\nSee '${0} -h'"
    exit 1
fi

exit=0
input=(${@})

for file in ${input}
do
    if ! [[ -f "${file}" ]]
    then
        exit=1
        echo "No file found: ${file}"

        continue
    fi

    output="${file%.*}_t.mp4"
    echo "Re-encoding: ${file}"

    if ffmpeg -i "${file}" \
        -loglevel ${loglevel} \
        -map_metadata -1 \
        -profile:v high \
        -vcodec libx264 \
        -vf "fps=${fps},${filters}" \
        -pix_fmt yuv420p \
        -${acodec[@]} \
        -preset ${preset} \
        -level 4.0 \
        -crf ${crf} \
        -movflags +faststart \
        "${output}" -y 2>&1
    then
        if (( delete == 1 ))
        then
            rm -f "${file}"
            mv "${output}" "${file%.*}.mp4"

            echo "Succesfully re-encoded: ${file%.*}.mp4"
        else
            echo "Succesfully re-encoded: ${output}"
        fi
    else
        exit=1
        echo "Failed to re-encode: ${file}"
    fi
done

exit ${exit}