#!/bin/sh

# The MIT License (MIT)
#
# Copyright (c) 2026 pacman64
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


# v [option...] [files...]
#
#
# View is a simple non-interactive file viewer, which handles plain-text files
# and pictures of all commonly-used formats.
#
# The options are, available in single and double-dashed versions
#
#   -h           show this help message
#   -help        show this help message
#
#   -header=n    always show first `n` lines at the top
#
#   -n           show line numbers for overall results
#   -N           show line numbers for overall results
#
#   -s           show pictures using the sixel format (experimental)
#   -sixel       show pictures using the sixel format (experimental)
#
#   -t           show first line at the top at all times
#   -top         show first line at the top at all times


case "$1" in
    -h|--h|-help|--help)
        awk '/^# +v /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
        exit 0
    ;;
esac

sixels=0
# less_options='-MKiCRS'
less_options='-MKiCS'

for arg in "$@"; do
    if [ "${arg}" = '--' ]; then
        shift
        break
    fi

    case "${arg}" in
        -n|--n|-N|--N)
            less_options="${less_options} -N"
            shift
            continue
        ;;

        --header=*)
            less_options="${less_options} ${arg}"
            shift
            continue
        ;;

        -s|--s|-sixel|--sixel|-sixels|--sixels)
            sixels=1
            # less_options="${less_options} -r"
            shift
            continue
        ;;

        -t|--t|-top|--top)
            less_options="${less_options} --header=1"
            shift
            continue
        ;;
    esac

    break
done

if [ "${sixels}" -eq 0 ]; then
    less_options="${less_options} -R"
fi

if [ $# -eq 0 ]; then
    less ${less_options} -f -
    exit $?
fi

bat_style='plain,header,numbers'
if [ $# -lt 2 ]; then
    bat_style='plain,numbers'
    less_options="${less_options} --header=1"
fi

# show all non-existing files given
failed=0
for arg in "$@"; do
    if [ "${arg}" = "-" ]; then
        continue
    fi
    if [ ! -e "${arg}" ]; then
        printf "no file named \"%s\"\n" "${arg}" > /dev/stderr
        failed=1
    fi
done

if [ "${failed}" -gt 0 ]; then
    exit 2
fi

bat=''
if [ -e /usr/bin/batcat ]; then
    bat='/usr/bin/batcat'
elif [ -e /usr/bin/bat ]; then
    bat='/usr/bin/bat'
else
    printf "file viewer 'bat'/'batcat' not found" > /dev/stderr
    exit 1
fi

view_pic=''
if [ -e /usr/bin/chafa ]; then
    view_pic='chafa'
    if [ "${sixels}" -eq 1 ]; then
        view_pic='chafa --format sixels'
    fi
fi

gap=0

for arg in "$@"; do
    [ "${gap}" -gt 0 ] && printf "\n"
    gap=1

    printf "\e[7m%-80s\e[0m\n" "${arg}"

    if [ "${arg}" = '-' ]; then
        kind='-: text/plain'
    else
        kind="$(file --mime-type "${arg}")"
    fi

    if echo "${kind}" | grep -E -q ' image/[a-z0-9\.-]+$'; then
        if [ -z "${view_pic}" ]; then
            printf "%s\n" "${kind}"
        else
            ${view_pic} "${arg}"
        fi
        continue
    fi

    if echo "${kind}" | grep -q ' inode/directory$'; then
        printf "%s is a folder\n" "${arg}"
        continue
    fi

    if echo "${kind}" | grep -E -q -v ' text/[a-z0-9\.\+-]+$'; then
        if echo "${kind}" | grep -E -q -v ' application/j(avascript|son)$'; then
            printf "%s\n" "${kind}"
            continue
        fi
    fi

    if [ -z "${bat}" ]; then
        awk '{ printf "%6d  %s\n", NR, $0 }' "${arg}"
        continue
    fi

    "${bat}" \
        --style="${bat_style}" \
        --theme='Monokai Extended Light' \
        --wrap=never --color=always --paging=never "${arg}" |
    # make colors readable even on light backgrounds
    sed -e 's-\x1b\[38;5;70m-\x1b[38;5;28m-g' \
        -e 's-\x1b\[38;5;214m-\x1b[38;5;208m-g' \
        -e 's-\x1b\[38;5;243m-\x1b[38;5;103m-g' \
        -e 's-\x1b\[38;5;238m-\x1b[38;5;245m-g' \
        -e 's-\x1b\[38;5;228m-\x1b[48;5;228m-g'
done 2>&1 | less ${less_options}