#!/bin/sh

# The MIT License (MIT)
#
# Copyright © 2020-2025 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.


# get [options...] [filepaths/URIs/data-URIs...]
#
# Get data from the named source given, whether this is a filename, a URI,
# or even a base64-encoded data-URI. Data-URIs are simply decoded into the
# bytes they represent, no loading/fetching required.
#
# The only options show this help message, via any of `-h`, `--h`, `-help`,
# or `--help`.


# set -o pipefail


# fail quits the script right after showing the message given, using
# exit code given as its 2nd arg
fail() {
    printf "\e[31m%s\e[0m\n" "$1" > /dev/stderr
    exit "${2:-1}"
}


if [ $# -eq 0 ]; then
    cat
    exit $?
fi

dashes=0
for name in "${@:--}"; do
    if [ "${name}" = "-" ]; then
        dashes="$((dashes + 1))"
    fi

    if [ "${dashes}" -gt 1 ]; then
        printf "\e[31mcan't use dash/stdin multiple times\e[0m\n" > /dev/stderr
        exit 1
    fi
done

for name in "${@:--}"; do
    if [ -z "${name}" ]; then
        continue
    fi

    # if the argument given is an existing file, just use `cat`, even if the
    # name looks like a protocol presumably meant for `curl`
    if [ -e "${name}" ]; then
        cat "${name}" || fail "failed to read file '${name}'" $?
        continue
    fi

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

        http://*|https://*|ftp://*)
            # handle the commonest kinds of URIs
            # wget -O - "${name}" || fail "failed to fetch URI '${name}'" $?
            curl -s -L "${name}" || fail "failed to fetch URI '${name}'" $?
        ;;

        dict://*|ftps://*|gopher://*|gophers://*|rtmp://*|rtsp://*|scp://*|\
        sftp://*|smb://*|smbs://*|telnet://*|tftp://*)
            # handle more kinds of URIs
            curl -s -L "${name}" || fail "failed to fetch URI '${name}'" $?
        ;;

        data:*)
            # handle data-URIs
            {
                echo "${name}" | sed -E 's-^data:.{0,50};base64,--' | base64 -d
            } || fail "failed to decode data-URI '${name}'" $?
        ;;

        file://*)
            # handle files
            cat "$(echo "${name}" | sed 's-^file://--')" 2> /dev/null ||
                fail "failed to open file '${name}'" $?
        ;;

        -)
            # handle standard input
            cat "${name}" 2> /dev/null ||
                fail "failed to read from the standard input" $?
        ;;

        *)
            # handle files
            cat "${name}" 2> /dev/null ||
                fail "failed to open file '${name}'" $?
        ;;
    esac
done