#!/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.


# fetch [options...] [URIs/data-URIs...]
#
# Fetch/web-request all URIs given, using protcol HTTPS when none is given.
# Base64-encoded data-URI are also supported, being 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`.


# fail quits the script right after showing the message given, using
# exit code given as its 2nd arg
fail() {
    if [ "$2" = 23 ] || [ "$2" = 141 ]; then
        exit 0
    fi
    printf "%s\n" "$1" > /dev/stderr
    exit "${2:-1}"
}


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

[ "$1" = '--' ] && shift

if [ $# -eq 0 ]; then
    awk '/^# +fetch /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
    exit 0
fi

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

if [ "${dashes}" -gt 1 ]; then
    printf "can't use dash (standard input) more than once\n" >&2
    exit 1
fi

command='curl -s'
# command='curl --show-error -s'

trap 'exit 0' PIPE

for uri in "$@"; do
    case "${uri}" in
        -) cat;;

        data:,) continue;;

        file://*)
            cat "$(echo "${uri}" | sed 's-^file://--')" ||
                fail "failed to fetch ${uri}" $?
        ;;

        https://*|http://*|ftp://*|ftps://*|sftp://*|dict://*)
            ${command} "${uri}" || fail "failed to fetch ${uri}" $?
        ;;

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

        *)
            if [ -e "${uri}" ]; then
                cat "${uri}" || fail "failed to fetch ${uri}" $?
                continue
            fi

            uri="https://${uri}"
            ${command} "${uri}" || fail "failed to fetch ${uri}" $?
        ;;
    esac
done