#!/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.


# dog [options...] [paths/URIs...]
#
# Dog fetches data from the named sources given to it, whether these are
# filenames or URIs. Single dashes stand for standard input, and can't be
# used more than once. When no names are given, stdin is read by default.


# 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}"
}

# when no args are given, just show the help message and quit
if [ $# -eq 0 ]; then
    exit $?
fi

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

# ensure single dashes aren't used multiple times
dashes=0
for name in "$@"; do
    if [ "${name}" = "-" ]; then
        if [ "$dashes" -gt 0 ]; then
            fail "can't use stdin (single-dash) more than once" 1
        fi
        dashes=1
    fi
done

for name in "$@"; do
    case "${name}" in
        # handle a dash by reading from stdin
        -) cat || exit $?;;

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

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

        # handle files and bytes-mode data-URIs
        *) cat "${name}" || fail "failed to open file ${name}" $?;;
    esac
done