#!/usr/bin/env sh
# compat: +ash +bash +dash +hush -ksh +mksh +oksh +osh +posh +yash +zsh

# **TL;DR RULES:**
# * no executables (for the most part)
# * no personal info (yours or otherwise)
# * no right-wing nonsense
# * no piracy or NSFW media
# * no command & control
# * no continuous integration
# * no backups, and no minecraft (for real)
# * nothing that's illegal in Germany

oxo() { ### @-
    ### upload files (or stdin) to [0x0.st.](https://0x0.st)
    ### this script exits with the number of failed uploads; up to 255 at once.
    ### file retention period (30 to 365 days) is only computed for arguments.
    ### directories are skipped. please review the terms of service
    ### [on the website](https://0x0.st) before uploading files.
    ###
    ### ```
    ### $ echo test | oxo
    ### https://0x0.st/sj2.txt
    ### oxo: successfully uploaded 1/1 file
    ###
    ### $ oxo ~/play/{hey,you,fake,empty}
    ### https://0x0.st/-3rz.txt
    ### oxo: expires in 365 days: /home/notwa/play/hey
    ### https://0x0.st/-3ri.txt
    ### oxo: expires in 365 days: /home/notwa/play/you
    ### oxo: no such file: /home/notwa/play/fake
    ### oxo: skipping empty file: /home/notwa/play/empty
    ### oxo: successfully uploaded 2/4 files
    ### oxo: failed to upload 2/4 files
    ### ```

    local look='\033[1m%s\033[0m\n'
    local bad='\033[31m%s\033[0m\n'
    local warn='\033[1;33m%s\033[0m\n'
    local err='\033[1;31m%s\033[0m\n'

    local hits=0 total=0
    local f= s=

    if [ $# -eq 0 ]; then
        curl -f -F'file=@-' https://0x0.st && : $((hits+=1)) || true
        total=1
    elif [ $# -gt 255 ]; then
        printf "$err" "oxo: too many arguments (max: 255)" >&2
        return 255
    else
        total=$#
    fi

    for f; do
        if [ ! -e "$f" ]; then
            printf "$bad" "oxo: no such file: $f" >&2
        elif [ -d "$f" ]; then
            printf "$bad" "oxo: skipping directory: $f" >&2
        elif [ ! -s "$f" ]; then
            printf "$bad" "oxo: skipping empty file: $f" >&2
        else
            local g="$f"

            # restrict the filepath to simple ascii characters that curl likes.
            if [ "$f" != "${f#*[! -~]}" ] || [ "$f" != "${f#*[\":<>?\\|]}" ]; then
                # copy the user's file to a temporary path and use that instead.
                g=/tmp/oxo.tmp
                #printf "$warn" "oxo: special characters found: $f" >&2
                if ! cp -p -- "$f" "$g"; then
                    printf "$bad" "oxo: failed to copy file: $f" >&2
                    continue
                fi
            fi

            local kib="$(du -k -- "$f")"
            kib="${kib%%[!0-9]*}" # strip the path, keep the size

            if [ "$kib" -gt 524288 ]; then
                printf "$bad" "oxo: file too large: $f" >&2
                continue
            fi

            # compute retention using (fixed point) integers only.
            # retention = 30 - (365 - 30) * ([file size] / [512 MiB] - 1)**3
            local a=$(( kib/16+1 ))
            local b=$(( (kib+64)/128-12288 ))
            local c=$(( a*a/16384 ))
            local d=$(( b*c/8192+3*kib/16+1-32768 ))
            local r=$(( (d*-335+16384)/32768+30 ))

            if ! curl -f -F"file=@\"$g\"" https://0x0.st; then
                printf "$bad" "oxo: failed to upload file: $f" >&2
            else
                : $((hits+=1))
                printf "$look" "oxo: expires in $r days: $f" >&2
            fi
        fi
    done

    if [ $hits -gt 0 ]; then
        [ $hits -eq 1 ] && s= || s=s
        printf "$look" "oxo: successfully uploaded $hits/$total file$s" >&2
    fi

    local fails=$((total-hits))
    if [ $fails -gt 0 ]; then
        [ $fails -eq 1 ] && s= || s=s
        printf "$err" "oxo: failed to upload $fails/$total file$s" >&2
    fi

    [ ! -e /tmp/oxo ] || rm /tmp/oxo

    return $fails
}

[ -n "${preload+-}" ] || oxo "$@"