#!/bin/sh
## twerk: a twtxt client in sh
# by Case Duckworth

### Entry point

usage() {
	cat >&2 <<EOF
TWERK: a twtxt client
usage: twerk [options] [file]

options:
 -h        show this help and quit
 -t        include time in post date
 -T        don't include time in post date (default)
 -n NUMBER limit posts to NUMBER (100)
 -w WIDTH  limit the width of the display (72)
 -H WIDTH  define the hanging indent of twts
 -u WIDTH  limit the width of the user display (12)
EOF
	exit "${1:-0}"
}

configure() {
	TWERK_INCLUDE_TIME=0
	TWERK_WIDTH="${COLUMNS:-72}"
	TWERK_USER_WIDTH=12
	while getopts hn:w:H:t opt; do
		case "$opt" in
			h) usage ;;
			n) TWERK_N="$OPTARG" ;;
			w) TWERK_WIDTH="$OPTARG" ;;
			H) TWERK_HANG="$OPTARG" ;;
			u) TWERK_USER_WIDTH="$OPTARG" ;;
			t) TWERK_INCLUDE_TIME=1 ;;
			T) TWERK_INCLUDE_TIME=0 ;;
			*) usage 1 ;;
		esac
	done
	if test -z "$TWERK_HANG"; then
		TWERK_HANG=$((TWERK_USER_WIDTH+(TWERK_INCLUDE_TIME*6)+10+3))
	fi

}

main() {
	configure "$@"; shift "$((OPTIND - 1))"
	cat "${@:--}" |
		curl_from_file
}

### Library

curl_from_file() {
	while read -r url name; do
		curl -sf "$url" |
			filter_posts |
			awk -v url="$url" -v name="$name" \
			    '{ printf "%s\t%s\t%s\n", name, url, $0; }'
	done |
		sort_posts |
		format_posts
}

filter_posts() {
	filter_comments | limit_posts "${TWERK_N:-100}"
}

filter_comments() {
	awk '/^[ \t]*#/{next;}/^$/{next;}{print;}'
}

limit_posts() {
	head -n "$1"
}


sort_posts() {
	sort -r
}

format_posts() {
	awk \
	    -v UW="$TWERK_USER_WIDTH" \
	    -v IT="$TWERK_INCLUDE_TIME" \
	    -v WIDTH="$TWERK_WIDTH" \
	    -v HANG="$TWERK_HANG" \
	    'BEGIN {FS="\t";}
!IT { sub(/T.*$/, "", $3); }
IT {
    sub(/+.*$/, "", $3);
    sub(/T/, " ", $3);
    sub(/:..$/,"",$3);
}

{ printf("%s | %" UW "s | ", $3, substr($1,1,UW-1)); }

# wrap lines
{
    w = HANG # width
    ls = 0 # lines
    split($2, words, /[ \t]/)
    for (i=1; i<=length(words); i++) {
	if (w+length(words[i]) >= WIDTH) {
	    print ""
	    w = 0
	    if (++ls) {
	        printf "%" HANG "s ` ", ""
		w += HANG + 2
	    }
	}
	printf "%s ", words[i]
	w += length(words[i])
    }
    print ""
}
'
}

###
test -z "$DEBUG" || set -x
test -z "$SOURCE" && main "$@"