#!/bin/bash
#
# Generates printer diagnostic files, so you can read a printer's real page
# capacity straight off the paper instead of guessing from paper geometry.
#
# Usage:
#   ./pagetest.sh [width] [lines]   - numbered lines padded with '#', to find
#                                      a printer's real lines-per-page (the
#                                      last line number printed on page 1)
#                                      (default width=64, lines=100)
#   ./pagetest.sh ruler [width]     - a single long ruler line marking every
#                                      10th column with its tens digit and
#                                      every 5th with '+', to find a
#                                      printer's real chars-per-line exactly
#                                      (default width=200)
#
# Print the result with PRINTER_A4=false in printer.conf (no rotation):
#   ./txt2printr.sh pagetest.txt

dir="$(dirname "$0")"
outfile="$dir/pagetest.txt"

if [ "$1" = "ruler" ]; then
    width="${2:-200}"
    awk -v width="$width" '
        BEGIN {
            line = ""
            for (i = 1; i <= width; i++) {
                if (i % 10 == 0) line = line (int(i / 10) % 10)
                else if (i % 5 == 0) line = line "+"
                else line = line "-"
            }
            print line
        }
    ' > "$outfile"
    echo "Wrote a $width-char ruler line to $outfile"
    echo "Every 10th column is marked with its tens digit (column 40 -> '4',"
    echo "column 100 -> '0'), every 5th with '+'. Read off the last marker"
    echo "that fully prints to get your printer's exact chars-per-line."
else
    width="${1:-64}"
    lines="${2:-100}"
    awk -v width="$width" -v lines="$lines" '
        BEGIN {
            for (i = 1; i <= lines; i++) {
                prefix = sprintf("%03d ", i)
                fill = width - length(prefix)
                if (fill < 0) fill = 0
                line = prefix
                for (j = 0; j < fill; j++) line = line "#"
                print line
            }
        }
    ' > "$outfile"
    echo "Wrote $lines lines x $width chars to $outfile"
fi

echo "Print it with: PRINTER_DEV=/dev/lp0 \"$dir/txt2printr.sh\" \"$outfile\""