<?php
##
## Default renderer: plain text on stdin -> ImageMagick draw script on stdout.
##
## Used for any slate script that emits text rather than an image. A blank
## first line is treated as no header.
##
## Usage: render-text.php <width> <height>
##

date_default_timezone_set(getenv('SLATE_TZ') ?: 'UTC');

$W = (int)($argv[1] ?? 1072);
$H = (int)($argv[2] ?? 1448);

$MARGIN = 44;
$INK    = 'black';
$FADED  = '#9a9a9a';

$lines = [];
while (($raw = fgets(STDIN)) !== false) $lines[] = rtrim($raw, "\n");
while (count($lines) && $lines[count($lines) - 1] === '') array_pop($lines);

function esc($s) { return str_replace(["\\", "'"], ["\\\\", "\\'"], $s); }

$head    = count($lines) ? array_shift($lines) : '';
$head_h  = $head === '' ? $MARGIN : 132;
$avail   = $H - $head_h - $MARGIN;
$n       = max(count($lines), 1);
$row_h   = min(64, intdiv($avail, $n));

## size to fit the widest line as well as the row height, so wide output
## shrinks instead of getting clipped
$widest  = 0;
foreach ($lines as $l) $widest = max($widest, strlen($l));
$fs_h    = (int)($row_h * 0.62);
$fs_w    = $widest ? (int)((($W - 2 * $MARGIN)) / ($widest * 0.60)) : $fs_h;
$fs      = max(12, min($fs_h, $fs_w));

$out = [];
$out[] = "push graphic-context";

if ($head !== '') {
  $out[] = "font-size 60";
  $out[] = "fill $INK";
  $out[] = sprintf("text %d,%d '%s'", $MARGIN, 74, esc($head));
  $out[] = "font-size 30";
  $out[] = "fill $FADED";
  $out[] = sprintf("text %d,%d '%s'", $MARGIN, 110, esc(date('D j M H:i')));
  $out[] = "fill $INK";
  $out[] = sprintf("rectangle %d,%d %d,%d", $MARGIN, 124, $W - $MARGIN, 127);
}

## clip to what fits rather than running off the edge
$room = (int)((($W - $MARGIN) - $MARGIN) / ($fs * 0.60));

$y = $head_h;
$out[] = "font-size $fs";
$out[] = "fill $INK";
foreach ($lines as $line) {
  $y += $row_h;
  if ($y > $H - $MARGIN) break;
  if (strlen($line) > $room) $line = substr($line, 0, $room - 3) . '...';
  if ($line === '') continue;
  $out[] = sprintf("text %d,%d '%s'", $MARGIN, $y, esc($line));
}

$out[] = "pop graphic-context";
echo implode("\n", $out), "\n";