#!/usr/bin/perl
use strict;
use warnings FATAL => 'all';
use LWP::Simple;
use Image::Magick;

my %config   = (
  zoom    => 3,          # Google Maps zoom level (1 == smallest resolution)
  x_start => -2387,      # Upper-left map tile "x" CGI GET parameter
  y_start => -1095,      # Upper-left map tile "y" CGI GET parameter
  rows    => 108,        # Number of rows (i.e. y-axis or height) to fetch
  cols    => 47,         # Number of columns (i.e. x-axis or width) to fetch
  file    => 'map.gif',  # Filename to save the merged tiles into
  s_secs  => 5,          # Number of seconds to sleep in each fetch interval
  s_every => 18,         # Number of tiles to fetch in a given interval
  get_est => 0.21,       # Estimated number of seconds to fetch a tile
  width   => 768,        # Desired width for cut image plates
  height  => 1008        # Desired height for cut image plates
);

my ($tiles_count, $tiles_total) = (0, $config{rows} * $config{cols});
my $eta = $config{rows} * $config{cols} / $config{s_every} * $config{s_secs}
 + $config{rows} * $config{cols} * $config{get_est};
my $start_time = time;

for (my $y = 0; $y < $config{rows}; $y++) {
  for (my $x = 0; $x < $config{cols}; $x++) {
    $tiles_count++;
    getstore(
      'http://mt.google.com/mt?' . 'x=' . ( $config{x_start} + $x ) .
       '&y=' . ( $config{y_start} + $y ) . '&zoom=' . $config{zoom},
      join('_', 'plate', $x, $y) . '.gif'
    );
    sleep $config{s_secs}
     if (int($tiles_count/$config{s_every}) == $tiles_count/$config{s_every});
  }
}

my $plates = new Image::Magick;
for (my $y = 0; $y < $config{rows}; $y++) {
  for (my $x = 0; $x < $config{cols}; $x++) {
    $plates->Read('plate_' . $x . '_' . $y . '.gif');
  }
}

my $width  = $plates->[0]->Get('columns');
my $height = $plates->[0]->Get('rows');
my $single_map = $plates->Montage(
  geometry => $width . 'x' . $height . '+0+0',
  tile     => $config{cols}
);
$single_map->Write($config{file});

for (my $y = 0; $y < $config{rows}; $y++) {
  for (my $x = 0; $x < $config{cols}; $x++) {
    unlink 'plate_' . $x . '_' . $y . '.gif';
  }
}

$single_map->Rotate(degrees => 90);
$width  = $single_map->[0]->Get('columns');
$height = $single_map->[0]->Get('rows');
my $x_count = int($width / $config{width});
my $y_count = int($height / $config{height});

for (my $x = 0; $x <= $x_count; $x++) {
  for (my $y = 0; $y <= $y_count; $y++) {
    my ($w, $h) = ($config{width}, $config{height});
    $w = $width - $x_count * $config{width}   if ($x == $x_count);
    $h = $height - $y_count * $config{height} if ($y == $y_count);
    my $geometry = $w . 'x' . $h .
     '+' . $config{width} * $x . '+' . $config{height} * $y;

    my $plate = $single_map->Clone;
    $plate->Crop(geometry => $geometry);
    $plate->Montage(geometry => $w . 'x' . $h . '+0+0')->Write(
      'plate_' . $x . '_' . $y . '.gif'
    );
  }
}