#!/usr/bin/env perl6
use v6;
use Test;
use lib my $dir = $?FILE.IO.dirname;
use JSON::Fast;

my $exercise = 'Grains';
my $version = v1;
my $module = %*ENV<EXERCISM> ?? 'Example' !! $exercise;
plan 13;

use-ok $module or bail-out;
require ::($module);

if ::($exercise).^ver !~~ $version {
  warn "\nExercise version mismatch. Further tests may fail!"
    ~ "\n$exercise is $(::($exercise).^ver.gist). "
    ~ "Test is $($version.gist).\n";
  bail-out 'Example version must match test version.' if %*ENV<EXERCISM>;
}

require ::($module) <&grains-on-square &total-grains>;

my $c-data;
for @($c-data<cases>[0]<cases>) {
  if .<expected> == -1 {
    throws-like { grains-on-square(.<input>) }, Exception, .<description>;
  } else {
    is grains-on-square(.<input>), |.<expected description>;
  }
}
is total-grains, |$c-data<cases>[1]<expected description>;

if %*ENV<EXERCISM> {
  if (my $c-data-file = "$dir/../../problem-specifications/exercises/{$dir.IO.resolve.basename}/canonical-data.json".IO.resolve) ~~ :f {
    is-deeply $c-data, EVAL('use JSON::Fast; from-json($c-data-file.slurp);'), 'canonical-data';
  } else { flunk 'canonical-data' }
} else { skip }

done-testing;

INIT {
$c-data := from-json q:to/END/;

{
  "exercise": "grains",
  "version": "1.0.0",
  "comments": [
    "The final tests of square test error conditions",
    "The expection for these tests is -1, indicating an error",
    "In these cases you should expect an error as is idiomatic for your language"
  ],
  "cases": [
    {
      "description": "returns the number of grains on the square",
      "cases": [
        {
          "description": "1",
          "property": "square",
          "input": 1,
          "expected": 1
        },
        {
          "description": "2",
          "property": "square",
          "input": 2,
          "expected": 2
        },
        {
          "description": "3",
          "property": "square",
          "input": 3,
          "expected": 4
        },
        {
          "description": "4",
          "property": "square",
          "input": 4,
          "expected": 8
        },
        {
          "description": "16",
          "property": "square",
          "input": 16,
          "expected": 32768
        },
        {
          "description": "32",
          "property": "square",
          "input": 32,
          "expected": 2147483648
        },
        {
          "description": "64",
          "property": "square",
          "input": 64,
          "expected": 9223372036854775808
        },
        {
          "description": "square 0 raises an exception",
          "property": "square",
          "input": 0,
          "expected": -1
        },
        {
          "description": "negative square raises an exception",
          "property": "square",
          "input": -1,
          "expected": -1
        },
        {
          "description": "square greater than 64 raises an exception",
          "property": "square",
          "input": 65,
          "expected": -1
        }
      ]
    },
    {
      "description": "returns the total number of grains on the board",
      "property": "total",
      "expected": 18446744073709551615
    }
  ]
}

END
}