var test = require('tape');
var fs = require('fs');
var path = require('path');
var PNG = require('../lib/png').PNG;
var stream = require('stream');

function parseFile(filename, cb) {
  fs.createReadStream(path.join(__dirname, "png-parse-data", filename))
    .pipe(new PNG())
    .on('error', function (e) {
      console.log("error");
      cb(e);
    })
    .on('parsed', function () {
      cb(null, this);
    });
}

function parseBuffer(buffer, cb) {

  var bufferStream = new stream.PassThrough();
  bufferStream.end(buffer);

  bufferStream
    .pipe(new PNG({}))
    .on('error', function (e) {
      cb(e);
    })
    .on('parse', function () {
      cb(null, this);
    });
}

function getPixel(png, x, y) {
  return png.data.readUInt32BE((x + (y * png.width)) * 4);
}

test("should correctly parse an 1-bit colormap png", function (t) {
  t.timeoutAfter(5000);
  parseFile("1bit.png", function (err, png) {
    t.equal(err, null, "there should be no error");
    t.equal(png.width, 1024, "the width should be 1024");
    t.equal(png.height, 1024, "the height should be 1024");
    //t.equal(png.bpp, 1, "the bpp should be 1");
    t.equal(png.data.length, 1024 * 1024 * 4);
    //t.equal(png.trailer.length, 0);

    var y = 1024,
      x;

    var isOk = true;
    while (y--) {
      x = 1024;
      while (x--)
        if (getPixel(png, x, y) !== 0x000000FF) {
          t.fail("pixel does not match - " + getPixel(png, x, y) + " !== 0x000000FF");
          isOk = false;
          break;
        }
    }
    t.ok(isOk, "The pixels should all be black");

    t.end();
  });
});

test("should correctly parse an 8-bit grayscale png", function (t) {
  parseFile("grayscale.png", function (err, png) {
    t.equal(err, null);
    t.equal(png.width, 16);
    t.equal(png.height, 16);
    //t.equal(png.bpp, 1);
    t.equal(png.data.length, 16 * 16 * 4);
    //t.equal(png.trailer.toString(), "Hello, world!\n");

    var y = 16,
      x;

    var isOk = true;
    while (y--) {
      x = 16;
      while (x--) {
        if (getPixel(png, x, y) !== (x ^ y) * 286331136 + 255) {
          t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + ((x ^ y) * 286331136 + 255));
          isOk = false;
          break;
        }
      }
    }
    t.ok(isOk, "The pixels should match");

    t.end();
  })
});

test("should correctly parse an 8-bit truecolor png", function (t) {
  parseFile("truecolor.png", function (err, png) {
    t.equal(err, null);
    t.equal(png.width, 16);
    t.equal(png.height, 16);
    //t.equal(png.bpp, 3);
    t.equal(png.data.length, 16 * 16 * 4);
    //t.equal(png.trailer.length, 0);

    var y = 16,
      x;

    var isOk = true;
    while (y--) {
      x = 16;
      while (x--) {
        if (getPixel(png, x, y) !== x * 285212672 + y * 1114112 + (x ^ y) * 4352 + 255) {
          t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + (x * 285212672 + y * 1114112 + (x ^ y) * 4352 + 255));
          isOk = false;
          break;
        }
      }
    }
    t.ok(isOk, "The pixels should match");

    t.end();
  })
})

test("should correctly parse an 8-bit truecolor png with alpha", function (t) {
  parseFile("truecoloralpha.png", function (err, png) {
    t.equal(err, null);
    t.equal(png.width, 16);
    t.equal(png.height, 16);
    //t.equal(png.bpp, 4);
    t.equal(png.data.length, 16 * 16 * 4);
    //t.equal(png.trailer.length, 0);

    var y = 16,
      x;
    var isOk = true;

    while (y--) {
      x = 16;
      while (x--) {
        if (getPixel(png, x, y) !== x * 285212672 + y * 1114112 + (x ^ y) * 17) {
          t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + (x * 285212672 + y * 1114112 + (x ^ y) * 17));
          isOk = false;
          break;
        }
      }
    }
    t.ok(isOk, "The pixels should match");

    t.end();
  })
})

test("should correctly read image with scanline filter", function (t) {
  parseFile("accum.png", function (err, png) {
    t.equal(err, null);
    t.equal(png.width, 1024);
    t.equal(png.height, 1024);
    //t.equal(png.bpp, 3);
    t.equal(png.data.length, 1024 * 1024 * 4);
    //t.equal(png.trailer.length, 0);

    t.equal(getPixel(png, 0, 0), 0xFF0000FF);
    t.equal(getPixel(png, 1, 0), 0xFF0000FF);
    t.equal(getPixel(png, 420, 308), 0xFF0029FF);
    t.equal(getPixel(png, 433, 308), 0x0A299DFF);
    t.equal(getPixel(png, 513, 308), 0x0066FFFF);
    t.equal(getPixel(png, 728, 552), 0xFF0047FF);

    t.end();
  })
})

test("should correctly read an indexed color image", function (t) {
  parseFile("indexed.png", function (err, png) {
    t.equal(err, null);
    t.equal(png.width, 16);
    t.equal(png.height, 16);
    //t.equal(png.bpp, 3);
    t.equal(png.data.length, 16 * 16 * 4);
    //t.equal(png.trailer.length, 0);

    var y = 16,
      x;
    var isOk = true;

    while (y--) {
      x = 16;
      while (x--) {
        var expected;
        if (x + y < 8) {
          expected = 0xFF0000FF;

        } else if (x + y < 16) {
          expected = 0x00FF00FF;

        } else if (x + y < 24) {
          expected = 0x0000FFFF;

        } else {
          expected = 0x000000FF;
        }

        if (getPixel(png, x, y) !== expected) {
          t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + expected);
          isOk = false;
          break;
        }
      }
    }
    t.ok(isOk, "The pixels should match");
    t.end();
  });
});

test("should correctly read an indexed color image with alpha", function (t) {
  parseFile("indexedalpha.png", function (err, png) {
    t.equal(err, null);
    t.equal(png.width, 16);
    t.equal(png.height, 16);
    //t.equal(png.bpp, 4);
    t.equal(png.data.length, 16 * 16 * 4);
    //t.equal(png.trailer.length, 0);

    var y = 16,
      x;
    var isOk = true;

    while (y--) {
      x = 16;
      while (x--) {
        var expected;
        if (x >= 4 && x < 12) {
          expected = 0x00000000;

        } else if (x + y < 8) {
          expected = 0xFF0000FF;

        } else if (x + y < 16) {
          expected = 0x00FF00FF;

        } else if (x + y < 24) {
          expected = 0x0000FFFF;

        } else {
          expected = 0x000000FF;
        }

        if (getPixel(png, x, y) !== expected) {
          t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + expected);
          isOk = false;
          break;
        }
      }
    }
    t.ok(isOk, "The pixels should match");

    t.end();
  });
});

test("should correctly support crazily-filtered images", function (t) {
  parseFile("paeth.png", function (err, png) {
    t.equal(err, null);
    t.equal(png.width, 512);
    t.equal(png.height, 512);
    //t.equal(png.bpp, 4);
    t.equal(png.data.length, 512 * 512 * 4);

    t.equal(getPixel(png, 0, 0), 0xFF000000)
    t.equal(getPixel(png, 1, 0), 0xFF000000)
    t.equal(getPixel(png, 0, 1), 0xFF000000)
    t.equal(getPixel(png, 2, 2), 0xFF000000)
    t.equal(getPixel(png, 0, 50), 0xFF000000)
    t.equal(getPixel(png, 219, 248), 0xFF000D00)
    t.equal(getPixel(png, 220, 248), 0xFF000D00)
    t.equal(getPixel(png, 215, 249), 0xFF000C00)
    t.equal(getPixel(png, 216, 249), 0xFF000C00)
    t.equal(getPixel(png, 217, 249), 0xFF000D00)
    t.equal(getPixel(png, 218, 249), 0xFF000D00)
    t.equal(getPixel(png, 219, 249), 0xFF000E00)
    t.equal(getPixel(png, 220, 249), 0xFF000E00)
    t.equal(getPixel(png, 263, 319), 0xFF002100)
    t.equal(getPixel(png, 145, 318), 0x05535A00)
    t.equal(getPixel(png, 395, 286), 0x0007FF00)
    t.equal(getPixel(png, 152, 167), 0x052C3500)
    t.equal(getPixel(png, 153, 167), 0x04303600)
    t.equal(getPixel(png, 154, 167), 0x042F3700)
    t.equal(getPixel(png, 100, 168), 0xFF000400)
    t.equal(getPixel(png, 120, 168), 0xFF000900)
    t.equal(getPixel(png, 140, 168), 0xFF001B00)
    t.equal(getPixel(png, 150, 168), 0x05313600)
    t.equal(getPixel(png, 152, 168), 0x04343C00)
    t.equal(getPixel(png, 153, 168), 0x03343F00)
    t.equal(getPixel(png, 154, 168), 0x03344100)
    t.equal(getPixel(png, 155, 168), 0x02344300)
    t.equal(getPixel(png, 156, 168), 0x02314400)
    t.equal(getPixel(png, 157, 168), 0x02323F00)
    t.equal(getPixel(png, 158, 168), 0x03313900)

    t.end();
  });
});

test("should bail with an error given an invalid PNG", function (t) {
  var buf = new Buffer("I AM NOT ACTUALLY A PNG", "utf8")

  return parseBuffer(buf, function (err) {
    t.ok(err instanceof Error, "Error should be received");
    t.end();
  })
})

test("should return an error if a PNG is normal except for a missing IEND", function (t) {
  var buf = new Buffer("89504e470d0a1a0a0000000d49484452000000100000001008000000003a98a0bd000000017352474200aece1ce90000002174455874536f6674776172650047726170686963436f6e7665727465722028496e74656c297787fa190000008849444154789c448e4111c020100363010b58c00216b080052c60010b58c0c259c00216ae4d3b69df99dd0d1062caa5b63ee6b27d1c012996dceae86b6ef38398106acb65ae3e8edbbef780564b5e73743fdb409e1ef2f4803c3de4e901797ac8d3f3f0f490a7077ffffd03f5f507eaeb0fd4d71fa8af3f505f7fa0befe7c7dfdb9000000ffff0300c0fd7f8179301408", "hex")

  return parseBuffer(buf, function (err) {
    t.ok(err instanceof Error, "Error should be received");
    t.end();
  });
});