var root = this;

var EXIF = function(obj) {
if (obj instanceof EXIF) return obj;
if (!(this instanceof EXIF)) return new EXIF(obj);
this.EXIFwrapped = obj;
};

if (typeof exports !== 'undefined') {
if (typeof module !== 'undefined' && module.exports) {
exports = module.exports = EXIF;
}
exports.EXIF = EXIF;
} else {
root.EXIF = EXIF;
}

var ExifTags = EXIF.Tags = {

// version tags
0x9000 : "ExifVersion",// EXIF version
0xA000 : "FlashpixVersion",// Flashpix format version

// colorspace tags
0xA001 : "ColorSpace",// Color space information tag

// image configuration
0xA002 : "PixelXDimension",// Valid width of meaningful image
0xA003 : "PixelYDimension",// Valid height of meaningful image
0x9101 : "ComponentsConfiguration",// Information about channels
0x9102 : "CompressedBitsPerPixel",// Compressed bits per pixel

// user information
0x927C : "MakerNote",// Any desired information written by the manufacturer
0x9286 : "UserComment",// Comments by user

// related file
0xA004 : "RelatedSoundFile",// Name of related sound file

// date and time
0x9003 : "DateTimeOriginal",// Date and time when the original image was generated
0x9004 : "DateTimeDigitized",// Date and time when the image was stored digitally
0x9290 : "SubsecTime",// Fractions of seconds for DateTime
0x9291 : "SubsecTimeOriginal",// Fractions of seconds for DateTimeOriginal
0x9292 : "SubsecTimeDigitized",// Fractions of seconds for DateTimeDigitized

// picture-taking conditions
0x829A : "ExposureTime",// Exposure time (in seconds)
0x829D : "FNumber",// F number
0x8822 : "ExposureProgram",// Exposure program
0x8824 : "SpectralSensitivity",// Spectral sensitivity
0x8827 : "ISOSpeedRatings",// ISO speed rating
0x8828 : "OECF",// Optoelectric conversion factor
0x9201 : "ShutterSpeedValue",// Shutter speed
0x9202 : "ApertureValue",// Lens aperture
0x9203 : "BrightnessValue",// Value of brightness
0x9204 : "ExposureBias",// Exposure bias
0x9205 : "MaxApertureValue",// Smallest F number of lens
0x9206 : "SubjectDistance",// Distance to subject in meters
0x9207 : "MeteringMode",// Metering mode
0x9208 : "LightSource",// Kind of light source
0x9209 : "Flash",// Flash status
0x9214 : "SubjectArea",// Location and area of main subject
0x920A : "FocalLength",// Focal length of the lens in mm
0xA20B : "FlashEnergy",// Strobe energy in BCPS
0xA20C : "SpatialFrequencyResponse",//
0xA20E : "FocalPlaneXResolution",// Number of pixels in width direction per FocalPlaneResolutionUnit
0xA20F : "FocalPlaneYResolution",// Number of pixels in height direction per FocalPlaneResolutionUnit
0xA210 : "FocalPlaneResolutionUnit",// Unit for measuring FocalPlaneXResolution and FocalPlaneYResolution
0xA214 : "SubjectLocation",// Location of subject in image
0xA215 : "ExposureIndex",// Exposure index selected on camera
0xA217 : "SensingMethod",// Image sensor type
0xA300 : "FileSource",// Image source (3 == DSC)
0xA301 : "SceneType",// Scene type (1 == directly photographed)
0xA302 : "CFAPattern",// Color filter array geometric pattern
0xA401 : "CustomRendered",// Special processing
0xA402 : "ExposureMode",// Exposure mode
0xA403 : "WhiteBalance",// 1 = auto white balance,2 = manual
0xA404 : "DigitalZoomRation",// Digital zoom ratio
0xA405 : "FocalLengthIn35mmFilm",// Equivalent foacl length assuming 35mm film camera (in mm)
0xA406 : "SceneCaptureType",// Type of scene
0xA407 : "GainControl",// Degree of overall image gain adjustment
0xA408 : "Contrast",// Direction of contrast processing applied by camera
0xA409 : "Saturation",// Direction of saturation processing applied by camera
0xA40A : "Sharpness",// Direction of sharpness processing applied by camera
0xA40B : "DeviceSettingDescription",//
0xA40C : "SubjectDistanceRange",// Distance to subject

// other tags
0xA005 : "InteroperabilityIFDPointer",0xA420 : "ImageUniqueID"      // Identifier assigned uniquely to each image

};

var TiffTags = EXIF.TiffTags = {
0x0100 : "ImageWidth",0x0101 : "ImageHeight",0x8769 : "ExifIFDPointer",0x8825 : "GPSInfoIFDPointer",0xA005 : "InteroperabilityIFDPointer",0x0102 : "BitsPerSample",0x0103 : "Compression",0x0106 : "PhotometricInterpretation",0x0112 : "Orientation",0x0115 : "SamplesPerPixel",0x011C : "PlanarConfiguration",0x0212 : "YCbCrSubSampling",0x0213 : "YCbCrPositioning",0x011A : "XResolution",0x011B : "YResolution",0x0128 : "ResolutionUnit",0x0111 : "StripOffsets",0x0116 : "RowsPerStrip",0x0117 : "StripByteCounts",0x0201 : "JPEGInterchangeFormat",0x0202 : "JPEGInterchangeFormatLength",0x012D : "TransferFunction",0x013E : "WhitePoint",0x013F : "PrimaryChromaticities",0x0211 : "YCbCrCoefficients",0x0214 : "ReferenceBlackWhite",0x0132 : "DateTime",0x010E : "ImageDescription",0x010F : "Make",0x0110 : "Model",0x0131 : "Software",0x013B : "Artist",0x8298 : "Copyright"
};

var GPSTags = EXIF.GPSTags = {
0x0000 : "GPSVersionID",0x0001 : "GPSLatitudeRef",0x0002 : "GPSLatitude",0x0003 : "GPSLongitudeRef",0x0004 : "GPSLongitude",0x0005 : "GPSAltitudeRef",0x0006 : "GPSAltitude",0x0007 : "GPSTimeStamp",0x0008 : "GPSSatellites",0x0009 : "GPSStatus",0x000A : "GPSMeasureMode",0x000B : "GPSDOP",0x000C : "GPSSpeedRef",0x000D : "GPSSpeed",0x000E : "GPSTrackRef",0x000F : "GPSTrack",0x0010 : "GPSImgDirectionRef",0x0011 : "GPSImgDirection",0x0012 : "GPSMapDatum",0x0013 : "GPSDestLatitudeRef",0x0014 : "GPSDestLatitude",0x0015 : "GPSDestLongitudeRef",0x0016 : "GPSDestLongitude",0x0017 : "GPSDestBearingRef",0x0018 : "GPSDestBearing",0x0019 : "GPSDestDistanceRef",0x001A : "GPSDestDistance",0x001B : "GPSProcessingMethod",0x001C : "GPSAreaInformation",0x001D : "GPSDateStamp",0x001E : "GPSDifferential"
};

var StringValues = EXIF.StringValues = {
ExposureProgram : {
0 : "Not defined",1 : "Manual",2 : "Normal program",3 : "Aperture priority",4 : "Shutter priority",5 : "Creative program",6 : "Action program",7 : "Portrait mode",8 : "Landscape mode"
},MeteringMode : {
0 : "Unknown",1 : "Average",2 : "CenterWeightedAverage",3 : "Spot",4 : "MultiSpot",5 : "Pattern",6 : "Partial",255 : "Other"
},LightSource : {
0 : "Unknown",1 : "Daylight",2 : "Fluorescent",3 : "Tungsten (incandescent light)",4 : "Flash",9 : "Fine weather",10 : "Cloudy weather",11 : "Shade",12 : "Daylight fluorescent (D 5700 - 7100K)",13 : "Day white fluorescent (N 4600 - 5400K)",14 : "Cool white fluorescent (W 3900 - 4500K)",15 : "White fluorescent (WW 3200 - 3700K)",17 : "Standard light A",18 : "Standard light B",19 : "Standard light C",20 : "D55",21 : "D65",22 : "D75",23 : "D50",24 : "ISO studio tungsten",Flash : {
0x0000 : "Flash did not fire",0x0001 : "Flash fired",0x0005 : "Strobe return light not detected",0x0007 : "Strobe return light detected",0x0009 : "Flash fired,compulsory flash mode",0x000D : "Flash fired,compulsory flash mode,return light not detected",0x000F : "Flash fired,return light detected",0x0010 : "Flash did not fire,0x0018 : "Flash did not fire,auto mode",0x0019 : "Flash fired,0x001D : "Flash fired,auto mode,0x001F : "Flash fired,0x0020 : "No flash function",0x0041 : "Flash fired,red-eye reduction mode",0x0045 : "Flash fired,red-eye reduction mode,0x0047 : "Flash fired,0x0049 : "Flash fired,0x004D : "Flash fired,0x004F : "Flash fired,0x0059 : "Flash fired,0x005D : "Flash fired,return light not detected,0x005F : "Flash fired,return light detected,red-eye reduction mode"
},SensingMethod : {
1 : "Not defined",2 : "One-chip color area sensor",3 : "Two-chip color area sensor",4 : "Three-chip color area sensor",5 : "Color sequential area sensor",7 : "Trilinear sensor",8 : "Color sequential linear sensor"
},SceneCaptureType : {
0 : "Standard",1 : "Landscape",2 : "Portrait",3 : "Night scene"
},SceneType : {
1 : "Directly photographed"
},CustomRendered : {
0 : "Normal process",1 : "Custom process"
},WhiteBalance : {
0 : "Auto white balance",1 : "Manual white balance"
},GainControl : {
0 : "None",1 : "Low gain up",2 : "High gain up",3 : "Low gain down",4 : "High gain down"
},Contrast : {
0 : "Normal",1 : "Soft",2 : "Hard"
},Saturation : {
0 : "Normal",1 : "Low saturation",2 : "High saturation"
},Sharpness : {
0 : "Normal",SubjectDistanceRange : {
0 : "Unknown",1 : "Macro",2 : "Close view",3 : "Distant view"
},FileSource : {
3 : "DSC"
},Components : {
0 : "",1 : "Y",2 : "Cb",3 : "Cr",4 : "R",5 : "G",6 : "B"
}
};

function addEvent(element,event,handler) {
if (element.addEventListener) {
element.addEventListener(event,handler,false);
} else if (element.attachEvent) {
element.attachEvent("on" + event,handler);
}
}

function imageHasData(img) {
return !!(img.exifdata);
}

function base64ToArrayBuffer(base64,contentType) {
contentType = contentType || base64.match(/^data\:([^\;]+)\;base64,/mi)[1] || ''; // e.g. 'data:image/jpeg;base64,...' => 'image/jpeg'
base64 = base64.replace(/^data\:([^\;]+)\;base64,/gmi,'');
var binary = atob(base64);
var len = binary.length;
var buffer = new ArrayBuffer(len);
var view = new Uint8Array(buffer);
for (var i = 0; i < len; i++) {
view[i] = binary.charCodeAt(i);
}
return buffer;
}

function objectURLToBlob(url,callback) {
var http = new XMLHttpRequest();
http.open("GET",url,true);
http.responseType = "blob";
http.onload = function(e) {
if (this.status == 200 || this.status === 0) {
callback(this.response);
}
};
http.send();
}

function getImageData(img,callback) {
function handleBinaryFile(binFile) {
var data = findEXIFinJPEG(binFile);
var iptcdata = findIPTCinJPEG(binFile);
img.exifdata = data || {};
img.iptcdata = iptcdata || {};
if (callback) {
callback.call(img);
}
}

if (img.src) {
  if (/^data\:/i.test(img.src)) { // Data URI
    var arrayBuffer = base64ToArrayBuffer(img.src);
    handleBinaryFile(arrayBuffer);

  } else if (/^blob\:/i.test(img.src)) { // Object URL
    var fileReader = new FileReader();
    fileReader.onload = function(e) {
      handleBinaryFile(e.target.result);
    };
    objectURLToBlob(img.src,function (blob) {
      fileReader.readAsArrayBuffer(blob);
    });
  } else {
    var http = new XMLHttpRequest();
    http.onload = function() {
      if (this.status == 200 || this.status === 0) {
        handleBinaryFile(http.response);
      } else {
        throw "Could not load image";
      }
      http = null;
    };
    http.open("GET",img.src,true);
    http.responseType = "arraybuffer";
    http.send(null);
  }
} else if (window.FileReader && (img instanceof window.Blob || img instanceof window.File)) {
  var fileReader = new FileReader();
  fileReader.onload = function(e) {
    if (debug) console.log("Got file of length " + e.target.result.byteLength);
    handleBinaryFile(e.target.result);
  };

  fileReader.readAsArrayBuffer(img);
}

}

function findEXIFinJPEG(file) {
var dataView = new DataView(file);

if (debug) console.log("Got file of length " + file.byteLength);
if ((dataView.getUint8(0) != 0xFF) || (dataView.getUint8(1) != 0xD8)) {
  if (debug) console.log("Not a valid JPEG");
  return false; // not a valid jpeg
}

var offset = 2,length = file.byteLength,marker;

while (offset < length) {
  if (dataView.getUint8(offset) != 0xFF) {
    if (debug) console.log("Not a valid marker at offset " + offset + ",found: " + dataView.getUint8(offset));
    return false; // not a valid marker,something is wrong
  }

  marker = dataView.getUint8(offset + 1);
  if (debug) console.log(marker);

  // we could implement handling for other markers here,// but we're only looking for 0xFFE1 for EXIF data

  if (marker == 225) {
    if (debug) console.log("Found 0xFFE1 marker");

    return readEXIFData(dataView,offset + 4,dataView.getUint16(offset + 2) - 2);

    // offset += 2 + file.getShortAt(offset+2,true);

  } else {
    offset += 2 + dataView.getUint16(offset+2);
  }

}

}

function findIPTCinJPEG(file) {
var dataView = new DataView(file);

if (debug) console.log("Got file of length " + file.byteLength);
if ((dataView.getUint8(0) != 0xFF) || (dataView.getUint8(1) != 0xD8)) {
  if (debug) console.log("Not a valid JPEG");
  return false; // not a valid jpeg
}

var offset = 2,length = file.byteLength;


var isFieldSegmentStart = function(dataView,offset){
  return (
    dataView.getUint8(offset) === 0x38 &&
    dataView.getUint8(offset+1) === 0x42 &&
    dataView.getUint8(offset+2) === 0x49 &&
    dataView.getUint8(offset+3) === 0x4D &&
    dataView.getUint8(offset+4) === 0x04 &&
    dataView.getUint8(offset+5) === 0x04
  );
};

while (offset < length) {

  if ( isFieldSegmentStart(dataView,offset )){

    // Get the length of the name header (which is padded to an even number of bytes)
    var nameHeaderLength = dataView.getUint8(offset+7);
    if(nameHeaderLength % 2 !== 0) nameHeaderLength += 1;
    // Check for pre photoshop 6 format
    if(nameHeaderLength === 0) {
      // Always 4
      nameHeaderLength = 4;
    }

    var startOffset = offset + 8 + nameHeaderLength;
    var sectionLength = dataView.getUint16(offset + 6 + nameHeaderLength);

    return readIPTCData(file,startOffset,sectionLength);

    break;

  }


  // Not the marker,continue searching
  offset++;

}

}
var IptcFieldMap = {
0x78 : 'caption',0x6E : 'credit',0x19 : 'keywords',0x37 : 'dateCreated',0x50 : 'byline',0x55 : 'bylineTitle',0x7A : 'captionWriter',0x69 : 'headline',0x74 : 'copyright',0x0F : 'category'
};
function readIPTCData(file,sectionLength){
var dataView = new DataView(file);
var data = {};
var fieldValue,fieldName,dataSize,segmentType,segmentSize;
var segmentStartPos = startOffset;
while(segmentStartPos < startOffset+sectionLength) {
if(dataView.getUint8(segmentStartPos) === 0x1C && dataView.getUint8(segmentStartPos+1) === 0x02){
segmentType = dataView.getUint8(segmentStartPos+2);
if(segmentType in IptcFieldMap) {
dataSize = dataView.getInt16(segmentStartPos+3);
segmentSize = dataSize + 5;
fieldName = IptcFieldMap[segmentType];
fieldValue = getStringFromDB(dataView,segmentStartPos+5,dataSize);
// Check if we already stored a value with this name
if(data.hasOwnProperty(fieldName)) {
// Value already stored with this name,create multivalue field
if(data[fieldName] instanceof Array) {
data[fieldName].push(fieldValue);
}
else {
data[fieldName] = [data[fieldName],fieldValue];
}
}
else {
data[fieldName] = fieldValue;
}
}

  }
  segmentStartPos++;
}
return data;

}

function readTags(file,tiffStart,dirStart,strings,bigEnd) {
var entries = file.getUint16(dirStart,!bigEnd),tags = {},entryOffset,tag,i;

for (i=0;i<entries;i++) {
  entryOffset = dirStart + i*12 + 2;
  tag = strings[file.getUint16(entryOffset,!bigEnd)];
  if (!tag && debug) console.log("Unknown tag: " + file.getUint16(entryOffset,!bigEnd));
  tags[tag] = readTagValue(file,bigEnd);
}
return tags;

}

function readTagValue(file,bigEnd) {
var type = file.getUint16(entryOffset+2,numValues = file.getUint32(entryOffset+4,valueOffset = file.getUint32(entryOffset+8,!bigEnd) + tiffStart,offset,vals,val,n,numerator,denominator;

switch (type) {
  case 1: // byte,8-bit unsigned int
  case 7: // undefined,8-bit byte,value depending on field
    if (numValues == 1) {
      return file.getUint8(entryOffset + 8,!bigEnd);
    } else {
      offset = numValues > 4 ? valueOffset : (entryOffset + 8);
      vals = [];
      for (n=0;n<numValues;n++) {
        vals[n] = file.getUint8(offset + n);
      }
      return vals;
    }

  case 2: // ascii,8-bit byte
    offset = numValues > 4 ? valueOffset : (entryOffset + 8);
    return getStringFromDB(file,numValues-1);

  case 3: // short,16 bit int
    if (numValues == 1) {
      return file.getUint16(entryOffset + 8,!bigEnd);
    } else {
      offset = numValues > 2 ? valueOffset : (entryOffset + 8);
      vals = [];
      for (n=0;n<numValues;n++) {
        vals[n] = file.getUint16(offset + 2*n,!bigEnd);
      }
      return vals;
    }

  case 4: // long,32 bit int
    if (numValues == 1) {
      return file.getUint32(entryOffset + 8,!bigEnd);
    } else {
      vals = [];
      for (n=0;n<numValues;n++) {
        vals[n] = file.getUint32(valueOffset + 4*n,!bigEnd);
      }
      return vals;
    }

  case 5:  // rational = two long values,first is numerator,second is denominator
    if (numValues == 1) {
      numerator = file.getUint32(valueOffset,!bigEnd);
      denominator = file.getUint32(valueOffset+4,!bigEnd);
      val = new Number(numerator / denominator);
      val.numerator = numerator;
      val.denominator = denominator;
      return val;
    } else {
      vals = [];
      for (n=0;n<numValues;n++) {
        numerator = file.getUint32(valueOffset + 8*n,!bigEnd);
        denominator = file.getUint32(valueOffset+4 + 8*n,!bigEnd);
        vals[n] = new Number(numerator / denominator);
        vals[n].numerator = numerator;
        vals[n].denominator = denominator;
      }
      return vals;
    }

  case 9: // slong,32 bit signed int
    if (numValues == 1) {
      return file.getInt32(entryOffset + 8,!bigEnd);
    } else {
      vals = [];
      for (n=0;n<numValues;n++) {
        vals[n] = file.getInt32(valueOffset + 4*n,!bigEnd);
      }
      return vals;
    }

  case 10: // signed rational,two slongs,second is denominator
    if (numValues == 1) {
      return file.getInt32(valueOffset,!bigEnd) / file.getInt32(valueOffset+4,!bigEnd);
    } else {
      vals = [];
      for (n=0;n<numValues;n++) {
        vals[n] = file.getInt32(valueOffset + 8*n,!bigEnd) / file.getInt32(valueOffset+4 + 8*n,!bigEnd);
      }
      return vals;
    }
}

}

function getStringFromDB(buffer,start,length) {
var outstr = "";
for (n = start; n < start+length; n++) {
outstr += String.fromCharCode(buffer.getUint8(n));
}
return outstr;
}

function readEXIFData(file,start) {
if (getStringFromDB(file,4) != "Exif") {
if (debug) console.log("Not valid EXIF data! " + getStringFromDB(file,4));
return false;
}

var bigEnd,tags,exifData,gpsData,tiffOffset = start + 6;

// test for TIFF validity and endianness
if (file.getUint16(tiffOffset) == 0x4949) {
  bigEnd = false;
} else if (file.getUint16(tiffOffset) == 0x4D4D) {
  bigEnd = true;
} else {
  if (debug) console.log("Not valid TIFF data! (no 0x4949 or 0x4D4D)");
  return false;
}

if (file.getUint16(tiffOffset+2,!bigEnd) != 0x002A) {
  if (debug) console.log("Not valid TIFF data! (no 0x002A)");
  return false;
}

var firstIFDOffset = file.getUint32(tiffOffset+4,!bigEnd);

if (firstIFDOffset < 0x00000008) {
  if (debug) console.log("Not valid TIFF data! (First offset less than 8)",file.getUint32(tiffOffset+4,!bigEnd));
  return false;
}

tags = readTags(file,tiffOffset,tiffOffset + firstIFDOffset,TiffTags,bigEnd);

if (tags.ExifIFDPointer) {
  exifData = readTags(file,tiffOffset + tags.ExifIFDPointer,ExifTags,bigEnd);
  for (tag in exifData) {
    switch (tag) {
      case "LightSource" :
      case "Flash" :
      case "MeteringMode" :
      case "ExposureProgram" :
      case "SensingMethod" :
      case "SceneCaptureType" :
      case "SceneType" :
      case "CustomRendered" :
      case "WhiteBalance" :
      case "GainControl" :
      case "Contrast" :
      case "Saturation" :
      case "Sharpness" :
      case "SubjectDistanceRange" :
      case "FileSource" :
        exifData[tag] = StringValues[tag][exifData[tag]];
        break;

      case "ExifVersion" :
      case "FlashpixVersion" :
        exifData[tag] = String.fromCharCode(exifData[tag][0],exifData[tag][1],exifData[tag][2],exifData[tag][3]);
        break;

      case "ComponentsConfiguration" :
        exifData[tag] =
          StringValues.Components[exifData[tag][0]] +
          StringValues.Components[exifData[tag][1]] +
          StringValues.Components[exifData[tag][2]] +
          StringValues.Components[exifData[tag][3]];
        break;
    }
    tags[tag] = exifData[tag];
  }
}

if (tags.GPSInfoIFDPointer) {
  gpsData = readTags(file,tiffOffset + tags.GPSInfoIFDPointer,GPSTags,bigEnd);
  for (tag in gpsData) {
    switch (tag) {
      case "GPSVersionID" :
        gpsData[tag] = gpsData[tag][0] +
          "." + gpsData[tag][1] +
          "." + gpsData[tag][2] +
          "." + gpsData[tag][3];
        break;
    }
    tags[tag] = gpsData[tag];
  }
}

return tags;

}

EXIF.getData = function(img,callback) {
if ((img instanceof Image || img instanceof HTMLImageElement) && !img.complete) return false;

if (!imageHasData(img)) {
  getImageData(img,callback);
} else {
  if (callback) {
    callback.call(img);
  }
}
return true;

}

EXIF.getTag = function(img,tag) {
if (!imageHasData(img)) return;
return img.exifdata[tag];
}

EXIF.getAllTags = function(img) {
if (!imageHasData(img)) return {};
var a,data = img.exifdata,tags = {};
for (a in data) {
if (data.hasOwnProperty(a)) {
tags[a] = data[a];
}
}
return tags;
}

EXIF.pretty = function(img) {
if (!imageHasData(img)) return "";
var a,strPretty = "";
for (a in data) {
if (data.hasOwnProperty(a)) {
if (typeof data[a] == "object") {
if (data[a] instanceof Number) {
strPretty += a + " : " + data[a] + " [" + data[a].numerator + "/" + data[a].denominator + "]\r\n";
} else {
strPretty += a + " : [" + data[a].length + " values]\r\n";
}
} else {
strPretty += a + " : " + data[a] + "\r\n";
}
}
}
return strPretty;
}

EXIF.readFromBinaryFile = function(file) {
return findEXIFinJPEG(file);
}

if (typeof define === 'function' && define.amd) {
define('exif-js',[],function() {
return EXIF;
});
}
}.call(this));