/*
 * This file is subject to the terms and conditions defined in
 * file 'LICENSE.md', which is part of this source code package.
 */

package model

import (
	"errors"

	"github.com/unidoc/unidoc/common"
	. "github.com/unidoc/unidoc/pdf/core"
)

// XObjectForm (Table 95 in 8.10.2).
type XObjectForm struct {
	Filter StreamEncoder

	FormType      PdfObject
	BBox          PdfObject
	Matrix        PdfObject
	Resources     PdfObject
	Group         PdfObject
	Ref           PdfObject
	MetaData      PdfObject
	PieceInfo     PdfObject
	LastModified  PdfObject
	StructParent  PdfObject
	StructParents PdfObject
	OPI           PdfObject
	OC            PdfObject
	Name          PdfObject

	FormResources *PdfPageResources
	// Stream data.
	Stream []byte
	// Primitive
	primitive *PdfObjectStream
}

// Create a brand new XObject Form. Creates a new underlying PDF object stream primitive.
func NewXObjectForm() *XObjectForm {
	xobj := &XObjectForm{}
	stream := &PdfObjectStream{}
	stream.PdfObjectDictionary = &PdfObjectDictionary{}
	xobj.primitive = stream
	return xobj
}

// Build the Form XObject from a stream object.
// XXX: Should this be exposed? Consider different access points.
func NewXObjectFormFromStream(stream *PdfObjectStream) (*XObjectForm, error) {
	form := &XObjectForm{}
	form.primitive = stream

	dict := *(stream.PdfObjectDictionary)

	encoder, err := NewEncoderFromStream(stream)
	if err != nil {
		return nil, err
	}
	form.Filter = encoder

	if obj, isDefined := dict["Subtype"]; isDefined {
		name, ok := obj.(*PdfObjectName)
		if !ok {
			return nil, errors.New("Type error")
		}
		if *name != "Form" {
			common.Log.Debug("Invalid form subtype")
			return nil, errors.New("Invalid form subtype")
		}
	}

	if obj, isDefined := dict["FormType"]; isDefined {
		form.FormType = obj
	}
	if obj, isDefined := dict["BBox"]; isDefined {
		form.BBox = obj
	}
	if obj, isDefined := dict["Matrix"]; isDefined {
		form.Matrix = obj
	}
	if obj, isDefined := dict["Resources"]; isDefined {
		form.Resources = obj
		obj = TraceToDirectObject(obj)
		d, ok := obj.(*PdfObjectDictionary)
		if !ok {
			common.Log.Debug("Invalid XObject Form Resources object, pointing to non-dictionary")
			return nil, errors.New("Type check error")
		}
		res, err := NewPdfPageResourcesFromDict(d)
		if err != nil {
			common.Log.Debug("Failed getting form resources")
			return nil, err
		}
		form.FormResources = res
		common.Log.Trace("Form resources: %#v", form.FormResources)
	}

	if obj, isDefined := dict["Group"]; isDefined {
		form.Group = obj
	}
	if obj, isDefined := dict["Ref"]; isDefined {
		form.Ref = obj
	}
	if obj, isDefined := dict["MetaData"]; isDefined {
		form.MetaData = obj
	}
	if obj, isDefined := dict["PieceInfo"]; isDefined {
		form.PieceInfo = obj
	}
	if obj, isDefined := dict["LastModified"]; isDefined {
		form.LastModified = obj
	}
	if obj, isDefined := dict["StructParent"]; isDefined {
		form.StructParent = obj
	}
	if obj, isDefined := dict["StructParents"]; isDefined {
		form.StructParents = obj
	}
	if obj, isDefined := dict["OPI"]; isDefined {
		form.OPI = obj
	}
	if obj, isDefined := dict["OC"]; isDefined {
		form.OC = obj
	}
	if obj, isDefined := dict["Name"]; isDefined {
		form.Name = obj
	}

	form.Stream = stream.Stream

	return form, nil
}

func (xform *XObjectForm) GetContainingPdfObject() PdfObject {
	return xform.primitive
}

func (xform *XObjectForm) GetContentStream() ([]byte, error) {
	decoded, err := DecodeStream(xform.primitive)
	if err != nil {
		return nil, err
	}

	return decoded, nil
}

// Return a stream object.
func (xform *XObjectForm) ToPdfObject() PdfObject {
	stream := xform.primitive

	dict := stream.PdfObjectDictionary
	if xform.Filter != nil {
		// Pre-populate the stream dictionary with the
		// encoding related fields.
		dict = xform.Filter.MakeStreamDict()
		stream.PdfObjectDictionary = dict
	}
	dict.Set("Type", MakeName("XObject"))
	dict.Set("Subtype", MakeName("Form"))

	dict.SetIfNotNil("FormType", xform.FormType)
	dict.SetIfNotNil("BBox", xform.BBox)
	dict.SetIfNotNil("Matrix", xform.Matrix)
	dict.SetIfNotNil("Resources", xform.Resources)
	dict.SetIfNotNil("Group", xform.Group)
	dict.SetIfNotNil("Ref", xform.Ref)
	dict.SetIfNotNil("MetaData", xform.MetaData)
	dict.SetIfNotNil("PieceInfo", xform.PieceInfo)
	dict.SetIfNotNil("LastModified", xform.LastModified)
	dict.SetIfNotNil("StructParent", xform.StructParent)
	dict.SetIfNotNil("StructParents", xform.StructParents)
	dict.SetIfNotNil("OPI", xform.OPI)
	dict.SetIfNotNil("OC", xform.OC)
	dict.SetIfNotNil("Name", xform.Name)

	dict.Set("Length", MakeInteger(int64(len(xform.Stream))))
	stream.Stream = xform.Stream

	return stream
}

// XObjectImage (Table 89 in 8.9.5.1).
// Implements PdfModel interface.
type XObjectImage struct {
	//ColorSpace       PdfObject
	Width            *int64
	Height           *int64
	ColorSpace       PdfColorspace
	BitsPerComponent *int64
	Filter           StreamEncoder

	Intent       PdfObject
	ImageMask    PdfObject
	Mask         PdfObject
	Decode       PdfObject
	Interpolate  PdfObject
	Alternatives PdfObject
	SMask        PdfObject
	SMaskInData  PdfObject
	Name         PdfObject
	StructParent PdfObject
	ID           PdfObject
	OPI          PdfObject
	Metadata     PdfObject
	OC           PdfObject
	Stream       []byte
	// Primitive
	primitive *PdfObjectStream
}

func NewXObjectImage() *XObjectImage {
	xobj := &XObjectImage{}
	stream := &PdfObjectStream{}
	stream.PdfObjectDictionary = &PdfObjectDictionary{}
	xobj.primitive = stream
	return xobj
}

// Creates a new XObject Image from an image object with default
// options.
func NewXObjectImageFromImage(name PdfObjectName, img *Image) (*XObjectImage, error) {
	xobj := NewXObjectImage()

	xobj.Name = &name
	xobj.Stream = img.Data

	// Width and height.
	imWidth := img.Width
	imHeight := img.Height
	xobj.Width = &imWidth
	xobj.Height = &imHeight

	// Bits.
	xobj.BitsPerComponent = &img.BitsPerComponent

	//xobj.ColorSpace = MakeName("DeviceRGB")
	xobj.ColorSpace = NewPdfColorspaceDeviceRGB()

	// define color space?

	return xobj, nil
}

// Build the image xobject from a stream object.
// An image dictionary is the dictionary portion of a stream object representing an image XObject.
func NewXObjectImageFromStream(stream *PdfObjectStream) (*XObjectImage, error) {
	img := &XObjectImage{}
	img.primitive = stream

	dict := *(stream.PdfObjectDictionary)

	encoder, err := NewEncoderFromStream(stream)
	if err != nil {
		return nil, err
	}
	img.Filter = encoder

	if obj, isDefined := dict["Width"]; isDefined {
		iObj, ok := obj.(*PdfObjectInteger)
		if !ok {
			return nil, errors.New("Invalid image width object")
		}
		iVal := int64(*iObj)
		img.Width = &iVal
	} else {
		return nil, errors.New("Width missing")
	}

	if obj, isDefined := dict["Height"]; isDefined {
		iObj, ok := obj.(*PdfObjectInteger)
		if !ok {
			return nil, errors.New("Invalid image height object")
		}
		iVal := int64(*iObj)
		img.Height = &iVal
	} else {
		return nil, errors.New("Height missing")
	}

	if obj, isDefined := dict["ColorSpace"]; isDefined {
		//img.ColorSpace = obj
		cs, err := newPdfColorspaceFromPdfObject(obj)
		if err != nil {
			return nil, err
		}
		img.ColorSpace = cs
	} else {
		// If not specified, assume gray..
		common.Log.Debug("XObject Image colorspace not specified - assuming 1 color component")
		img.ColorSpace = NewPdfColorspaceDeviceGray()
	}

	if obj, isDefined := dict["BitsPerComponent"]; isDefined {
		iObj, ok := obj.(*PdfObjectInteger)
		if !ok {
			return nil, errors.New("Invalid image height object")
		}
		iVal := int64(*iObj)
		img.BitsPerComponent = &iVal
	}

	if obj, isDefined := dict["Intent"]; isDefined {
		img.Intent = obj
	}
	if obj, isDefined := dict["ImageMask"]; isDefined {
		img.ImageMask = obj
	}
	if obj, isDefined := dict["Mask"]; isDefined {
		img.Mask = obj
	}
	if obj, isDefined := dict["Decode"]; isDefined {
		img.Decode = obj
	}
	if obj, isDefined := dict["Interpolate"]; isDefined {
		img.Interpolate = obj
	}
	if obj, isDefined := dict["Alternatives"]; isDefined {
		img.Alternatives = obj
	}
	if obj, isDefined := dict["SMask"]; isDefined {
		img.SMask = obj
	}
	if obj, isDefined := dict["SMaskInData"]; isDefined {
		img.SMaskInData = obj
	}
	if obj, isDefined := dict["Name"]; isDefined {
		img.Name = obj
	}
	if obj, isDefined := dict["StructParent"]; isDefined {
		img.StructParent = obj
	}
	if obj, isDefined := dict["ID"]; isDefined {
		img.ID = obj
	}
	if obj, isDefined := dict["OPI"]; isDefined {
		img.OPI = obj
	}
	if obj, isDefined := dict["Metadata"]; isDefined {
		img.Metadata = obj
	}
	if obj, isDefined := dict["OC"]; isDefined {
		img.OC = obj
	}

	img.Stream = stream.Stream

	return img, nil
}

// This will convert to an Image which can be transformed or saved out.
// The image data is decoded and the Image returned.
func (ximg *XObjectImage) ToImage() (*Image, error) {
	image := &Image{}

	if ximg.Height == nil {
		return nil, errors.New("Height attribute missing")
	}
	image.Height = *ximg.Height

	if ximg.Width == nil {
		return nil, errors.New("Width attribute missing")
	}
	image.Width = *ximg.Width

	if ximg.BitsPerComponent == nil {
		return nil, errors.New("Bits per component missing")
	}
	image.BitsPerComponent = *ximg.BitsPerComponent

	image.ColorComponents = ximg.ColorSpace.GetNumComponents()

	decoded, err := DecodeStream(ximg.primitive)
	if err != nil {
		return nil, err
	}
	image.Data = decoded

	if ximg.Decode != nil {
		darr, ok := ximg.Decode.(*PdfObjectArray)
		if !ok {
			common.Log.Debug("Invalid Decode object")
			return nil, errors.New("Invalid type")
		}
		decode, err := darr.ToFloat64Array()
		if err != nil {
			return nil, err
		}
		image.decode = decode
	}

	return image, nil
}

func (ximg *XObjectImage) GetContainingPdfObject() PdfObject {
	return ximg.primitive
}

// Return a stream object.
func (ximg *XObjectImage) ToPdfObject() PdfObject {
	stream := ximg.primitive

	dict := stream.PdfObjectDictionary
	if ximg.Filter != nil {
		//dict.Set("Filter", ximg.Filter)
		// Pre-populate the stream dictionary with the
		// encoding related fields.
		dict = ximg.Filter.MakeStreamDict()
		stream.PdfObjectDictionary = dict
	}
	dict.Set("Type", MakeName("XObject"))
	dict.Set("Subtype", MakeName("Image"))
	dict.Set("Width", MakeInteger(*(ximg.Width)))
	dict.Set("Height", MakeInteger(*(ximg.Height)))

	if ximg.BitsPerComponent != nil {
		dict.Set("BitsPerComponent", MakeInteger(*(ximg.BitsPerComponent)))
	}

	if ximg.ColorSpace != nil {
		dict.SetIfNotNil("ColorSpace", ximg.ColorSpace.ToPdfObject())
	}
	dict.SetIfNotNil("Intent", ximg.Intent)
	dict.SetIfNotNil("ImageMask", ximg.ImageMask)
	dict.SetIfNotNil("Mask", ximg.Mask)
	dict.SetIfNotNil("Decode", ximg.Decode)
	dict.SetIfNotNil("Interpolate", ximg.Interpolate)
	dict.SetIfNotNil("Alternatives", ximg.Alternatives)
	dict.SetIfNotNil("SMask", ximg.SMask)
	dict.SetIfNotNil("SMaskInData", ximg.SMaskInData)
	dict.SetIfNotNil("Name", ximg.Name)
	dict.SetIfNotNil("StructParent", ximg.StructParent)
	dict.SetIfNotNil("ID", ximg.ID)
	dict.SetIfNotNil("OPI", ximg.OPI)
	dict.SetIfNotNil("Metadata", ximg.Metadata)
	dict.SetIfNotNil("OC", ximg.OC)

	dict.Set("Length", MakeInteger(int64(len(ximg.Stream))))
	stream.Stream = ximg.Stream

	return stream
}