// xslx is a package designed to help with reading data from
// spreadsheets stored in the XLSX format used in recent versions of
// Microsoft's Excel spreadsheet.
//
// For a concise example of how to use this library why not check out
// the source for xlsx2csv here: https://github.com/tealeg/xlsx2csv

package xlsx

import (
	"encoding/xml"
	"fmt"
	"strconv"
	"strings"
)

var (
	NumFmtRefTable map[int]xlsxNumFmt
)

// xlsxStyle directly maps the styleSheet element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxStyleSheet struct {
	XMLName xml.Name `xml:"http://schemas.openxmlformats.org/spreadsheetml/2006/main styleSheet"`

	Fonts        xlsxFonts        `xml:"fonts,omitempty"`
	Fills        xlsxFills        `xml:"fills,omitempty"`
	Borders      xlsxBorders      `xml:"borders,omitempty"`
	CellStyleXfs xlsxCellStyleXfs `xml:"cellStyleXfs,omitempty"`
	CellXfs      xlsxCellXfs      `xml:"cellXfs,omitempty"`
	NumFmts      xlsxNumFmts      `xml:"numFmts,omitempty"`
}

func (styles *xlsxStyleSheet) buildNumFmtRefTable() (numFmtRefTable map[int]xlsxNumFmt) {
	numFmtRefTable = make(map[int]xlsxNumFmt)
	for _, numFmt := range styles.NumFmts.NumFmt {
		numFmtRefTable[numFmt.NumFmtId] = numFmt
	}
	return numFmtRefTable
}

func (styles *xlsxStyleSheet) getStyle(styleIndex int) (style Style) {
	var styleXf xlsxXf
	style = Style{}
	style.Border = Border{}
	style.Fill = Fill{}
	style.Font = Font{}

	xfCount := styles.CellXfs.Count
	if styleIndex > -1 && xfCount > 0 && styleIndex <= xfCount {
		xf := styles.CellXfs.Xf[styleIndex]

		// Google docs can produce output that has fewer
		// CellStyleXfs than CellXfs - this copes with that.
		if styleIndex < styles.CellStyleXfs.Count {
			styleXf = styles.CellStyleXfs.Xf[styleIndex]
		} else {
			styleXf = xlsxXf{}
		}

		style.ApplyBorder = xf.ApplyBorder || styleXf.ApplyBorder
		style.ApplyFill = xf.ApplyFill || styleXf.ApplyFill
		style.ApplyFont = xf.ApplyFont || styleXf.ApplyFont

		if xf.BorderId > -1 && xf.BorderId < styles.Borders.Count {
			style.Border.Left = styles.Borders.Border[xf.BorderId].Left.Style
			style.Border.Right = styles.Borders.Border[xf.BorderId].Right.Style
			style.Border.Top = styles.Borders.Border[xf.BorderId].Top.Style
			style.Border.Bottom = styles.Borders.Border[xf.BorderId].Bottom.Style
		}

		if xf.FillId > -1 && xf.FillId < styles.Fills.Count {
			xFill := styles.Fills.Fill[xf.FillId]
			style.Fill.PatternType = xFill.PatternFill.PatternType
			style.Fill.FgColor = xFill.PatternFill.FgColor.RGB
			style.Fill.BgColor = xFill.PatternFill.BgColor.RGB
		}

		if xf.FontId > -1 && xf.FontId < styles.Fonts.Count {
			xfont := styles.Fonts.Font[xf.FontId]
			style.Font.Size, _ = strconv.Atoi(xfont.Sz.Val)
			style.Font.Name = xfont.Name.Val
			style.Font.Family, _ = strconv.Atoi(xfont.Family.Val)
			style.Font.Charset, _ = strconv.Atoi(xfont.Charset.Val)
		}
	}
	return style

}

func (styles *xlsxStyleSheet) getNumberFormat(styleIndex int) string {
	if styles.CellXfs.Xf == nil {
		return ""
	}
	var numberFormat string = ""
	if styleIndex > -1 && styleIndex <= styles.CellXfs.Count {
		xf := styles.CellXfs.Xf[styleIndex]
		numFmt := NumFmtRefTable[xf.NumFmtId]
		numberFormat = numFmt.FormatCode
	}
	return strings.ToLower(numberFormat)
}

func (styles *xlsxStyleSheet) addFont(xFont xlsxFont) (index int) {
	var font xlsxFont
	for index, font = range styles.Fonts.Font {
		if font.Equals(xFont) {
			return index
		}
	}
	styles.Fonts.Font = append(styles.Fonts.Font, xFont)
	index = styles.Fonts.Count
	styles.Fonts.Count += 1
	return
}

func (styles *xlsxStyleSheet) addFill(xFill xlsxFill) (index int) {
	styles.Fills.Fill = append(styles.Fills.Fill, xFill)
	index = styles.Fills.Count
	styles.Fills.Count += 1
	return
}

func (styles *xlsxStyleSheet) addBorder(xBorder xlsxBorder) (index int) {
	styles.Borders.Border = append(styles.Borders.Border, xBorder)
	index = styles.Borders.Count
	styles.Borders.Count += 1
	return
}

func (styles *xlsxStyleSheet) addCellStyleXf(xCellStyleXf xlsxXf) (index int) {
	styles.CellStyleXfs.Xf = append(styles.CellStyleXfs.Xf, xCellStyleXf)
	index = styles.CellStyleXfs.Count
	styles.CellStyleXfs.Count += 1
	return
}

func (styles *xlsxStyleSheet) addCellXf(xCellXf xlsxXf) (index int) {
	styles.CellXfs.Xf = append(styles.CellXfs.Xf, xCellXf)
	index = styles.CellXfs.Count
	styles.CellXfs.Count += 1
	return
}

func (styles *xlsxStyleSheet) addNumFmt(xNumFmt xlsxNumFmt) (index int) {
	numFmt, ok := NumFmtRefTable[xNumFmt.NumFmtId]
	if !ok {
		if NumFmtRefTable == nil {
			NumFmtRefTable = make(map[int]xlsxNumFmt)
		}
		styles.NumFmts.NumFmt = append(styles.NumFmts.NumFmt, xNumFmt)
		NumFmtRefTable[xNumFmt.NumFmtId] = xNumFmt
		index = styles.NumFmts.Count
		styles.NumFmts.Count += 1
		return
	}
	numFmt.FormatCode = xNumFmt.FormatCode
	return
}

func (styles *xlsxStyleSheet) Marshal() (result string, err error) {
	var xNumFmts string
	var xfonts string
	var xfills string
	var xborders string
	var xcellStyleXfs string
	var xcellXfs string

	var outputFontMap map[int]int = make(map[int]int)
	var outputFillMap map[int]int = make(map[int]int)
	var outputBorderMap map[int]int = make(map[int]int)

	result = xml.Header
	result += `<styleSheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">`

	xNumFmts, err = styles.NumFmts.Marshal()
	if err != nil {
		return
	}
	result += xNumFmts

	xfonts, err = styles.Fonts.Marshal(outputFontMap)
	if err != nil {
		return
	}
	result += xfonts

	xfills, err = styles.Fills.Marshal(outputFillMap)
	if err != nil {
		return
	}
	result += xfills

	xborders, err = styles.Borders.Marshal(outputBorderMap)
	if err != nil {
		return
	}
	result += xborders

	xcellStyleXfs, err = styles.CellStyleXfs.Marshal(outputBorderMap, outputFillMap, outputFontMap)
	if err != nil {
		return
	}
	result += xcellStyleXfs

	xcellXfs, err = styles.CellXfs.Marshal(outputBorderMap, outputFillMap, outputFontMap)
	if err != nil {
		return
	}
	result += xcellXfs

	result += `</styleSheet>`
	return
}

// xlsxNumFmts directly maps the numFmts element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxNumFmts struct {
	Count  int          `xml:"count,attr"`
	NumFmt []xlsxNumFmt `xml:"numFmt,omitempty"`
}

func (numFmts *xlsxNumFmts) Marshal() (result string, err error) {
	if numFmts.Count > 0 {
		result = fmt.Sprintf(`<numFmts count="%d">`, numFmts.Count)
		for _, numFmt := range numFmts.NumFmt {
			var xNumFmt string
			xNumFmt, err = numFmt.Marshal()
			if err != nil {
				return
			}
			result += xNumFmt
		}
		result += `</numFmts>`
	}
	return
}

// xlsxNumFmt directly maps the numFmt element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxNumFmt struct {
	NumFmtId   int    `xml:"numFmtId,omitempty"`
	FormatCode string `xml:"formatCode,omitempty"`
}

func (numFmt *xlsxNumFmt) Marshal() (result string, err error) {
	return fmt.Sprintf(`<numFmt numFmtId="%d" formatCode="%s"/>`, numFmt.NumFmtId, numFmt.FormatCode), nil
}

// xlsxFonts directly maps the fonts element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxFonts struct {
	XMLName xml.Name `xml:"fonts"`

	Count int        `xml:"count,attr"`
	Font  []xlsxFont `xml:"font,omitempty"`
}

func (fonts *xlsxFonts) Marshal(outputFontMap map[int]int) (result string, err error) {
	emittedCount := 0
	subparts := ""

	for i, font := range fonts.Font {
		var xfont string
		xfont, err = font.Marshal()
		if err != nil {
			return
		}
		if xfont != "" {
			outputFontMap[i] = emittedCount
			emittedCount += 1
			subparts += xfont
		}
	}
	if emittedCount > 0 {
		result = fmt.Sprintf(`<fonts count="%d">`, fonts.Count)
		result += subparts
		result += `</fonts>`
	}
	return
}

// xlsxFont directly maps the font element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxFont struct {
	Sz      xlsxVal   `xml:"sz,omitempty"`
	Name    xlsxVal   `xml:"name,omitempty"`
	Family  xlsxVal   `xml:"family,omitempty"`
	Charset xlsxVal   `xml:"charset,omitempty"`
	Color   xlsxColor `xml:"color,omitempty"`
}

func (font *xlsxFont) Equals(other xlsxFont) bool {
	return font.Sz.Val == other.Sz.Val && font.Name.Val == other.Name.Val && font.Family.Val == other.Family.Val && font.Charset.Val == other.Charset.Val && font.Color.RGB == other.Color.RGB
}

func (font *xlsxFont) Marshal() (result string, err error) {
	result = `<font>`
	if font.Sz.Val != "" {
		result += fmt.Sprintf(`<sz val="%s"/>`, font.Sz.Val)
	}
	if font.Name.Val != "" {
		result += fmt.Sprintf(`<name val="%s"/>`, font.Name.Val)
	}
	if font.Family.Val != "" {
		result += fmt.Sprintf(`<family val="%s"/>`, font.Family.Val)
	}
	if font.Charset.Val != "" {
		result += fmt.Sprintf(`<charset val="%s"/>`, font.Charset.Val)
	}
	if font.Color.RGB != "" {
		result += fmt.Sprintf(`<color rgb="%s"/>`, font.Color.RGB)
	}
	result += `</font>`
	return
}

// xlsxVal directly maps the val element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxVal struct {
	Val string `xml:"val,attr,omitempty"`
}

// xlsxFills directly maps the fills element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxFills struct {
	Count int        `xml:"count,attr"`
	Fill  []xlsxFill `xml:"fill,omitempty"`
}

func (fills *xlsxFills) Marshal(outputFillMap map[int]int) (result string, err error) {
	emittedCount := 0
	subparts := ""
	for i, fill := range fills.Fill {
		var xfill string
		xfill, err = fill.Marshal()
		if err != nil {
			return
		}
		if xfill != "" {
			outputFillMap[i] = emittedCount
			emittedCount += 1
			subparts += xfill
		}
	}
	if emittedCount > 0 {
		result = fmt.Sprintf(`<fills count="%d">`, emittedCount)
		result += subparts
		result += `</fills>`
	}
	return
}

// xlsxFill directly maps the fill element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxFill struct {
	PatternFill xlsxPatternFill `xml:"patternFill,omitempty"`
}

func (fill *xlsxFill) Marshal() (result string, err error) {
	if fill.PatternFill.PatternType != "" {
		var xpatternFill string
		result = `<fill>`

		xpatternFill, err = fill.PatternFill.Marshal()
		if err != nil {
			return
		}
		result += xpatternFill
		result += `</fill>`
	}
	return
}

// xlsxPatternFill directly maps the patternFill element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxPatternFill struct {
	PatternType string    `xml:"patternType,attr,omitempty"`
	FgColor     xlsxColor `xml:"fgColor,omitempty"`
	BgColor     xlsxColor `xml:"bgColor,omitempty"`
}

func (patternFill *xlsxPatternFill) Marshal() (result string, err error) {
	result = fmt.Sprintf(`<patternFill patternType="%s"`, patternFill.PatternType)
	ending := `/>`
	subparts := ""
	if patternFill.FgColor.RGB != "" {
		ending = `>`
		subparts += fmt.Sprintf(`<fgColor rgb="%s"/>`, patternFill.FgColor.RGB)
	}
	if patternFill.BgColor.RGB != "" {
		ending = `>`
		subparts += fmt.Sprintf(`<bgColor rgb="%s"/>`, patternFill.BgColor.RGB)
	}
	result += ending
	result += subparts
	result += `</patternFill>`
	return
}

// xlsxColor is a common mapping used for both the fgColor and bgColor
// elements in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxColor struct {
	RGB string `xml:"rgb,attr,omitempty"`
}

// xlsxBorders directly maps the borders element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxBorders struct {
	Count  int          `xml:"count,attr"`
	Border []xlsxBorder `xml:"border,omitempty"`
}

func (borders *xlsxBorders) Marshal(outputBorderMap map[int]int) (result string, err error) {
	result = ""
	emittedCount := 0
	subparts := ""
	for i, border := range borders.Border {
		var xborder string
		xborder, err = border.Marshal()
		if err != nil {
			return
		}
		if xborder != "" {
			outputBorderMap[i] = emittedCount
			emittedCount += 1
			subparts += xborder
		}
	}
	if emittedCount > 0 {
		result += fmt.Sprintf(`<borders count="%d">`, emittedCount)
		result += subparts
		result += `</borders>`
	}
	return
}

// xlsxBorder directly maps the border element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxBorder struct {
	Left   xlsxLine `xml:"left,omitempty"`
	Right  xlsxLine `xml:"right,omitempty"`
	Top    xlsxLine `xml:"top,omitempty"`
	Bottom xlsxLine `xml:"bottom,omitempty"`
}

func (border *xlsxBorder) Marshal() (result string, err error) {
	emit := false
	subparts := ""
	if border.Left.Style != "" {
		emit = true
		subparts += fmt.Sprintf(`<left style="%s"/>`, border.Left.Style)
	}
	if border.Right.Style != "" {
		emit = true
		subparts += fmt.Sprintf(`<right style="%s"/>`, border.Right.Style)
	}
	if border.Top.Style != "" {
		emit = true
		subparts += fmt.Sprintf(`<top style="%s"/>`, border.Top.Style)
	}
	if border.Bottom.Style != "" {
		emit = true
		subparts += fmt.Sprintf(`<bottom style="%s"/>`, border.Bottom.Style)
	}
	if emit {
		result += `<border>`
		result += subparts
		result += `</border>`
	}
	return
}

// xlsxLine directly maps the line style element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxLine struct {
	Style string `xml:"style,attr,omitempty"`
}

// xlsxCellStyleXfs directly maps the cellStyleXfs element in the
// namespace http://schemas.openxmlformats.org/spreadsheetml/2006/main
// - currently I have not checked it for completeness - it does as
// much as I need.
type xlsxCellStyleXfs struct {
	Count int      `xml:"count,attr"`
	Xf    []xlsxXf `xml:"xf,omitempty"`
}

func (cellStyleXfs *xlsxCellStyleXfs) Marshal(outputBorderMap, outputFillMap, outputFontMap map[int]int) (result string, err error) {
	if cellStyleXfs.Count > 0 {
		result = fmt.Sprintf(`<cellStyleXfs count="%d">`, cellStyleXfs.Count)
		for _, xf := range cellStyleXfs.Xf {
			var xxf string
			xxf, err = xf.Marshal(outputBorderMap, outputFillMap, outputFontMap)
			if err != nil {
				return
			}
			result += xxf
		}
		result += `</cellStyleXfs>`
	}
	return
}

// xlsxCellXfs directly maps the cellXfs element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxCellXfs struct {
	Count int      `xml:"count,attr"`
	Xf    []xlsxXf `xml:"xf,omitempty"`
}

func (cellXfs *xlsxCellXfs) Marshal(outputBorderMap, outputFillMap, outputFontMap map[int]int) (result string, err error) {
	if cellXfs.Count > 0 {
		result = fmt.Sprintf(`<cellXfs count="%d">`, cellXfs.Count)
		for _, xf := range cellXfs.Xf {
			var xxf string
			xxf, err = xf.Marshal(outputBorderMap, outputFillMap, outputFontMap)
			if err != nil {
				return
			}
			result += xxf
		}
		result += `</cellXfs>`
	}
	return
}

// xlsxXf directly maps the xf element in the namespace
// http://schemas.openxmlformats.org/spreadsheetml/2006/main -
// currently I have not checked it for completeness - it does as much
// as I need.
type xlsxXf struct {
	ApplyAlignment  bool          `xml:"applyAlignment,attr"`
	ApplyBorder     bool          `xml:"applyBorder,attr"`
	ApplyFont       bool          `xml:"applyFont,attr"`
	ApplyFill       bool          `xml:"applyFill,attr"`
	ApplyProtection bool          `xml:"applyProtection,attr"`
	BorderId        int           `xml:"borderId,attr"`
	FillId          int           `xml:"fillId,attr"`
	FontId          int           `xml:"fontId,attr"`
	NumFmtId        int           `xml:"numFmtId,attr"`
	alignment       xlsxAlignment `xml:"alignment"`
}

func (xf *xlsxXf) Marshal(outputBorderMap, outputFillMap, outputFontMap map[int]int) (result string, err error) {
	var xalignment string
	result = fmt.Sprintf(`<xf applyAlignment="%t" applyBorder="%t" applyFont="%t" applyFill="%t" applyProtection="%t" borderId="%d" fillId="%d" fontId="%d" numFmtId="%d">`, xf.ApplyAlignment, xf.ApplyBorder, xf.ApplyFont, xf.ApplyFill, xf.ApplyProtection, outputBorderMap[xf.BorderId], outputFillMap[xf.FillId], outputFontMap[xf.FontId], xf.NumFmtId)
	xalignment, err = xf.alignment.Marshal()
	if err != nil {
		return
	}
	result += xalignment
	result += `</xf>`
	return
}

type xlsxAlignment struct {
	Horizontal   string `xml:"horizontal,attr"`
	Indent       int    `xml:"indent,attr"`
	ShrinkToFit  bool   `xml:"shrinkToFit,attr"`
	TextRotation int    `xml:"textRotation,attr"`
	Vertical     string `xml:"vertical,attr"`
	WrapText     bool   `xml:"wrapText,attr"`
}

func (alignment *xlsxAlignment) Marshal() (result string, err error) {
	result = fmt.Sprintf(`<alignment horizontal="%s" indent="%d" shrinkToFit="%t" textRotation="%d" vertical="%s" wrapText="%t"/>`, alignment.Horizontal, alignment.Indent, alignment.ShrinkToFit, alignment.TextRotation, alignment.Vertical, alignment.WrapText)
	return
}