Huge refactorig for consistent col/row numbering (#356)

* Huge refactorig for consistent col/row numbering

Started from simply changing ToALphaString()/TitleToNumber() logic and related fixes.
But have to go deeper, do fixes, after do related fixes and again and again.

Major improvements:

1. Tests made stronger again (But still be weak).
2. "Empty" returns for incorrect input replaces with panic.
3. Check for correct col/row/cell naming & addressing by default.
4. Removed huge amount of duplicated code.
5. Removed ToALphaString(), TitleToNumber() and it helpers functions at all,
and replaced with SplitCellName(), JoinCellName(), ColumnNameToNumber(), ColumnNumberToName(), CellNameToCoordinates(), CoordinatesToCellName().
6. Minor fixes for internal variable naming for code readability (ex. col, row for input params, colIdx, rowIdx for slice indexes etc).

* Formatting fixes

1 files changed, 229 insertions, 0 deletions

diff --git a/adjust.go b/adjust.go
new file mode 100644
index 0000000..ee2065f
--- /dev/null
+++ b/adjust.go
@@ -0,0 +1,229 @@
+package excelize
+
+import (
+	"strings"
+)
+
+type adjustDirection bool
+
+const (
+	columns adjustDirection = false
+	rows    adjustDirection = true
+)
+
+// adjustHelper provides a function to adjust rows and columns dimensions,
+// hyperlinks, merged cells and auto filter when inserting or deleting rows or
+// columns.
+//
+// sheet: Worksheet name that we're editing
+// column: Index number of the column we're inserting/deleting before
+// row: Index number of the row we're inserting/deleting before
+// offset: Number of rows/column to insert/delete negative values indicate deletion
+//
+// TODO: adjustCalcChain, adjustPageBreaks, adjustComments,
+// adjustDataValidations, adjustProtectedCells
+//
+func (f *File) adjustHelper(sheet string, dir adjustDirection, num, offset int) {
+	xlsx := f.workSheetReader(sheet)
+
+	if dir == rows {
+		f.adjustRowDimensions(xlsx, num, offset)
+	} else {
+		f.adjustColDimensions(xlsx, num, offset)
+	}
+	f.adjustHyperlinks(xlsx, sheet, dir, num, offset)
+	f.adjustMergeCells(xlsx, dir, num, offset)
+	f.adjustAutoFilter(xlsx, dir, num, offset)
+
+	checkSheet(xlsx)
+	checkRow(xlsx)
+}
+
+// adjustColDimensions provides a function to update column dimensions when
+// inserting or deleting rows or columns.
+func (f *File) adjustColDimensions(xlsx *xlsxWorksheet, col, offset int) {
+	for rowIdx := range xlsx.SheetData.Row {
+		for colIdx, v := range xlsx.SheetData.Row[rowIdx].C {
+			cellCol, cellRow, _ := CellNameToCoordinates(v.R)
+			if col <= cellCol {
+				if newCol := cellCol + offset; newCol > 0 {
+					xlsx.SheetData.Row[rowIdx].C[colIdx].R, _ = CoordinatesToCellName(newCol, cellRow)
+				}
+			}
+		}
+	}
+}
+
+// adjustRowDimensions provides a function to update row dimensions when
+// inserting or deleting rows or columns.
+func (f *File) adjustRowDimensions(xlsx *xlsxWorksheet, row, offset int) {
+	for i, r := range xlsx.SheetData.Row {
+		if newRow := r.R + offset; r.R >= row && newRow > 0 {
+			f.ajustSingleRowDimensions(&xlsx.SheetData.Row[i], newRow)
+		}
+	}
+}
+
+// ajustSingleRowDimensions provides a function to ajust single row dimensions.
+func (f *File) ajustSingleRowDimensions(r *xlsxRow, num int) {
+	r.R = num
+	for i, col := range r.C {
+		colName, _, _ := SplitCellName(col.R)
+		r.C[i].R, _ = JoinCellName(colName, num)
+	}
+}
+
+// adjustHyperlinks provides a function to update hyperlinks when inserting or
+// deleting rows or columns.
+func (f *File) adjustHyperlinks(xlsx *xlsxWorksheet, sheet string, dir adjustDirection, num, offset int) {
+	// short path
+	if xlsx.Hyperlinks == nil || len(xlsx.Hyperlinks.Hyperlink) == 0 {
+		return
+	}
+
+	// order is important
+	if offset < 0 {
+		for rowIdx, linkData := range xlsx.Hyperlinks.Hyperlink {
+			colNum, rowNum, _ := CellNameToCoordinates(linkData.Ref)
+
+			if (dir == rows && num == rowNum) || (dir == columns && num == colNum) {
+				f.deleteSheetRelationships(sheet, linkData.RID)
+				if len(xlsx.Hyperlinks.Hyperlink) > 1 {
+					xlsx.Hyperlinks.Hyperlink = append(xlsx.Hyperlinks.Hyperlink[:rowIdx],
+						xlsx.Hyperlinks.Hyperlink[rowIdx+1:]...)
+				} else {
+					xlsx.Hyperlinks = nil
+				}
+			}
+		}
+	}
+
+	if xlsx.Hyperlinks == nil {
+		return
+	}
+
+	for i := range xlsx.Hyperlinks.Hyperlink {
+		link := &xlsx.Hyperlinks.Hyperlink[i] // get reference
+		colNum, rowNum, _ := CellNameToCoordinates(link.Ref)
+
+		if dir == rows {
+			if rowNum >= num {
+				link.Ref, _ = CoordinatesToCellName(colNum, rowNum+offset)
+			}
+		} else {
+			if colNum >= num {
+				link.Ref, _ = CoordinatesToCellName(colNum+offset, rowNum)
+			}
+		}
+	}
+}
+
+// adjustAutoFilter provides a function to update the auto filter when
+// inserting or deleting rows or columns.
+func (f *File) adjustAutoFilter(xlsx *xlsxWorksheet, dir adjustDirection, num, offset int) {
+	if xlsx.AutoFilter == nil {
+		return
+	}
+
+	rng := strings.Split(xlsx.AutoFilter.Ref, ":")
+	firstCell := rng[0]
+	lastCell := rng[1]
+
+	firstCol, firstRow, err := CellNameToCoordinates(firstCell)
+	if err != nil {
+		panic(err)
+	}
+
+	lastCol, lastRow, err := CellNameToCoordinates(lastCell)
+	if err != nil {
+		panic(err)
+	}
+
+	if (dir == rows && firstRow == num && offset < 0) || (dir == columns && firstCol == num && lastCol == num) {
+		xlsx.AutoFilter = nil
+		for rowIdx := range xlsx.SheetData.Row {
+			rowData := &xlsx.SheetData.Row[rowIdx]
+			if rowData.R > firstRow && rowData.R <= lastRow {
+				rowData.Hidden = false
+			}
+		}
+		return
+	}
+
+	if dir == rows {
+		if firstRow >= num {
+			firstCell, _ = CoordinatesToCellName(firstCol, firstRow+offset)
+		}
+		if lastRow >= num {
+			lastCell, _ = CoordinatesToCellName(lastCol, lastRow+offset)
+		}
+	} else {
+		if lastCol >= num {
+			lastCell, _ = CoordinatesToCellName(lastCol+offset, lastRow)
+		}
+	}
+
+	xlsx.AutoFilter.Ref = firstCell + ":" + lastCell
+}
+
+// adjustMergeCells provides a function to update merged cells when inserting
+// or deleting rows or columns.
+func (f *File) adjustMergeCells(xlsx *xlsxWorksheet, dir adjustDirection, num, offset int) {
+	if xlsx.MergeCells == nil {
+		return
+	}
+
+	for i, areaData := range xlsx.MergeCells.Cells {
+		rng := strings.Split(areaData.Ref, ":")
+		firstCell := rng[0]
+		lastCell := rng[1]
+
+		firstCol, firstRow, err := CellNameToCoordinates(firstCell)
+		if err != nil {
+			panic(err)
+		}
+
+		lastCol, lastRow, err := CellNameToCoordinates(lastCell)
+		if err != nil {
+			panic(err)
+		}
+
+		adjust := func(v int) int {
+			if v >= num {
+				v += offset
+				if v < 1 {
+					return 1
+				}
+				return v
+			}
+			return v
+		}
+
+		if dir == rows {
+			firstRow = adjust(firstRow)
+			lastRow = adjust(lastRow)
+		} else {
+			firstCol = adjust(firstCol)
+			lastCol = adjust(lastCol)
+		}
+
+		if firstCol == lastCol && firstRow == lastRow {
+			if len(xlsx.MergeCells.Cells) > 1 {
+				xlsx.MergeCells.Cells = append(xlsx.MergeCells.Cells[:i], xlsx.MergeCells.Cells[i+1:]...)
+				xlsx.MergeCells.Count = len(xlsx.MergeCells.Cells)
+			} else {
+				xlsx.MergeCells = nil
+			}
+		}
+
+		if firstCell, err = CoordinatesToCellName(firstCol, firstRow); err != nil {
+			panic(err)
+		}
+
+		if lastCell, err = CoordinatesToCellName(lastCol, lastRow); err != nil {
+			panic(err)
+		}
+
+		areaData.Ref = firstCell + ":" + lastCell
+	}
+}