/**
 * 需要 ExcelJS 套件
 * 提供一些 function，可以把呼叫 ExcelJS 的方法，把 html 的 table 轉成 excel
 */

// let namespace = window.exhelper;

(function (ns) {
    'use strict';

    // create a self-reference
    var _self = ns;

    /**
     * 以 0 為起始的行、列座標
     * @param {Number} col 行座標
     * @param {Number} row 列座標
     */
    _self.CellCoordinate = function (col, row) {
        this.col = col || 0;
        this.row = row || 0;
    }

    /**
     * 每格的資料
     * @param {String} addr 位址 (A1, A2...)
     * @param {Any} val 值
     * @param {Object} style 格式
     * @param {Number} type 型別 (預設 3 string)
     */
    _self.CellData = function(addr, val, style, type){
        this.address = addr || "";
        this.value = val || "";
        this.style = style || {};
        this.type = type || 3;
    }

    /**
     * 合併欄位的資料
     * @param {Number} top
     * @param {Number} left
     * @param {Number} bottom
     * @param {Number} right
     */
    _self.MergedRange = function(top, left, bottom, right){
        this.top = top || 0;
        this.left = left || 0;
        this.bottom = bottom || 0;
        this.right = right || 0;
    }

    /**
     * 傳入 CellCoordinate { col: 0, row: 0 } 回傳 A1 
     * @param {CellCoordinate} coordinate
     * @return {String} 格位標記
     */
    _self.parseCelltoTag = function (coordinate) {
        if (parseInt(coordinate.col) < 0) {
            console.log("傳入參數有誤，Coordinate 的 col 要大於 0");
            return;
        }

        return _self.getAlphabetByInt(parseInt(coordinate.col)) + (parseInt(coordinate.row) + 1);

    }

    /**
     * 傳入數字，回傳對應的字母 ( 0=>A, 1=>B...)
     * @param {Number} idx 要對應的數字
     * @param {Number} alphabetBase 要用幾個字母去對應，預設 26，最大 26 
     */
    _self.getAlphabetByInt = function (idx, alphabetBase) {

        if (!alphabetBase)
            alphabetBase = 26;

        let alphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

        // 在 base 內，一個字母就可以處理
        if (idx < alphabetBase) {
            return alphabets.charAt(idx);
        }

        let result = "";

        let quotient = idx;

        while (quotient >= alphabetBase) {

            let mod = quotient % alphabetBase;

            quotient = Math.floor(idx / alphabetBase);

            result = alphabets.charAt(mod) + result;

        }

        // 最後一碼
        result = alphabets.charAt(quotient - 1) + result;

        return result;

    }


    /**
     * 傳入字母，回傳對應的數值 ( A=>0, B=>2...)
     * @param {String} a 要對應的字串
     * @param {Number} alphabetBase 要用幾個字母去對應，預設 26，最大 26
     */
    _self.getIdxByAlphbet = function (a, alphabetBase) {
        if (!alphabetBase)
            alphabetBase = 26;

        let alphabets = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

        // 全部轉大寫
        a = a.toUpperCase();

        let result = 0;

        for (let i = 0; i < a.length; i++) {
            // 如果是第二碼以上，就要加 1 再去乘
            let modifier = (i == 0) ? 0 : 1;
            result += (alphabets.indexOf(a.charAt(a.length - (i + 1))) + modifier) * Math.pow(alphabetBase, i);
        }

        return result;

    }

    /**
     * 傳入格位代碼，回傳以 0 起始的座標物件
     * @param {String} tag 格位代碼 (A1, A2...)
     * @return {CellCoordinate} { col: 0, row: 0}
     */
    _self.parseCelltoCoordinate = function (tag) {

        let re = /([A-Za-z])(\d+)/;
        let match = tag.match(re);

        return new _self.CellCoordinate(_self.getIdxByAlphbet(match[1]), parseInt(match[2]) - 1);

    }

    /**
     * 儲存 Blob 資料至下載檔案
     * @param {String} fileName 檔案名稱(含副檔名)
     * @param {object} byte 檔案內容 byte 陣列
     */
    _self.saveBlob = function (fileName, byte) {
        var blob = new Blob([byte], {
            type: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
        });
        if (window.navigator && window.navigator.msSaveOrOpenBlob) {
            // for IE
            window.navigator.msSaveOrOpenBlob(blob, fileName);
        } else {
            // for other browsers
            var url = window.URL.createObjectURL(blob, {
                type: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
            });
            /*
            var a = $("<a style='display: none;'/>");
            a.attr("href", url);
            a.attr("download", fileName);
            $("body").append(a);
            a[0].click();
            window.URL.revokeObjectURL(url);
            a.remove();
            */

            var a = document.createElement("a");
            a.style.display = "none";
            a.setAttribute("href", url);
            a.setAttribute("download", fileName);
            document.body.appendChild(a);
            a.click();
            window.URL.revokeObjectURL(url);
            a.remove();
        }
    }

    /**
     * 將 ExcelJS.Workbook 物件存成 excel 檔案，並開始下載
     * @param {String} filename 檔案名稱含副檔名
     * @param {object} Workbook 物件
     */
    _self.saveXlsx = function (filename, wb) {
        wb.xlsx.writeBuffer().then(
            function (result) {
                _self.saveBlob(filename, result);
            },
            function (err) {
                console.log("error: ", err);
            }
        );
    }


    /**
     * 傳入 table 物件，回傳 ExcelJS.Workbook 物件
     * @param {object} elt table 物件
     * @param {object} opt 屬性設定 => { sheet: "sheet 名稱 預設 Sheet1" }
     * @return {object} ExcelJS.Workbook 物件
     */
    _self.tableToBook = function (elt, opt) {

        if (!opt)
            opt = {};

        // 沒有這個方法 => 可能是 jquery 物件，要轉成原始的 html 物件
        if (!elt.getElementsByTagName)
            elt = elt.get(0);

        var wb = new ExcelJS.Workbook();

        wb.creator = "gamapay";
        wb.lastModifiedBy = "gamapay";
        wb.created = new Date();
        wb.modified = new Date();

        let sheetName = opt.sheet || "Sheet1";

        // Set workbook dates to 1904 date system
        wb.properties.date1904 = true;

        var ws = wb.addWorksheet(sheetName);

        var rows = elt.getElementsByTagName("tr");

        var mergedCells = new Array(rows.length);

        for (let i = 0; i < rows.length; i++) {
            // 取得格位資料
            var cols = rows[i].querySelectorAll("th,td");

            // 計算要右移幾格 (因為合併)
            let shiftCell = 0;

            for (let j = 0; j < cols.length; j++) {
                let colElem = cols[j];
                let colspan = colElem.getAttribute("colspan");
                let rowspan = colElem.getAttribute("rowspan");

                let colValue = colElem.innerHTML;
                // 如果有值，就進行移除所有的 html tag 運算
                if (colValue) {
                    colValue = colValue.replace(/<\/?[^>]+(>|$)/g, "");
                }

                // 初始化本列的合併格位陣列 (如果是合併列的話，可能已經有初始化了)
                if (!mergedCells[i])
                    mergedCells[i] = [];

                // 檢查目前的格位有沒有在合併欄位中，有的話就右移一格
                while (mergedCells[i].indexOf(j + shiftCell) >= 0) {
                    shiftCell++;
                }

                // 目前的格位 (位移後)
                let currCell = new _self.CellCoordinate(j + shiftCell, i);

                // 轉成 tag
                let currTag = _self.parseCelltoTag(currCell);

                // 設定本格的值
                ws.getCell(currTag).value = colValue;

                // 是否有合併欄位
                let hasMerge = false;

                // 要合併欄位
                let toCell = new _self.CellCoordinate(j + shiftCell, i);

                if (colspan && colspan != 1) {
                    hasMerge = true;
                    toCell.col += parseInt(colspan) - 1;
                }

                if (rowspan && rowspan != 1) {
                    hasMerge = true;
                    toCell.row += parseInt(rowspan) - 1;
                }


                if (hasMerge) {
                    // 把合併的欄位加到陣列中
                    for (let idr = currCell.row; idr <= toCell.row; idr++) {
                        // 如果是列之間的合併格位，會遇到還沒有初始化，所以在這要初始化
                        if (!mergedCells[idr])
                            mergedCells[idr] = [];
                        for (let idx = currCell.col; idx <= toCell.col; idx++) {
                            // 將合併的欄位加到陣列中
                            mergedCells[idr].push(idx);
                        }
                    }

                    // 將要合併的欄位轉成 tag
                    let toTag = _self.parseCelltoTag(toCell);
                    // 進行合併
                    ws.mergeCells(currTag + ":" + toTag);

                }

            }
        }

        return wb;
    }

    /**
     * 在指定位置插入指定行數的空行
     * @param {Object} sheet Worksheet object
     * @param {Number} pos 要插入的位置
     * @param {Number} cnt 要插入幾行
     */
    _self.insertRows = function (sheet, pos, cnt){

        // 建立要合併的欄位
        var merged = [];
        
        for(let cell in sheet._merges){
            let model = sheet._merges[cell].model;

            let range = new _self.MergedRange(model.top, model.left, model.bottom, model.right);

            merged.push(range);
            
            // 清除 merge 資訊
            sheet.unMergeCells(cell);
        }


        // 紀錄所有格位資料
        let cells = [];
        sheet.eachRow(function(row, rowNumber) {
            row.eachCell(function(cell, colNumber){
                let model = cell._value.model;
                let cellData = new _self.CellData(model.address, model.value, model. style, model.type); 
                cells.push(cellData);
            });
        });


        // 清空所有資料
        sheet._rows = [];
        sheet._columns = [];

        for(let i = 0; i < cells.length; i++){
            let cell = cells[i];

            let cellCoordinate = _self.parseCelltoCoordinate(cell.address);

            // col 原則上不會變
            let newCol = cellCoordinate.col + 1;
            let newRow = cellCoordinate.row + 1;

            // row 依插入幾行而變
            if(newRow >= pos){
                newRow = newRow + cnt;
            }

            // 將原本的值寫入
            sheet.getRow(newRow).getCell(newCol).value = cell.value;

        }

        // 重新 merge
        for(let i = 0; i < merged.length; i++){
            let range = merged[i];

            // 如果插入的行在merge行的中間，那就不進行merge
            if(range.top > pos && range.bottom <= pos)
                continue;

            // 原本合併的行在插入行之下，下移指定行數
            // ，在插入行之上，維持不變
            if(range.top >= pos){
                range.top += cnt;
                range.bottom += cnt;
            }

            // 進行合併
            sheet.mergeCells(range.top, range.left, range.bottom, range.right);
        }
    }
    /**
     * 為 worksheet 物件增加表頭
     * @param {object} sheet ExcelJS.Worksheet 物件
     * @param {String} title 表頭
     */
    _self.addTitle = function (sheet, title) {

        _self.insertRows(sheet, 1, 1);

        // 插入表頭
        sheet.mergeCells(1, 1, 1, sheet.columnCount);
        let titleCell = sheet.getRow(1).getCell(1);
        titleCell.value = title;
        titleCell.alignment = { vertical: 'middle', horizontal: 'center' };
        titleCell.font = { bold: true };
    }

    /**
     * 合併兩個 sheet
     * @param {object} fromSheet
     * @param {object} toSheet
     * @param {Number} rowSeperate
     */
    _self.mergeSheets = function(fromSheet, toSheet, rowSeperate){

        // 兩個 table 之間的空行數
        let seperate = rowSeperate + 1;

        // fromSheet 新的開始行
        let startRow = toSheet.rowCount + 1 + rowSeperate;

        for (let r = 1; r <= fromSheet.rowCount; r++) {
            for (let c = 1; c <= fromSheet.columnCount; c++) {

                let newRow = r + startRow;

                toSheet.getRow(newRow).getCell(c).value = fromSheet.getRow(r).getCell(c).value;

            }
        }

        // 建立要合併的欄位
        var merged = [];

        for (let cell in fromSheet._merges) {
            let model = fromSheet._merges[cell].model;

            let range = new _self.MergedRange(model.top, model.left, model.bottom, model.right);

            merged.push(range);
        }

        for (let i = 0; i < merged.length; i++) {
            let range = merged[i];
            toSheet.mergeCells(range.top + startRow, range.left, range.bottom + startRow, range.right);
        }

    }


    // reasign everything just incase
    _self = ns;


})(window.exhelper = window.exhelper || {});