var txtReader = function(options) {
	this.version = "1.0.0.0";
	this.bookId = typeof (options.bookId) != "undefined" ? options.bookId : null;
	this.pageNum = typeof (options.pageNum) != "undefined" ? options.pageNum : null;
	this.totalPageNum = typeof (options.totalPageNum) != "undefined" ? options.totalPageNum : null;
	//已经加载的页面的第一章
	this.loadPageFirst = typeof (options.loadPageFirst) != "undefined" ? options.loadPageFirst : null;
	//已经加载的页面的最后一章
	this.loadPageLast = typeof (options.loadPageLast) != "undefined" ? options.loadPageLast : null;
};

txtReader.prototype = {
		
	/** 初始化 */
	initTxtReader : function() {
		this.loadPageComment(1);
		this.pagingSkip(null);
		this.bind();
	},
	
	/** 绑定事件 */
	bind : function() {
		$("div.page-container div.leftbar_w40 a").click(function() {
			$("div.unfold").hide();

			var obj = $(this).attr("obj");
			if (typeof (obj) == "undefined")
				return true;
			$("#" + obj).show();

			$("div.page-container div.leftbar_w40 a").each(function() {
				var v = $(this).attr("obj");
				if (v == undefined)
					return false;
				$(this).removeClass(v + "_on");
			});
			$(this).addClass(obj + "_on");
		});
		
		$("a.cross").click(function() {
			$("div.unfold").hide();
			$("div.page-container div.leftbar_w40 a").each(function() {
				var v = $(this).attr("obj");
				if (v == undefined)
					return false;
				$(this).removeClass(v + "_on");
			});
		});
		
		$(window).keydown(function(event) {
			switch (event.keyCode) {
			case 37:
				txtReader.pagingSkip(-1);
				break;
			case 39:
				txtReader.pagingSkip(0);
				break;
			}
		});
		
		$("#catalogList a").click(function() {
			var page = $(this).attr("page");
			if (typeof (page) == "undefined")
				return;
			txtReader.pagingSkip(Number(page));
		});
		
		$("#currPage").keydown(function(event) {
			if (event.keyCode == 13) {
				txtReader.pagingSkip(Number($(this).val()));
			}
		});
		
		$("#controlContainer").scroll(function() {
			txtReader.pagingScroll();
		});
	},
	
	/** 加载评论 */
	loadPageComment : function(currPage) {
		webDwr.getBookComment(this.bookId, currPage, 0, function(info) {
			var jsonArr = eval("(" + info + ")");
			var comments = "";
			for (var i = 0; i < jsonArr["comments"].length; i++) {
				comments += "<li> <img title=\"" + jsonArr["comments"][i].user
						+ "\" src=\"" + jsonArr["comments"][i].portraint
						+ "\">";
				comments += "<div class=\"right\"><div>"
						+ jsonArr["comments"][i].content + "</div>";
				comments += "<div class=\"time\"><span>"
						+ jsonArr["comments"][i].user + "</span>";
				comments += "<span class=\"fright\">"
						+ jsonArr["comments"][i].pubTime
						+ "</span></div></div></li>";
			}
			document.getElementById("commentList").innerHTML = comments;
		});
	},
	
	/** 内容区滚动 */
	pagingScroll : function() {
		var obj = $("#controlContainer");
		var divHeight = $(obj).height();
		var divPaddingTop = parseInt($(obj).css("padding-top"));
		var divPaddingBottom = parseInt($(obj).css("padding-bottom"));
		var nScrollHeight = $(obj)[0].scrollHeight;
		var nScrollTop = $(obj)[0].scrollTop;

		if(nScrollTop <= 0 && this.loadPageFirst > 1) {
			this.loadPageFirst--;
			this.pageNum = this.loadPageFirst;
			this.prependContext(this.loadPageFirst);
		} else if((nScrollTop + divHeight + divPaddingTop + divPaddingBottom) >= nScrollHeight 
				&& this.loadPageLast < this.totalPageNum) {
			this.loadPageLast++;
			this.pageNum = this.loadPageLast;
			this.appendContext(txtReader.loadPageLast);
		}
		$("#currPage").val(this.pageNum);
		this.selectSection(nScrollTop);
	},
	
	/** 选择章节 */
	selectSection : function(nScrollTop) {
		var nScrollHeight = 0;
		
		$("#controlContainer div.txtChapter").each(function() {
			var chapterHeight = $(this).height();
			if(nScrollTop >= nScrollHeight && nScrollTop <= (nScrollHeight + chapterHeight)) {
				var pageNum = $(this).attr("objPageNum");
				$("#currPage").val(pageNum);
				var section = $("#catalogList a[page='" + pageNum + "']").html();
				$("#section").html(section);
				txtReader.pageNum = parseInt(pageNum);
				nScrollHeight += chapterHeight;
				return true;
			}
			nScrollHeight += chapterHeight;
		});
	},
	
	/** 加载指定页面 */
	pagingSkip : function(pageNum) {
		if (pageNum != null && pageNum != -1 && pageNum != 0) {
			if(pageNum > this.totalPageNum) {
				this.pageNum = this.totalPageNum;
			} else if(pageNum <= 0) {
				this.pageNum = 1;
			} else {
				this.pageNum = pageNum;
			}
		} else if (pageNum == -1) {
			if (this.pageNum > 1)
				this.pageNum = this.pageNum - 1;
			else
				return;
		} else if (pageNum == 0) {
			if (this.pageNum == this.totalPageNum)
				return;
			else
				this.pageNum = this.pageNum + 1;
		}
		$("#currPage").val(this.pageNum);
				
		webDwr.getTxtBookContent4Screen(this.bookId, this.pageNum, function(info) {
			var pageNum = $("#currPage").val();
			var html = "<div class='txtChapter' objPageNum='";
			html += pageNum + "'>"
			if (info.indexOf("\"content\":") < 0) {
				html += info;
			} else {
				var jsonArr = eval("(" + info + ")");
				if (jsonArr.title) {
					$("#section").html(jsonArr.title);
					html += "<b>&nbsp;&nbsp;&nbsp;&nbsp;" 
					html += jsonArr.title + "</b><br></br>";
					html += jsonArr.content;
				}
			}
			html += "</div>";
			$("#controlContainer").html(html);
			txtReader.loadPageFirst = txtReader.pageNum;
			txtReader.loadPageLast = txtReader.pageNum;
						
			var obj = document.getElementById("controlContainer");
			if(obj.scrollHeight <= obj.clientHeight ) {
				$("#controlContainer").attr("loadStatus", "0");
				txtReader.appendContext();
			} else {
				$("#controlContainer").attr("loadStatus", "1");
				obj.scrollTop = 10;
			}
		});
	},
	
	/** 向后追加章节 */
	appendContext: function(pageNum) {
		if(!pageNum) {
			if(this.loadPageLast >= this.totalPageNum) {
				return;
			} else {
				pageNum = this.loadPageLast + 1;
			}
		}
				
		webDwr.getTxtBookContent4Screen(this.bookId, pageNum, function(info) {
			var html = "<div class='txtChapter' objPageNum='";
			html += pageNum + "'>"
			if (info.indexOf("\"content\":") < 0) {
				html += info;
			} else {
				var jsonArr = eval("(" + info + ")");
				if (jsonArr.title) {
					html += "<b>&nbsp;&nbsp;&nbsp;&nbsp;" 
					html += jsonArr.title + "</b><br></br>";
					html += jsonArr.content;
				}
			}
			html += "</div>";

			$("#controlContainer").append(html);
			txtReader.loadPageLast = pageNum;
			
			var loadStatus = $("#controlContainer").attr("loadStatus");
			var obj = document.getElementById("controlContainer");
			if(loadStatus == "0") {
				if(obj.scrollHeight <= obj.clientHeight ) {
					txtReader.appendContext();
				} else {
					$("#controlContainer").attr("loadStatus", "1");
					obj.scrollTop = 10;
				}
			}
		});
			
	},

	/** 向前追加长章节 */
	prependContext: function(pageNum) {
		if(!pageNum) {
			if(this.loadPageFirst <= 1){
				return;
			} else {
				pageNum = this.loadPageFirst - 1;
			}
		}
			
		webDwr.getTxtBookContent4Screen(this.bookId, pageNum, function(info) {
			var html = "<div class='txtChapter' objPageNum='";
			html += pageNum + "'>"
			if (info.indexOf("\"content\":") < 0) {
				html += info;
			} else {
				var jsonArr = eval("(" + info + ")");
				if (jsonArr.title) {
					html += "<b>&nbsp;&nbsp;&nbsp;&nbsp;" 
					html += jsonArr.title + "</b><br></br>";
					html += jsonArr.content;
				}
			}
			html += "</div>";
			$("#controlContainer").prepend(html);
			txtReader.loadPageFirst = pageNum;

			var nScrollTop = $("#controlContainer div.txtChapter").eq(0).height();
			document.getElementById("controlContainer").scrollTop = nScrollTop + 10;
		});
	},

	/**  添加评论 */
	addComment : function() {
		var content = $("#commentContext").val();
		if (content == "") {
			alert("请输入评论内容！");
			return;
		}
		if (content.length > 1000) {
			alert("评论内容不能超过1000字！你现在输入的内容有" + content.length + "个字");
			return;
		}
		webDwr.addBookComment(this.bookId, content, function(info) {
			if (info != "") {
				if (info == "noLogged") {
					alert("请登录后再发表评论");
					return;
				}
				txtReader.loadPageComment(1);
				$("#commentContext").val("");
			}
		});
	}
};

var resetTxtContent = function() {
	var h = $(window).height() - 127;
	$("#controlContainer").height(h-51);
	$("#catalog").height(h - 31);
	$("#comment").height(h - 31);
	$("#catalogList").height(h - 83);
	//$("#noteList").height(h - 81);
	$("#commentList").height(h - 113);
};