const fs = require('fs');
const path = require('path');

let MainRunner = {
	sourcePath: process.argv[2],
	destPath: process.argv[3],
	
	start() {
		// 非绝对路径则前缀加上当前目录
		if (!path.isAbsolute(this.sourcePath)) {
            this.sourcePath = path.join(__dirname, this.sourcePath);
        }
		if (!path.isAbsolute(this.destPath)) {
            this.destPath = path.join(__dirname, this.destPath);
		}
		
		this.delAllFiles(this.destPath); // 先删除旧文件
		this.traversalDir(this.sourcePath, this.destPath);
	},
	
	// 删除目录下所有文件
	delAllFiles(path) {
		if (fs.existsSync(path)) {
			let files = fs.readdirSync(path);
			files.forEach((file, index) => {
				let curPath = path + '/' + file;
				if (!fs.statSync(curPath).isDirectory()) {
					fs.unlinkSync(curPath);
				}
			});
		}
	},
	
	// 遍历文件夹找到
	traversalDir: function(srcDir, destDir) {
		let files = [];
		if ( fs.existsSync(srcDir) ) {    //判断给定的路径是否存在
			files = fs.readdirSync(srcDir);    //返回文件和子目录的数组
			for (let i = 0, len = files.length; i < len; i++) {
				let file = files[i];
				let srcFile = path.join(srcDir, file);
				let destFile = path.join(destDir, file);

				let baseName = path.basename(srcFile, '.json');
				let names = baseName.split('_');
				if (names[0] !== 'track') {
					continue;
				}
			
				fs.readFile(srcFile, (err, data) => {
					if (err) {
						console.error(err);
						return;
					}

					//console.log('Success to read file: ' +srcFile);

					let strTrack = this.convertTrack(data);
					if (!strTrack || strTrack.length <= 0) {
						console.log('track is invalid: ' +srcFile);
						return;
					}

					fs.writeFile(destFile, strTrack, (err) => {
						if (err) {
							console.error(err);
							return;
						}
						//console.log('Success to write file: ' +destFile);
					});
				});

			}
		}
		return files;
	},

	convertTrack(data) {
		let str = '';
        try {
			let track = JSON.parse(data);
			str += '"';
			for (let i = 0, len = track.length; i < len; i++) {
                str += track[i].fishId + ';';
                str += track[i].pathId + ';';
                str += track[i].enterTime + ';';
                str += track[i].exitTime;
                if ((i+1) < len) {
                    str += '#';
                }
            }
            str += '"';
        } catch(e) {
            console.error('convertTrack: error to convert track');
        }

        return str;
	},

};

module.exports = MainRunner;

MainRunner.start();