$.namespace('azkaban');

azkaban.LogDataModel = Backbone.Model.extend({
    TIMESTAMP_REGEX: /^.*? - /gm,

    JOB_TRACKER_URL_REGEX: /https?:\/\/[-\w\.]+(?::\d+)?\/[\w\/\.]*\?\S+(job_\d{12}_\d{4,})\S*/,

    // Command properties
    COMMAND_START: "Command: ",
    CLASSPATH_REGEX: /(?:-cp|-classpath)\s+(\S+)/g,
    ENVIRONMENT_VARIABLES_REGEX: /-D(\S+)/g,
    JVM_MEMORY_REGEX: /(-Xm\S+)/g,
    PIG_PARAMS_REGEX: /-param\s+(\S+)/g,

    JOB_TYPE_REGEX: /Building (\S+) job executor/,

    PIG_JOB_SUMMARY_START: "HadoopVersion",
    PIG_JOB_STATS_START: "Job Stats (time in seconds):",

    HIVE_PARSING_START: "Parsing command: ",
    HIVE_PARSING_END: "Parse Completed",
    HIVE_NUM_MAP_REDUCE_JOBS_STRING: "Total MapReduce jobs = ",
    HIVE_MAP_REDUCE_JOB_START: "Starting Job",
    HIVE_MAP_REDUCE_JOBS_SUMMARY: "MapReduce Jobs Launched:",
    HIVE_MAP_REDUCE_SUMMARY_REGEX: /Job (\d+): Map: (\d+)  Reduce: (\d+)   HDFS Read: (\d+) HDFS Write: (\d+)/,

    initialize: function() {
        this.set("offset", 0 );
        this.set("logData", "");
        this.on("change:logData", this.parseLogData);
    },

    refresh: function() {
        var requestURL = contextURL + "/executor"; 
        var finished = false;

        var date = new Date();
        var startTime = date.getTime();
        
        while (!finished) {
            var requestData = {
                "execid": execId,
                "jobId": jobId,
                "ajax":"fetchExecJobLogs",
                "offset": this.get("offset"),
                "length": 50000,
                "attempt": attempt
            };

            var self = this;

            var successHandler = function(data) {
                console.log("fetchLogs");
                if (data.error) {
                    console.log(data.error);
                    finished = true;
                }
                else if (data.length == 0) {
                    finished = true;
                }
                else {
                    var date = new Date();
                    var endTime = date.getTime();
                    if ((endTime - startTime) > 10000) {
                        finished = true;
                        showDialog("Alert","The log is taking a long time to finish loading. Azkaban has stopped loading them. Please click Refresh to restart the load.");
                    }

                    self.set("offset", data.offset + data.length);
                    self.set("logData", self.get("logData") + data.data);
                }
            }

            $.ajax({
                url: requestURL,
                type: "get",
                async: false,
                data: requestData,
                dataType: "json",
                error: function(data) {
                    console.log(data);
                    finished = true;
                },
                success: successHandler
            });
        }
    },

    parseLogData: function() {
        var data = this.get("logData").replace(this.TIMESTAMP_REGEX, "");
        var lines = data.split("\n");

        if (this.parseCommand(lines)) {
            this.parseJobTrackerUrls(lines);

            var jobType = this.parseJobType(lines);
            if (jobType.indexOf("pig") !== -1) {
                this.parsePigTable(lines, "pigSummary", this.PIG_JOB_SUMMARY_START, "", 0);
                this.parsePigTable(lines, "pigStats", this.PIG_JOB_STATS_START, "", 1);
            } else if (jobType.indexOf("hive") !== -1) {
                this.parseHiveQueries(lines);
            }
        }
    },

    parseCommand: function(lines) {
        var commandStartIndex = -1;
        var numLines = lines.length;
        for (var i = 0; i < numLines; i++) {
            if (lines[i].indexOf(this.COMMAND_START) === 0) {
                commandStartIndex = i;
                break;
            }
        }
        
        if (commandStartIndex != -1) {
            var commandProperties = {};

            var command = lines[commandStartIndex].substring(this.COMMAND_START.length);
            commandProperties.Command = command;
            
            this.parseCommandProperty(command, commandProperties, "Classpath", this.CLASSPATH_REGEX, ':');
            this.parseCommandProperty(command, commandProperties, "-D", this.ENVIRONMENT_VARIABLES_REGEX);
            this.parseCommandProperty(command, commandProperties, "Memory Settings", this.JVM_MEMORY_REGEX);
            this.parseCommandProperty(command, commandProperties, "Params", this.PIG_PARAMS_REGEX);
            
            this.set("commandProperties", commandProperties);

            return true;
        }
        
        return false;
    },

    parseCommandProperty: function(command, commandProperties, propertyName, regex, split) {
        var results = [];
        var match;
        while (match = regex.exec(command)) {
            if (split) {
                results = results.concat(match[1].split(split));
            } else {
                results.push(match[1]);
            }
        }

        if (results.length > 0) {
            commandProperties[propertyName] = results;
        }
    },

    parseJobTrackerUrls: function(lines) {
        var jobTrackerUrls = {};
        var jobTrackerUrlsOrdered = [];
        var numLines = lines.length;
        var match;
        for (var i = 0; i < numLines; i++) {
            if ((match = this.JOB_TRACKER_URL_REGEX.exec(lines[i])) && !jobTrackerUrls[match[1]]) {
                jobTrackerUrls[match[1]] = match[0];
                jobTrackerUrlsOrdered.push(match[0]);
            }
        }
        this.set("jobTrackerUrls", jobTrackerUrls);
        this.set("jobTrackerUrlsOrdered", jobTrackerUrlsOrdered);
    },

    parseJobType: function(lines) {
        var numLines = lines.length;
        var match;
        for (var i = 0; numLines; i++) {
            if (match = this.JOB_TYPE_REGEX.exec(lines[i])) {
                return match[1];
            }
        }
        
        return null;
    },

    parsePigTable: function(lines, tableName, startPattern, endPattern, linesToSkipAfterStart) {
        var index = -1;
        var numLines = lines.length;
        for (var i = 0; i < numLines; i++) {
            if (lines[i].indexOf(startPattern) === 0) {
                index = i + linesToSkipAfterStart;
                break;
            }
        }
        
        if (index != -1) {
            var table = [];
            var line;
            while ((line = lines[index]) !== endPattern) {
                var columns = line.split("\t");
                // If first column is a job id, make it a link to the job tracker.
                if (this.get("jobTrackerUrls")[columns[0]]) {
                    columns[0] = "<a href='" + this.get("jobTrackerUrls")[columns[0]] + "'>" + columns[0] + "</a>";
                }
                table.push(columns);
                index++;
            }

            this.set(tableName, table);
        }
    },

    parseHiveQueries: function(lines) {
        var hiveQueries = [];
        var hiveQueryJobs = [];

        var currMapReduceJob = 0;
        var numLines = lines.length;
        for (var i = 0; i < numLines;) {
            var line = lines[i];
            var parsingCommandIndex = line.indexOf(this.HIVE_PARSING_START);
            if (parsingCommandIndex === -1) {
                i++;
                continue;
            }

            // parse query text, which could span multiple lines
            var queryStartIndex = parsingCommandIndex + this.HIVE_PARSING_START.length;
            var query = line.substring(queryStartIndex) + "<br/>";
            
            i++;
            while (i < numLines && (line = lines[i]).indexOf(this.HIVE_PARSING_END) === -1) {
                query += line + "<br/>";
                i++;
            }
            hiveQueries.push(query);
            i++;
            
            // parse the query's Map-Reduce jobs, if any.
            var numMRJobs = 0;
            while (i < numLines) {
                line = lines[i];
                if (line.contains(this.HIVE_NUM_MAP_REDUCE_JOBS_STRING)) {
                    // query involves map reduce jobs
                    var numMRJobs = parseInt(line.substring(this.HIVE_NUM_MAP_REDUCE_JOBS_STRING.length),10);
                    i++;
                    
                    // get the map reduce jobs summary
                    while (i < numLines) {
                        line = lines[i];
                        if (line.contains(this.HIVE_MAP_REDUCE_JOBS_SUMMARY)) {
                            // job summary table found
                            i++;
                            
                            var queryJobs = [];
                            
                            var previousJob = -1;
                            var numJobsSeen = 0;
                            while (numJobsSeen < numMRJobs && i < numLines) {
                                line = lines[i];
                                var match;
                                if (match = this.HIVE_MAP_REDUCE_SUMMARY_REGEX.exec(line)) {
                                    var currJob = parseInt(match[1], 10);
                                    if (currJob === previousJob) {
                                        i++;
                                        continue;
                                    }
                                    
                                    var job = [];
                                    job.push("<a href='" + this.get("jobTrackerUrlsOrdered")[currMapReduceJob++] + "'>" + currJob + "</a>");
                                    job.push(match[2]);
                                    job.push(match[3]);
                                    job.push(match[4]);
                                    job.push(match[5]);
                                    queryJobs.push(job);
                                    previousJob = currJob;
                                    numJobsSeen++;
                                }
                                i++;
                            }
                            
                            if (numJobsSeen === numMRJobs) {
                                hiveQueryJobs.push(queryJobs);
                            }
                            
                            break;
                        }
                        i++;
                    } 
                    break;
                }
                else if (line.contains(this.HIVE_PARSING_START)) {
                    if (numMRJobs === 0) {
                        hiveQueryJobs.push(null);
                    }
                    break;
                }
                i++;
            }
            continue;
        }

        if (hiveQueries.length > 0) {
            this.set("hiveSummary", {
                hiveQueries: hiveQueries,
                hiveQueryJobs: hiveQueryJobs
            });
        }
    }
});
