define(function(require, exports, module) {
    main.consumes = [
        "c9", "Plugin", "editors", "dialog.error",
        "terminal.monitor.message_view", "tabManager",
        "proc", "commands"
    ];
    main.provides = ["terminal.monitor"];
    return main;

    function main(options, imports, register) {
        var BASHBIN = options.bashBin || "/bin/bash";
        
        var c9 = imports.c9;
        var Plugin = imports.Plugin;
        var editors = imports.editors;
        var messageView = imports["terminal.monitor.message_view"];
        var tabManager = imports.tabManager;
        var commands = imports.commands;
        var proc = imports.proc;
        
        var messageMatchers = require("./message_matchers")(c9).matchers;
        
        var plugin = new Plugin("Ajax.org", main.consumes);
        
        var loaded = false;
        function load() {
            if (loaded) return false;
            loaded = true;
            
            messageView.on("action", function(cmd, message) {
                proc.execFile(BASHBIN, {
                    args: ["--login", "-c", cmd]
                }, function() {
                    messageView.hide(message);
                });
            }, plugin);
            
            editors.on("create", function(e) {
                if (!e.editor || e.editor.type !== "terminal" && e.editor.type !== "output")
                    return;
                
                e.editor.on("documentLoad", onDocumentLoad);
            }, plugin);
            
            function onDocumentLoad(e) {
                var session = e.doc.getSession();
                session.once("terminalReady", setupTerminalMessageHandler);
            }
        }
        
        function setupTerminalMessageHandler(session) {
            var terminal = session.terminal;
            var seenUpTo = 0;
            var lastNewLine = 0;
            var hasResizeCompleted = false;
            var timer = null;
            
            terminal.on("discardOldScrollback", function(e) {
                seenUpTo = Math.max(seenUpTo - e, 0);
                if (lastNewLine) 
                    lastNewLine -= e;
            });
            terminal.on("newline", function(e) {
                lastNewLine = e.y + e.ybase - 1;
                if (!timer)
                    timer = setTimeout(checkNewText);
            });
            function checkNewText() {
                timer = null;
                if (!hasResizeCompleted)
                    return;
                
                var lines = terminal.lines;
                if (lastNewLine >= lines.length) lastNewLine = lines.length - 1;
                var lineContents = "";
                for (var i = Math.min(seenUpTo, lastNewLine); i <= lastNewLine; i++) {
                    var line = lines[i];
                    if (!line)
                        continue;
                    lineContents += lineToString(line);
                    if (line.wrapped)
                        continue;
                    seenUpTo = i + 1;
                    handleMessage(lineContents, session.tab);
                    lineContents = "";
                }
            }
            
            var resizeTimeout;
            terminal.on("resizeStart", function() {
                hasResizeCompleted = false;
                if (resizeTimeout) {
                    clearTimeout(resizeTimeout);
                }
                
                messageView.repositionMessages(session.tab);
                
                resizeTimeout = setTimeout(function() {
                    resizeTimeout = null;
                    hasResizeCompleted = true;
                }, 1000);
            });
        }
        
        function lineToString(line) {
            return line.map(function(character) {
                return character && character[1];
            }).join("");
        }
        
        function handleMessage(data, tab) {
            messageMatchers.forEach(function(trigger) {
                var matches = trigger.pattern.exec(data);
    
                if (matches !== null) {
                    var message = trigger.message;
                    message = message && message.replace(/{(\d)}/g, function(_, num) {
                        return matches[num] || _;
                    });
                    if (!trigger.onMatch)
                        messageView.show(message, trigger.action, tab);
                    else if (typeof trigger.onMatch == "function")
                        trigger.onMatch(matches, tab);
                    else if (trigger.onMatch == "reloadPreview")
                        reloadPreview();
                }
            });
        }
        
        function reloadPreview() {
            commands.exec("reloadpreview");
        }
        
        function addMessageMatcher(matcher) {
            messageMatchers.pushUnique(matcher);
        }
        
        function removeMessageMatcher(matcher) {
            messageMatchers.remove(matcher);
        }
        /***** Lifecycle *****/
        
        plugin.on("load", function() {
            load();
        });
        
        plugin.on("unload", function() {
             loaded = false;
        });
        
        plugin.freezePublicAPI({
            /**
             * @ignore
             */
            addMessageMatcher: addMessageMatcher,
            /**
             * @ignore
             */
            removeMessageMatcher: removeMessageMatcher,
            /**
             * for testing
             * @ignore
             */
            get messageMatchers() { return messageMatchers; },
            /**
             * for testing
             * @ignore
             */
            handleMessage: handleMessage,
        });
        
        /***** Register and define API *****/
        register(null, {
            "terminal.monitor": plugin
        });
    }
});