require("amd-loader");

var fs = require("fs");
var util = require("util");
var lib = require("./lib");
var pathlib = require("path");
var parseLanguage = lib.parsePlist;

var tk = require("./regexp_tokenizer");
var tokenize = tk.tokenize;
var toStr = tk.toStr;

function last(array) {return array[array.length - 1]}

function convertHexEscape(tokens) {
    var inChClass = false;
    tokens.forEach(function(t) {
        if (t.type == "charclass")
            inChClass = true;
        else if (t.type == "charclass.end")
            inChClass = false;
        else if (t.type == "charType"){
            if (t.value == "\\h") {
                t.type = "text";
                t.value = inChClass ? "\\da-fA-F" : "[\\da-fA-F]";
            }
            else if (t.value == "\\H") {
                if (inChClass) {
                    console.warn("can't convert \\H in charclass");
                    return;
                }
                t.type = "text";
                t.value = "[^\\da-fA-F]";
            }
        }
    });
    return tokens;
}

function convertNewLinesTo$(str) {
    var tokens = tokenize(str);
    for (var i = 0; i < tokens.length; i++) {
        var t= tokens[i];
        if (t.type == "char" && t.value == "\\n") {
            var p = tokens[i + 1] || {};
            if (p.type != "quantifier") {
                t.value = "$";
                while (p.value == "\\n" || p.type == "quantifier") {
                    p.value = "";
                    p = tokens[++i + 1] || {};
                }
            } else if (/\?|\*|{,|{0,/.test(p.value)) {
                t.value = p.value = "";
            } else
                p.value = "";
        }
    }
    return toStr(tokens).replace(/[$]+/g, "$");
}

function convertCharacterTypes(str) {
    var tokens = tokenize(str);
    tokens = convertHexEscape(tokens);

    var warn = false;
    tokens.forEach(function(t){
        if (t.type == "quantifier") {
            var val = t.value;
            if (val.slice(-1) == "+" && val.length > 1) {
                t.value = val.slice(0, -1);
                warn = val;
            }
        }
    });
    if (warn)
        console.log("converted possesive quantifier " + warn + " to *");
    return toStr(tokens);
}

function removeInlineFlags(str, rule) {
    var tokens = tokenize(str);
    var caseInsensitive = false;
    tokens.forEach(function(t, i) {
        if (t.type == "group.start" && /[imsx]/.test(t.value)) {
            if (/i/.test(t.value))
                caseInsensitive = true;
            t.value = t.value.replace(/[imsx\-]/g, "");
            var next = tokens[i + 1];
            if (next && next.type == "group.end") {
                t.value = next.value = "";
            }
        }
    });
    if (caseInsensitive && rule)
        rule.caseInsensitive = true;
    return toStr(tokens);
}

function convertToNonCapturingGroups(str) {
    var tokens = tokenize(str);
    tokens.forEach(function(t, i) {
        if (t.type == "group.start" && t.value == "(")
            t.value += "?:";
    });
    return toStr(tokens);
}

function simplifyNonCapturingGroups(str) {
    var tokens = tokenize(str);
    var t = tokens[0] || {};
    if (t.type == "group.start" && t.value == "(?:"
        && t.end == last(tokens)) {
        t.value = t.end.value = "";
    }
    var i = 0;
    function iter(f) {
        for (i = 0; i < tokens.length; i++)
            f(tokens[i]);
    }
    function iterGroup(end, f) {
        for (var i1 = i + 1; i1 < tokens.length; i1++) {
            var t = tokens[i1];
            if (t == end)
                break;
            var index = f && f(t);
            if (index > i1)
                i1 = index;
        }
        return i1;
    }

    iter(function (t) {
        if (t.type == "group.start" && t.value == "(?:") {
            if (!t.end)
                return console.error("malformed regex: " + str);

            var canRemove = true;
            var next = tokens[tokens.indexOf(t.end, i) + 1];
            if (next && next.type == "quantifier")
                return;
            iterGroup(t.end, function(t) {
                if (t.type == "alternation")
                    canRemove = false;
                else if (t.type == "group.start" && t.end)
                    return iterGroup(t.end);
            });
            if (canRemove)
                t.value = t.end.value = "";
        }
    });

    return toStr(tokens);
}

function removeLookBehinds(str) {
    var tokens = tokenize(str);
    var toRemove = null;
    tokens.forEach(function(t, i) {
        if (!toRemove && t.type == "group.start" && /</.test(t.value)) {
            toRemove = t.end;
            toRemove.content = [];
        }
        if (toRemove) {
            toRemove.content.push(t.value);
            t.value = "";
        }
        if (t == toRemove) {
            var c = toRemove.content.slice(1, -1).join("");
            if (/\^/.test(c))
                toRemove.value = "(?:" + c +")";

            toRemove = null;
        }
    });
    return toStr(tokens);
}

function convertBeginEndBackrefs(rule) {
    if (!/\\\d/.test(rule.end))
        return;
    var startTokens = tokenize(rule.begin);
    var endTokens = tokenize(rule.end);


    var groups = {};
    startTokens.forEach(function(t, i) {
        if (t.number && t.end && t.type == "group.start") {
            var endIndex = startTokens.indexOf(t.end, i + 1);
            var content = startTokens.slice(i+1, endIndex);
            groups[t.number] = toStr(content);
        }
    });

    endTokens.forEach(function(t) {
        if (t.type == "backRef") {
            var num = t.value.substr(1);
            if (groups[num])
                t.value = "(?:" + groups[num] + ")";
        }
    });

    rule.end = toStr(endTokens);

    console.warn("Begin-End-Backreference is detected", rule);
}

function checkForNamedCaptures(str) {
    var tokens = tokenize(str);
    tokens.forEach(function(t) {
        if (t.type == "group.start" && t.name)
            console.warn("named capture not implemented", str);
        if (t.type == "backRef")
            console.warn("backRef not implemented ", str);
    });
}

function fixGroups(captures, defaultName, regex) {
    var tokens = tokenize(regex);

    var opened = [], isStart = true, i = 0;
    function open() {
        var t = {value: "(", type: "group.start", isGroup: true};
        opened.push(t);
        tokens.splice(i++, 0, t);
    }
    function close() {
        var t = {value: ")", type: "group.start"};
        t.start = opened.pop();
        t.start.end = t;
        tokens.splice(i++, 0, t);
    }
    function tryOpen(){if (isStart) {open(); isStart = false}}
    function tryClose(){if (opened.length) close()}
    function skip(t) {
        var i1 = tokens.indexOf(t.end, i);
        if (i1 > i)
            i = i1;
    }
    function lst(t) {return t[t.length - 1]}
    function iter(f) {
        for (i = 0; i < tokens.length; i++)
            f(tokens[i]);
    }
    function iterGroup(end, f) {
        for (var i1 = i + 1; i1 < tokens.length; i1++) {
            var t = tokens[i1];
            if (t == end)
                break;
            f(t);
        }
    }
    function peek() { return tokens[i + 1] || {}}

    // groupify
    iter(function(t){
        if (t.type == "group.start") {
            tryClose();
            isStart = true;
            if (!t.hasChildren || t.isSpecial)
                skip(t);
        } else if (t.type == "group.end") {
            isStart = true;
            tryClose();
        } else if (t.type == "alternation") {
            isStart = true;
            tryClose();
        } else if (t.type != "anchor" && t.type != "quantifier"){
            tryOpen();
        }
    });
    tryClose();

    // remove redundand groups
    var names = [defaultName];
    iter(function(t){
        if (t.type == "group.start" && !t.isSpecial) {
            var captureName = captures[t.number];

            if (!t.hasChildren) {
                t.tokenName = captureName || lst(names);
                skip(t);
            }  else {
                var hasCapture = false;
                iterGroup(t.end, function(t1) {
                    if (t1.type == "group.start" && captures[t1.number])
                        hasCapture = true;
                });
                if (hasCapture) {
                    t.value = "(?:";
                    if (captureName) {
                        names.push(captureName);
                        t.isTokenGroup = true;
                    }
                } else {
                    t.tokenName = captureName || lst(names);
                    iterGroup(t.end, function(t1) {
                        if (t1.value == "(")
                            t1.value = "(?:";
                    });
                }
            }
        } else if (t.type == "group.end") {
            if (t.start.isTokenGroup)
                names.pop();
        }
    });

    // wrap capturing groups with quantifier
    iter(function(t){
        if (t.type == "group.end" && t.start.value == "(" && peek().type == "quantifier") {
            peek().value += ")";
            t.start.value += "(?:";
        }
    });

    names = [];
    tokens.forEach(function(t) {
        if (t.value == "(" || t.value == "((?:" )
            t.tokenName && names.push(t.tokenName);
    });
    return {
        names: names,
        regex: toStr(tokens)
    };
}

/***** converter */

function logDebug(string, obj) {
    console.log(string, obj);
}


// tmLanguage processor

// for tracking token states
var states = {start: []};

function processRules(rules){
    if (rules.patterns)
        states.start = processPatterns(rules.patterns);
    if (rules.repository)
        processRepository(rules.repository);
    return states;
}
function processRepository(r) {
    for (var key in r) {
        var p = r[key];
        if (p.begin)
            var stateObj = [processPattern(r[key])];
        else if (p.patterns && !p.repository)
            var stateObj = processPatterns(p.patterns);
        else
            var stateObj = [processPattern(r[key])];

        if (stateObj)
            states["#" + key] = stateObj;
    }
}
function processPatterns(pl) {
    return pl.map(processPattern);
}
function processPattern(p) {
    if (p.end == "(?!\\G)" && p.patterns && p.patterns.length == 1) {
        var rule = processPattern(p.patterns[0]);
    }
    else if (p.begin != null && p.end != null) {
        convertBeginEndBackrefs(p);

        var rule = simpleRule(p.begin, p.name, p.beginCaptures || p.captures);

        var next = processPatterns(p.patterns || []);
        var endRule = simpleRule(p.end, p.name, p.endCaptures || p.captures);
        endRule.next = "pop";
        if (p.applyEndPatternLast)
            next.push(endRule);
        else
            next.unshift(endRule);

        if (p.name || p.contentName)
            next.push({defaultToken: p.name || p.contentName});

        rule.push = next;

        rule = removeIncludeSelf(rule);
    }
    else if (p.match) {
        var rule = simpleRule(p.match, p.name, p.captures);
    }
    else if (p.include) {
        var rule =  {include: p.include};
    }
    else {
        var rule =  {todo: p};
    }

    if (p.comment)
        rule.comment = (rule.comment || "") +  p.comment;

    if (p.repository)
        processRepository(p.repository);
    return rule;
}
function simpleRule(regex, name, captures) {
    name = name || "text";
    var rule = {token: "", regex: ""};

    var origRegex = regex;
    regex = transformRegExp(origRegex, rule);
    if (captures) {
        var tokenArray = [];
        Object.keys(captures).forEach(function(x){
            tokenArray[x] = captures[x] && captures[x].name;
        });

        if (tokenArray.length == 1) {
            name = tokenArray[0];
        } else {
            var fixed = fixGroups(tokenArray, name, regex);
            name = fixed.names;
            regex = fixed.regex;
            if (name.length == 1)
                name = name[0];
        }
    }

    if (typeof name == "string")
        regex = convertToNonCapturingGroups(regex);

    regex = simplifyNonCapturingGroups(regex);

    try {new RegExp(regex);} catch(e) {
        rule.TODO = "FIXME: regexp doesn't have js equivalent";
        rule.originalRegex = origRegex;

        // lookbehinds are mostly used to force ordering
        // regex = removeLookBehinds(regex);
    }
    rule.token = name;
    rule.regex = regex;
    return rule;
}

function removeIncludeSelf(rule) {
    if (!rule.push)
        return rule;
    var hasSelfInclude = false;
    var escapeRule = null;
    var complexSelfInclude = false;
    rule.push.forEach(function(sub) {
        if (sub.include == "$self") {
            hasSelfInclude = true;
        } else if (sub.defaultToken) {
            return;
        } else if (sub.next == "pop") {
            escapeRule = sub;
        } else
            complexSelfInclude = true;
    });

    if (hasSelfInclude) {
        console.warn("can't convert include $self");
        return {todo: rule};
        
        if (complexSelfInclude) {
            console.warn("can't convert include $self");
            rule.toDo = "include $self not fully supported";
            return rule;
        }
        console.warn("include $self not fully supported");
        delete rule.push;
        delete escapeRule.next;
        rule.includeSelf = true;
        escapeRule.includeSelf = true;
        return [rule, escapeRule];
    }
    return rule;
}

// regex transformation

function removeXFlag(str) {
    var tokens = tokenize(str);
    return toStr(tokens);
}

function transformRegExp(str, rule) {
    str = convertNewLinesTo$(str);

    str = removeInlineFlags(str, rule);

    str = str.replace(/(\\[xu]){([a-fA-F\d]+)}/g, '$1$2');

    str = convertCharacterTypes(str, rule);

    checkForNamedCaptures(str);

    return str;
}

//
function extractPatterns(tmRules) {
    return  processRules(tmRules);
}


function detectLoops(states) {
    var data = {};
    var keys = Object.keys(states);
    var flattenedStates = {};
    function addRef(item, name) {
        if (item.refs.indexOf(name) == -1)
            item.refs.push(name);
    }
    function anonStateId(name, next) {
        var i = 0, old = name;
        while (flattenedStates[name] || states[name]) {
            name = old + "_" + i++;
        }
        // console.log(old, name)
        return name;
    }
    function addState(key, rules) {
        if (rules && !flattenedStates[key])
            flattenedStates[key] = rules;
        return rules || flattenedStates[key];
    }
    
    
    for (var i = 0; i < keys.length; i++) {
        var key = keys[i];
        var state = addState(key, states[key]);
        
        var item = data[key] || (data[key] = {/* name: key, */ refs: []});
        state.forEach(function(rule) {
            var next = rule.push || rule.next;
            if (next == "pop") {
                // nothing
            } else if (typeof next == "string") {
                addRef(item, next);
            } else if (next) {
                var anonId = anonStateId(key, next);
                addState(anonId, next);
                if (rule.push)
                    addRef(item, anonId);
                keys.push(anonId);
            } else if (rule.include) {
                addRef(item, rule.include);
            }
        });
    }
    
    
    var cycles = [];
    function addPath(start, path) {
        var node = data[start];
        path.push(start);
        if (!node || !node.refs)
            console.log(start);
        var i = path.indexOf(start);
        if (i > -1 && i != path.length - 1 || start == "$self" || start == "$base") {
            if (i != -1)
                path = path.slice(i);
            for (var j = 0; j < cycles.length; j++) {
                if (cycles[j] + "" == path + "")
                    return;
            }
            return cycles.push(path);
        }
        
        if (!node || !node.refs || !node.refs.length || path.length>30)
            return;
        node.refs.forEach(function(x) {
            addPath(x, path.concat());
        });
    }
    addPath("start", []);
    
    console.error(cycles.join("\n"));
}


function test(fileName) {
    console.log("testing highlighter");
    try {
        var module = require(fileName);
        var Mode = module[Object.keys(module)[0]];
        var mode = new Mode();
        mode.getTokenizer().getLineTokens("hello world");
    } catch(e) {
        console.log(e);
    }
}

function guessComment(patterns) {
    var comment = {};
    for (var i in patterns) {
        var state = patterns[i];
        state.forEach(function(r) {
            if (typeof r.token == "string") {
                if (/\bcomment\b/.test(r.token)) {
                    comment.line = r.regex;
                }
            }
        });
    }

    return comment;
}

// cli stuff
var modeTemplate = fs.readFileSync(__dirname + "/templates/mode.js", "utf8");
var modeHighlightTemplate = fs.readFileSync(__dirname + "/templates/highlight_rules.js", "utf8");

function fetchAndConvert(name) {
    console.log("Converting " + name);
    if (/^http/.test(name)) {
        if (/:\/\/github.com/.test(name)) {
            name = name.replace(/\/blob\//, "/").replace("github.com", "raw.github.com");
        }
        return lib.download(name, function(data) {
            convertTmLanguage(name, data);
        });
    }
    var path = /^(\/|\w:)/.test(name) ? name : process.cwd() + "/" + name;
    var langStr = fs.readFileSync(path, "utf8");
    convertTmLanguage(name, langStr);
}


function convertTmLanguage(name, langStr) {
    parseLanguage(langStr, function(language) {
        var highlighterFilename = lib.snakeCase(language.name).replace(/[^\w]/g, "");
        var languageNameSanitized = lib.camelCase(language.name).replace(/[^\w]/g, "");
        
        require("./add_mode")(languageNameSanitized, (language.fileTypes || []).join("|"));

        var highlighterFile = pathlib.normalize(lib.AceLib + "ace/mode/" + highlighterFilename + "_highlight_rules.js");
        var modeFile = pathlib.normalize(lib.AceLib + "ace/mode/" + highlighterFilename + ".js");

        if (devMode) {
            console.log(util.inspect(language.patterns, false, 4));
            console.log(util.inspect(language.repository, false, 4));
        }

        var patterns = extractPatterns(language);
        detectLoops(patterns);
        
        // var uuid = language.uuid
        delete language.uuid;
        delete language.patterns;
        delete language.repository;

        var comment = guessComment(patterns);
        var languageMode = lib.fillTemplate(modeTemplate, {
            language: languageNameSanitized,
            languageHighlightFilename: highlighterFilename,
            lineCommentStart: JSON.stringify(comment.line || "//"),
            blockCommentStart: JSON.stringify(comment.start || "/*"),
            blockCommentEnd: JSON.stringify(comment.end || "*/")
        });

        var languageHighlightRules = lib.fillTemplate(modeHighlightTemplate, {
            language: languageNameSanitized,
            languageTokens: lib.formatJS(patterns, "    ").trim(),
            uuid: language.uuid,
            name: name,
            metaData: lib.formatJS(language, "").trim()
        });

        if (devMode) {
            console.log(languageMode);
            console.log(languageHighlightRules);
            console.log("Not writing, 'cause we're in dev mode, baby.");
        }
        else {
            fs.writeFileSync(highlighterFile, languageHighlightRules);
            fs.writeFileSync(modeFile, languageMode);
            console.log("created file " + highlighterFile);
            test(modeFile);
        }
    });
}

if (!module.parent) {
    var args = process.argv.splice(2);
    var devMode = args[0] == "--dev";
    if (devMode)
        args.shift();
    if (args.length < 1) {
        console.error("Usage: node tmlanguage.js [--dev] path/or/url/to/syntax.file ...");
        process.exit(1);
    }
    args.forEach(fetchAndConvert);
} else {
    exports.fetchAndConvert = fetchAndConvert;
}