// pipe-ipc.js
// https://github.com/gnh1201/welsonjs

var STD = require("lib/std");

// https://learn.microsoft.com/en-us/office/vba/language/reference/user-interface-help/opentextfile-method
var ForReading = 1;
var ForWriting = 2;
var ForAppending = 8;
var TristateUseDefault = -2;
var TristateTrue = -1;
var TristateFalse = 0;

// https://learn.microsoft.com/en-us/office/client-developer/access/desktop-database-reference/streamtypeenum
var adTypeBinary = 1;
var adTypeText = 2;

// https://learn.microsoft.com/ko-kr/sql/ado/reference/ado-api/saveoptionsenum?view=sql-server-ver16
var adSaveCreateNotExist = 1;
var adSaveCreateOverWrite = 2;

// https://learn.microsoft.com/en-us/sql/ado/reference/ado-api/connectmodeenum?view=sql-server-ver16
var adModeRead = 1;
var adModeReadWrite = 3;
var adModeRecursive = 0x400000;
var adModeShareDenyNone = 16;
var adModeShareDenyRead = 4;
var adModeShareDenyWrite = 8;
var adModeShareExclusive = 12;
var adModeUnknown = 0;
var adModeWrite = 2;

// https://learn.microsoft.com/en-us/previous-versions/exchange-server/exchange-10/ms527267(v=exchg.10)
// https://learn.microsoft.com/en-us/previous-versions/exchange-server/exchange-10/ms526296(v=exchg.10)
var CdoBIG5        = "big5";
var CdoEUC_JP      = "euc-jp";
var CdoEUC_KR      = "euc-kr";
var CdoGB2312      = "gb2312";
var CdoISO_2022_JP = "iso-2022-jp";
var CdoISO_2022_KR = "iso-2022-kr";
var CdoISO_8859_1  = "iso-8859-1";
var CdoISO_8859_2  = "iso-8859-2";
var CdoISO_8859_3  = "iso-8859-3";
var CdoISO_8859_4  = "iso-8859-4";
var CdoISO_8859_5  = "iso-8859-5";
var CdoISO_8859_6  = "iso-8859-6";
var CdoISO_8859_7  = "iso-8859-7";
var CdoISO_8859_8  = "iso-8859-8";
var CdoISO_8859_9  = "iso-8859-9";
var cdoKOI8_R      = "koi8-r";
var cdoShift_JIS   = "shift-jis";
var CdoUS_ASCII    = "us-ascii";
var CdoUTF_7       = "utf-7";
var CdoUTF_8       = "utf-8";

function PipeIPC() {
    this.path = "data\\.pipe_:pipename";
    this.delimiter = "\r\n";
    this.reader = null;
    this.writer = null;
    this.recorder = null;
    this.savefile = null;
    this.tmpfile = null;
    this.charset = CdoUTF_8;
    this.lastReadTime = -1;
    this.lastWriteTime = -1;
    this.maxSentences = 0;

    this.getCurrentTime = function() {
        return new Date().getTime();
    };

    this.setCharset = function(charset) {
        this.charset = charset;
    };
    
    this.setDelimiter = function(delimiter) {
        this.delimiter = delimiter;
    };

    this.setMaxSentences = function(maxSentences) {
        this.maxSentences = maxSentences;
    };

    this.connect = function(pipename, callback) {
        this.path = this.path.replace(":pipename", pipename);
        //this.openWriter();
        this.openReader();
        if (typeof callback === "function") {
            callback(this, this.reader, this.writer);
        }
        return this;
    };

    this.openWriter = function(iomode) {
        while (this.writer == null) {
            try {
                this.writer = CreateObject("Scripting.FileSystemObject").OpenTextFile(this.path, iomode, true, TristateTrue);
            } catch (e) {}
        }
    };

    this.closeWriter = function() {
        if (this.writer != null) {
            this.writer.Close();
            this.writer = null;
        }
    };

    this.openReader = function() {
        while (this.reader == null) {
            try {
                this.reader = CreateObject("Scripting.FileSystemObject").OpenTextFile(this.path, ForReading, true, TristateTrue);
            } catch (e) {}
        }
    };

    this.closeReader = function() {
        if (this.reader != null) {
            this.reader.Close();
            this.reader = null;
        }
    };

    this.startRecorder = function(filename) {
        this.savefile = filename;
        this.tmpfile = this.savefile + ".tmp";
        this.openRecorder();
    };

    this.stopRecorder = function() {
        this.savefile = null;
        this.tmpfile = null;
    };

    this.openRecorder = function() {
        while (this.recorder == null) {
            try {
                this.recorder = CreateObject("Scripting.FileSystemObject").OpenTextFile(this.tmpfile, ForAppending, true, TristateTrue);
            } catch (e) {}
        }
    };

    this.closeRecorder = function() {
        if (this.recorder != null) {
            this.recorder.Close();
            this.recorder = null;
        }
    };

    this._write = function(message) {
        this.writer.Write(message + this.delimiter);
    };

    this.write = function(message) {
        if (this.savefile != null) {
            this.record(message);
        }

        var isWritten = false;
        while (!isWritten) {
            try {
                this.flush();
                this.openWriter(ForAppending);
                this._write(message);
                this.closeWriter();
                isWritten = true;
                this.lastWriteTime = this.getCurrentTime();
            } catch (e) {
                this.closeWriter();
                isWritten = false;
            }
        }

        return isWritten;
    };

    this._record = function(message) {
        this.recorder.Write(message);
    };

    this.record = function(message) {
        var _this = this;  // Because of the variable scope
        var commit = function(src, dst, charset) {
            var isCommited = false;

            // define functions
            var    StripAdoBOM = function(adoObj) {
                var newAdoObj = CreateObject("ADODB.Stream");
                newAdoObj.Type = adTypeBinary;
                newAdoObj.Mode = adModeReadWrite;
                newAdoObj.Open();
                adoObj.Position = 3;
                adoObj.CopyTo(newAdoObj);
                adoObj.Flush();
                adoObj.Close();
                return newAdoObj;
            };

            while (!isCommited) {
                try {
                    // Open a temporary file
                    var fso = CreateObject("Scripting.FileSystemObject").OpenTextFile(src, ForReading, true, TristateTrue);
                    var text = fso.ReadAll();
                    var sentences = text.split(_this.delimiter);
                    var newSentences = [], str = '';

                    // if enabled "maxSentences" feature
                    if (_this.maxSentences > 0) {
                        while (sentences.length > 0 && newSentences.length < _this.maxSentences) {
                            newSentences.push(sentences.pop());
                        }
                        str = newSentences.reverse().join(_this.delimiter);
                    } else {
                        str = text;
                    }

                    // Convert UTF-16 BOM to UTF-8
                    var ado = CreateObject("ADODB.Stream");
                    ado.Type = adTypeText;
                    ado.Charset = charset;
                    ado.Open();
                    ado.WriteText(str);
                    ado = StripAdoBOM(ado);
                    ado.SaveToFile(dst, adSaveCreateOverWrite);
                    ado.Close();

                    /*
                    // Write a new temporary file
                    var _fso = CreateObject("Scripting.FileSystemObject").OpenTextFile(src, ForWriting, true, TristateTrue);
                    _fso.Write(str);
                    _fso.Close();
                    */

                    // Set a result
                    isCommited = true;
                } catch (e) {
                    isCommited = false;
                }
            }

            // Close a temporary file
            fso.Close(); 
        };

        var isRecorded = false;
        while (!isRecorded) {
            try {
                this.openRecorder();
                this._record(message);
                this.closeRecorder();
                commit(this.tmpfile, this.savefile, this.charset);
                isRecorded = true;
            } catch (e) {
                //console.log(e.message);
                this.closeRecorder();
                isRecorded = false;
            }
        }

        return isRecorded;
    };

    this.flush = function() {
        var isFlushed = false;

        while (!isFlushed) {
            try {
                this.openWriter(ForWriting);
                this._write('');
                this.closeWriter();
                isFlushed = true;
            } catch (e) {
                isFlushed = false;
            }
        }

        return isFlushed;
    };

    this._read = function() {
        return this.reader.ReadAll();
    };

    this.read = function() {
        var isRead = false;
        var text = "";

        while (!isRead) {
            try {
                text += this._read();
                isRead = true;
                this.lastReadTime = this.getCurrentTime();
            } catch (e) {
                this.closeReader();
                this.openReader();
            }
        }

        return text;
    };

    this.close = function() {
        this.closeWriter();
        this.closeReader();
        this.closeRecorder();
    };
}

exports.create = function() {
    return new PipeIPC();
};

exports.connect = function(path, callback) {
    return exports.create().connect(path, callback);
};

exports.ForReading = ForReading;
exports.ForWriting = ForWriting;
exports.ForAppending = ForAppending;
exports.CdoUTF_8 = CdoUTF_8;

exports.VERSIONINFO = "PIPE-based IPC Module (pipe-ipc.js) version 0.1.5";
exports.AUTHOR = "abuse@catswords.net";
exports.global = global;
exports.require = require;