var TextBox = function (position) {
    UI.makeControl(this);
    var local = this;

    this.curText = "";
    this.visibleText = "";
    this.visibleTextStart = 0;
    this.texQuad = new Quad({ });
    this.texQuad.setSize(256, 32);
    this.texQuad.setTexture("Interface\\ChatFrame\\UI-ChatInputBorder.blp");
    this.caretPos = 0;
    this.caretQuad = new Quad({});
    this.caretQuad.setSize(2, 15);
    this.caretQuad.setPosition(0, 0);
    this.prevCaretStr = "";
    this.prevCaretLen = 0.0;
    this.isCaretVisible = true;
    this.caretEvent = new TimedEvent({ This: local, callback: (function(scope) { return function() { scope.caretUpdate(); };})(local), interval: 1000 });
    this.caretEvent.enable();

    this.curPosition = [0, 0];

    if (typeof position !== "undefined") {
        this.setPosition(position);
        this.curPosition = { x: position.x, y: position.y };
    }
}

TextBox.prototype.caretUpdate = function (arg) {

}

TextBox.prototype.onDraw = function () {
    this.texQuad.draw();

    if (this.visibleText.length > 0) {
        UI.drawString(this.visibleText, this.curPosition.x + 10, this.curPosition.y + 8);
    }

    this.caretQuad.setPosition(this.curPosition.x + 10 - 1 + this.prevCaretLen, this.curPosition.y + 8);
    this.caretQuad.draw();
}

TextBox.prototype.onMessage = function (message) {
    if (message.type === MessageType.CharPressed) {
        var chr = message.character[0];
        var chrCode = message.character.charCodeAt(0);

        if (Char.isWhitespace(chr) === true && chr !== ' ') {
            return;
        }

        var modifiers = Char.listModifiers(chr);
        if ((modifiers.control == true || modifiers.alt == true || chrCode < 32) && chr != '\b') {
            this.handleSpecialCharacter(chrCode, modifiers.control, modifiers.alt);
            return;
        }

        if (chrCode < 32 && chr != '\b') {
            return;
        }

        switch (chr) {
            case '\b':
                this.removeCharacter();
                break;

            default:
                this.addCharacter(chr);
                break;
        }

    } else if (message.type === MessageType.VirtualKeyDown) {
        var code = message.code;

        switch (code) {
            case 0x23:
                this.setCaretExtreme(false);
                break;

            case 0x24:
                this.setCaretExtreme(true);
                break;

            case 0x25:
                this.moveCaret(true);
                break;

            case 0x27:
                this.moveCaret(false);
                break;

            case 0x2E:
                {
                    if (this.caretPos < this.curText.length) {
                        var startStr = "";
                        if (this.caretPos > 0) {
                            startStr = this.curText.substr(0, this.caretPos);
                        }

                        var endStr = "";

                        if (this.caretPos < this.curText.length) {
                            endStr = this.curText.substr(this.caretPos + 1, (this.curText.length - this.caretPos - 1));
                        }

                        this.curText = startStr + endStr;
                        this.updateCaret();
                    }
                }
                break;

            default:
                break;
        }
    }
}

TextBox.prototype.setCaretExtreme = function (left) {
    if (this.curText.length === 0) {
        return;
    }

    if (left === true && this.caretPos !== 0) {
        this.caretPos = 0;
        this.visibleText = "";
        this.visibleTextStart = 0;

        while (UI.measureString(this.visibleText) < 230 && this.visibleText.length < this.curText.length) {
            this.visibleText = this.curText.substr(0, this.visibleText.length + 1);
        }

        this.updateCaret();
    } else if (left === false && this.caretPos !== this.curText.length) {
        this.caretPos = this.curText.length;
        this.visibleTextStart = this.curText.length - 1;
        this.visibleText = this.curText.substr(this.visibleTextStart, 1);
        while (UI.measureString(this.visibleText) < 230 && this.visibleTextStart > 0) {
            --this.visibleTextStart;
            this.visibleText = this.curText.substr(this.visibleTextStart, this.curText.length - this.visibleTextStart);
        }

        this.updateCaret();
    }
}

TextBox.prototype.handleSpecialCharacter = function (char, ctrl, alt) {
    if (char === 3) {
        Debug.print("__missing_implementation__: CTRL + C");
    } else if (char === 22) {
        var text = System.getClipboardText();
        for (var i = 0; i < text.length; ++i) {
            this.addCharacter(text[i]);
        }
    }
}

TextBox.prototype.moveCaret = function (left) {
    if (left === true) {
        this.caretPos -= 1;
        if (this.caretPos < 0) {
            this.caretPos = 0;
            return;
        }

        if (this.caretPos === this.visibleTextStart) {
            this.visibleTextStart -= 10;
            if (this.visibleTextStart < 0) {
                this.visibleTextStart = 0;
            }

            this.visibleText = this.curText.substr(this.visibleTextStart, this.visibleText.length + 15);
            while (UI.measureString(this.visibleText) > 230) {
                this.visibleText = this.visibleText.substr(0, this.visibleText.length - 1);
            }
        }
    } else {
        this.caretPos += 1;
        if (this.caretPos > this.curText.length) {
            this.caretPos = this.curText.length;
            return;
        }

        if (this.caretPos >= this.visibleTextStart + this.visibleText.length) {
            var add = Math.min(this.curText.length - this.visibleTextStart - this.visibleText.length, 10);
            var endIndex = this.visibleTextStart + this.visibleText.length + add;

            this.visibleText = this.curText.substr(this.visibleTextStart, endIndex - this.visibleTextStart);

            while (UI.measureString(this.visibleText) > 230) {
                this.visibleTextStart += 1;
                this.visibleText = this.curText.substr(this.visibleTextStart, endIndex - this.visibleTextStart);
            }
        }
    }

    this.updateCaret();
}

TextBox.prototype.addCharacter = function (chr) {
    var startStr = "";
    if (this.caretPos > 0) {
        startStr = this.curText.substr(0, this.caretPos);
    }

    var endStr = "";

    if (this.caretPos < this.curText.length) {
        endStr = this.curText.substr(this.caretPos, (this.curText.length - this.caretPos));
    }

    this.curText = startStr + chr + endStr;
    this.caretPos += 1;

    var curTotalLength = UI.measureString(this.curText);
    if (curTotalLength <= 230) {
        this.visibleText = this.curText;
        this.visibleTextStart = 0;
    } else {
        if (this.caretPos === this.curText.length) {
            this.visibleText += chr;
            while (UI.measureString(this.visibleText) > 230) {
                this.visibleText = this.visibleText.substr(1, this.visibleText.length - 1);
                this.visibleTextStart += 1;
            }
        } else if ((this.caretPos - this.visibleTextStart) >= this.visibleText.length) {
            var add = Math.min(this.curText.length - this.visibleTextStart - this.visibleText.length, 10);
            var endIndex = this.visibleTextStart + this.visibleText.length + add;

            this.visibleText = this.curText.substr(this.visibleTextStart, endIndex - this.visibleTextStart);

            while (UI.measureString(this.visibleText) > 230) {
                this.visibleTextStart += 1;
                this.visibleText = this.curText.substr(this.visibleTextStart, endIndex - this.visibleTextStart);
            }
        } else {
            this.visibleText = this.curText.substr(this.visibleTextStart, Math.min(this.curText.length - this.visibleTextStart, this.visibleText.length + 5));

            while (UI.measureString(this.visibleText) > 230) {
                this.visibleText = this.visibleText.substr(0, this.visibleText.length - 1);
            }
        }
    }

    this.updateCaret();
}

TextBox.prototype.removeCharacter = function () {
    if (this.caretPos > this.curText.length || this.caretPos <= 0) {
        return;
    }

    var startStr = "";
    if (this.caretPos > 1) {
        startStr = this.curText.substr(0, this.caretPos - 1);
    }

    var endStr = "";

    if (this.caretPos < this.curText.length) {
        endStr = this.curText.substr(this.caretPos, (this.curText.length - this.caretPos));
    }

    var oldText = this.curText;

    this.curText = startStr + endStr;
    this.caretPos -= 1;

    if (this.caretPos == 0) {
        this.visibleText = "";
        this.visibleTextStart = 0;

        while (UI.measureString(this.visibleText) < 230 && this.visibleText.length < this.curText.length) {
            this.visibleText = this.curText.substr(0, this.visibleText.length + 1);
        }
    } else if (this.caretPos === this.visibleTextStart) {
        this.visibleTextStart -= 10;
        if (this.visibleTextStart <= 0) {
            this.visibleTextStart = 0;
        }

        this.visibleText = this.curText.substr(this.visibleTextStart, Math.min(this.curText.length - this.visibleTextStart, this.visibleText.length + 15));
        while (UI.measureString(this.visibleText) > 230) {
            this.visibleText = this.visibleText.substr(0, this.visibleText.length - 1);
        }
    } else {
        this.visibleTextStart -= 1;
        if(this.visibleTextStart <= 0) {
            this.visibleTextStart = 0;
        }

        this.visibleText = this.curText.substr(this.visibleTextStart, Math.min(this.curText.length - this.visibleTextStart, this.visibleText.length + 15));
        while (UI.measureString(this.visibleText) > 230) {
            this.visibleText = this.visibleText.substr(0, this.visibleText.length - 1);
        }
    }

    this.updateCaret();
}

TextBox.prototype.updateCaret = function () {
    if(this.caretPos === 0 || this.curText.length === 0) {
        this.prevCaretStr = "";
        this.prevCaretLen = 0.0;
        return;
    }

    var caretOffset = this.caretPos - this.visibleTextStart;

    this.prevCaretStr = this.curText.substr(this.visibleTextStart, caretOffset);
    this.prevCaretLen = UI.measureString(this.prevCaretStr);
}

TextBox.prototype.updateVisibleText = function () {
    var curTotalLength = UI.measureString(this.curText);
    if (curTotalLength < 230) {
        this.visibleText = this.curText;
        this.visibleTextStart = 0;
        return;
    }


}

TextBox.prototype.setPosition = function (pos) {
    if (typeof pos === "undefined") {
        return;
    }

    if (typeof pos.x === "undefined" || typeof pos.y === "undefined") {
        return;
    }

    this.curPosition = { x: pos.x, y: pos.y };

    this.texQuad.setPosition(pos.x, pos.y);
}