'use strict';

import * as vscode from 'vscode';

import * as fs from 'fs';

import { sprintf } from 'sprintf-js';

import { getFileSize, getBuffer } from './util';

var hexdump = require('hexy');

export default class HexdumpContentProvider implements vscode.TextDocumentContentProvider {

private static s_instance: HexdumpContentProvider = null;

private _onDidChange = new vscode.EventEmitter<vscode.Uri>();

constructor() {

if(HexdumpContentProvider.s_instance) {

HexdumpContentProvider.s_instance.dispose();

}

HexdumpContentProvider.s_instance = this;

}

static get instance() {

return HexdumpContentProvider.s_instance;

}

public dispose() {

this._onDidChange.dispose();

if(HexdumpContentProvider.s_instance) {

HexdumpContentProvider.s_instance.dispose();

HexdumpContentProvider.s_instance = null;

}

}

public provideTextDocumentContent(uri: vscode.Uri): Thenable<string> {

const config = vscode.workspace.getConfiguration('hexdump');

const hexLineLength = config['width'] * 2;

const firstByteOffset = config['showAddress'] ? 10 : 0;

const lastByteOffset = firstByteOffset + hexLineLength + hexLineLength / config['nibbles'] - 1;

const firstAsciiOffset = lastByteOffset + (config['nibbles'] == 2 ? 4 : 2);

const lastAsciiOffset = firstAsciiOffset + config['width'];

const charPerLine = lastAsciiOffset + 1;

const sizeWarning = config['sizeWarning'];

const sizeDisplay = config['sizeDisplay'];

return new Promise( async (resolve) => {

let hexyFmt = {

format : config['nibbles'] == 8 ? 'eights' :

config['nibbles'] == 4 ? 'fours' :

'twos',

width : config['width'],

caps : config['uppercase'] ? 'upper' : 'lower',

numbering : config['showAddress'] ? "hex_digits" : "none",

annotate : config['showAscii'] ? "ascii" : "none",

length : sizeDisplay

};

let header = config['showOffset'] ? this.getHeader() : "";

let tail = '(Reached the maximum size to display. You can change "hexdump.sizeDisplay" in your settings.)';

let proceed = getFileSize(uri) < sizeWarning ? 'Open' : await vscode.window.showWarningMessage('File might be too big, are you sure you want to continue?', 'Open');

if (proceed == 'Open') {

let buf = getBuffer(uri);

let hexString = header;

hexString += hexdump.hexy(buf, hexyFmt).toString();

if (buf.length > sizeDisplay) {

hexString += tail;

}

return resolve(hexString);

} else {

return resolve('(hexdump cancelled.)');

}

});

}

get onDidChange(): vscode.Event<vscode.Uri> {

return this._onDidChange.event;

}

public update(uri: vscode.Uri) {

this._onDidChange.fire(uri);

}

private getHeader(): string {

const config = vscode.workspace.getConfiguration('hexdump');

let header = config['showAddress'] ? " Offset: " : "";

for (var i = 0; i < config['width']; ++i) {

header += sprintf('%02X', i);

if ((i+1) % (config['nibbles'] / 2) == 0) {

header += ' ';

}

}

header += "\t\n";

return header;

}

}