#!/usr/bin/env node
/* js-codepage (C) 2014-present SheetJS -- http://sheetjs.com */
/* vim: set ts=2 ft=javascript: */
/* eslint-env node */
var codepage = require('codepage');
require('exit-on-epipe');
var fs = require('fs'), program/*:any*/ = (require('commander')/*:any*/);
function run() {
	program
		.version(codepage.version)
		.usage('[options] <file>')
		.option('-f, --from-code <code>', 'codepage of input (default 65001 utf8)')
		.option('-t, --to-code <code>', 'codepage of output (default 65001 utf8)')
		.option('-o, --output <file>', 'output file (<file>.<to> if specified)')
		.option('-B, --bom', 'write BOM (for unicode codepages)')
		.option('-F, --force', 'force writing to stdout for non-utf8 codepages')
		.option('-l, --list', 'List supported codepages');

	program.on('--help', function () {
		console.log('  Codepage descriptions can be found in the README');
		console.log('      http://oss.sheetjs.com/js-codepage/README.md');
		console.log('  Support email: dev.codepage@sheetjs.com');
	});

	program.parse(process.argv);

	if (program.list) {
		var l/*:Array<number>*/ = [];
		Object.keys(codepage).forEach(function (x) { if (parseInt(x, 10) == +x) l.push(+x); });
		Object.keys(codepage.utils.magic).forEach(function (x) { if (parseInt(x, 10) == +x && +x != 16969) l.push(+x); });
		l.sort(function (a, b) { return a - b; }).forEach(function (x) { console.log(x); });
		process.exit();
	}

	var fr = +program.fromCode || 65001;
	var to = +program.toCode || 65001;
	var f = program.args[0];
	var o = program.output;

	if (!process.stdin.isTTY) f = f || "-";

	if (f !== "-" && !fs.existsSync(f)) {
		console.error('codepage: must specify a filename');
		process.exit(13);
	}

	function concat(func) {
		// $FlowIgnore
		var writable = require('stream').Writable();
		var buf = [];
		writable._write = function (chunk, e, cb) { buf.push(chunk); cb(); };
		writable._writev = function (chunks, cb) { chunks.forEach(function (c) { buf.push(c.chunk); cb(); }); };
		writable.on('finish', function () { func(Buffer.concat(buf)); });
		return writable;
	}

	if (f === "-") process.stdin.pipe(concat(process_text));
	else process_text(fs.readFileSync(f));

	function process_text(text/*:Buffer*/) {
		var dec/*:Buffer*/ = (codepage.utils.decode(fr, text)/*:any*/);

		var bom/*:Array<Buffer>*/ = [];
		bom[1200] = new Buffer([0xFF, 0xFE]);
		bom[1201] = new Buffer([0xFE, 0xFF]);
		bom[12000] = new Buffer([0xFF, 0xFE, 0x00, 0x00]);
		bom[12001] = new Buffer([0x00, 0x00, 0xFE, 0xFF]);
		bom[16969] = new Buffer([0x69, 0x69]);
		bom[65000] = new Buffer([0x2B, 0x2F, 0x76, 0x2B]);
		bom[65001] = new Buffer([0xEF, 0xBB, 0xBF]);

		var mybom = (program.bom && bom[to] ? bom[to] : "");
		var out/*:any*/ = to === 65001 ? dec.toString('utf8') : codepage.utils.encode(to, dec);

		/* if output file is specified */
		if (o) writefile(o, out, mybom);
		/* utf8 -> print to stdout */
		else if (to === 65001) logit(out, mybom);
		/* stdout piped to process -> print */
		else if (!process.stdout.isTTY) logit(out, mybom);
		/* forced */
		else if (program.force) logit(out, mybom);
		/* input file specified -> write to file */
		else if (f !== "-") writefile(f + "." + to, out, mybom);
		else {
			console.error('codepage: use force (-F, --force) to print ' + to + ' codes');
			process.exit(14);
		}
	}

	function logit(out/*:Buffer*/, bom) {
		process.stdout.write(bom);
		process.stdout.write(out);
	}

	function writefile(o, out/*:Buffer*/, bom) {
		fs.writeFileSync(o, bom);
		fs.appendFileSync(o, out);
	}
} 

module.exports = run;