var fs = require('fs');

//////////////////////////
// Library Initialization
//////////////////////////

// checking for command line arguments
var argv = process.argv;

if (argv.length != 4) {
    console.log('Incorrect number of command line arguments');
    console.log('Usage: node example.js full_path_to_dir_containing_jsjibonlu full_path_to_datadir')
    console.log('Example: node example.js /Users/my_user/my_directory_containig_jsjibonlu/ /Users/my_user/my_directory/data');
    process.exit(1);
}

// gteting install prefix
var install_prefix = argv[2];
var datadir = argv[3];

// Loading jsjibonlu library
var jsjibonlu = require(install_prefix + '/jsjibonlu');

// Setting datapath (directory with factory rules
// and word lists
jsjibonlu.set_data_dir(datadir)

// Setting fst error behavior so that it does not crash
// every time there is an error
jsjibonlu.set_fst_error_behavior();

//////////////////////////
// Compiling a rule
//////////////////////////

// Rule to be compiled
var grm = "TopRule = $* hello{nl='hello'}|goodbye{nl='goodbye'} $* $factory:date{date=date._date_nl} $* ;";

// Compiling rule (use a handle name)
var fst1 = jsjibonlu.compile_fst_from_text(grm, "handle:my_handle");

//////////////////////////
// Parsing 
//////////////////////////

// Creating rule parser
var parser = jsjibonlu.build_sentence_parser(fst1);

// Parsing sentence
var sentence = "aaaa hello and the day is july the 29th of the year 1995 yeah";
var parses_json = parser.parse_sentence(sentence);
var parses_obj = JSON.parse(parses_json);
console.log("*** These are the parses of sentence:" + sentence)
console.log(parses_obj)

//////////////////////////
// Parsing from an fst that is already
// in memory
//////////////////////////
var fst4 = jsjibonlu.read_fst_from_uri("handle:my_handle");
var parser = jsjibonlu.build_sentence_parser(fst4);
var sentence = "aaaa hello and the day is july the 29th of the year 1995 yeah";
var parses_json = parser.parse_sentence(sentence);
var parses_obj = JSON.parse(parses_json);
console.log("*** These are the parses of sentence:" + sentence)
console.log(parses_obj)

//////////////////////////
// Saving compiled fst
//////////////////////////
// Saving compiled rule
fst1.save_fst("myfst.fst");

//////////////////////////
// getting buffer from copiled fst 
//////////////////////////
// getting buffer 
buf = fst1.to_buffer();
console.log("*** example of fst returned as a buffer");
console.log(buf);

//////////////////////////
// Openingfst from file
//////////////////////////
var fst2 = jsjibonlu.read_fst_from_uri("file:myfst.fst");
var fst3 = jsjibonlu.load_fst_from_fst_file("./myfst.fst", "handle:my_fst_file_handle");

//////////////////////////
// Parsing Using fst in parallel
//////////////////////////

// Creating parallel parser
fsts = [fst1, fst2];
var parser = jsjibonlu.build_sentence_parser(fsts);

// Parsing sentence
var sentence = "aaaa hello and the day is july the 29th of the year 1995 yeah";
var parses_json = parser.parse_sentence(sentence);
var parses_obj = JSON.parse(parses_json);
console.log("*** These are the parses of sentence:" + sentence)
console.log(parses_obj)

//////////////////////////
// Parsing with union fst 
//////////////////////////

// grms 
var grm_union_1 = "TopRule = $* hello{nl='hello'}|goodbye{nl='goodbye'} $* $factory:date{date=date._date_nl} $* ;";
var grm_union_2 = "TopRule = $* here{nl='here'}|there{nl='there'} $* $factory:date{date=date._date_nl} $* ;";

// Compiling rule (use a handle name)
var fst_union_part1 = jsjibonlu.compile_fst_from_text(grm_union_1, "handle:my_handle_union_1");
var fst_union_part2 = jsjibonlu.compile_fst_from_text(grm_union_2, "handle:my_handle_union_2");

// get the union
var fst_union = jsjibonlu.union_fst(["handle:my_handle_union_1", "handle:my_handle_union_2"], "handle:my_handle_union_handle");

// remove parts from memory
jsjibonlu.remove_from_memory("handle:my_handle_union_1");
jsjibonlu.remove_from_memory("handle:my_handle_union_2");

// parse
var parser_union = jsjibonlu.build_sentence_parser(fst_union);
var parsed_union = parser_union.parse_sentence("hello july 31st 1995");
var parsed_union = parser_union.parse_sentence("here july 31st 1995");

///////////////////////////
// Removing rom memory
//////////////////////////
// Atempting to remove from memory a uri that does not exist
// will not throw an error
jsjibonlu.remove_from_memory("file:myfst.fst");
jsjibonlu.remove_from_memory("handle:my_handle");
// the statement in the following line will fail, since it has been removed from memory:
// var fst3 = jsjibonlu.read_fst_from_uri("handle:my_handle");

///////////////////////////
// syntax check (without compiling) 
//////////////////////////

// The only difference between compile_fst_from_text and
// syntax_check is that syntax_check does not compile the 
// fst. all the syntax checks are exactly the same.
// compile_fst_from_text throws exactly the same errors
// (in the same json format) when finding syntax errors

// correcty syntax (does not throw)
jsjibonlu.syntax_check(grm);

// incorrect syntax (does throw)
var wrong_rule = "TopRule = a b c $a {ret='a'}; a = a {m='b};"
try {
    jsjibonlu.syntax_check(wrong_rule)
} catch (e) {
    err_obj = JSON.parse(e.message);
    console.log("*** Example of compilation error object:");
    console.log(err_obj);
    console.log("*** example of error member in the error object:");
    console.log(err_obj.info.msg);
}


// Rule to be compiled
var grm = "TopRule = $* hello{nl='hello'}|goodbye{nl='goodbye'} $* $factory:date{date=date._date_nl} $* ;";

// Compiling rule (use a handle name)
var fst1 = jsjibonlu.compile_fst_from_text(grm, "handle:my_handle");

//////////////////////////
// Parsing 
//////////////////////////

// Compiling rule (use a handle name)
grm = "TopRule = $handle:hndl{nl=hndl._nl};";
hndl = "TopRule = julius{_nl='julius'}|marcus{_nl='marcus'};";
var fst1 = jsjibonlu.compile_fst_from_text(grm, "handle:my_handle");
var fst2 = jsjibonlu.compile_fst_from_text(hndl, "handle:hndl");

var parser = jsjibonlu.build_sentence_parser(fst1);

var sentence = 'julius';
console.log("*** Example parsing with handle rules referenced inside another rule:");
var parses_json = parser.parse_sentence(sentence);
console.log(parses_json);
var sentence = 'marcus';
var parses_json = parser.parse_sentence(sentence);
console.log(parses_json);

///////////////////////
// With include files
///////////////////////

grm = "TopRule = $include:./myfile.rule:my_rule;";
fs.writeFileSync("./myfile.rule","my_rule = aa;\n");
jsjibonlu.syntax_check(grm, process.cwd() + "/file.rule");
var f = function()  {jsjibonlu.syntax_check(grm, process.cwd() + "/file.rule");};

////////////////////////
// reset memory example
////////////////////////

// reset memory eliminates all fsts from memory, except for factories
jsjibonlu.reset_memory();

////////////////////////
// change locale example 
////////////////////////
jsjibonlu.reset_memory();
jsjibonlu.change_locale('zh-cn');
grm = "TopRule = [$factory:yes_no{% nl = this.yes_no._nl %}];";
txt = "是";
var fst1 = jsjibonlu.compile_fst_from_text(grm, "handle:my_handle");
var parser = jsjibonlu.build_sentence_parser(fst1);
var parses_json = parser.parse_sentence(txt);
console.log("*** Example parsing with different locale");
console.log(parses_json);

////////////////////////
// locale back to en-us
////////////////////////
jsjibonlu.reset_memory();
jsjibonlu.change_locale('en-us');