/*
  Copyright (C) 2019, 2020 Leo Tenenbaum.
  This file is part of toc. toc is distributed under version 3 of the GNU General Public License, without any warranty whatsoever.
  You should have received a copy of the GNU General Public License along with toc. If not, see <https://www.gnu.org/licenses/>.
*/

/* 
   NOTE:
   Structure of the toc compiler:
   tokenizer => parser => typing (types.c) => typdefs_cgen, decls_cgen, cgen 
   (lexing)

   toc tries to continue even after the first error. 
   It will not continue during cgen, but it will during tokenization,
   parsing, and typing. If one stage fails, the following ones do not
   start.
*/

/* 
TODO:
packages
---
X ::= newtype(int); or something
don't allow while {3; 5} (once break is added)
better printing of types (take was_expr into account)
any odd number of "s for a string
make sure futurely/currently-declared types are only used by pointer/slice
allow omission of trailing ; in foo ::= fn() {}?
 */


#include "toc.c"


int main(int argc, char **argv) {
#ifdef TOC_DEBUG
	test_all();
#endif

	const char *in_filename;
	if (argc < 2) {
#ifdef TOC_DEBUG
		in_filename = "test.toc";
#else
		fprintf(stderr, "Please specify an input file.\n");
		return EXIT_FAILURE;
#endif
	} else {
		in_filename = argv[1];
	}
	const char *out_filename = "out.c";

	for (int i = 2; i < argc-1; ++i) {
		if (strcmp(argv[i], "-o") == 0)
			out_filename = argv[i+1];
	}
	
	FILE *in = fopen(in_filename, "r");
	if (!in) {
		fprintf(stderr, "Could not open file: %s.\n", argv[1]);
		return EXIT_FAILURE;
	}
	
	char *contents = err_malloc(4096);
	long contents_cap = 4095;
	long contents_len = 0;
	while (fgets(contents + contents_len, (int)(contents_cap - contents_len), in)) {
		contents_len += (long)strlen(contents + contents_len);
		
		if (contents_len >= (long)contents_cap - 1024) {
			contents_cap *= 2;
			/* allocate +1 so that pointers don't overflow */
			contents = err_realloc(contents, (size_t)contents_cap + 1);
		}
	}
	if (ferror(in)) {
		fprintf(stderr, "Error reading input file: %s.\n", argv[1]);
		return EXIT_FAILURE;
	}
	fclose(in);
	Identifiers idents;
	idents_create(&idents);
	Tokenizer t;
	Allocator main_allocr;
	allocr_create(&main_allocr);
	ErrCtx err_ctx = {0};
	err_ctx.filename = in_filename;
	err_ctx.enabled = true;
	tokr_create(&t, &idents, &err_ctx, &main_allocr);
	if (!tokenize_string(&t, contents)) {
		
		err_fprint(TEXT_IMPORTANT("Errors occured while preprocessing.\n"));
		return EXIT_FAILURE;
	}

#if 0
	arr_foreach(t.tokens, Token, token) {
		if (token != t.tokens)
			printf("    ");
		fprint_token(stdout, token);
	}
	printf("\n");
#endif
	
	Parser p;
	parser_create(&p, &t, &main_allocr);
	ParsedFile f;
	if (!parse_file(&p, &f)) {
		
		err_fprint(TEXT_IMPORTANT("Errors occured while parsing.\n"));
		return EXIT_FAILURE;
	}
	/* fprint_parsed_file(stdout, &f); */
	/* printf("\n\n-----\n\n"); */
	
	tokr_free(&t);
	
	Typer tr;
	Evaluator ev;
	Exporter exptr;
	evalr_create(&ev, &tr, &main_allocr);
	typer_create(&tr, &ev, &main_allocr);
	tr.exptr = &exptr;
	
#ifdef TOC_DEBUG
	FILE *out_pkg = fopen("out.top", "wb");
	exptr_create(&exptr, out_pkg, contents);
	exptr.export_locations = false;
#endif
	if (!block_enter(NULL, f.stmts, SCOPE_CHECK_REDECL)) /* enter global scope */
		return false;

	if (!types_file(&tr, &f)) {
		/* TODO(eventually): fix this if the error occured while exporting something */
	    err_fprint(TEXT_IMPORTANT("Errors occured while determining types.\n"));
		return EXIT_FAILURE;
	}
#ifdef TOC_DEBUG
	if (!exptr_finish(&exptr)) {
		fclose(out_pkg);
		err_fprint(TEXT_IMPORTANT("Errors occured while exporting things.\n"));
		return EXIT_FAILURE;
	}
	fclose(out_pkg);
#endif
#ifdef TOC_DEBUG
	printf("\n\n");	
	fprint_parsed_file(stdout, &f);
#endif
	FILE *out = fopen(out_filename, "w");
	if (!out) {
		err_fprint(TEXT_IMPORTANT("Could not open output file (out.c).\n"));
		return EXIT_FAILURE;
	}
	CGenerator g;
	cgen_create(&g, out, &idents, &ev, &main_allocr);
	if (!cgen_file(&g, &f)) {
		fclose(out);
		err_fprint(TEXT_IMPORTANT("Errors occured while generating C code.\n"));
		return EXIT_FAILURE;
	}
	
	block_exit(NULL, f.stmts); /* exit global scope */
	
	free(contents);
	allocr_free_all(&main_allocr);
	evalr_free(&ev);
	
	fclose(out);
	idents_free(&idents);
	return 0;
}