#define _POSIX_C_SOURCE 200809L

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdnoreturn.h>
#include <string.h>
#include "lex.h"
#include "parse.h"
#include "util.h"

static noreturn void
error(struct location loc, const char *fmt, ...)
{
	fprintf(stderr, "%s:%d:%d ", loc.file, loc.line, loc.column);

	va_list ap;
	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	va_end(ap);

	fprintf(stderr, "\n");
	exit(EXIT_CHECK);
}

static void
check_import(struct ast_import *imports, int i)
{
	for (int j = 0; j < i; ++j) {
		if (j == i) {
			continue;
		}

		if (!strcmp(imports[j].name, imports[i].name)) {
			error(imports[i].loc,
				"import collision (previous import at %s:%d:%d)",
				imports[j].loc.file,
				imports[j].loc.line,
				imports[j].loc.column);
		}
	}
}

static void
check_imports(struct ast_import *imports, int n)
{
	for (int i = 0; i < n; ++i) {
		check_import(imports, i);
	}
}

static void
check_toplevels(struct ast_toplevel *tops, int n)
{
	/* TODO */
}

void
check(struct ast_unit *ast)
{
	check_imports(ast->imports, ast->implen);
	check_toplevels(ast->tops, ast->toplen);
}