1 files changed, 133 insertions, 0 deletions
diff --git a/source/checkParams.c b/source/checkParams.c
new file mode 100644
index 0000000..47bdeef
--- /dev/null
+++ b/source/checkParams.c
@@ -0,0 +1,133 @@
+/*
+	Copyright 2022-2023 Gabriel Bjørnager Jensen.
+
+	This file is part of agbsum.
+
+	agbsum is free software: you can redistribute it
+	and/or modify it under the terms of the GNU
+	Affero General Public License as published by
+	the Free Software Foundation, either version 3
+	of the License, or (at your option) any later
+	version.
+
+	agbsum is distributed in the hope that it will
+	be useful, but WITHOUT ANY WARRANTY; without
+	even the implied warranty of MERCHANTABILITY
+	or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU Affero General Public License for more
+	details.
+
+	You should have received a copy of the GNU
+	Affero General Public License along with agbsum.
+	If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <agbsum.h>
+
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+noreturn static void
+agb_expectedParamValue (char const charParam)
+{
+	fprintf (stderr, "Expected value for character parameter '%c'\n", charParam);
+	agb_exit (agb_Cnd_Error, NULL);
+}
+
+static bool
+agb_checkCharParam (struct agb_Data* const restrict data, char const* const restrict param)
+{
+	// Returns true if the rest of the parameter is
+	// used as a value.
+
+	char const charParam = param[0x0];
+	if (charParam == '\x0') {return true;}
+
+	char const* const restrict paramval = &param[0x1];
+
+	switch (charParam) {
+	default:
+		fprintf (stderr, "Invalid character parameter '%c'\n", charParam);
+		agb_exit (agb_Cnd_Error, NULL);
+
+	case 'h':
+		agb_help ();
+		agb_exit (agb_Cnd_Ok, NULL);
+
+	case 'i':
+		{
+			if (paramval[0x0] == '\x0') {agb_expectedParamValue (charParam);}
+			data->path = paramval;
+		}
+		return true;
+
+	case 'p':
+		data->doPatch = true;
+		return false;
+
+	case 's':
+		data->silent = true;
+		return false;
+	}
+}
+
+void
+agb_checkParams (struct agb_Data* const restrict data, int const argc, char const* const* const argv) {
+	if (argc < 0x2) {
+		agb_help ();
+		agb_exit (agb_Cnd_Ok, NULL);
+	}
+
+	size_t const numParams = argc; // Prettier.
+
+	for (ptrdiff_t index = 0x1; index < (ptrdiff_t)numParams; ++index) {
+		// Iterate over the parameters. One hyphen denotes character parameters (-h) whilst two denote long paramters (--help).
+
+		char const* const param = argv[index];
+		if (param[0x0] == '-') {
+			if (param[0x1] == '-') {
+				char const* const longParam = &param[0x2];
+
+				// Check long parameters.
+
+				if (longParam[0x0] == '\x0') {
+					fputs ("Missing long parameter after '--' sequence\n", stderr);
+					agb_exit (agb_Cnd_Error, NULL);
+				}
+
+				if (!strcmp (longParam, "help")) {
+					agb_help ();
+					agb_exit (agb_Cnd_Ok, NULL);
+				}
+
+				if (!strcmp (longParam, "version")) {
+					agb_copyright();
+					agb_exit (agb_Cnd_Ok, NULL);
+				}
+
+				fprintf (stderr, "Invalid long parameter \"%s\"\n", longParam);
+				agb_exit (agb_Cnd_Error, NULL);
+			}
+
+			if (param[0x1] == '\x0') {
+				fputs ("Missing character parameter after '-'\n", stderr);
+				agb_exit (agb_Cnd_Error, NULL);
+			}
+
+			// Check character parameters.
+
+			for (char const* charIndex = &param[0x1];; ++charIndex) { if (agb_checkCharParam (data, charIndex)) { break; } }
+
+			continue;
+		}
+
+		// We did not find the 'i' parameter, so we don't know where the ROM is.
+
+		if (data->path == NULL) {
+			fputs ("ROM not set (missing character parameter 'i')\n", stderr);
+			agb_exit (agb_Cnd_Error, NULL);
+		}
+	}
+}