/* SPDX-License-Identifier: MIT */
/*
 * konscriptc.h
 *
 * Copyright (c) 2026 KonAki
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/*
 * what every converter uses to write konscript as C, so there is one place that does it and one place to check.
 * in one .c file: #define KONSCRIPTC_IMPLEMENTATION before including it
 *
 * the text goes through the real parser first, so every jump lands on a label that is there, and nothing is written if it
 * doesn't parse. what comes out is only constant data: a list of kon_cmd_t, a sorted list of labels and a find function.
 * strings are written as literals where everything but plain printable characters is an octal escape, so what is in the
 * script can't be anything but text to the compiler. there is no pointer arithmetic, no generated logic and nothing to overrun
 *
 * writes prefix.h and prefix.c, and with split also prefix_0.inc, prefix_1.inc and so on that prefix.c includes inside
 * the one array, so a big script is several files for the editor and one list for the program
 */

#ifndef KONSCRIPTC_H
#define KONSCRIPTC_H

#include <stdio.h>

#ifdef __cplusplus
extern "C" {
#endif

typedef struct konsc_result {
	int commands, labels;
} konsc_result_t;

/* name is the start of every name in the files, letters digits and _, not starting with a digit.
   split is how many commands go in each .inc, 0 for none. 0 if it worked, -1 and a message in error if not */
int konsc_write(const char *source, size_t size, const char *prefix, const char *name, int split, konsc_result_t *result, char *error, int errorSize);

/* a C string literal of s, or NULL. long ones are cut into pieces the compiler joins */
void konsc_string(FILE *f, const char *s);

/* a name for the files made from the end of a path, "out/my game.c" becomes my_game */
void konsc_name(char *out, size_t size, const char *path);

#ifdef __cplusplus
}
#endif

#ifdef KONSCRIPTC_IMPLEMENTATION

#include "konscript.h"

#include <ctype.h>
#include <stdlib.h>
#include <string.h>

static const char *const konsc__ops[] = {
	"KON_OP_END", "KON_OP_SAY", "KON_OP_MENU", "KON_OP_OPTION", "KON_OP_JUMP", "KON_OP_SWITCH", "KON_OP_VAR",
	"KON_OP_IFSWITCH", "KON_OP_IFVAR", "KON_OP_WAIT", "KON_OP_HOST", "KON_OP_CALL", "KON_OP_RETURN"
};

static int konsc__compareLabels(const void *a, const void *b)
{
	return strcmp(((const kon_scriptLabel_t *)a)->name, ((const kon_scriptLabel_t *)b)->name);
}

void konsc_string(FILE *f, const char *s)
{
	size_t i, column = 0;

	if (!s) {
		fputs("NULL", f);
		return;
	}
	fputc('"', f);
	for (i = 0; s[i]; i++) {
		unsigned char c = (unsigned char)s[i];

		if (column >= 100) {
			fputs("\"\n\t\t\"", f);
			column = 0;
		}
		if (c == '"' || c == '\\' || c == '?') {
			fprintf(f, "\\%c", c);
			column += 2;
		} else if (c == '\n' || c == '\t') {
			fputs(c == '\n' ? "\\n" : "\\t", f);
			column += 2;
		} else if (c >= 0x20 && c < 0x7F) {
			fputc(c, f);
			column++;
		} else {
			fprintf(f, "\\%03o", c);
			column += 4;
		}
	}
	fputc('"', f);
}

void konsc_name(char *out, size_t size, const char *path)
{
	const char *base = strrchr(path, '/');
	size_t i, n = 0;

	base = base ? base + 1 : path;
	for (i = 0; base[i] && base[i] != '.' && n + 1 < size; i++) out[n++] = isalnum((unsigned char)base[i]) ? (char)tolower((unsigned char)base[i]) : '_';
	out[n] = '\0';
	if (!n || isdigit((unsigned char)out[0])) {
		memmove(out + 1, out, n + 1 < size ? n + 1 : size - 1);
		out[0] = 'k';
	}
}

static void konsc__row(FILE *f, const kon_cmd_t *c)
{
	fprintf(f, "\t{%s, %d, %d, %d, %d, ", konsc__ops[c->op], c->a, c->b, c->c, c->d);
	konsc_string(f, c->text);
	fputs("},\n", f);
}

static int konsc__fail(char *error, int errorSize, const char *what, const char *detail)
{
	if (error && errorSize > 0) snprintf(error, (size_t)errorSize, "%s%s", what, detail ? detail : "");
	return -1;
}

static FILE *konsc__create(const char *prefix, const char *suffix, char *error, int errorSize)
{
	char path[1024];
	FILE *f;

	if (snprintf(path, sizeof path, "%s%s", prefix, suffix) >= (int)sizeof path) {
		konsc__fail(error, errorSize, "path too long", NULL);
		return NULL;
	}
	f = fopen(path, "wb");
	if (!f) konsc__fail(error, errorSize, "cannot write ", path);
	return f;
}

int konsc_write(const char *source, size_t size, const char *prefix, const char *name, int split, konsc_result_t *result, char *error, int errorSize)
{
	char upper[64];
	const char *base = strrchr(prefix, '/');
	kon_scriptBuild_t b;
	kon_cmd_t *cmds;
	size_t k;
	int i, rows, lines = 1, status = -1;
	FILE *f;

	base = base ? base + 1 : prefix;
	if (!name[0] || strlen(name) >= sizeof upper || isdigit((unsigned char)name[0])) return konsc__fail(error, errorSize, "the name has to be letters, digits and _ and not start with a digit", NULL);
	for (k = 0; name[k]; k++) {
		if (!isalnum((unsigned char)name[k]) && name[k] != '_') return konsc__fail(error, errorSize, "the name has to be letters, digits and _ and not start with a digit", NULL);
		upper[k] = (char)toupper((unsigned char)name[k]);
	}
	upper[k] = '\0';
	if (split < 0 || size > 1000000000u) return konsc__fail(error, errorSize, "bad split or a script that is too big", NULL);

	for (k = 0; k < size; k++) {
		if (source[k] == '\n') lines++;
	}
	memset(&b, 0, sizeof b);
	b.maxCmds = lines + 2;
	b.maxLabels = lines + 2;
	b.poolSize = (int)size + 16;
	b.hashSize = 16;
	while (b.hashSize < 2 * b.maxLabels) b.hashSize *= 2;
	cmds = malloc((size_t)b.maxCmds * sizeof *cmds);
	b.cmds = cmds;
	b.pool = malloc((size_t)b.poolSize);
	b.labels = malloc((size_t)b.maxLabels * sizeof *b.labels);
	b.hash = malloc((size_t)b.hashSize * sizeof *b.hash);
	if (!cmds || !b.pool || !b.labels || !b.hash) {
		konsc__fail(error, errorSize, "out of memory", NULL);
		goto done;
	}
	if (!kon_scriptParse(&b, source)) {
		if (error && errorSize > 0) snprintf(error, (size_t)errorSize, "line %d: %s", b.errorLine, b.error);
		goto done;
	}

	/* a label at the very end would point past the list, so the list gets an end of its own to land on */
	cmds[b.count].op = KON_OP_END;
	cmds[b.count].a = cmds[b.count].b = cmds[b.count].c = cmds[b.count].d = 0;
	cmds[b.count].text = NULL;
	rows = b.count + 1;
	qsort(b.labels, (size_t)b.labelCount, sizeof *b.labels, konsc__compareLabels);

	if (split) {
		int part, first;

		for (part = 0, first = 0; first < rows; part++, first += split) {
			char suffix[32];
			int last = first + split < rows ? first + split : rows;

			snprintf(suffix, sizeof suffix, "_%d.inc", part);
			f = konsc__create(prefix, suffix, error, errorSize);
			if (!f) goto done;
			fprintf(f, "/* part %d of %s, commands %d to %d, included by %s.c */\n", part, name, first, last - 1, base);
			for (i = first; i < last; i++) konsc__row(f, &cmds[i]);
			if (fclose(f) != 0) {
				konsc__fail(error, errorSize, "write failed", NULL);
				goto done;
			}
		}
	}

	f = konsc__create(prefix, ".c", error, errorSize);
	if (!f) goto done;
	fprintf(f, "/* made by konscriptc, don't edit */\n\n#include \"%s.h\"\n\n#include <string.h>\n\n", base);
	fprintf(f, "const int %s_count = %d;\n\n", name, rows);
	fprintf(f, "const kon_cmd_t %s_cmds[%d] = {\n", name, rows);
	if (split) {
		int part, first;

		for (part = 0, first = 0; first < rows; part++, first += split) fprintf(f, "#include \"%s_%d.inc\"\n", base, part);
	} else {
		for (i = 0; i < rows; i++) konsc__row(f, &cmds[i]);
	}
	fprintf(f, "};\n\n");
	fprintf(f, "const int %s_labelCount = %d;\n\n", name, b.labelCount);
	fprintf(f, "const kon_scriptLabel_t %s_labels[%d] = {\n", name, b.labelCount > 0 ? b.labelCount : 1);
	for (i = 0; i < b.labelCount; i++) {
		fputs("\t{", f);
		konsc_string(f, b.labels[i].name);
		fprintf(f, ", %d},\n", b.labels[i].at);
	}
	if (b.labelCount == 0) fputs("\t{\"\", 0}\n", f);
	fputs("};\n\n", f);
	fprintf(f, "int %s_find(const char *label)\n{\n\tint low = 0, high = %s_labelCount - 1;\n\n", name, name);
	fprintf(f, "\twhile (low <= high) {\n\t\tint mid = low + (high - low) / 2;\n\t\tint order = strcmp(label, %s_labels[mid].name);\n\n", name);
	fprintf(f, "\t\tif (order == 0) return %s_labels[mid].at;\n\t\tif (order < 0) high = mid - 1;\n\t\telse low = mid + 1;\n\t}\n\treturn -1;\n}\n", name);
	if (fclose(f) != 0) {
		konsc__fail(error, errorSize, "write failed", NULL);
		goto done;
	}

	f = konsc__create(prefix, ".h", error, errorSize);
	if (!f) goto done;
	fprintf(f, "/* made by konscriptc, don't edit */\n\n#ifndef %s_H\n#define %s_H\n\n#include \"konscript.h\"\n\n", upper, upper);
	fputs("#ifdef __cplusplus\nextern \"C\" {\n#endif\n\n", f);
	fprintf(f, "#define %s_COUNT %d\n\n", upper, rows);
	fprintf(f, "extern const int %s_count;\nextern const kon_cmd_t %s_cmds[%d];\n", name, name, rows);
	fprintf(f, "extern const int %s_labelCount;\nextern const kon_scriptLabel_t %s_labels[%d];\n\n", name, name, b.labelCount > 0 ? b.labelCount : 1);
	fprintf(f, "/* where a label is, or -1 */\nint %s_find(const char *label);\n\n", name);
	fputs("#ifdef __cplusplus\n}\n#endif\n#endif\n", f);
	if (fclose(f) != 0) {
		konsc__fail(error, errorSize, "write failed", NULL);
		goto done;
	}

	if (result) {
		result->commands = rows;
		result->labels = b.labelCount;
	}
	status = 0;
done:
	free(cmds);
	free(b.pool);
	free(b.labels);
	free(b.hash);
	return status;
}

#endif /* end of KONSCRIPTC_IMPLEMENTATION */
#endif