/* SPDX-License-Identifier: MIT */
/*
 * konscript.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.
 */

#ifndef KONSCRIPT_H
#define KONSCRIPT_H

#include <stddef.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

/*** definition ***/

/* a script is a flat list of commands and jumps go to a place in the list. no nesting, so a converter can write one
(or write it as C) without a parser, and a person can write one by hand. the program does the talking and the
showing: say, menus and anything else the script cannot know about are handed over and the script waits */

typedef enum {
	KON_OP_END,
	KON_OP_SAY,	/* a: who (your own number, -1 for nobody), text */
	KON_OP_MENU,	/* a: how many OPTION commands follow */
	KON_OP_OPTION,	/* a: where to go, b: switch that must be on to show it (-1 always), text */
	KON_OP_JUMP,	/* a: where */
	KON_OP_SWITCH,	/* a: switch, b: 0 off, 1 on, 2 flip */
	KON_OP_VAR,	/* a: variable, b: KON_SET.., c: number, or KON_VARIABLE + a variable */
	KON_OP_IFSWITCH,	/* a: switch, b: wanted 0 or 1, c: where to go if it is not */
	KON_OP_IFVAR,	/* a: variable, b: KON_IS.., c: number or KON_VARIABLE + a variable, d: where to go if not */
	KON_OP_WAIT,	/* a: milliseconds */
	KON_OP_HOST,	/* a: your own command number, b, c, d, text: yours to use */
	KON_OP_CALL,	/* a: where, comes back at the RETURN */
	KON_OP_RETURN
} kon_op_t;

enum { KON_SET, KON_ADD, KON_SUB, KON_MUL, KON_DIV, KON_MOD };
enum { KON_IS_EQ, KON_IS_NE, KON_IS_GE, KON_IS_LE, KON_IS_GT, KON_IS_LT };

/* add a variable number to this to use that variable where a command wants a number */
#define KON_VARIABLE 0x40000000

typedef struct kon_cmd {
	int op, a, b, c, d;
	const char *text;
} kon_cmd_t;

/* so a script written by hand or by a converter reads as a list */
#define KON_END() {KON_OP_END, 0, 0, 0, 0, NULL}
#define KON_SAY(who, text) {KON_OP_SAY, who, 0, 0, 0, text}
#define KON_MENU(count) {KON_OP_MENU, count, 0, 0, 0, NULL}
#define KON_OPTION(text, where, needs) {KON_OP_OPTION, where, needs, 0, 0, text}
#define KON_JUMP(where) {KON_OP_JUMP, where, 0, 0, 0, NULL}
#define KON_SWITCH(id, how) {KON_OP_SWITCH, id, how, 0, 0, NULL}
#define KON_VAR(id, how, n) {KON_OP_VAR, id, how, n, 0, NULL}
#define KON_IFSWITCH(id, want, elseWhere) {KON_OP_IFSWITCH, id, want, elseWhere, 0, NULL}
#define KON_IFVAR(id, how, n, elseWhere) {KON_OP_IFVAR, id, how, n, elseWhere, NULL}
#define KON_WAIT(ms) {KON_OP_WAIT, ms, 0, 0, 0, NULL}
#define KON_HOST(id, b, c, d, text) {KON_OP_HOST, id, b, c, d, text}
#define KON_CALL(where) {KON_OP_CALL, where, 0, 0, 0, NULL}
#define KON_RETURN() {KON_OP_RETURN, 0, 0, 0, 0, NULL}

typedef enum {
	KON_SCRIPT_DONE,
	KON_SCRIPT_RUNNING,	/* started, kon_scriptRun has not stopped it yet */
	KON_SCRIPT_SAY,	/* show kon_scriptText, then kon_scriptResume */
	KON_SCRIPT_MENU,	/* show the options, then kon_scriptChoose */
	KON_SCRIPT_WAIT,	/* kon_scriptUpdate counts it down */
	KON_SCRIPT_HOST,	/* the host function wanted to wait, kon_scriptResume when it is over */
	KON_SCRIPT_ERROR	/* bad jump, calls too deep, or going round and round without stopping */
} kon_scriptStatus_t;

#define KON_SCRIPT_MAX_OPTIONS 16
#define KON_SCRIPT_MAX_CALLS 64

struct kon_script;
typedef int (*kon_hostFn)(struct kon_script *vm, const kon_cmd_t *cmd, void *user);

typedef struct kon_script {
	const kon_cmd_t *cmds;
	int count;
	uint8_t *switches;
	int switchCount;
	int32_t *vars;
	int varCount;
	int yieldAtLimit; /* 0 makes a script that runs 100000 commands without waiting an ERROR, 1 makes kon_scriptRun give back RUNNING and carry on next call, like RPG Maker does */
	kon_hostFn host; /* returns nonzero to make the script wait for kon_scriptResume */
	void *user;
	kon_scriptStatus_t status;
	int pc;
	int cmd; /* the command that is being waited on */
	float wait;
	int stack[KON_SCRIPT_MAX_CALLS], depth;
	int options[KON_SCRIPT_MAX_OPTIONS], optionCount;
} kon_script_t;

/*** script ***/

/* the switches and variables are yours, they start however you left them, and a number past the end reads as 0 and is not written */
void kon_scriptInit(kon_script_t *vm, const kon_cmd_t *cmds, int count, uint8_t *switches, int switchCount, int32_t *vars, int varCount);
void kon_scriptStart(kon_script_t *vm, int where);

/* goes until it has to wait for something and says what, call it each frame (it does nothing while waiting) */
kon_scriptStatus_t kon_scriptRun(kon_script_t *vm);
void kon_scriptUpdate(kon_script_t *vm, float dt);
void kon_scriptResume(kon_script_t *vm);

const kon_cmd_t *kon_scriptCurrent(const kon_script_t *vm);
int kon_scriptOptionCount(const kon_script_t *vm);
const char *kon_scriptOption(const kon_script_t *vm, int i);
void kon_scriptChoose(kon_script_t *vm, int i);

int kon_scriptSwitch(const kon_script_t *vm, int id);
int32_t kon_scriptVar(const kon_script_t *vm, int id);
void kon_scriptSetSwitch(kon_script_t *vm, int id, int on);
void kon_scriptSetVar(kon_script_t *vm, int id, int32_t value);

/*** text scripts ***/

/* the same commands as text, so a script can be written, read and changed by hand and a converter can write one.
one command a line, # starts a comment, labels are names to jump to:

	start:
		say ada "Morning."
		host enter 0 1
		menu
			option "Sorry." sorry
			option "About the key..." key if s0
	sorry:
		set v1 = 0
		if v1 < 2 else done
		jump start
	done:
		end

say who "text" | menu | option "text" label [if sN] | jump label | call label | return | end | wait ms
on sN | off sN | flip sN | set vN (= += -= *= /= %=) number-or-vM
if sN on|off else label | if vN (== != >= <= > <) number-or-vM else label
host name-or-number [b [c [d]]] ["text"]

who and the host name are numbers, or names from the lists you give. use - for nobody. in strings, \" \\ \n and \t work */

#define KON_SCRIPT_LABEL 32

typedef struct kon_scriptLabel {
	char name[KON_SCRIPT_LABEL];
	int at;
} kon_scriptLabel_t;

typedef struct kon_scriptNames {
	const char *const *speakers;
	int speakerCount;
	const char *const *hosts;
	int hostCount;
} kon_scriptNames_t;

typedef struct kon_scriptBuild {
	const kon_scriptNames_t *names; /* can be NULL */
	kon_cmd_t *cmds;
	int maxCmds;
	char *pool; /* where the strings go, the commands point into it so keep it as long as them */
	int poolSize;
	kon_scriptLabel_t *labels;
	int maxLabels;
	int *hash; /* optional, makes looking up labels fast for big scripts. hashSize is a power of two, at least twice maxLabels */
	int hashSize;

	int count, labelCount, poolUsed; /* what it made */
	int errorLine; /* 0 if no error */
	char error[64];
} kon_scriptBuild_t;

/* 1 if it worked, 0 and errorLine, error if not */
int kon_scriptParse(kon_scriptBuild_t *b, const char *source);
int kon_scriptFind(const kon_scriptBuild_t *b, const char *label); /* where a label is, or -1 */


#ifdef __cplusplus
}
#endif
#endif /* KONSCRIPT_H */