// Part of JoeyLib, Copyright (c) 2026 Scott Duensing, under the MIT License.
// See LICENSE.md for license information.
// SPDX-License-Identifier: MIT
//
// gateArg.h - command lines for the gate tools: numbers, pairs of numbers,
// and ports, each read whole (one that is not is the tool's usage error);
// tools of several modes; and usage text.

#ifndef GATE_ARG_H
#define GATE_ARG_H

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

// What a gate tool exits with when its command line is wrong.
#define GATE_USAGE_EXIT 2

// How many entries an array has.
#define GATE_COUNT_OF(a) (sizeof(a) / sizeof((a)[0]))

// A tool's mode: its name, how many arguments follow the name, and what it
// does with them (returning the tool's exit code).
typedef int (*GateModeFnT)(char **args);

typedef struct GateModeT {
    const char *name;
    int         argCount;
    GateModeFnT run;
} GateModeT;

// Print "<tool>: bad NAME: TEXT" to stderr and exit GATE_USAGE_EXIT.
void gateArgBad(const char *name, const char *text) __attribute__((noreturn));

// A finite number, all of text (strtod's form); anything else is
// gateArgBad.
double gateArgDouble(const char *name, const char *text);

// A whole number, all of text, decimal, in a long's range; anything else is
// gateArgBad.
long gateArgLong(const char *name, const char *text);

// Two whole numbers, as gateArgLong reads them, separated by separator
// ("X,Y" or "WxH"); anything else is gateArgBad.
void gateArgPair(const char *name, const char *text, char separator, long *first, long *second);

// Whether text is all one finite number, or one whole number as
// gateArgLong takes them (no white space round it); its value in out.
bool gateArgParseDouble(const char *text, double *out);
bool gateArgParseLong(const char *text, long *out);

// A TCP port: a whole number from 0 to 65535; anything else is gateArgBad.
uint16_t gateArgPort(const char *text);

// Run the mode argv[1] names, given the arguments after it; false (and
// nothing run) when no mode has that name and that many arguments.
bool gateModeRun(const GateModeT *modes, size_t count, int argc, char **argv, int *exitCode);

// Print a tool's usage, a line a string, to stderr; returns
// GATE_USAGE_EXIT.
int gateUsage(const char *const *lines, size_t count);

#endif