/* Licensed under GPLv2+ - see LICENSE file for details */
#include <ccan/opt/opt.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <stdarg.h>
#include <stdint.h>
#include "private.h"

struct opt_table *opt_table;
unsigned int opt_count, opt_num_short, opt_num_short_arg, opt_num_long;
const char *opt_argv0;
struct opt_alloc opt_alloc = {
	malloc, realloc, free
};

/* Returns string after first '-'. */
static const char *first_name(const char *names, unsigned *len)
{
	*len = strcspn(names + 1, "|= ");
	return names + 1;
}

static const char *next_name(const char *names, unsigned *len)
{
	names += *len;
	if (names[0] == ' ' || names[0] == '=' || names[0] == '\0')
		return NULL;
	return first_name(names + 1, len);
}

static const char *first_opt(unsigned *i, unsigned *len)
{
	for (*i = 0; *i < opt_count; (*i)++) {
		if (opt_table[*i].type == OPT_SUBTABLE)
			continue;
		return first_name(opt_table[*i].names, len);
	}
	return NULL;
}

static const char *next_opt(const char *p, unsigned *i, unsigned *len)
{
	for (; *i < opt_count; (*i)++) {
		if (opt_table[*i].type == OPT_SUBTABLE)
			continue;
		if (!p)
			return first_name(opt_table[*i].names, len);
		p = next_name(p, len);
		if (p)
			return p;
	}
	return NULL;
}

const char *first_lopt(unsigned *i, unsigned *len)
{
	const char *p;
	for (p = first_opt(i, len); p; p = next_opt(p, i, len)) {
		if (p[0] == '-') {
			/* Skip leading "-" */
			(*len)--;
			p++;
			break;
		}
	}
	return p;
}

const char *next_lopt(const char *p, unsigned *i, unsigned *len)
{
	for (p = next_opt(p, i, len); p; p = next_opt(p, i, len)) {
		if (p[0] == '-') {
			/* Skip leading "-" */
			(*len)--;
			p++;
			break;
		}
	}
	return p;
}

const char *first_sopt(unsigned *i)
{
	const char *p;
	unsigned int len = 0 /* GCC bogus warning */;

	for (p = first_opt(i, &len); p; p = next_opt(p, i, &len)) {
		if (p[0] != '-')
			break;
	}
	return p;
}

const char *next_sopt(const char *p, unsigned *i)
{
	unsigned int len = 1;
	for (p = next_opt(p, i, &len); p; p = next_opt(p, i, &len)) {
		if (p[0] != '-')
			break;
	}
	return p;
}

/* Avoids dependency on err.h or ccan/err */
#ifndef failmsg
#define failmsg(fmt, ...) \
	do { fprintf(stderr, fmt, __VA_ARGS__); exit(1); } while(0)
#endif

static void check_opt(const struct opt_table *entry)
{
	const char *p;
	unsigned len;

	if (entry->type != OPT_HASARG && entry->type != OPT_NOARG
	    && entry->type != (OPT_EARLY|OPT_HASARG)
	    && entry->type != (OPT_EARLY|OPT_NOARG))
		failmsg("Option %s: unknown entry type %u",
			entry->names, entry->type);

	if (!entry->desc)
		failmsg("Option %s: description cannot be NULL", entry->names);


	if (entry->names[0] != '-')
		failmsg("Option %s: does not begin with '-'", entry->names);

	for (p = first_name(entry->names, &len); p; p = next_name(p, &len)) {
		if (*p == '-') {
			if (len == 1)
				failmsg("Option %s: invalid long option '--'",
					entry->names);
			opt_num_long++;
		} else {
			if (len != 1)
				failmsg("Option %s: invalid short option"
					" '%.*s'", entry->names, len+1, p-1);
			opt_num_short++;
			if (entry->type == OPT_HASARG)
				opt_num_short_arg++;
		}
		/* Don't document args unless there are some. */
		if (entry->type == OPT_NOARG) {
			if (p[len] == ' ' || p[len] == '=')
				failmsg("Option %s: does not take arguments"
					" '%s'", entry->names, p+len+1);
		}
	}
}

static void add_opt(const struct opt_table *entry)
{
	opt_table = opt_alloc.realloc(opt_table,
				      sizeof(opt_table[0]) * (opt_count+1));
	opt_table[opt_count++] = *entry;
}

void _opt_register(const char *names, enum opt_type type,
		   char *(*cb)(void *arg),
		   char *(*cb_arg)(const char *optarg, void *arg),
		   void (*show)(char buf[OPT_SHOW_LEN], const void *arg),
		   const void *arg, const char *desc)
{
	struct opt_table opt;
	opt.names = names;
	opt.type = type;
	opt.cb = cb;
	opt.cb_arg = cb_arg;
	opt.show = show;
	opt.u.carg = arg;
	opt.desc = desc;
	check_opt(&opt);
	add_opt(&opt);
}

bool opt_unregister(const char *names)
{
	int found = -1, i;

	for (i = 0; i < opt_count; i++) {
		if (opt_table[i].type == OPT_SUBTABLE)
			continue;
		if (strcmp(opt_table[i].names, names) == 0)
			found = i;
	}
	if (found == -1)
		return false;
	opt_count--;
	memmove(&opt_table[found], &opt_table[found+1],
		(opt_count - found) * sizeof(opt_table[found]));
	return true;
}

void opt_register_table(const struct opt_table entry[], const char *desc)
{
	unsigned int i, start = opt_count;

	if (desc) {
		struct opt_table heading = OPT_SUBTABLE(NULL, desc);
		add_opt(&heading);
	}
	for (i = 0; entry[i].type != OPT_END; i++) {
		if (entry[i].type == OPT_SUBTABLE)
			opt_register_table(subtable_of(&entry[i]),
					   entry[i].desc);
		else {
			check_opt(&entry[i]);
			add_opt(&entry[i]);
		}
	}
	/* We store the table length in arg ptr. */
	if (desc)
		opt_table[start].u.tlen = (opt_count - start);
}

/* Parse your arguments. */
bool opt_parse(int *argc, char *argv[], void (*errlog)(const char *fmt, ...))
{
	int ret;
	unsigned offset = 0;

	/* This helps opt_usage. */
	opt_argv0 = argv[0];

	while ((ret = parse_one(argc, argv, 0, &offset, errlog, false)) == 1);

	/* parse_one returns 0 on finish, -1 on error */
	return (ret == 0);
}

static bool early_parse(int argc, char *argv[],
			void (*errlog)(const char *fmt, ...),
			bool ignore_unknown)
{
	int ret;
	unsigned off = 0;
	char **tmpargv = opt_alloc.alloc(sizeof(argv[0]) * (argc + 1));

	/* We could avoid a copy and skip instead, but this is simple. */
	memcpy(tmpargv, argv, sizeof(argv[0]) * (argc + 1));

	/* This helps opt_usage. */
	opt_argv0 = argv[0];

	while ((ret = parse_one(&argc, tmpargv, OPT_EARLY, &off, errlog, ignore_unknown)) == 1);

	opt_alloc.free(tmpargv);

	/* parse_one returns 0 on finish, -1 on error */
	return (ret == 0);
}

bool opt_early_parse(int argc, char *argv[],
		     void (*errlog)(const char *fmt, ...))
{
	return early_parse(argc, argv, errlog, false);
}

bool opt_early_parse_incomplete(int argc, char *argv[],
				void (*errlog)(const char *fmt, ...))
{
	return early_parse(argc, argv, errlog, true);
}

void opt_free_table(void)
{
	opt_alloc.free(opt_table);
	opt_table = NULL;
	opt_count = opt_num_short = opt_num_short_arg = opt_num_long = 0;
}

void opt_log_stderr(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	fprintf(stderr, "\n");
	va_end(ap);
}

void opt_log_stderr_exit(const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	fprintf(stderr, "\n");
	va_end(ap);
	exit(1);
}

char *opt_invalid_argument(const char *arg)
{
	char *str = opt_alloc.alloc(sizeof("Invalid argument '%s'") + strlen(arg));
	sprintf(str, "Invalid argument '%s'", arg);
	return str;
}

void opt_set_alloc(void *(*allocfn)(size_t size),
		   void *(*reallocfn)(void *ptr, size_t size),
		   void (*freefn)(void *ptr))
{
	opt_alloc.alloc = allocfn;
	opt_alloc.realloc = reallocfn;
	opt_alloc.free = freefn;
}
