// Copyright (C) 2002 Andrew Tridgell
// Copyright (C) 2009-2016 Joel Rosdahl
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 3 of the License, or (at your option)
// any later version.
//
// This program 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 General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program; if not, write to the Free Software Foundation, Inc., 51
// Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

#include "ccache.h"

struct args *
args_init(int init_argc, char **init_args)
{
	struct args *args = (struct args *)x_malloc(sizeof(struct args));
	args->argc = 0;
	args->argv = (char **)x_malloc(sizeof(char *));
	args->argv[0] = NULL;
	for (int i = 0; i < init_argc; i++) {
		args_add(args, init_args[i]);
	}
	return args;
}

struct args *
args_init_from_string(const char *command)
{
	char *p = x_strdup(command);
	char *q = p;
	char *word, *saveptr = NULL;
	struct args *args = args_init(0, NULL);
	while ((word = strtok_r(q, " \t\r\n", &saveptr))) {
		args_add(args, word);
		q = NULL;
	}

	free(p);
	return args;
}

struct args *
args_init_from_gcc_atfile(const char *filename)
{
	char *argtext;
	if (!(argtext = read_text_file(filename, 0))) {
		return NULL;
	}

	struct args *args = args_init(0, NULL);
	char *pos = argtext;
	char *argbuf = x_malloc(strlen(argtext) + 1);
	char *argpos = argbuf;

	// Used to track quoting state; if \0, we are not inside quotes. Otherwise
	// stores the quoting character that started it, for matching the end quote.
	char quoting = '\0';

	while (1) {
		switch (*pos) {
		case '\\':
			pos++;
			if (*pos == '\0') {
				continue;
			}
			break;

		case '\"':
		case '\'':
			if (quoting != '\0') {
				if (quoting == *pos) {
					quoting = '\0';
					pos++;
					continue;
				} else {
					break;
				}
			} else {
				quoting = *pos;
				pos++;
				continue;
			}

		case '\n':
		case '\r':
		case '\t':
		case ' ':
			if (quoting) {
				break;
			}
		// Fall through.

		case '\0':
			// End of token
			*argpos = '\0';
			if (argbuf[0] != '\0') {
				args_add(args, argbuf);
			}
			argpos = argbuf;
			if (*pos == '\0') {
				goto out;
			} else {
				pos++;
				continue;
			}
		}

		*argpos = *pos;
		pos++;
		argpos++;
	}

out:
	free(argbuf);
	free(argtext);
	return args;
}

struct args *
args_copy(struct args *args)
{
	return args_init(args->argc, args->argv);
}

// Insert all arguments in src into dest at position index. If replace is true,
// the element at dest->argv[index] is replaced with the contents of src and
// everything past it is shifted. Otherwise, dest->argv[index] is also shifted.
//
// src is consumed by this operation and should not be freed or used again by
// the caller.
void
args_insert(struct args *dest, int index, struct args *src, bool replace)
{
	// Adjustments made if we are replacing or shifting the element currently at
	// dest->argv[index].
	int offset = replace ? 1 : 0;

	if (replace) {
		free(dest->argv[index]);
	}

	if (src->argc == 0) {
		if (replace) {
			// Have to shift everything down by 1 since we replaced with an empty
			// list.
			for (int i = index; i < dest->argc; i++) {
				dest->argv[i] = dest->argv[i + 1];
			}
			dest->argc--;
		}
		args_free(src);
		return;
	}

	if (src->argc == 1 && replace) {
		// Trivial case; replace with 1 element.
		dest->argv[index] = src->argv[0];
		src->argc = 0;
		args_free(src);
		return;
	}

	dest->argv = (char **)x_realloc(
	  dest->argv,
	  (src->argc + dest->argc + 1 - offset) *
	  sizeof(char *));

	// Shift arguments over.
	for (int i = dest->argc; i >= index + offset; i--) {
		dest->argv[i + src->argc - offset] = dest->argv[i];
	}

	// Copy the new arguments into place.
	for (int i = 0; i < src->argc; i++) {
		dest->argv[i + index] = src->argv[i];
	}

	dest->argc += src->argc - offset;
	src->argc = 0;
	args_free(src);
}

void
args_free(struct args *args)
{
	if (!args) {
		return;
	}
	for (int i = 0; i < args->argc; ++i) {
		if (args->argv[i]) {
			free(args->argv[i]);
		}
	}
	free(args->argv);
	free(args);
}

void
args_add(struct args *args, const char *s)
{
	args->argv = (char **)x_realloc(args->argv,
	                                (args->argc + 2) * sizeof(char *));
	args->argv[args->argc] = x_strdup(s);
	args->argc++;
	args->argv[args->argc] = NULL;
}

// Add all arguments in to_append to args.
void
args_extend(struct args *args, struct args *to_append)
{
	for (int i = 0; i < to_append->argc; i++) {
		args_add(args, to_append->argv[i]);
	}
}

// Pop the last element off the args list.
void
args_pop(struct args *args, int n)
{
	while (n--) {
		args->argc--;
		free(args->argv[args->argc]);
		args->argv[args->argc] = NULL;
	}
}

// Set argument at given index.
void
args_set(struct args *args, int index, const char *value)
{
	assert(index < args->argc);
	free(args->argv[index]);
	args->argv[index] = x_strdup(value);
}

// Remove the first element of the argument list.
void
args_remove_first(struct args *args)
{
	free(args->argv[0]);
	memmove(&args->argv[0], &args->argv[1], args->argc * sizeof(args->argv[0]));
	args->argc--;
}

// Add an argument into the front of the argument list.
void
args_add_prefix(struct args *args, const char *s)
{
	args->argv = (char **)x_realloc(args->argv,
	                                (args->argc + 2) * sizeof(char *));
	memmove(&args->argv[1], &args->argv[0],
	        (args->argc+1) * sizeof(args->argv[0]));
	args->argv[0] = x_strdup(s);
	args->argc++;
}

// Strip any arguments beginning with the specified prefix.
void
args_strip(struct args *args, const char *prefix)
{
	for (int i = 0; i < args->argc; ) {
		if (str_startswith(args->argv[i], prefix)) {
			free(args->argv[i]);
			memmove(&args->argv[i],
			        &args->argv[i+1],
			        (args->argc - i) * sizeof(args->argv[i]));
			args->argc--;
		} else {
			i++;
		}
	}
}

// Format args to a space-separated string. Does not quote spaces. Caller
// frees.
char *
args_to_string(struct args *args)
{
	unsigned size = 0;
	for (char **p = args->argv; *p; p++) {
		size += strlen(*p) + 1;
	}

	char *result = x_malloc(size + 1);
	int pos = 0;
	for (char **p = args->argv; *p; p++) {
		pos += sprintf(&result[pos], "%s ", *p);
	}
	result[pos - 1] = '\0';
	return result;
}

// Returns true if args1 equals args2, else false.
bool
args_equal(struct args *args1, struct args *args2)
{
	if (args1->argc != args2->argc) {
		return false;
	}
	for (int i = 0; i < args1->argc; i++) {
		if (!str_eq(args1->argv[i], args2->argv[i])) {
			return false;
		}
	}
	return true;
}