/*
 * Copyright (c) 2008 Tim Post
 * Copyright (c) 2011 Jiri Svoboda
 * Copyright (c) 2011 Martin Sucha
 * Copyright (c) 2018 Matthieu Riolo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <str.h>
#include <io/console.h>
#include <io/keycode.h>
#include <io/style.h>
#include <io/color.h>
#include <vfs/vfs.h>
#include <clipboard.h>
#include <macros.h>
#include <errno.h>
#include <assert.h>
#include <stdbool.h>
#include <tinput.h>
#include <adt/odict.h>

#include "config.h"
#include "compl.h"
#include "util.h"
#include "scli.h"
#include "input.h"
#include "errors.h"
#include "exec.h"
#include "tok.h"

extern volatile unsigned int cli_quit;

/** Text input field. */
static tinput_t *tinput;

/* Private helpers */
static int run_command(char **, cliuser_t *, iostate_t *);
static void print_pipe_usage(void);

/*
 * Tokenizes input from console, sees if the first word is a built-in, if so
 * invokes the built-in entry point (a[0]) passing all arguments in a[] to
 * the handler
 */
errno_t process_input(cliuser_t *usr)
{
	token_t *tokens_buf = calloc(WORD_MAX, sizeof(token_t));
	if (tokens_buf == NULL)
		return ENOMEM;
	token_t *tokens = tokens_buf;

	char *cmd[WORD_MAX];
	errno_t rc = EOK;
	tokenizer_t tok;
	unsigned int i, pipe_count, processed_pipes;
	unsigned int pipe_pos[2];
	char *redir_from = NULL;
	char *redir_to = NULL;

	if (usr->line == NULL) {
		free(tokens_buf);
		return EINVAL;
	}

	rc = tok_init(&tok, usr->line, tokens, WORD_MAX);
	if (rc != EOK) {
		goto finit;
	}

	size_t tokens_length;
	rc = tok_tokenize(&tok, &tokens_length);
	if (rc != EOK) {
		goto finit;
	}

	if (tokens_length > 0 && tokens[0].type == TOKTYPE_SPACE) {
		tokens++;
		tokens_length--;
	}

	if (tokens_length > 0 && tokens[tokens_length - 1].type == TOKTYPE_SPACE) {
		tokens_length--;
	}

	/*
	 * Until full support for pipes is implemented, allow for a simple case:
	 * [from <file> |] command [| to <file>]
	 *
	 * First find the pipes and check that there are no more
	 */
	for (i = 0, pipe_count = 0; i < tokens_length; i++) {
		if (tokens[i].type == TOKTYPE_PIPE) {
			if (pipe_count >= 2) {
				print_pipe_usage();
				rc = ENOTSUP;
				goto finit;
			}
			pipe_pos[pipe_count] = i;
			pipe_count++;
		}
	}

	unsigned int cmd_token_start = 0;
	unsigned int cmd_token_end = tokens_length;

	processed_pipes = 0;

	/* Check if the first part (from <file> |) is present */
	if (pipe_count > 0 && (pipe_pos[0] == 3 || pipe_pos[0] == 4) && str_cmp(tokens[0].text, "from") == 0) {
		/* Ignore the first three tokens (from, file, pipe) and set from */
		redir_from = tokens[2].text;
		cmd_token_start = pipe_pos[0] + 1;
		processed_pipes++;
	}

	/* Check if the second part (| to <file>) is present */
	if ((pipe_count - processed_pipes) > 0 &&
	    (pipe_pos[processed_pipes] == tokens_length - 4 ||
	    (pipe_pos[processed_pipes] == tokens_length - 5 &&
	    tokens[tokens_length - 4].type == TOKTYPE_SPACE)) &&
	    str_cmp(tokens[tokens_length - 3].text, "to") == 0) {
		/* Ignore the last three tokens (pipe, to, file) and set to */
		redir_to = tokens[tokens_length - 1].text;
		cmd_token_end = pipe_pos[processed_pipes];
		processed_pipes++;
	}

	if (processed_pipes != pipe_count) {
		print_pipe_usage();
		rc = ENOTSUP;
		goto finit;
	}

	/* Convert tokens of the command to string array */
	unsigned int cmd_pos = 0;
	for (i = cmd_token_start; i < cmd_token_end; i++) {
		if (tokens[i].type != TOKTYPE_SPACE) {
			cmd[cmd_pos++] = tokens[i].text;
		}
	}
	cmd[cmd_pos++] = NULL;

	if (cmd[0] == NULL) {
		print_pipe_usage();
		rc = ENOTSUP;
		goto finit;
	}



	/* test if the passed cmd is an alias */
	odlink_t* alias_link = odict_find_eq(&alias_dict, (void*)cmd[0], NULL);
	if (alias_link != NULL) {
		alias_t* data = odict_get_instance(alias_link, alias_t, odict);
		char* oldLine = usr->line;
		

		const size_t input_length = str_size(usr->line) - str_size(cmd[0]) + str_size(data->value) + 1;
		usr->line = (char*)malloc(INPUT_MAX * sizeof(char));
		usr->line[0] = '\0';

		unsigned int cmd_replace_index = cmd_token_start;
		for (i = 0; i < tokens_length; i++) {
			if (i == cmd_replace_index) {
				//if there is a pipe symbol than cmd_token_start will point at the SPACE after the pipe symbol
				if (tokens[i].type == TOKTYPE_SPACE) {
					cmd_replace_index++;
					str_append(usr->line, input_length, tokens[i].text);
					continue;
				}

				str_append(usr->line, input_length, data->value);
			} else {
				str_append(usr->line, input_length, tokens[i].text);
			}
		}

		//reprocess input after string replace
		rc = process_input(usr);
		usr->line = oldLine;
		goto finit;
	}


	iostate_t new_iostate = {
		.stdin = stdin,
		.stdout = stdout,
		.stderr = stderr
	};

	FILE *from = NULL;
	FILE *to = NULL;

	if (redir_from) {
		from = fopen(redir_from, "r");
		if (from == NULL) {
			printf("Cannot open file %s\n", redir_from);
			rc = errno;
			goto finit_with_files;
		}
		new_iostate.stdin = from;
	}

	if (redir_to) {
		to = fopen(redir_to, "w");
		if (to == NULL) {
			printf("Cannot open file %s\n", redir_to);
			rc = errno;
			goto finit_with_files;
		}
		new_iostate.stdout = to;
	}

	if (run_command(cmd, usr, &new_iostate) == 0) {
		rc = EOK;
	} else {
		rc = EINVAL;
	}

finit_with_files:
	if (from != NULL) {
		fclose(from);
	}
	if (to != NULL) {
		fclose(to);
	}

finit:
	if (NULL != usr->line) {
		free(usr->line);
		usr->line = (char *) NULL;
	}

	tok_fini(&tok);
	free(tokens_buf);

	return rc;
}

void print_pipe_usage(void)
{
	printf("Invalid syntax!\n");
	printf("Usage of redirection (pipes in the future):\n");
	printf("from filename | command ...\n");
	printf("from filename | command ... | to filename\n");
	printf("command ... | to filename\n");

}

int run_command(char **cmd, cliuser_t *usr, iostate_t *new_iostate)
{
	int id = 0;

	/* We have rubbish */
	if (NULL == cmd[0]) {
		return CL_ENOENT;
	}

	/* Is it a builtin command ? */
	if ((id = (is_builtin(cmd[0]))) > -1) {
		return run_builtin(id, cmd, usr, new_iostate);
	}

	/* Is it a module ? */
	if ((id = (is_module(cmd[0]))) > -1) {
		return run_module(id, cmd, new_iostate);
	}

	/* See what try_exec thinks of it */
	return try_exec(cmd[0], cmd, new_iostate);
}

void get_input(cliuser_t *usr)
{
	char *str;
	errno_t rc;

	tinput_set_prompt(tinput, usr->prompt);

	rc = tinput_read(tinput, &str);
	if (rc == ENOENT) {
		/* User requested exit */
		cli_quit = 1;
		putchar('\n');
		return;
	}

	if (rc != EOK) {
		/* Error in communication with console */
		cli_quit = 1;
		return;
	}

	/* Check for empty input. */
	if (str_cmp(str, "") == 0) {
		free(str);
		return;
	}

	usr->line = str;
	return;
}

int input_init(void)
{
	tinput = tinput_new();
	if (tinput == NULL) {
		printf("Failed to initialize input.\n");
		return 1;
	}

	tinput_set_compl_ops(tinput, &compl_ops);

	return 0;
}