/*
 * Copyright (c) 2019 Stefan Strobel <stefan.strobel@shimatta.net>
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

/**
 * @file    shellmatta_autocomplete.c
 * @brief   autocomplete function of shellmatta
 * @author  Stefan Strobel <stefan.strobel@shimatta.net>
 */

/**
 * @addtogroup shellmatta_autocomplete
 * @{
 */

#include "shellmatta.h"
#include "shellmatta_autocomplete.h"
#include "shellmatta_utils.h"
#include <stdint.h>
#include <string.h>

/**
 * @brief       searches the registered commands for matching ones and prints
 *              the common part of all matching commands on the output
 *              if called twice all matching commands are printed
 * @param[in]   inst    pointer to a shellmatta instance
 */
void autocomplete_run(shellmatta_instance_t *inst)
{
    shellmatta_cmd_t   *cmd         = inst->cmdList;
    char               *tempCmd     = NULL;
    uint32_t            minLen      = 0u;
    uint32_t            sizeDiff    = 0u;
    bool                exactMatch  = true;
    uint32_t            printedLen  = 0u;
    uint32_t            tempCursor  = 0u;

    /** -# increase the tab counter to print all matching commands next time */
    inst->tabCounter++;

    /** -# on douple tab show all matching commands */
    if (1u < inst->tabCounter)
    {
        inst->tabCounter        = 0u;

        /** -# loop through all registered commands */
        while (NULL != cmd)
        {
            /** -# check if command matches the input */
            if(    (strlen(cmd->cmd) >= inst->cursor)
                && (0 == strncmp(cmd->cmd, inst->buffer, inst->cursor)))
            {
                /** -# add newline on first find */
                if(0u == printedLen)
                {
                    inst->write("\r\n", 2u);
                }
                inst->write(cmd->cmd, strlen(cmd->cmd));
                printedLen += strlen(cmd->cmd);
                inst->write("    ", 4u);
                printedLen += 4u;
            }
            /** -# check if command alias matches the input */
            if(    (NULL != cmd->cmdAlias)
                && (strlen(cmd->cmdAlias) >= inst->cursor)
                && (0 == strncmp(cmd->cmdAlias, inst->buffer, inst->cursor)))
            {
                /** -# add newline on first find */
                if(0u == printedLen)
                {
                    inst->write("\r\n", 2u);
                }
                inst->write(cmd->cmdAlias, strlen(cmd->cmdAlias));
                printedLen += strlen(cmd->cmdAlias);
                inst->write("    ", 4u);
                printedLen += 4u;
            }
            cmd = cmd->next;
        }
        /** -# print input again if a commands was found */
        if(printedLen > 0u)
        {
            utils_writeEcho(inst, "\r\n", 2u);
            utils_writeEcho(inst, inst->prompt, strlen(inst->prompt));
            utils_writeEcho(inst, inst->buffer, inst->inputCount);
            tempCursor = inst->cursor;
            inst->cursor = inst->inputCount;
            utils_rewindCursor(inst, inst->inputCount - tempCursor);
        }
    }
    /** -# on single tab autocomplete as far as possible */
    else if(0u != inst->cursor)
    {
        /** -# loop through all registered commands */
        while (NULL != cmd)
        {
            /** -# check if command matches the input */
            if(    (strlen(cmd->cmd) >= inst->cursor)
                && (0 == strncmp(cmd->cmd, inst->buffer, inst->cursor)))
            {
                /** -# store first match */
                if(NULL == tempCmd)
                {
                    tempCmd = cmd->cmd;
                    minLen = strlen(cmd->cmd);
                }
                /** -# find common part of the matching commands */
                else
                {
                    exactMatch = false;
                    minLen = SHELLMATTA_MIN(strlen(cmd->cmd), minLen);
                    for(uint32_t i = 0u; i < minLen; i++)
                    {
                        if(cmd->cmd[i] != tempCmd[i])
                        {
                            minLen = i;
                        }
                    }
                }
            }

            /** -# check if command Alias matches the input */
            if(    (NULL != cmd->cmdAlias)
                && (strlen(cmd->cmdAlias) >= inst->cursor)
                && (0 == strncmp(cmd->cmdAlias, inst->buffer, inst->cursor)))
            {
                /** -# store first match */
                if(NULL == tempCmd)
                {
                    tempCmd = cmd->cmdAlias;
                    minLen = strlen(cmd->cmdAlias);
                }
                /** -# find common part of the matches */
                else
                {
                    exactMatch = false;
                    minLen = SHELLMATTA_MIN(strlen(cmd->cmdAlias), minLen);
                    for(uint32_t i = 0u; i < minLen; i++)
                    {
                        if(cmd->cmdAlias[i] != tempCmd[i])
                        {
                            minLen = i;
                        }
                    }
                }
            }
            cmd = cmd->next;
        }

        /** -# autocomplete found command */
        if(NULL != tempCmd)
        {
            /** -# calculate the size of the command to be inserted */
            sizeDiff = minLen - inst->cursor;

            /** -# copy the found part into the buffer and display it */
            utils_insertChars(inst, &(tempCmd[inst->cursor]), sizeDiff);

            /** -# on exact match there is no need to double Tab to display all */
            if(true == exactMatch)
            {
                inst->tabCounter = 0u;
            }
        }
    }
    else
    {
        /* nothing to do here */
    }
}

/**
 * @}
 */