/**
 * Copyright (c) 2018, Timothy Stack
 *
 * 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.
 * * Neither the name of Timothy Stack nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''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 REGENTS OR CONTRIBUTORS 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.
 *
 * @file input_dispatcher.cc
 */

#include "config.h"

#include <string.h>
#include <sys/time.h>
#include <array>

#if defined HAVE_NCURSESW_CURSES_H
#  include <ncursesw/curses.h>
#elif defined HAVE_NCURSESW_H
#  include <ncursesw.h>
#elif defined HAVE_NCURSES_CURSES_H
#  include <ncurses/curses.h>
#elif defined HAVE_NCURSES_H
#  include <ncurses.h>
#elif defined HAVE_CURSES_H
#  include <curses.h>
#else
#  error "SysV or X/Open-compatible Curses header file required"
#endif

#include "base/lnav_log.hh"
#include "input_dispatcher.hh"
#include "lnav_util.hh"

template<typename A>
static void to_key_seq(A &dst, char *src)
{
    dst[0] = '\0';
    for (size_t lpc = 0; src[lpc]; lpc++) {
        snprintf(dst.data() + strlen(dst.data()),
                 dst.size() - strlen(dst.data()),
                 "x%02x",
                 src[lpc] & 0xff);
    }
}

void input_dispatcher::new_input(const struct timeval &current_time, int ch)
{
    nonstd::optional<bool> handled = nonstd::nullopt;
    std::array<char, 32 * 3 + 1> keyseq{0};

    switch (ch) {
        case KEY_ESCAPE:
            this->reset_escape_buffer(ch, current_time);
            break;
        case KEY_MOUSE:
            this->id_mouse_handler();
            break;
        default:
            if (this->id_escape_index > 0) {
                this->append_to_escape_buffer(ch);

                if (strcmp("\x1b[", this->id_escape_buffer) == 0) {
                    this->id_mouse_handler();
                    this->id_escape_index = 0;
                } else if (this->id_escape_expected_size == -1 ||
                           this->id_escape_index ==
                           this->id_escape_expected_size) {
                    to_key_seq(keyseq, this->id_escape_buffer);
                    switch (this->id_escape_matcher(keyseq.data())) {
                        case escape_match_t::NONE: {
                            if (this->id_escape_expected_size == -1) {
                                for (int lpc = 0; this->id_escape_buffer[lpc]; lpc++) {
                                    handled = this->id_key_handler(
                                        this->id_escape_buffer[lpc]);
                                }
                            } else {
                                handled = false;
                            }
                            this->id_escape_index = 0;
                            break;
                        }
                        case escape_match_t::PARTIAL:
                            break;
                        case escape_match_t::FULL:
                            this->id_escape_handler(keyseq.data());
                            this->id_escape_index = 0;
                            break;
                    }
                }
                if (this->id_escape_expected_size != -1 &&
                    this->id_escape_index == this->id_escape_expected_size) {
                    this->id_escape_index = 0;
                }
            } else if ((ch & 0xf8) == 0xf0) {
                this->reset_escape_buffer(ch, current_time, 4);
            } else if ((ch & 0xf0) == 0xe0) {
                this->reset_escape_buffer(ch, current_time, 3);
            } else if ((ch & 0xe0) == 0xc0) {
                this->reset_escape_buffer(ch, current_time, 2);
            } else {
                snprintf(keyseq.data(), keyseq.size(), "x%02x", ch & 0xff);
                handled = this->id_key_handler(ch);
            }
            break;
    }

    if (handled && !handled.value()) {
        this->id_unhandled_handler(keyseq.data());
    }
}

void input_dispatcher::poll(const struct timeval &current_time)
{
    if (this->id_escape_index == 1) {
        static const struct timeval escape_threshold = { 0, 10000 };
        struct timeval diff;

        timersub(&current_time, &this->id_escape_start_time, &diff);
        if (escape_threshold < diff) {
            this->id_key_handler(KEY_CTRL_RBRACKET);
            this->id_escape_index = 0;
        }
    }
}

void input_dispatcher::reset_escape_buffer(int ch, const timeval &current_time,
                                           ssize_t expected_size)
{
    this->id_escape_index = 0;
    this->append_to_escape_buffer(ch);
    this->id_escape_expected_size = expected_size;
    this->id_escape_start_time = current_time;
}

void input_dispatcher::append_to_escape_buffer(int ch)
{
    if (this->id_escape_index < (sizeof(this->id_escape_buffer) - 1)) {
        this->id_escape_buffer[this->id_escape_index++] = static_cast<char>(ch);
        this->id_escape_buffer[this->id_escape_index] = '\0';
    }
}
