/*
 * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
 * Copyright (c) 2021 Glenford Williams <gw_dev@outlook.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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.
 */

#include "CalculatorWidget.h"
#include <AK/Assertions.h>
#include <Applications/Calculator/CalculatorGML.h>
#include <LibGUI/Button.h>
#include <LibGUI/Label.h>
#include <LibGUI/TextBox.h>
#include <LibGfx/Font.h>
#include <LibGfx/FontDatabase.h>
#include <LibGfx/Palette.h>

CalculatorWidget::CalculatorWidget()
{
    load_from_gml(calculator_gml);

    m_entry = *find_descendant_of_type_named<GUI::TextBox>("entry_textbox");
    m_entry->set_relative_rect(5, 5, 244, 26);
    m_entry->set_text_alignment(Gfx::TextAlignment::CenterRight);
    m_entry->set_font(Gfx::FontDatabase::default_fixed_width_font());

    m_label = *find_descendant_of_type_named<GUI::Label>("label");

    m_label->set_frame_shadow(Gfx::FrameShadow::Sunken);
    m_label->set_frame_shape(Gfx::FrameShape::Container);
    m_label->set_frame_thickness(2);

    for (int i = 0; i < 10; i++) {
        m_digit_button[i] = *find_descendant_of_type_named<GUI::Button>(String::formatted("{}_button", i));
        add_digit_button(*m_digit_button[i], i);
    }

    m_mem_add_button = *find_descendant_of_type_named<GUI::Button>("mem_add_button");
    add_operation_button(*m_mem_add_button, Calculator::Operation::MemAdd);

    m_mem_save_button = *find_descendant_of_type_named<GUI::Button>("mem_save_button");
    add_operation_button(*m_mem_save_button, Calculator::Operation::MemSave);

    m_mem_recall_button = *find_descendant_of_type_named<GUI::Button>("mem_recall_button");
    add_operation_button(*m_mem_recall_button, Calculator::Operation::MemRecall);

    m_mem_clear_button = *find_descendant_of_type_named<GUI::Button>("mem_clear_button");
    add_operation_button(*m_mem_clear_button, Calculator::Operation::MemClear);

    m_clear_button = *find_descendant_of_type_named<GUI::Button>("clear_button");
    m_clear_button->on_click = [this](auto) {
        m_keypad.set_value(0.0);
        m_calculator.clear_operation();
        update_display();
    };

    m_clear_error_button = *find_descendant_of_type_named<GUI::Button>("clear_error_button");
    m_clear_error_button->on_click = [this](auto) {
        m_keypad.set_value(0.0);
        update_display();
    };

    m_backspace_button = *find_descendant_of_type_named<GUI::Button>("backspace_button");
    m_backspace_button->on_click = [this](auto) {
        m_keypad.type_backspace();
        update_display();
    };

    m_decimal_point_button = *find_descendant_of_type_named<GUI::Button>("decimal_button");
    m_decimal_point_button->on_click = [this](auto) {
        m_keypad.type_decimal_point();
        update_display();
    };

    m_sign_button = *find_descendant_of_type_named<GUI::Button>("sign_button");
    add_operation_button(*m_sign_button, Calculator::Operation::ToggleSign);

    m_add_button = *find_descendant_of_type_named<GUI::Button>("add_button");
    add_operation_button(*m_add_button, Calculator::Operation::Add);

    m_subtract_button = *find_descendant_of_type_named<GUI::Button>("subtract_button");
    add_operation_button(*m_subtract_button, Calculator::Operation::Subtract);

    m_multiply_button = *find_descendant_of_type_named<GUI::Button>("multiply_button");
    add_operation_button(*m_multiply_button, Calculator::Operation::Multiply);

    m_divide_button = *find_descendant_of_type_named<GUI::Button>("divide_button");
    add_operation_button(*m_divide_button, Calculator::Operation::Divide);

    m_sqrt_button = *find_descendant_of_type_named<GUI::Button>("sqrt_button");
    add_operation_button(*m_sqrt_button, Calculator::Operation::Sqrt);

    m_inverse_button = *find_descendant_of_type_named<GUI::Button>("inverse_button");
    add_operation_button(*m_inverse_button, Calculator::Operation::Inverse);

    m_percent_button = *find_descendant_of_type_named<GUI::Button>("mod_button");
    add_operation_button(*m_percent_button, Calculator::Operation::Percent);

    m_equals_button = *find_descendant_of_type_named<GUI::Button>("equal_button");
    m_equals_button->on_click = [this](auto) {
        double argument = m_keypad.value();
        double res = m_calculator.finish_operation(argument);
        m_keypad.set_value(res);
        update_display();
    };
}

CalculatorWidget::~CalculatorWidget()
{
}

void CalculatorWidget::add_operation_button(GUI::Button& button, Calculator::Operation operation)
{
    button.on_click = [this, operation](auto) {
        double argument = m_keypad.value();
        double res = m_calculator.begin_operation(operation, argument);
        m_keypad.set_value(res);
        update_display();
    };
}

void CalculatorWidget::add_digit_button(GUI::Button& button, int digit)
{
    button.on_click = [this, digit](auto) {
        m_keypad.type_digit(digit);
        update_display();
    };
}

String CalculatorWidget::get_entry()
{
    return m_entry->text();
}

void CalculatorWidget::set_entry(double value)
{
    m_keypad.set_value(value);
    update_display();
}

void CalculatorWidget::update_display()
{
    m_entry->set_text(m_keypad.to_string());
    if (m_calculator.has_error())
        m_label->set_text("E");
    else
        m_label->set_text("");
}

void CalculatorWidget::keydown_event(GUI::KeyEvent& event)
{
    //Clear button selection when we are typing
    m_equals_button->set_focus(true);
    m_equals_button->set_focus(false);

    if (event.key() == KeyCode::Key_Return) {
        m_keypad.set_value(m_calculator.finish_operation(m_keypad.value()));

    } else if (event.key() >= KeyCode::Key_0 && event.key() <= KeyCode::Key_9) {
        m_keypad.type_digit(atoi(event.text().characters()));

    } else if (event.key() == KeyCode::Key_Period) {
        m_keypad.type_decimal_point();

    } else if (event.key() == KeyCode::Key_Escape) {
        m_keypad.set_value(0.0);
        m_calculator.clear_operation();

    } else if (event.key() == KeyCode::Key_Backspace) {
        m_keypad.type_backspace();

    } else {
        Calculator::Operation operation;

        switch (event.key()) {
        case KeyCode::Key_Plus:
            operation = Calculator::Operation::Add;
            break;
        case KeyCode::Key_Minus:
            operation = Calculator::Operation::Subtract;
            break;
        case KeyCode::Key_Asterisk:
            operation = Calculator::Operation::Multiply;
            break;
        case KeyCode::Key_Slash:
            operation = Calculator::Operation::Divide;
            break;
        case KeyCode::Key_Percent:
            operation = Calculator::Operation::Percent;
            break;
        default:
            return;
        }

        m_keypad.set_value(m_calculator.begin_operation(operation, m_keypad.value()));
    }

    update_display();
}