/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * 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 <LibCore/ConfigFile.h>
#include <LibGfx/SystemTheme.h>
#include <string.h>

namespace Gfx {

static SystemTheme dummy_theme;
static const SystemTheme* theme_page = &dummy_theme;
static Core::AnonymousBuffer theme_buffer;

const SystemTheme& current_system_theme()
{
    VERIFY(theme_page);
    return *theme_page;
}

Core::AnonymousBuffer& current_system_theme_buffer()
{
    VERIFY(theme_buffer.is_valid());
    return theme_buffer;
}

void set_system_theme(Core::AnonymousBuffer buffer)
{
    theme_buffer = move(buffer);
    theme_page = theme_buffer.data<SystemTheme>();
}

Core::AnonymousBuffer load_system_theme(const String& path)
{
    auto file = Core::ConfigFile::open(path);
    auto buffer = Core::AnonymousBuffer::create_with_size(sizeof(SystemTheme));

    auto* data = buffer.data<SystemTheme>();

    auto get_color = [&](auto& name) {
        auto color_string = file->read_entry("Colors", name);
        auto color = Color::from_string(color_string);
        if (!color.has_value())
            return Color(Color::Black);
        return color.value();
    };

    auto get_metric = [&](auto& name, auto role) {
        int metric = file->read_num_entry("Metrics", name, -1);
        if (metric == -1) {
            switch (role) {
            case (int)MetricRole::TitleHeight:
                return 19;
            case (int)MetricRole::TitleButtonHeight:
                return 15;
            case (int)MetricRole::TitleButtonWidth:
                return 15;
            default:
                dbgln("Metric {} has no fallback value!", name);
                return 16;
            }
        }
        return metric;
    };

    auto get_path = [&](auto& name, auto role, bool allow_empty) {
        auto path = file->read_entry("Paths", name);
        if (path.is_empty()) {
            switch (role) {
            case (int)PathRole::TitleButtonIcons:
                return "/res/icons/16x16/";
            default:
                return allow_empty ? "" : "/res/";
            }
        }
        return &path[0];
    };

#undef __ENUMERATE_COLOR_ROLE
#define __ENUMERATE_COLOR_ROLE(role) \
    data->color[(int)ColorRole::role] = get_color(#role).value();
    ENUMERATE_COLOR_ROLES(__ENUMERATE_COLOR_ROLE)
#undef __ENUMERATE_COLOR_ROLE

#define DO_METRIC(x) \
    data->metric[(int)MetricRole::x] = get_metric(#x, (int)MetricRole::x)

    DO_METRIC(TitleHeight);
    DO_METRIC(TitleButtonWidth);
    DO_METRIC(TitleButtonHeight);

#define DO_PATH(x, allow_empty)                                                                                  \
    do {                                                                                                         \
        auto path = get_path(#x, (int)PathRole::x, allow_empty);                                                 \
        memcpy(data->path[(int)PathRole::x], path, min(strlen(path) + 1, sizeof(data->path[(int)PathRole::x]))); \
        data->path[(int)PathRole::x][sizeof(data->path[(int)PathRole::x]) - 1] = '\0';                           \
    } while (0)

    DO_PATH(TitleButtonIcons, false);
    DO_PATH(ActiveWindowShadow, true);
    DO_PATH(InactiveWindowShadow, true);
    DO_PATH(TaskBarShadow, true);
    DO_PATH(MenuShadow, true);
    DO_PATH(TooltipShadow, true);

    return buffer;
}

}