OpenRCT2/src/interface/Theme.cpp

#include <jansson.h>

extern "C"
{
    #include "../common.h"
    #include "../config.h"
    #include "themes.h"
    #include "window.h"
}

#include "../core/Json.hpp"
#include "../core/List.hpp"
#include "../core/Math.hpp"
#include "../core/Memory.hpp"
#include "../core/Path.hpp"
#include "../core/String.hpp"
#include "../core/Util.hpp"

struct WindowThemeDesc;

// Don't try to load theme files that exceed 64 MiB
constexpr uint64 MAX_THEME_SIZE = 64 * 1024 * 1024;

/**
 * Represents a window theming style such as the colour scheme.
 */
struct WindowTheme
{
    colour_t Colours[6];
};

/**
 * Represents the style for a particular type of window.
 */
struct UIThemeWindowEntry
{
    rct_windowclass WindowClass;
    WindowTheme     Theme;


           json_t *           ToJson() const;
    static UIThemeWindowEntry FromJson(const WindowThemeDesc * wtDesc, const json_t * json);
};

/**
 * Represents a user interface theme. Contains window colour schemes and appearance features.
 */
class UITheme
{
public:
    utf8 *                   Name;
    List<UIThemeWindowEntry> Entries;
    uint8                    Flags;

    UITheme(const utf8 * name);
    UITheme(const UITheme & name);
    ~UITheme();

    void                       SetName(const utf8 * name);
    const UIThemeWindowEntry * GetEntry(rct_windowclass windowClass) const;
    void                       SetEntry(const UIThemeWindowEntry * entry);
    void                       RemoveEntry(rct_windowclass windowClass);

    json_t * ToJson() const;
    bool     WriteToFile(const utf8 * path) const;

    static UITheme * FromJson(const json_t * json);
    static UITheme * FromFile(const utf8 * path);
    static UITheme   CreatePredefined(const utf8 * name, const UIThemeWindowEntry * entries, uint8 flags);
};

/**
 * Represents the theme descriptor for a specific window type including the default colour scheme.
 */
struct WindowThemeDesc
{
    rct_windowclass WindowClass;
    const utf8 *    WindowClassSZ;
    rct_string_id   WindowName;
    uint8           NumColours;
    WindowTheme     DefaultTheme;
};

#pragma region Window Theme Descriptors

#define COLOURS_1(c0) 1, { { (c0), 0, 0, 0, 0, 0 } }
#define COLOURS_2(c0, c1) 2, { { (c0), (c1), 0, 0, 0, 0 } }
#define COLOURS_3(c0, c1, c2) 3, { { (c0), (c1), (c2), 0, 0, 0 } }
#define COLOURS_4(c0, c1, c2, c3) 4, { { (c0), (c1), (c2), (c3), 0, 0 } }
#define COLOURS_5(c0, c1, c2, c3, c4) 5, { { (c0), (c1), (c2), (c3), (c4), 0 } }
#define COLOURS_6(c0, c1, c2, c3, c4, c5) 6, { { (c0), (c1), (c2), (c3), (c4), (c5) } }

#define THEME_DEF_END { 0xFF, { 0, 0, 0, 0, 0, 0 } }

#define TWINDOW(window_class, window_name, window_string_id, theme) { window_class, window_name, window_string_id, theme }

#define THEME_WC(wc) wc, #wc

WindowThemeDesc WindowThemeDescriptors[] =
{
   // WindowClass, WindowClassSZ                   WindowName  NumColours, DefaultTheme
    { THEME_WC(WC_TOP_TOOLBAR),                    5245,       COLOURS_4(COLOUR_LIGHT_BLUE,               COLOUR_DARK_GREEN,               COLOUR_DARK_BROWN,             COLOUR_GREY         ) },
    { THEME_WC(WC_BOTTOM_TOOLBAR),                 5246,       COLOURS_4(TRANSLUCENT(COLOUR_DARK_GREEN),  TRANSLUCENT(COLOUR_DARK_GREEN),  COLOUR_BLACK,                  COLOUR_BRIGHT_GREEN ) },
    { THEME_WC(WC_RIDE),                           5203,       COLOURS_3(COLOUR_GREY,                     COLOUR_BORDEAUX_RED,             COLOUR_GREY                                        ) },
    { THEME_WC(WC_RIDE_CONSTRUCTION),              5199,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN                                  ) },
    { THEME_WC(WC_RIDE_LIST),                      5204,       COLOURS_3(COLOUR_GREY,                     COLOUR_BORDEAUX_RED,             COLOUR_BORDEAUX_RED                                ) },
    { THEME_WC(WC_SAVE_PROMPT),                    5223,       COLOURS_1(TRANSLUCENT(COLOUR_BORDEAUX_RED)                                                                                     ) },
    { THEME_WC(WC_CONSTRUCT_RIDE),                 5201,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_BORDEAUX_RED,             COLOUR_BORDEAUX_RED                                ) },
    { THEME_WC(WC_DEMOLISH_RIDE_PROMPT),           5224,       COLOURS_1(TRANSLUCENT(COLOUR_BORDEAUX_RED)                                                                                     ) },
    { THEME_WC(WC_SCENERY),                        5197,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_DARK_GREEN,               COLOUR_DARK_GREEN                                  ) },
    { THEME_WC(WC_OPTIONS),                        5219,       COLOURS_3(COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE                                  ) },
    { THEME_WC(WC_FOOTPATH),                       5198,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN                                  ) },
    { THEME_WC(WC_LAND),                           5193,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN                                  ) },
    { THEME_WC(WC_WATER),                          5194,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN                                  ) },
    { THEME_WC(WC_PEEP),                           5205,       COLOURS_3(COLOUR_GREY,                     COLOUR_OLIVE_GREEN,              COLOUR_OLIVE_GREEN                                 ) },
    { THEME_WC(WC_GUEST_LIST),                     5206,       COLOURS_3(COLOUR_GREY,                     COLOUR_OLIVE_GREEN,              COLOUR_OLIVE_GREEN                                 ) },
    { THEME_WC(WC_STAFF_LIST),                     5208,       COLOURS_3(COLOUR_GREY,                     COLOUR_LIGHT_PURPLE,             COLOUR_LIGHT_PURPLE                                ) },
    { THEME_WC(WC_FIRE_PROMPT),                    5225,       COLOURS_1(TRANSLUCENT(COLOUR_BORDEAUX_RED)                                                                                     ) },
    { THEME_WC(WC_PARK_INFORMATION),               5253,       COLOURS_3(COLOUR_GREY,                     COLOUR_DARK_YELLOW,              COLOUR_DARK_YELLOW                                 ) },
    { THEME_WC(WC_FINANCES),                       5187,       COLOURS_3(COLOUR_GREY,                     COLOUR_DARK_YELLOW,              COLOUR_DARK_YELLOW                                 ) },
    { THEME_WC(WC_TITLE_MENU),                     5249,       COLOURS_3(TRANSLUCENT(COLOUR_DARK_GREEN),  TRANSLUCENT(COLOUR_DARK_GREEN),  TRANSLUCENT(COLOUR_DARK_GREEN)                     ) },
    { THEME_WC(WC_TITLE_EXIT),                     5250,       COLOURS_3(TRANSLUCENT(COLOUR_DARK_GREEN),  TRANSLUCENT(COLOUR_DARK_GREEN),  TRANSLUCENT(COLOUR_DARK_GREEN)                     ) },
    { THEME_WC(WC_RECENT_NEWS),                    5192,       COLOURS_3(COLOUR_GREY,                     COLOUR_GREY,                     COLOUR_BLACK                                       ) },
    { THEME_WC(WC_SCENARIO_SELECT),                5252,       COLOURS_3(COLOUR_GREY,                     COLOUR_BORDEAUX_RED,             COLOUR_BORDEAUX_RED                                ) },
    { THEME_WC(WC_TRACK_DESIGN_LIST),              5202,       COLOURS_3(COLOUR_BORDEAUX_RED,             COLOUR_BORDEAUX_RED,             COLOUR_BORDEAUX_RED                                ) },
    { THEME_WC(WC_TRACK_DESIGN_PLACE),             5200,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN                                  ) },
    { THEME_WC(WC_NEW_CAMPAIGN),                   5188,       COLOURS_3(COLOUR_DARK_YELLOW,              COLOUR_DARK_YELLOW,              COLOUR_DARK_YELLOW                                 ) },
    { THEME_WC(WC_KEYBOARD_SHORTCUT_LIST),         5220,       COLOURS_3(COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE                                  ) },
    { THEME_WC(WC_CHANGE_KEYBOARD_SHORTCUT),       5221,       COLOURS_3(COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE                                  ) },
    { THEME_WC(WC_MAP),                            5190,       COLOURS_2(COLOUR_DARK_GREEN,               COLOUR_DARK_BROWN                                                                   ) },
    { THEME_WC(WC_BANNER),                         5209,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN                                  ) },
    { THEME_WC(WC_EDITOR_OBJECT_SELECTION),        5210,       COLOURS_3(COLOUR_LIGHT_PURPLE,             COLOUR_GREY,                     COLOUR_GREY                                        ) },
    { THEME_WC(WC_EDITOR_INVENTION_LIST),          5211,       COLOURS_3(COLOUR_LIGHT_PURPLE,             COLOUR_GREY,                     COLOUR_GREY                                        ) },
    { THEME_WC(WC_EDITOR_SCENARIO_OPTIONS),        5212,       COLOURS_3(COLOUR_LIGHT_PURPLE,             COLOUR_GREY,                     COLOUR_GREY                                        ) },
    { THEME_WC(WC_EDTIOR_OBJECTIVE_OPTIONS),       5213,       COLOURS_3(COLOUR_LIGHT_PURPLE,             COLOUR_GREY,                     COLOUR_GREY                                        ) },
    { THEME_WC(WC_MANAGE_TRACK_DESIGN),            5215,       COLOURS_3(COLOUR_GREY,                     COLOUR_GREY,                     COLOUR_GREY                                        ) },
    { THEME_WC(WC_TRACK_DELETE_PROMPT),            5226,       COLOURS_3(COLOUR_BORDEAUX_RED,             COLOUR_BORDEAUX_RED,             COLOUR_BORDEAUX_RED                                ) },
    { THEME_WC(WC_INSTALL_TRACK),                  5216,       COLOURS_3(COLOUR_BORDEAUX_RED,             COLOUR_BORDEAUX_RED,             COLOUR_BORDEAUX_RED                                ) },
    { THEME_WC(WC_CLEAR_SCENERY),                  5195,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN                                  ) },
    { THEME_WC(WC_CHEATS),                         5217,       COLOURS_3(COLOUR_GREY,                     COLOUR_DARK_YELLOW,              COLOUR_DARK_YELLOW                                 ) },
    { THEME_WC(WC_RESEARCH),                       5189,       COLOURS_3(COLOUR_GREY,                     COLOUR_DARK_YELLOW,              COLOUR_DARK_YELLOW                                 ) },
    { THEME_WC(WC_VIEWPORT),                       5191,       COLOURS_3(COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN                                  ) },
    { THEME_WC(WC_MAPGEN),                         5214,       COLOURS_3(COLOUR_DARK_GREEN,               COLOUR_DARK_BROWN,               COLOUR_DARK_BROWN                                  ) },
    { THEME_WC(WC_LOADSAVE),                       5222,       COLOURS_3(COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE                                  ) },
    { THEME_WC(WC_LOADSAVE_OVERWRITE_PROMPT),      5227,       COLOURS_1(TRANSLUCENT(COLOUR_BORDEAUX_RED)                                                                                     ) },
    { THEME_WC(WC_TITLE_OPTIONS),                  5251,       COLOURS_3(TRANSLUCENT(COLOUR_DARK_GREEN),  TRANSLUCENT(COLOUR_DARK_GREEN),  TRANSLUCENT(COLOUR_DARK_GREEN)                     ) },
    { THEME_WC(WC_LAND_RIGHTS),                    5196,       COLOURS_3(COLOUR_DARK_YELLOW,              COLOUR_DARK_YELLOW,              COLOUR_DARK_YELLOW                                 ) },
    { THEME_WC(WC_THEMES),                         5218,       COLOURS_3(COLOUR_GREY,                     COLOUR_DARK_GREEN,               COLOUR_DARK_GREEN                                  ) },
    { THEME_WC(WC_STAFF),                          5207,       COLOURS_3(COLOUR_GREY,                     COLOUR_LIGHT_PURPLE,             COLOUR_LIGHT_PURPLE                                ) },
    { THEME_WC(WC_EDITOR_TRACK_BOTTOM_TOOLBAR),    5247,       COLOURS_3(TRANSLUCENT(COLOUR_LIGHT_BLUE),  TRANSLUCENT(COLOUR_LIGHT_BLUE),  TRANSLUCENT(COLOUR_LIGHT_BLUE)                     ) },
    { THEME_WC(WC_EDITOR_SCENARIO_BOTTOM_TOOLBAR), 5248,       COLOURS_3(TRANSLUCENT(COLOUR_LIGHT_BROWN), TRANSLUCENT(COLOUR_LIGHT_BROWN), TRANSLUCENT(COLOUR_MOSS_GREEN)                     ) },
    { THEME_WC(WC_TITLE_EDITOR),                   5433,       COLOURS_3(COLOUR_GREY,                     COLOUR_OLIVE_GREEN,              COLOUR_OLIVE_GREEN                                 ) },
    { THEME_WC(WC_TILE_INSPECTOR),                 5314,       COLOURS_2(COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE                                                                   ) },
    { THEME_WC(WC_CHANGELOG),                      5344,       COLOURS_2(COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE                                                                   ) },
    { THEME_WC(WC_MULTIPLAYER),                    5502,       COLOURS_3(COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE                                  ) },
    { THEME_WC(WC_PLAYER),                         5736,       COLOURS_3(COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE                                  ) },
    { THEME_WC(WC_NETWORK_STATUS),                 5735,       COLOURS_1(COLOUR_LIGHT_BLUE                                                                                                    ) },
    { THEME_WC(WC_SERVER_LIST),                    5498,       COLOURS_2(COLOUR_LIGHT_BLUE,               COLOUR_LIGHT_BLUE                                                                   ) },
};

#pragma endregion

#pragma region Pre-defined Themes

#define COLOURS_RCT1(c0, c1, c2, c3, c4, c5) { { (c0), (c1), (c2), (c3), (c4), (c5) } }

UIThemeWindowEntry PredefinedThemeRCT1_Entries[] =
{
    { WC_TOP_TOOLBAR,     COLOURS_RCT1(COLOUR_GREY,               COLOUR_GREY,                COLOUR_GREY,                COLOUR_GREY,     COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_BOTTOM_TOOLBAR,  COLOURS_RCT1(TRANSLUCENT(COLOUR_GREY),  TRANSLUCENT(COLOUR_GREY),   COLOUR_BLACK,               COLOUR_YELLOW,   COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_RIDE,            COLOURS_RCT1(COLOUR_BORDEAUX_RED,       COLOUR_GREY,                COLOUR_SATURATED_GREEN,     COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_RIDE_LIST,       COLOURS_RCT1(COLOUR_BORDEAUX_RED,       COLOUR_GREY,                COLOUR_GREY,                COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_CONSTRUCT_RIDE,  COLOURS_RCT1(COLOUR_BORDEAUX_RED,       COLOUR_GREY,                COLOUR_GREY,                COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_PEEP,            COLOURS_RCT1(COLOUR_LIGHT_BROWN,        COLOUR_BORDEAUX_RED,        COLOUR_BORDEAUX_RED,        COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_GUEST_LIST,      COLOURS_RCT1(COLOUR_LIGHT_BROWN,        COLOUR_BORDEAUX_RED,        COLOUR_BORDEAUX_RED,        COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_STAFF_LIST,      COLOURS_RCT1(COLOUR_DARK_GREEN,         COLOUR_LIGHT_PURPLE,        COLOUR_LIGHT_PURPLE,        COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_FINANCES,        COLOURS_RCT1(COLOUR_LIGHT_PURPLE,       COLOUR_GREY,                COLOUR_GREY,                COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_TITLE_MENU,      COLOURS_RCT1(TRANSLUCENT(COLOUR_GREY),  TRANSLUCENT(COLOUR_GREY),   TRANSLUCENT(COLOUR_GREY),   COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_TITLE_EXIT,      COLOURS_RCT1(TRANSLUCENT(COLOUR_GREY),  TRANSLUCENT(COLOUR_GREY),   TRANSLUCENT(COLOUR_GREY),   COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_NEW_CAMPAIGN,    COLOURS_RCT1(COLOUR_LIGHT_PURPLE,       COLOUR_LIGHT_PURPLE,        COLOUR_GREY,                COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_TITLE_OPTIONS,   COLOURS_RCT1(TRANSLUCENT(COLOUR_GREY),  TRANSLUCENT(COLOUR_GREY),   TRANSLUCENT(COLOUR_GREY),   COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    { WC_STAFF,           COLOURS_RCT1(COLOUR_DARK_GREEN,         COLOUR_LIGHT_PURPLE,        COLOUR_LIGHT_PURPLE,        COLOUR_BLACK,    COLOUR_BLACK,    COLOUR_BLACK)    },
    THEME_DEF_END
};

UIThemeWindowEntry PredefinedThemeRCT2_Entries[] =
{
    THEME_DEF_END
};

const UITheme PredefinedThemeRCT1 = UITheme::CreatePredefined(
    "RCT1", PredefinedThemeRCT1_Entries, UITHEME_FLAG_USE_LIGHTS_RIDE |
                                         UITHEME_FLAG_USE_LIGHTS_PARK |
                                         UITHEME_FLAG_USE_ALTERNATIVE_SCENARIO_SELECT_FONT);

const UITheme PredefinedThemeRCT2 = UITheme::CreatePredefined(
    "RCT2", PredefinedThemeRCT2_Entries, 0);

const UITheme * PredefinedThemes[] = {
    &PredefinedThemeRCT1,
    &PredefinedThemeRCT2,
    nullptr
};

#pragma endregion

static const WindowThemeDesc * GetWindowThemeDescriptor(rct_windowclass windowClass)
{
    for (size_t i = 0; i < Util::CountOf(WindowThemeDescriptors); i++)
    {
        const WindowThemeDesc * desc = &WindowThemeDescriptors[i];
        if (desc->WindowClass == windowClass)
        {
            return desc;
        }
    }
    return nullptr;
}

static const WindowThemeDesc * GetWindowThemeDescriptor(const utf8 * windowClassSZ)
{
    for (size_t i = 0; i < Util::CountOf(WindowThemeDescriptors); i++)
    {
        const WindowThemeDesc * desc = &WindowThemeDescriptors[i];
        if (String::Equals(desc->WindowClassSZ, windowClassSZ))
        {
            return desc;
        }
    }
    return nullptr;
}

static void ThrowThemeLoadException()
{
    throw Exception("Invalid JSON UI theme entry.");
}

#pragma region UIThemeEntry

json_t * UIThemeWindowEntry::ToJson() const
{
    const WindowThemeDesc * wtDesc = GetWindowThemeDescriptor(WindowClass);
        
    json_t * jsonColours = json_array();
    for (uint8 i = 0; i < wtDesc->NumColours; i++) {
        colour_t colour = Theme.Colours[i];
        json_array_append_new(jsonColours, json_integer(colour));
    }

    json_t * jsonEntry = json_object();
    json_object_set_new(jsonEntry, "colours", jsonColours);

    return jsonEntry;
}

UIThemeWindowEntry UIThemeWindowEntry::FromJson(const WindowThemeDesc * wtDesc, const json_t * json)
{
    json_t * jsonColours = json_object_get(json, "colours");
    if (jsonColours == nullptr)
    {
        ThrowThemeLoadException();
    }

    uint8 numColours = (uint8)json_array_size(jsonColours);
    numColours = Math::Min(numColours, wtDesc->NumColours);

    UIThemeWindowEntry result;
    result.WindowClass = wtDesc->WindowClass;
    result.Theme = wtDesc->DefaultTheme;
    
    for (uint8 i = 0; i < numColours; i++)
    {
        result.Theme.Colours[i] = (colour_t)json_integer_value(json_array_get(jsonColours, i));
    }

    return result;
}

#pragma endregion

#pragma region UITheme

UITheme::UITheme(const utf8 * name)
{
    Name = String::Duplicate(name);
    Flags = 0;
}

UITheme::UITheme(const UITheme & copy)
{
    Name = String::Duplicate(copy.Name);
    Flags = copy.Flags;
    Entries = copy.Entries;
}

UITheme::~UITheme()
{
    Memory::Free(Name);
}

void UITheme::SetName(const utf8 * name)
{
    String::DiscardDuplicate(&Name, name);
}

const UIThemeWindowEntry * UITheme::GetEntry(rct_windowclass windowClass) const
{
    for (size_t i = 0; i < Entries.GetCount(); i++)
    {
        const UIThemeWindowEntry * entry = &Entries[i];
        if (entry->WindowClass == windowClass)
        {
            return entry;
        }
    }
    return nullptr;
}

void UITheme::SetEntry(const UIThemeWindowEntry * newEntry)
{
    // Try to replace existing entry
    for (size_t i = 0; i < Entries.GetCount(); i++)
    {
        UIThemeWindowEntry * entry = &Entries[i];
        if (entry->WindowClass == newEntry->WindowClass)
        {
            *entry = *newEntry;
            return;
        }
    }

    Entries.Add(*newEntry);
}

void UITheme::RemoveEntry(rct_windowclass windowClass)
{
    // Remove existing entry
    for (size_t i = 0; i < Entries.GetCount(); i++)
    {
        UIThemeWindowEntry * entry = &Entries[i];
        if (entry->WindowClass == windowClass)
        {
            Entries.RemoveAt(i);
            break;
        }
    }
}

json_t * UITheme::ToJson() const
{
    // Create entries
    json_t * jsonEntries = json_object();
    for (const UIThemeWindowEntry & entry : Entries)
    {
        const WindowThemeDesc * wtDesc = GetWindowThemeDescriptor(entry.WindowClass);
        json_object_set_new(jsonEntries, wtDesc->WindowClassSZ, entry.ToJson());
    }

    // Create theme object
    json_t * jsonTheme = json_object();
    json_object_set_new(jsonTheme, "name", json_string(Name));
    json_object_set_new(jsonTheme, "entries", jsonEntries);

    json_object_set_new(jsonTheme, "useLightsRide", json_boolean(Flags & UITHEME_FLAG_USE_LIGHTS_RIDE));
    json_object_set_new(jsonTheme, "useLightsPark", json_boolean(Flags & UITHEME_FLAG_USE_LIGHTS_PARK));
    json_object_set_new(jsonTheme,
                        "useAltScenarioSelectFont",
                        json_boolean(Flags & UITHEME_FLAG_USE_ALTERNATIVE_SCENARIO_SELECT_FONT));

    return jsonTheme;
}

bool UITheme::WriteToFile(const utf8 * path) const
{
    json_t * jsonTheme = ToJson();
    bool     result;
    try
    {
        Json::WriteToFile(path, jsonTheme, JSON_INDENT(4) | JSON_PRESERVE_ORDER);
        result = true;
    }
    catch (Exception ex)
    {
        log_error("Unable to save %s: %s", path, ex.GetMessage());
        result = false;
    }

    json_decref(jsonTheme);
    return result;
}

UITheme * UITheme::FromJson(const json_t * json)
{
    const char * themeName = json_string_value(json_object_get(json, "name"));
    if (themeName == nullptr)
    {
        ThrowThemeLoadException();
    }

    json_t * jsonEntries = json_object_get(json, "entries");
    size_t numEntries = json_object_size(jsonEntries);

    UITheme * result = nullptr;
    try
    {
        result = new UITheme(themeName);

        if (json_is_true(json_object_get(json, "useLightsRide")))
        {
            result->Flags |= UITHEME_FLAG_USE_LIGHTS_RIDE;
        }
        if (json_is_true(json_object_get(json, "useLightsPark")))
        {
            result->Flags |= UITHEME_FLAG_USE_LIGHTS_PARK;
        }
        if (json_is_true(json_object_get(json, "useAltScenarioSelectFont")))
        {
            result->Flags |= UITHEME_FLAG_USE_ALTERNATIVE_SCENARIO_SELECT_FONT;
        }

        const char * jkey;
        json_t     * jvalue;
        size_t       i = 0;
        json_object_foreach(jsonEntries, jkey, jvalue)
        {
            const WindowThemeDesc * wtDesc = GetWindowThemeDescriptor(jkey);
            if (wtDesc == nullptr) continue;

            UIThemeWindowEntry entry = UIThemeWindowEntry::FromJson(wtDesc, jvalue);
            result->SetEntry(&entry);
        }

        return result;
    }
    catch (Exception ex)
    {
        delete result;
        throw ex;
    }
}

UITheme * UITheme::FromFile(const utf8 * path)
{
    json_t  * json = nullptr;
    UITheme * result = nullptr;
    try
    {
        json = Json::ReadFromFile(path);
        result = UITheme::FromJson(json);
    }
    catch (Exception ex)
    {
        log_error("Unable to read theme: %s", path);
        result = nullptr;
    }

    json_decref(json);
    return result;
}

UITheme UITheme::CreatePredefined(const utf8 * name, const UIThemeWindowEntry * entries, uint8 flags)
{
    auto theme = UITheme(name);
    theme.Flags = flags | UITHEME_FLAG_PREDEFINED;

    size_t numEntries = 0;
    for (const UIThemeWindowEntry * entry = entries; entry->WindowClass != 255; entry++)
    {
        numEntries++;
    }

    theme.Entries = List<UIThemeWindowEntry>(entries, numEntries);
    return theme;
}

#pragma endregion

namespace ThemeManager
{
    struct AvailableTheme
    {
        utf8 Path[MAX_PATH];
        utf8 Name[96];
    };

    utf8 *               CurrentThemePath;
    UITheme *            CurrentTheme;
    List<AvailableTheme> AvailableThemes;
    size_t               ActiveAvailableThemeIndex = SIZE_MAX;
    size_t               NumPredefinedThemes = 0;

    void GetThemeFileName(utf8 * buffer, size_t bufferSize, const utf8 * name);

    void GetAvailableThemes(List<AvailableTheme> * outThemes)
    {
        Guard::ArgumentNotNull(outThemes);

        outThemes->Clear();

        NumPredefinedThemes = 0;
        for (const UITheme * * predefinedTheme = PredefinedThemes; *predefinedTheme != nullptr; predefinedTheme++)
        {
            AvailableTheme theme;
            String::Set(theme.Path, sizeof(theme.Path), String::Empty);
            String::Set(theme.Name, sizeof(theme.Name), (*predefinedTheme)->Name);
            outThemes->Add(theme);

            NumPredefinedThemes++;
        }

        utf8 themesPattern[MAX_PATH];
        platform_get_user_directory(themesPattern, "themes");
        Path::Append(themesPattern, sizeof(themesPattern), "*.json");

        int handle = platform_enumerate_files_begin(themesPattern);
        if (handle != INVALID_HANDLE)
        {
            file_info fileInfo;
            while (platform_enumerate_files_next(handle, &fileInfo))
            {
                AvailableTheme theme;
                Path::GetFileNameWithoutExtension(theme.Name, sizeof(theme.Name), fileInfo.path);
                GetThemeFileName(theme.Path, sizeof(theme.Path), theme.Name);
                
                outThemes->Add(theme);

                if (Path::Equals(CurrentThemePath, fileInfo.path))
                {
                    ActiveAvailableThemeIndex = outThemes->GetCount() - 1;
                }
            }
            platform_enumerate_files_end(handle);
        }
    }

    void LoadTheme(UITheme * theme)
    {
        if (CurrentTheme == theme)
        {
            return;
        }

        if (CurrentTheme != nullptr)
        {
            if (!(CurrentTheme->Flags & UITHEME_FLAG_PREDEFINED))
            {
                delete CurrentTheme;
            }
        }

        CurrentTheme = theme;
        String::DiscardUse(&CurrentThemePath, nullptr);

        gfx_invalidate_screen();
    }

    void LoadTheme(const utf8 * path)
    {
        UITheme * theme = UITheme::FromFile(path);
        if (theme == nullptr)
        {
            // Fall-back to default
            theme = (UITheme *)&PredefinedThemeRCT2;
            LoadTheme(theme);
        }
        else
        {
            LoadTheme(theme);
            String::DiscardDuplicate(&CurrentThemePath, path);
        }
    }

    bool LoadThemeByName(const utf8 * name)
    {
        for (size_t i = 0; i < ThemeManager::AvailableThemes.GetCount(); i++)
        {
            if (String::Equals(name, ThemeManager::AvailableThemes[i].Name))
            {
                const utf8 * path = ThemeManager::AvailableThemes[i].Path;
                if (String::IsNullOrEmpty(path))
                {
                    LoadTheme((UITheme *)PredefinedThemes[i]);
                }
                else
                {
                    LoadTheme(ThemeManager::AvailableThemes[i].Path);
                }
                ActiveAvailableThemeIndex = i;
                return true;
            }
        }
        return false;
    }

    void Initialise()
    {
        ThemeManager::GetAvailableThemes(&ThemeManager::AvailableThemes);
        LoadTheme((UITheme *)&PredefinedThemeRCT2);
        ActiveAvailableThemeIndex = 1;

        bool configValid = false;
        if (!String::IsNullOrEmpty(gConfigInterface.current_theme_preset))
        {
            if (LoadThemeByName(gConfigInterface.current_theme_preset))
            {
                configValid = true;
            }
        }
        
        if (!configValid)
        {
            String::DiscardDuplicate(&gConfigInterface.current_theme_preset, theme_manager_get_available_theme_name(1));
        }
    }

    void GetThemeFileName(utf8 * buffer, size_t bufferSize, const utf8 * name)
    {
        platform_get_user_directory(buffer, "themes");
        Path::Append(buffer, bufferSize, name);
        String::Append(buffer, bufferSize, ".json");
    }
}

extern "C"
{
    void theme_manager_load_available_themes()
    {
        ThemeManager::GetAvailableThemes(&ThemeManager::AvailableThemes);
    }

    size_t theme_manager_get_num_available_themes()
    {
        return ThemeManager::AvailableThemes.GetCount();
    }

    const utf8 * theme_manager_get_available_theme_path(size_t index)
    {
        return ThemeManager::AvailableThemes[index].Path;
    }

    const utf8 * theme_manager_get_available_theme_name(size_t index)
    {
        return ThemeManager::AvailableThemes[index].Name;
    }

    size_t theme_manager_get_active_available_theme_index()
    {
        return ThemeManager::ActiveAvailableThemeIndex;
    }

    void theme_manager_set_active_available_theme(size_t index)
    {
        if (index < ThemeManager::NumPredefinedThemes)
        {
            ThemeManager::LoadTheme((UITheme *)PredefinedThemes[index]);
        }
        else
        {
            const utf8 * path = ThemeManager::AvailableThemes[index].Path;
            ThemeManager::LoadTheme(path);

            // HACK Check if theme load failed and fell back to RCT2
            if (ThemeManager::CurrentThemePath == nullptr)
            {
                index = 1;
            }
        }
        ThemeManager::ActiveAvailableThemeIndex = index;
        String::DiscardDuplicate(&gConfigInterface.current_theme_preset, theme_manager_get_available_theme_name(index));
    }

    uint8 theme_get_colour(rct_windowclass wc, uint8 index)
    {
        const UIThemeWindowEntry * entry = ThemeManager::CurrentTheme->GetEntry(wc);
        if (entry == nullptr)
        {
            const WindowThemeDesc * desc = GetWindowThemeDescriptor(wc);
            return desc->DefaultTheme.Colours[index];
        }
        else
        {
            return entry->Theme.Colours[index];
        }
    }

    void theme_set_colour(rct_windowclass wc, uint8 index, colour_t colour)
    {
        UIThemeWindowEntry entry;
        entry.WindowClass = wc;

        auto currentEntry = (UIThemeWindowEntry *)ThemeManager::CurrentTheme->GetEntry(wc);
        if (currentEntry != nullptr)
        {
            entry.Theme = currentEntry->Theme;
        }
        else
        {
            const WindowThemeDesc * desc = GetWindowThemeDescriptor(wc);
            entry.Theme = desc->DefaultTheme;
        }

        entry.Theme.Colours[index] = colour;
        ThemeManager::CurrentTheme->SetEntry(&entry);

        theme_save();
    }

    uint8 theme_get_flags()
    {
        return ThemeManager::CurrentTheme->Flags;
    }

    void theme_set_flags(uint8 flags)
    {
        ThemeManager::CurrentTheme->Flags = flags;
        theme_save();
    }

    void theme_save()
    {
        ThemeManager::CurrentTheme->WriteToFile(ThemeManager::CurrentThemePath);
    }

    void theme_rename(const utf8 * name)
    {
        const utf8 * oldPath = ThemeManager::CurrentThemePath;
        utf8         newPath[MAX_PATH];

        ThemeManager::GetThemeFileName(newPath, sizeof(newPath), name);
        platform_file_move(oldPath, newPath);
        String::DiscardDuplicate(&ThemeManager::CurrentThemePath, newPath);

        ThemeManager::CurrentTheme->SetName(name);
        ThemeManager::CurrentTheme->WriteToFile(ThemeManager::CurrentThemePath);

        theme_manager_load_available_themes();
        for (size_t i = 0; i < ThemeManager::AvailableThemes.GetCount(); i++)
        {
            if (Path::Equals(newPath, ThemeManager::AvailableThemes[i].Path))
            {
                ThemeManager::ActiveAvailableThemeIndex = i;
                String::DiscardDuplicate(&gConfigInterface.current_theme_preset, theme_manager_get_available_theme_name(1));
                break;
            }
        }
    }

    void theme_duplicate(const utf8 * name)
    {
        utf8 newPath[MAX_PATH];

        ThemeManager::GetThemeFileName(newPath, sizeof(newPath), name);
        String::DiscardDuplicate(&ThemeManager::CurrentThemePath, newPath);

        ThemeManager::CurrentTheme->SetName(name);
        ThemeManager::CurrentTheme->Flags &= ~UITHEME_FLAG_PREDEFINED;
        ThemeManager::CurrentTheme->WriteToFile(ThemeManager::CurrentThemePath);

        theme_manager_load_available_themes();
        for (size_t i = 0; i < ThemeManager::AvailableThemes.GetCount(); i++)
        {
            if (Path::Equals(newPath, ThemeManager::AvailableThemes[i].Path))
            {
                ThemeManager::ActiveAvailableThemeIndex = i;
                String::DiscardDuplicate(&gConfigInterface.current_theme_preset, theme_manager_get_available_theme_name(i));
                break;
            }
        }
    }

    void theme_delete()
    {
        platform_file_delete(ThemeManager::CurrentThemePath);
        ThemeManager::LoadTheme((UITheme *)&PredefinedThemeRCT2);
        ThemeManager::ActiveAvailableThemeIndex = 1;
        String::DiscardDuplicate(&gConfigInterface.current_theme_preset, theme_manager_get_available_theme_name(1));
    }

    void theme_manager_initialise()
    {
        ThemeManager::Initialise();
    }

    uint8 theme_desc_get_num_colours(rct_windowclass wc)
    {
        const WindowThemeDesc * desc = GetWindowThemeDescriptor(wc);
        return desc->NumColours;
    }

    rct_string_id theme_desc_get_name(rct_windowclass wc)
    {
        const WindowThemeDesc * desc = GetWindowThemeDescriptor(wc);
        return desc->WindowName;
    }

    void colour_scheme_update(rct_window * window)
    {
        colour_scheme_update_by_class(window, window->classification);
    }

    void colour_scheme_update_by_class(rct_window * window, rct_windowclass classification)
    {
        const WindowTheme *        windowTheme;
        const UIThemeWindowEntry * entry = ThemeManager::CurrentTheme->GetEntry(classification);
        if (entry != nullptr)
        {
            windowTheme = &entry->Theme;
        }
        else
        {
            const WindowThemeDesc * desc = GetWindowThemeDescriptor(classification);
            windowTheme = &desc->DefaultTheme;
        }

        bool transparent = false;
        for (int i = 0; i < 6; i++) {
            window->colours[i] = windowTheme->Colours[i];
            if (windowTheme->Colours[i] & COLOUR_FLAG_TRANSLUCENT) {
                transparent = true;
            }
        }
        // Some windows need to be transparent even if the colours aren't.
        // There doesn't seem to be any side-effects for all windows being transparent
        window->flags |= WF_TRANSPARENT;
    }
}