#pragma region Copyright (c) 2014-2017 OpenRCT2 Developers
/*****************************************************************************
 * OpenRCT2, an open source clone of Roller Coaster Tycoon 2.
 *
 * OpenRCT2 is the work of many authors, a full list can be found in contributors.md
 * For more information, visit https://github.com/OpenRCT2/OpenRCT2
 *
 * OpenRCT2 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * A full copy of the GNU General Public License can be found in licence.txt
 *****************************************************************************/
#pragma endregion

#include "../Context.h"
#include "../OpenRCT2.h"
#include "../core/Math.hpp"
#include "../core/Memory.hpp"

extern "C" {
    #include "../interface/widget.h"
    #include "../localisation/localisation.h"
    #include "../util/util.h"
}

enum {
    WIDX_BACKGROUND,
    WIDX_TITLE,
    WIDX_CLOSE,
    WIDX_CONTENT_PANEL,
    WIDX_SCROLL
};

#define WW 500
#define WH 400
#define MIN_WW 300
#define MIN_WH 200

rct_widget window_changelog_widgets[] = {
    { WWT_FRAME,            0,  0,          WW - 1, 0,      WH - 1,     0xFFFFFFFF,                     STR_NONE },             // panel / background
    { WWT_CAPTION,          0,  1,          WW - 2, 1,      14,         STR_CHANGELOG_TITLE,            STR_WINDOW_TITLE_TIP }, // title bar
    { WWT_CLOSEBOX,         0,  WW - 13,    WW - 3, 2,      13,         STR_CLOSE_X,                    STR_CLOSE_WINDOW_TIP }, // close x button
    { WWT_RESIZE,           1,  0,          WW - 1, 14,     WH - 1,     0xFFFFFFFF,                     STR_NONE },             // content panel
    { WWT_SCROLL,           1,  3,          WW - 3, 16,     WH - 15,    SCROLL_BOTH,                    STR_NONE },             // scroll area
    { WIDGETS_END },
};

static void window_changelog_close(rct_window *w);
static void window_changelog_mouseup(rct_window *w, rct_widgetindex widgetIndex);
static void window_changelog_resize(rct_window *w);
static void window_changelog_scrollgetsize(rct_window *w, sint32 scrollIndex, sint32 *width, sint32 *height);
static void window_changelog_invalidate(rct_window *w);
static void window_changelog_paint(rct_window *w, rct_drawpixelinfo *dpi);
static void window_changelog_scrollpaint(rct_window *w, rct_drawpixelinfo *dpi, sint32 scrollIndex);

static rct_window_event_list window_changelog_events = {
    window_changelog_close,
    window_changelog_mouseup,
    window_changelog_resize,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    window_changelog_scrollgetsize,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    window_changelog_invalidate,
    window_changelog_paint,
    window_changelog_scrollpaint
};

static bool window_changelog_read_file();
static void window_changelog_dispose_file();

static char *_changelogText = NULL;
static size_t _changelogTextSize = 0;
static char **_changelogLines = NULL;
static sint32 _changelogNumLines = 0;
static sint32 _changelogLongestLineWidth = 0;

static rct_window *_window_changelog_open()
{
    rct_window* window;

    window = window_bring_to_front_by_class(WC_CHANGELOG);
    if (window != NULL)
        return window;

    if (!window_changelog_read_file())
        return NULL;

    sint32 screenWidth = context_get_width();
    sint32 screenHeight = context_get_height();

    window = window_create_centred(
        screenWidth * 4 / 5,
        screenHeight * 4 / 5,
        &window_changelog_events,
        WC_CHANGELOG,
        WF_RESIZABLE
    );
    window->widgets = window_changelog_widgets;
    window->enabled_widgets = (1 << WIDX_CLOSE);

    window_init_scroll_widgets(window);
    window->min_width = MIN_WW;
    window->min_height = MIN_WH;
    window->max_width = MIN_WW;
    window->max_height = MIN_WH;
    return window;
}

static void window_changelog_close(rct_window *w)
{
    window_changelog_dispose_file();
}

static void window_changelog_mouseup(rct_window *w, rct_widgetindex widgetIndex)
{
    switch (widgetIndex) {
    case WIDX_CLOSE:
        window_close(w);
        break;
    }
}

static void window_changelog_resize(rct_window *w)
{
    sint32 screenWidth = context_get_width();
    sint32 screenHeight = context_get_height();

    w->max_width = (screenWidth * 4) / 5;
    w->max_height = (screenHeight * 4) / 5;

    w->min_width = MIN_WW;
    w->min_height = MIN_WH;
    if (w->width < w->min_width) {
        window_invalidate(w);
        w->width = w->min_width;
    }
    if (w->height < w->min_height) {
        window_invalidate(w);
        w->height = w->min_height;
    }
}

static void window_changelog_scrollgetsize(rct_window *w, sint32 scrollIndex, sint32 *width, sint32 *height)
{
    *width = _changelogLongestLineWidth + 4;
    *height = _changelogNumLines * 11;
}

static void window_changelog_invalidate(rct_window *w)
{
    window_changelog_widgets[WIDX_BACKGROUND].right = w->width - 1;
    window_changelog_widgets[WIDX_BACKGROUND].bottom = w->height - 1;
    window_changelog_widgets[WIDX_TITLE].right = w->width - 2;
    window_changelog_widgets[WIDX_CLOSE].left = w->width - 13;
    window_changelog_widgets[WIDX_CLOSE].right = w->width - 3;
    window_changelog_widgets[WIDX_CONTENT_PANEL].right = w->width - 1;
    window_changelog_widgets[WIDX_CONTENT_PANEL].bottom = w->height - 1;
    window_changelog_widgets[WIDX_SCROLL].right = w->width - 3;
    window_changelog_widgets[WIDX_SCROLL].bottom = w->height - 15;
}

static void window_changelog_paint(rct_window *w, rct_drawpixelinfo *dpi)
{
    window_draw_widgets(w, dpi);
}

static void window_changelog_scrollpaint(rct_window *w, rct_drawpixelinfo *dpi, sint32 scrollIndex)
{
    gCurrentFontFlags = 0;
    gCurrentFontSpriteBase = FONT_SPRITE_BASE_MEDIUM;

    sint32 x = 3;
    sint32 y = 3;
    for (sint32 i = 0; i < _changelogNumLines; i++) {
        gfx_draw_string(dpi, _changelogLines[i], w->colours[0], x, y);
        y += 11;
    }
}

static bool window_changelog_read_file()
{
    window_changelog_dispose_file();
    utf8 path[MAX_PATH];
    platform_get_changelog_path(path, sizeof(path));
    if (!readentirefile(path, (void**)&_changelogText, &_changelogTextSize)) {
        log_error("Unable to read changelog.txt");
        return false;
    }
    void* new_memory = realloc(_changelogText, _changelogTextSize + 1);
    if (new_memory == NULL) {
        log_error("Failed to reallocate memory for changelog text");
        return false;
    }
    _changelogText = (char*)new_memory;
    _changelogText[_changelogTextSize++] = 0;

    char *start = _changelogText;
    if (_changelogTextSize >= 3 && utf8_is_bom(_changelogText))
        start += 3;

    sint32 changelogLinesCapacity = 8;
    _changelogLines = Memory::Allocate<utf8*>(changelogLinesCapacity * sizeof(char*));
    _changelogLines[0] = start;
    _changelogNumLines = 1;

    char *ch = start;
    while (*ch != 0) {
        uint8 c = *ch;
        if (c == '\n') {
            *ch++ = 0;
            _changelogNumLines++;
            if (_changelogNumLines > changelogLinesCapacity) {
                changelogLinesCapacity *= 2;
                new_memory = realloc(_changelogLines, changelogLinesCapacity * sizeof(char*));
                if (new_memory == NULL) {
                    log_error("Failed to reallocate memory for change log lines");
                    return false;
                }
                _changelogLines = (char**)new_memory;
            }
            _changelogLines[_changelogNumLines - 1] = ch;
        } else if (c < 32 || c > 122) {
            // A character that won't be drawn or change state.
            *ch++ = FORMAT_OUTLINE_OFF;
        } else {
            ch++;
        }
    }

    new_memory = realloc(_changelogLines, _changelogNumLines * sizeof(char*));
    if (new_memory == NULL) {
        log_error("Failed to reallocate memory for change log lines");
        return false;
    }
    _changelogLines = (char**)new_memory;

    gCurrentFontSpriteBase = FONT_SPRITE_BASE_MEDIUM;
    _changelogLongestLineWidth = 0;
    for (sint32 i = 0; i < _changelogNumLines; i++) {
        sint32 width = gfx_get_string_width(_changelogLines[i]);
        _changelogLongestLineWidth = Math::Max(width, _changelogLongestLineWidth);
    }
    return true;
}

static void window_changelog_dispose_file()
{
    SafeFree(_changelogText);
    SafeFree(_changelogLines);
    _changelogTextSize = 0;
    _changelogNumLines = 0;
}

extern "C"
{
    rct_window *window_changelog_open()
    {
        return _window_changelog_open();
    }
}