require('common')
local Easing = require('common.easings');

local defaultFolderBgImage = gfx.CreateSkinImage('song_select/filter_wheel/bg.png', 0)

local cursorImage = gfx.CreateSkinImage('song_select/cursor.png', 0)

local ITEM_HEIGHT = 172;

local specialFolders = {
    {
        keys = {
            'SOUND VOLTEX BOOTH',
            'SDVX BOOTH',
            'SOUND VOLTEX I',
            'SDVX I',
            'SOUND VOLTEX 1',
            'SDVX 1'
        },
        folderBg = gfx.CreateSkinImage('song_select/filter_wheel/special_folder_bgs/Booth.png', 0)
    },
    {
        keys = {
            'SOUND VOLTEX INFINITE INFECTION',
            'SDVX INFINITE INFECTION',
            'SOUND VOLTEX II',
            'SDVX II',
            'SOUND VOLTEX 2',
            'SDVX 2'
        },
        folderBg = gfx.CreateSkinImage('song_select/filter_wheel/special_folder_bgs/Infinite Infection.png', 0)
    },
    -- {
    --     keys = {
    --         'SOUND VOLTEX GRAVITY WARS',
    --         'SDVX GRAVITY WARS',
    --         'SOUND VOLTEX III',
    --         'SDVX III',
    --         'SOUND VOLTEX 3',
    --         'SDVX 3'
    --     },
    --     folderBg = gfx.CreateSkinImage('song_select/filter_wheel/special_folder_bgs/Infinite Infection.png', 0)
    -- },
    {
        keys = {
            'SOUND VOLTEX HEAVENLY HAVEN',
            'SDVX HEAVENLY HAVEN',
            'SOUND VOLTEX IV',
            'SDVX IV',
            'SOUND VOLTEX 4',
            'SDVX 4'
        },
        folderBg = gfx.CreateSkinImage('song_select/filter_wheel/special_folder_bgs/Heavenly Haven.png', 0)
    },
    {
        keys = {
            'SOUND VOLTEX VIVID WAVE',
            'SDVX VIVID WAVE',
            'SOUND VOLTEX V',
            'SDVX V',
            'SOUND VOLTEX 5',
            'SDVX 5'
        },
        folderBg = gfx.CreateSkinImage('song_select/filter_wheel/special_folder_bgs/Vivid Wave.png', 0)
    },
    {
        keys = {
            'SOUND VOLTEX EXCEED GEAR',
            'SDVX EXCEED GEAR',
            'SOUND VOLTEX VI',
            'SDVX VI',
            'SOUND VOLTEX 6',
            'SDVX 6'
        },
        folderBg = gfx.CreateSkinImage('song_select/filter_wheel/special_folder_bgs/Exceed Gear.png', 0)
    },
}

-- AUDIO
game.LoadSkinSample('song_wheel/cursor_change.wav');

local resx, resy = game.GetResolution()
local desw, desh = 1080, 1920
local scale = 1;

local selectionMode = 'folders';
local selectedFolder = 1;
local selectedLevel = 1;

local transitionScrollScale = 0;
local transitionScrollOffsetY = 0;
local scrollingUp = false;

function resetLayoutInformation()
    resx, resy = game.GetResolution()
    scale = resx / desw
end

function getCorrectedIndex(from, offset)
    local total = 1;
    if selectionMode == 'folders' then
        total = #filters.folder;
    else
        total = #filters.level;
    end

    index = from + offset;

    if index < 1 then
        index = total + (from + offset) -- this only happens if the offset is negative
    end

    if index > total then
        indexesUntilEnd = total - from;
        index = offset - indexesUntilEnd -- this only happens if the offset is positive
    end

    return index;
end

function getFolderData(folderLabel)
    local folderType = 'unknown';
    if (string.find(folderLabel, 'Folder: ')) then
        folderType = 'folder';
        folderLabel = folderLabel:gsub('Folder: ', '') -- Delete the useless info
    end

    local labelMatcherString = string.upper(folderLabel)
    local folderBgImage = defaultFolderBgImage;
    local isSpecial = false;

    for i,specialFolder in ipairs(specialFolders) do
        for i,specialFolderKey in ipairs(specialFolder.keys) do
            if (specialFolderKey == labelMatcherString) then
                folderBgImage = specialFolder.folderBg;
                isSpecial = true;
            end
        end
    end

    return {
        type = folderType,
        label = folderLabel,
        bgImage = folderBgImage,
        isSpecial = isSpecial,
    }
end

function drawFolder(label, y)
    if (not label) then return end

    local x = desw / 2 + 0

    local folderData = getFolderData(label)

    -- Draw the bg
    gfx.BeginPath()
    gfx.ImageRect(x, y, 630*0.86, 200*0.86, folderData.bgImage, 1, 0)

    -- Draw the folder label, but only if the folder is not special
    if (not folderData.isSpecial) then 
        gfx.BeginPath();
        gfx.FontSize(38)
        gfx.TextAlign(gfx.TEXT_ALIGN_LEFT + gfx.TEXT_ALIGN_MIDDLE)
        gfx.FillColor(255, 255, 255, 255);
        gfx.Text(folderData.label, x+18, y+72);
    end
end

function drawFolderList()
    local numOfItemsAround = 7;
    local selectedIndex = 1;
    if selectionMode == 'folders' then
        selectedIndex = selectedFolder
    else
        selectedIndex = selectedLevel
    end

    local i = 1;
    while (i <= numOfItemsAround) do
        local index = getCorrectedIndex(selectedIndex, -i)
        drawFolder(filters.folder[index], desh / 2 - ITEM_HEIGHT / 2 -
                       ITEM_HEIGHT * i + transitionScrollOffsetY)
        i = i + 1;
    end

    -- Draw the selected song
    drawFolder(filters.folder[selectedIndex],
               desh / 2 - ITEM_HEIGHT / 2 + transitionScrollOffsetY)

    i = 1;
    while (i <= numOfItemsAround) do
        local index = getCorrectedIndex(selectedIndex, i)
        drawFolder(filters.folder[index], desh / 2 - ITEM_HEIGHT / 2 +
                       ITEM_HEIGHT * i + transitionScrollOffsetY)
        i = i + 1;
    end
end

function drawCursor()
    gfx.BeginPath()
    gfx.ImageRect(desw/2-14, desh/2-213/2, 555, 213, cursorImage, 1, 0)
end

function tickTransitions(deltaTime)
    if transitionScrollScale < 1 then
        transitionScrollScale = transitionScrollScale + deltaTime / 0.1 -- transition should last for that time in seconds
    else
        transitionScrollScale = 1
    end

    if scrollingUp then 
        transitionScrollOffsetY = Easing.inQuad(1-transitionScrollScale) * ITEM_HEIGHT;
    else
        transitionScrollOffsetY = Easing.inQuad(1-transitionScrollScale) * -ITEM_HEIGHT;
    end
end

render = function(deltaTime, shown)
    if not shown then return end
    gfx.ResetTransform()
    resetLayoutInformation()
    tickTransitions(deltaTime);
    gfx.Scale(scale,scale);

    drawFolderList()

    drawCursor()

    -- Debug text
    gfx.BeginPath();
    gfx.FontSize(18)
    gfx.TextAlign(gfx.TEXT_ALIGN_LEFT + gfx.TEXT_ALIGN_TOP)
    gfx.FillColor(255, 255, 255, 255);
    gfx.Text('S_M: ' .. selectionMode .. ' // S_F: ' .. selectedFolder ..
                 ' // S_L: ' .. selectedLevel .. ' // T_S_S: ' .. transitionScrollScale, 8, 1900);
end

set_selection = function(newIndex, isFolder)
    local oldIndex = 1;
    local total = 1;
    if isFolder then
        oldIndex = selectedFolder
        selectedFolder = newIndex
        total = #filters.folder;
    else
        oldIndex = selectedLevel
        selectedLevel = newIndex
        total = #filters.level;
    end

    transitionScrollScale = 0;

	scrollingUp = false;
	if ((newIndex > oldIndex and not (newIndex == total and oldIndex == 1)) or (newIndex == 1 and oldIndex == total)) then
		scrollingUp = true;
	end;

	game.PlaySample('song_wheel/cursor_change.wav');
end

set_mode = function(isFolder)
    if isFolder then
        selectionMode = 'folders'
    else
        selectionMode = 'levels'
    end
end