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

local backgroundImage = gfx.CreateSkinImage("song_select/bg.png", 1)
local dataPanelImage = gfx.CreateSkinImage("song_select/data_bg_overlay.png", 1)
local dataGlowOverlayImage = gfx.CreateSkinImage("song_select/data_panel/data_glow_overlay.png", 1)
local gradeBgImage = gfx.CreateSkinImage("song_select/data_panel/grade_bg.png", 1)
local badgeBgImage = gfx.CreateSkinImage("song_select/data_panel/clear_badge_bg.png", 1)
local effectedBgImage = gfx.CreateSkinImage("song_select/data_panel/effected_bg.png", 1)
local illustratedBgImage = gfx.CreateSkinImage("song_select/data_panel/illust_bg.png", 1)
local songPlateBg = gfx.CreateSkinImage("song_select/plate/bg.png", 1)
local songPlateBottomBarOverlayImage = gfx.CreateSkinImage("song_select/plate/bottom_bar_overlay.png", 1)

local cursorImage = gfx.CreateSkinImage("song_select/cursor.png", 1)
local diffCursorImage = gfx.CreateSkinImage("song_select/level_cursor.png", 1)

local searchBgImage = gfx.CreateSkinImage("song_select/search_bg.png", 1)

local defaultJacketImage = gfx.CreateSkinImage("song_select/loading.png", 0)

local difficultyLabelImages = {
    gfx.CreateSkinImage("song_select/plate/difficulty_labels/novice.png", 1),
    gfx.CreateSkinImage("song_select/plate/difficulty_labels/advanced.png", 1),
    gfx.CreateSkinImage("song_select/plate/difficulty_labels/exhaust.png", 1),
    gfx.CreateSkinImage("song_select/plate/difficulty_labels/maximum.png", 1),
    gfx.CreateSkinImage("song_select/plate/difficulty_labels/infinite.png", 1),
    gfx.CreateSkinImage("song_select/plate/difficulty_labels/gravity.png", 1),
    gfx.CreateSkinImage("song_select/plate/difficulty_labels/heavenly.png", 1),
    gfx.CreateSkinImage("song_select/plate/difficulty_labels/vivid.png", 1),
}

local badgeImages = {
    gfx.CreateSkinImage("song_select/medal/nomedal.png", 1),
    gfx.CreateSkinImage("song_select/medal/played.png", 1),
    gfx.CreateSkinImage("song_select/medal/clear.png", 1),
    gfx.CreateSkinImage("song_select/medal/hard.png", 1),
    gfx.CreateSkinImage("song_select/medal/uc.png", 1),
    gfx.CreateSkinImage("song_select/medal/puc.png", 1),
}

local gradeCutoffs = {
    D =     0000000,
    C =     7000000,
    B =     8000000,
    A =     8700000,
    A_P =   9000000,
    AA =    9300000,
    AA_P =  9500000,
    AAA =   9700000,
    AAA_P = 9800000,
    S =     9900000,
}

local gradeImages = {
    S = gfx.CreateSkinImage("common/grades/S.png", 0),
    AAA_P = gfx.CreateSkinImage("common/grades/AAA+.png", 0),
    AAA = gfx.CreateSkinImage("common/grades/AAA.png", 0),
    AA_P = gfx.CreateSkinImage("common/grades/AA+.png", 0),
    AA = gfx.CreateSkinImage("common/grades/AA.png", 0),
    A_P = gfx.CreateSkinImage("common/grades/A+.png", 0),
    A = gfx.CreateSkinImage("common/grades/A.png", 0),
    B = gfx.CreateSkinImage("common/grades/B.png", 0),
    C = gfx.CreateSkinImage("common/grades/C.png", 0),
    D = gfx.CreateSkinImage("common/grades/D.png", 0),
    none = gfx.CreateSkinImage("common/grades/none.png", 0),
}

local difficultyLabelUnderImages = {
    gfx.CreateSkinImage("songtransition/difficulty_labels/nov.png", 0),
    gfx.CreateSkinImage("songtransition/difficulty_labels/adv.png", 0),
    gfx.CreateSkinImage("songtransition/difficulty_labels/exh.png", 0),
    gfx.CreateSkinImage("songtransition/difficulty_labels/mxm.png", 0),
    gfx.CreateSkinImage("songtransition/difficulty_labels/inf.png", 0),
    gfx.CreateSkinImage("songtransition/difficulty_labels/grv.png", 0),
    gfx.CreateSkinImage("songtransition/difficulty_labels/hvn.png", 0),
    gfx.CreateSkinImage("songtransition/difficulty_labels/vvd.png", 0),
}

-- ANIMS
local laserAnimation = gfx.LoadSkinAnimation('song_select/laser_anim', 1/60, 0, false);

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

local difficultyNumbers;
local scoreNumbers;

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

local songPlateHeight = 172;

local selectedIndex = 1;
local selectedDifficulty = 1;

local jacketCache = {}

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

local transitionAfterscrollScale = 0;
local transitionAfterscrollDataOverlayAlpha = 0;
local transitionAfterscrollGradeAlpha = 0;
local transitionAfterscrollBadgeAlpha = 0;
local transitionAfterscrollTextSongTitle = 0;
local transitionAfterscrollTextSongArtist = 0;
local transitionAfterscrollDifficultiesAlpha = 0;
local transitionAfterscrollJacketBgAlpha = 0;

function resetLayoutInformation()
    resx, resy = game.GetResolution()
    desw = 1080
    desh = 1920
    scale = resx / desw
end

function load_number_image(path)
    local images = {}
    for i = 0, 9 do
        images[i + 1] = gfx.CreateSkinImage(string.format("%s/%d.png", path, i), 0)
    end
    return images
end

function draw_number(x, y, alpha, num, digits, images, is_dim, scale, kern)
    scale = scale or 1;
	kern = kern or 1;
	local tw, th = gfx.ImageSize(images[1])
	tw = tw * scale;
	th = th * scale;
    x = x + (tw * (digits - 1)) / 2
    y = y - th / 2
    for i = 1, digits do
        local mul = 10 ^ (i - 1)
        local digit = math.floor(num / mul) % 10
        local a = alpha
        if is_dim and num < mul then
            a = 0.4
        end
        gfx.BeginPath()
        gfx.ImageRect(x, y, tw, th, images[digit + 1], a, 0)
        x = x - (tw * kern)
    end
end

function getCorrectedIndex(from, offset) 
	total = #songwheel.songs;

	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 getJacketImage(song)
    if not jacketCache[song.id] or jacketCache[song.id]==defaultJacketImage then
        jacketCache[song.id] = gfx.LoadImageJob(song.difficulties[1].jacketPath, defaultJacketImage, 0, 0);
    end

    return jacketCache[song.id];
end

function getGradeImageForScore(score)
    local gradeImage = gradeImages.none;
    local bestGradeCutoff = 0;
    for gradeName, scoreCutoff in pairs(gradeCutoffs) do
        if scoreCutoff <= score then
            if scoreCutoff > bestGradeCutoff then 
                gradeImage = gradeImages[gradeName];
                bestGradeCutoff = scoreCutoff;
            end
        end
    end

    return gradeImage;
end

function drawBackground(deltaTime)
    gfx.BeginPath()
    gfx.ImageRect(0, 0, desw, desh, backgroundImage, 1, 0)

    -- If the score for song exists
    local song = songwheel.songs[selectedIndex];
    local diff = song.difficulties[selectedDifficulty];
    local bestScore = diff.scores[1];
    if song and diff then 
        local jacketImage = getJacketImage(song);
        gfx.BeginPath()
        gfx.ImageRect(0+transitionAfterscrollScale*-300, 0, 900, 900, jacketImage or defaultJacketImage, transitionAfterscrollJacketBgAlpha, 0)

        
        gfx.BeginPath();
        gfx.FillColor(0,0,0,math.floor(transitionAfterscrollJacketBgAlpha*64));
        gfx.Rect(0,0,900,900);
        gfx.Fill();
        gfx.ClosePath();
        gfx.BeginPath();
    end
    
    gfx.ImageRect(0, 0, desw, desh, dataPanelImage, 1, 0)

    if song and diff then 
        gfx.BeginPath()
        gfx.ImageRect(0, 0, desw, desh, dataGlowOverlayImage, transitionAfterscrollDataOverlayAlpha, 0)
        gfx.BeginPath()

        gfx.ImageRect(341, 754, 85, 85, gradeBgImage, transitionAfterscrollDataOverlayAlpha, 0)
        gfx.BeginPath()
        gfx.ImageRect(391, 687, 180*0.85, 226*0.85, badgeBgImage, transitionAfterscrollDataOverlayAlpha, 0)
        gfx.BeginPath()

        gfx.ImageRect(95, 1165, 433, 30, effectedBgImage, transitionAfterscrollDataOverlayAlpha, 0)
        gfx.BeginPath()
        gfx.ImageRect(95, 1195, 433, 30, illustratedBgImage, transitionAfterscrollDataOverlayAlpha, 0)
    end

    local laserAnimTickRes = gfx.TickAnimation(laserAnimation, deltaTime);
	if laserAnimTickRes == 1 then
        gfx.BeginPath()
        gfx.ImageRect(0, 0, desw, desh, laserAnimation, 1, 0);
        gfx.GlobalAlpha(1);
	end
end

function drawSong(song, y)
    if (not song) then return end;

    local songX = desw/2+28
    local selectedSongDifficulty = song.difficulties[selectedDifficulty]

    if not selectedSongDifficulty then
        return;
    end

    local bestScore;
    if selectedSongDifficulty.scores then 
        bestScore = selectedSongDifficulty.scores[1];
    end

    -- Draw the bg for the song plate
    gfx.BeginPath()
    gfx.ImageRect(songX, y, 515, 172, songPlateBg, 1, 0)
    
    -- Draw jacket
    local jacketImage = getJacketImage(song);
    gfx.BeginPath()
    gfx.ImageRect(songX+4, y+4, 163, 163, jacketImage or defaultJacketImage, 1, 0)

    -- Draw the overlay for the song plate (that bottom black bar)
    gfx.BeginPath()
    gfx.ImageRect(songX, y, 515, 172, songPlateBottomBarOverlayImage, 1, 0)
    
    -- Draw the difficulty notch background
    gfx.BeginPath()
    gfx.ImageRect(songX, y+95, 83, 74, difficultyLabelImages[selectedSongDifficulty.difficulty+1], 1, 0)

    -- Draw the difficulty level number
    gfx.BeginPath()
    draw_number(songX+30, y+125, 1.0, selectedSongDifficulty.level, 2, difficultyNumbers, false, 0.65, 1)

    -- Draw song title
    gfx.FontSize(24)
    gfx.TextAlign(gfx.TEXT_ALIGN_LEFT + gfx.TEXT_ALIGN_MIDDLE)
    gfx.Text(song.title, songX+90, y+155);

    -- Draw score badge
    local badgeImage = badgeImages[1];
    if bestScore then
        badgeImage = badgeImages[bestScore.badge+1];
    end
    gfx.BeginPath()
    gfx.ImageRect(songX+282, y+44, 79, 69, badgeImage, 1, 0)

    -- Draw grade
    local gradeImage = gradeImages.none;
    if bestScore then 
        gradeImage = getGradeImageForScore(bestScore.score)
    end

    gfx.BeginPath();
    gfx.ImageRect(songX+390, y+47, 60, 60, gradeImage, 1, 0);

end

function drawSongList()
    local numOfSongsAround = 7; -- How many songs should be up and how many should be down of the selected one


    local i=1;
    while (i <= numOfSongsAround) do
        local songIndex = getCorrectedIndex(selectedIndex, -i)
        drawSong(songwheel.songs[songIndex], desh/2-songPlateHeight/2-songPlateHeight*i + transitionScrollOffsetY)
        i=i+1;
    end;
    
    -- Draw the selected song
    drawSong(songwheel.songs[selectedIndex], desh/2-songPlateHeight/2 + transitionScrollOffsetY)

    i=1;
    while (i <= numOfSongsAround) do
        local songIndex = getCorrectedIndex(selectedIndex, i)
        drawSong(songwheel.songs[songIndex], desh/2-songPlateHeight/2+songPlateHeight*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

local scoreNumbers = load_number_image("score_num");
function drawData() -- Draws the song data on the left panel
    local song = songwheel.songs[selectedIndex];
    local diff = song.difficulties[selectedDifficulty];
    local bestScore = diff.scores[1];

    local jacketImage = getJacketImage(song);
    gfx.BeginPath()
    gfx.ImageRect(96, 324, 348, 348, jacketImage or defaultJacketImage, 1, 0)

    gfx.Save()
    if bestScore then 
        -- Draw best score
        gfx.BeginPath()
        draw_number(100, 793, 1.0, math.floor(bestScore.score / 10000), 4, scoreNumbers, true, 0.3, 1.12)
        draw_number(245, 797, 1.0, bestScore.score, 4, scoreNumbers, true, 0.22, 1.12)

        -- Draw grade
        local gradeImage = gradeImages.none;
        if bestScore then 
            gradeImage = getGradeImageForScore(bestScore.score)
        end

        gfx.BeginPath();
        gfx.ImageRect(360, 773, 45, 45, gradeImage, transitionAfterscrollGradeAlpha, 0);

        -- Draw badge
        badgeImage = badgeImages[bestScore.badge+1];
        gfx.BeginPath()
        gfx.ImageRect(425, 724, 93/1.1, 81/1.1, badgeImage, transitionAfterscrollBadgeAlpha, 0)
    end
    gfx.Restore()

    -- Draw BPM
    gfx.BeginPath();
    gfx.FontSize(24)
    gfx.TextAlign(gfx.TEXT_ALIGN_LEFT + gfx.TEXT_ALIGN_MIDDLE)
    gfx.Save()
    gfx.LoadSkinFont('Digital-Serial-Bold.ttf')
    gfx.GlobalAlpha(transitionAfterscrollDataOverlayAlpha) -- TODO: split this out
    gfx.Text(song.bpm, 85, 920);
    gfx.Restore()
    
    -- Draw song title
    gfx.FontSize(28)
    gfx.GlobalAlpha(transitionAfterscrollTextSongTitle);
    gfx.Text(song.title, 30+(1-transitionAfterscrollTextSongTitle)*20, 955);
    
    -- Draw artist
    gfx.GlobalAlpha(transitionAfterscrollTextSongArtist);
    gfx.Text(song.artist, 30+(1-transitionAfterscrollTextSongArtist)*30, 997);

    gfx.GlobalAlpha(1);

    -- Draw difficulties
    local DIFF_X_START = 98.5
    local DIFF_GAP = 114.8;
    gfx.GlobalAlpha(transitionAfterscrollDifficultiesAlpha);
    for index, diff in ipairs(song.difficulties) do
        gfx.BeginPath()

        if index == selectedDifficulty then
            gfx.ImageRect(DIFF_X_START+(index-1)*DIFF_GAP-(163*0.8)/2, 1028, 163*0.8, 163*0.8, diffCursorImage, 1, 0)
        end

        draw_number(85+(index-1)*DIFF_GAP, 1085, 1.0, diff.level, 2, difficultyNumbers, false, 0.8, 1)
        
        local diffLabelImage = difficultyLabelUnderImages[diff.difficulty+1];
        local tw, th = gfx.ImageSize(diffLabelImage)
        tw=tw*0.9
        th=th*0.9
        gfx.BeginPath()
        gfx.ImageRect(DIFF_X_START+(index-1)*DIFF_GAP-tw/2, 1050, tw, th, diffLabelImage, 1, 0)
    end
    gfx.GlobalAlpha(1);



    gfx.FontSize(22)
    gfx.GlobalAlpha(transitionAfterscrollDataOverlayAlpha);
    gfx.Text(diff.effector, 270, 1180);
    gfx.Text(diff.illustrator, 270, 1210);
    gfx.GlobalAlpha(1);
end

function drawSearch()
    if (not songwheel.searchInputActive) then
        return;
    end

    gfx.BeginPath();
    local tw, th = gfx.ImageSize(searchBgImage)
    gfx.ImageRect(desw-tw/2, 0, tw/2, th/2, searchBgImage, 1, 0)

    gfx.FontSize(28);
    gfx.Text(songwheel.searchText, desw-200, 30);
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 transitionAfterscrollScale < 1 then
        if transitionScrollScale == 1 then
            -- Only start the after scroll transition when the scroll transition is finished
            transitionAfterscrollScale = transitionAfterscrollScale + deltaTime / 15
        end
    else
        transitionAfterscrollScale = 1;
    end

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

    if transitionAfterscrollScale < 0.02 then
        transitionAfterscrollDataOverlayAlpha = math.min(1, transitionAfterscrollScale / 0.02)
    else
        transitionAfterscrollDataOverlayAlpha = 1;
    end

    -- Grade alpha
    if transitionAfterscrollScale >= 0.03 and transitionAfterscrollScale < 0.033 then
        transitionAfterscrollGradeAlpha = 0.5;
    elseif transitionAfterscrollScale >= 0.04 then
        transitionAfterscrollGradeAlpha = 1;
    else
        transitionAfterscrollGradeAlpha = 0;
    end
    
    -- Badge alpha
    if transitionAfterscrollScale >= 0.032 and transitionAfterscrollScale < 0.035 then
        transitionAfterscrollBadgeAlpha = 0.5;
    elseif transitionAfterscrollScale >= 0.042 then
        transitionAfterscrollBadgeAlpha = 1;
    else
        transitionAfterscrollBadgeAlpha = 0;
    end

    -- Song title alpha and pos
    if transitionAfterscrollScale < 0.025 then
        transitionAfterscrollTextSongTitle = Easing.outQuad(math.min(1, (transitionAfterscrollScale) / 0.025));
    else
        transitionAfterscrollTextSongTitle = 1
    end
    -- Song artist alpha and pos
    if transitionAfterscrollScale < 0.025 then
        transitionAfterscrollTextSongArtist = Easing.outQuad(math.min(1, (transitionAfterscrollScale) / 0.025));
    else
        transitionAfterscrollTextSongArtist = 1
    end
    
    -- Difficulties alpha
    if transitionAfterscrollScale < 0.025 then
        transitionAfterscrollDifficultiesAlpha = math.min(1, transitionAfterscrollScale / 0.025)
    else
        transitionAfterscrollDifficultiesAlpha = 1;
    end

    -- Jacket background alpha
    if transitionAfterscrollScale < 0.05 or transitionAfterscrollScale >= 1 then
        transitionAfterscrollJacketBgAlpha = 0;
    elseif transitionAfterscrollScale >= 0.05 and transitionAfterscrollScale < 0.1 then
        transitionAfterscrollJacketBgAlpha = math.min(1, (transitionAfterscrollScale-0.05) / 0.05);
    elseif transitionAfterscrollScale >= 0.95 and transitionAfterscrollScale < 1 then
        transitionAfterscrollJacketBgAlpha = math.min(1, 1-((transitionAfterscrollScale-0.95) / 0.05));
    else
        transitionAfterscrollJacketBgAlpha = 1;
    end
end


render = function (deltaTime)
    resetLayoutInformation();
    tickTransitions(deltaTime);
    gfx.Scale(scale, scale);

    if not difficultyNumbers then
        difficultyNumbers = load_number_image('diff_num')
    end

    drawBackground(deltaTime);

    drawSongList()
    drawCursor()

    drawData()

    drawSearch();


    gfx.BeginPath();
    gfx.FontSize(18)
    gfx.TextAlign(gfx.TEXT_ALIGN_LEFT + gfx.TEXT_ALIGN_TOP)
    local debugScrollingUp= "FALSE"
    if scrollingUp then debugScrollingUp = "TRUE" end;
    gfx.Text('DELTA: ' .. deltaTime .. ' // SELECTED_INDEX: ' .. selectedIndex .. ' // SELECTED_DIFF: ' .. selectedDifficulty .. ' // SCROLLING_UP: ' .. debugScrollingUp .. ' // AC_TS: ' .. transitionAfterscrollScale, 8, 8);
end

set_index = function(newIndex)
    transitionScrollScale = 0;
    transitionAfterscrollScale = 0;

	scrollingUp = false;
	if ((newIndex > selectedIndex and not (newIndex == #songwheel.songs and selectedIndex == 1)) or (newIndex == 1 and selectedIndex == #songwheel.songs)) then
		scrollingUp = true;
	end;

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

    selectedIndex = newIndex;
end;

set_diff = function(newDiff)
    selectedDifficulty = newDiff;
end;