--[[
    $84 - Ryu state bits
    ?, facing left, ?, blinking, attack, in air, invincible, damage boost
    7,           6, 5,        4,      3,      2,          1,            0
]]
lastxposAbs = 0
RyuRow = 0
curves = {}

function NGRAMview()
    xpos      = memory.readbyte(0x86)+memory.readbyte(0x85)/256
    yspdsub   = memory.readbyte(0x87)/0x37
    yspd      = memory.readbytesigned(0x89)+yspdsub/5
    yspda     = yspd/5
    yspdasub  = yspd%5
    ypos      = memory.readbyte(0x8A)
    scrnpos   = memory.readbyte(0xA3)
    scrnsub   = memory.readbyte(0xA2)
    xposAbs   = scrnpos+xpos+scrnsub/256+memory.readbytesigned(0x52)*256
    xspd      = xposAbs-lastxposAbs
    rngb      = memory.readbyte(0xBF)
    bosshp    = memory.readbyte(0x497)
    abosshp   = memory.readbyte(0x496)
    inv       = memory.readbyte(0x95)
    interrupt = AND(memory.readbyte(0x4C),0x40)
    collision = tobitstring(memory.readbyte(0x8c))
--  yposQ     = AND(ypos,0x10)
--  rnga      = memory.readbyte(0xB5)
--  shifted   = bit.rshift(rngb,1)
--  anded     = bit.band(rngb,1)
    ViewBG(1)
    PredictBird()
    for i = 0, 7 do
        id      = memory.readbyte(0x400+i)
        time    = memory.readbyte(0x408+i)
        some    = memory.readbyte(0x420+i)
        mov     = memory.readbyte(0x438+i)
        xsubspd = memory.readbyte(0x448+i)/0x10
        xspeed  = memory.readbytesigned(0x450+i)
        xsub    = memory.readbyte(0x458+i)
        x       = memory.readbyte(0x460+i)
        ysubspd = memory.readbyte(0x468+i)
        yspeed  = memory.readbytesigned(0x470+i)
        ysub    = memory.readbyte(0x478+i)
        y       = memory.readbyte(0x480+i)
        hp      = memory.readbyte(0x490+i)
        state   = memory.readbyte(0x498+i)
        if (state ~= 0) then
            gui.text(x,y,string.format("%d",i))
            if (time > 0) then gui.text(x,y,string.format("\n%d",time),color) end
        end
        if (interrupt > 0) then color = "red" else color = "white" end
        if  (id == 18) or ((id == 11) and (state ~= 0)) then
            gui.text(x,y,string.format("%d.%d",xspeed,xsubspd))
        end
        gui.text(i*32+3,1,string.format("%d\n%02X.%02X\n%02X.%02X",i,x,xsub,y,ysub))
    end
    gui.box(0,25,64,40,"#000000ff")
    gui.text(xpos,ypos-18,string.format("%.1f",xspd))
    gui.text(0, 25, string.format("X: %.1f\nY: %3d\nS: %.1f\nBG: %s",
        xposAbs,ypos,yspd,collision),"#44ffffff","#000000ff")
--  gui.text(1,25,"\n\n\nInterrupt",color,"#000000ff")
    lastxposAbs = xposAbs
    if inv > 0 then gui.text(161,33,string.format("%02d",inv)) end
    if bosshp > 0 then
        if bosshp > 16
            then gui.text(177,41,string.format("%02d",abosshp))
            else gui.text(177,41,string.format("%02d",bosshp))
        end
    end
end

function GetCell(X,Y)
    local temp = memory.readbyte(0xE7CC+SHIFT(X,4))+memory.readbyte(0x5F)
    if (temp >= 0xC0) then temp = temp-0xC0 end
    Y = Y-0x40
    if (Y < 0) then Y = 0 end
    temp = SHIFT(Y,5)+temp
    return temp
end

function DrawBG(arg,offset,x,y)
    local color2 = "#00ff00ff"
    local function box(color,text)
        gui.box(x,y+offset,x+16,y+offset+16,color)
        if (text == 1) then
            gui.text(x+1,y+offset+1,string.format("%d",arg))
        end
    end
    local function line(up,down,left,right)
        if (up    == 1) then gui.line(x   ,y+offset   ,x+16,y+offset   ,color2) end
        if (down  == 1) then gui.line(x   ,y+offset+16,x+16,y+offset   ,color2) end
        if (left  == 1) then gui.line(x   ,y+offset   ,x   ,y+offset+16,color2) end
        if (right == 1) then gui.line(x+16,y+offset   ,x+16,y+offset+16,color2) end
    end
    if (arg ~= 0) then
        if     (arg == 1) then line(0,0,0,1) -- right wall
        elseif (arg == 2) then line(0,0,1,0) -- left wall
        elseif (arg == 3) then line(0,0,1,1) -- two-sided wall
        elseif (arg == 4) then line(1,0,0,1) -- right corner
        elseif (arg == 5) then line(1,0,1,0) -- left corner
        elseif (arg == 6) then line(1,0,1,1) -- two-sided corner
        elseif (arg == 7) then line(1,0,0,0) -- floor
        elseif (arg == 8) then box("#ff000066",0) -- ejecting block
        elseif (arg == 9) then box("#00ff0066",0) -- ladder
        elseif (arg >= 12) and (arg <= 15)
        then box("#ffffff66",0) -- exits
        else box("#00ff0066",1)
        end
    end
end

function ViewBG(style)
    -- feos, 2014
    -- style: 0=none, 1=new, 2=old, 3=both
    local base = 0x300
    local RyuX = memory.readbyte(0x86)
    local RyuY = memory.readbyte(0x8A)
    local RyuYspeed = memory.readbytesigned(0x89)
    local RyuXspeed = memory.readbytesigned(0xAD)+memory.readbyte(0xAC)/256
    if (AND(memory.readbyte(0x84),4) == 0) then RyuYspeed = 0 end
    local RyuCell = GetCell(RyuX, RyuY+RyuYspeed)
    local RyuRow = math.floor(RyuCell/6)
    local Screen = memory.readwordsigned(0x51)
    if (AND(style,1) == 1)
    and (memory.readbyte(0x1FC) == 0x87)
    or  (memory.readbyte(0x1F3) == 0xD8) then
        for tRow = RyuRow-14, RyuRow+14 do
            for tLine = 0,5 do
                local address = base+((tRow*6+tLine)%0xC0)
                local hi = SHIFT(memory.readbyte(address),  4)
                local lo =   AND(memory.readbyte(address),0xF)
                local x = (tRow-RyuRow)*16+RyuX-RyuX%0x10-Screen%0x10
                local y = tLine*32+64
                DrawBG(hi, 0,x,y)
                DrawBG(lo,16,x,y)
            end
        end
        gui.box(xpos-9,ypos+RyuYspeed-1,xpos+5,ypos+RyuYspeed-5,"#0000ff66")
    end
    if (AND(style,2) == 2) then
        for cell = 0,191 do
            local hi = SHIFT(memory.readbyte(base+cell),  4)
            local lo =   AND(memory.readbyte(base+cell),0xF)
            local bX = math.floor(cell/6)
            local bY = cell%6
            local rX = (RyuRow%32)*6-1
            local rY = math.floor(RyuY/16)*8-32
            if (hi == 0) then hi = " " else hi = string.format("%X",hi) end
            if (lo == 0) then lo = " " else lo = string.format("%X",lo) end
            gui.text(bX*6,bY*16+9,hi.."\n"..lo)
            gui.box(rX,rY,rX+6,rY+8,"#00ff0000")
        end
    end
end

function PredictBird()
    -- feos, 2014
    -- draws birds trajectories
    -- color marks direction
    for slot = 0,7 do
        if (memory.readbyte(0x400+slot) ~= 11) or (memory.readbyte(0x498+slot) == 0) then
            curves.slot = nil
        else
            if (curves.slot == nil) then curves.slot = {} end
            local ryuY      = memory.readbyte(0x8A)
            local ryuX      = memory.readbyte(0x86)
            local birdY     = memory.readbyte(0x480+slot)
            local birdX     = memory.readbyte(0x460+slot)      +memory.readbyte(0x458+slot)/256
            local birdSpeed = memory.readbytesigned(0x450+slot)+memory.readbyte(0x448+slot)/256
            local newY = 0
            local newX = 0
            local newSpeed = 0
            while (#curves.slot <= 200) do
                if (#curves.slot == 0) then
                    if (birdY > ryuY)
                    then newY = birdY-1
                    else newY = birdY+1
                    end
                    if (birdX > ryuX)
                    then newSpeed = birdSpeed-16/256
                    else newSpeed = birdSpeed+16/256
                    end
                    newX = birdX+newSpeed
                else
                    local index = #curves.slot
                    local tempY = curves.slot[index].oldY
                    local tempX = curves.slot[index].oldX
                    local tempSpeed = curves.slot[index].oldSpeed
                    if (tempY > ryuY)
                    then newY = tempY-1
                    else newY = tempY+1
                    end
                    if (tempX > ryuX)
                    then newSpeed = tempSpeed-16/256
                    else newSpeed = tempSpeed+16/256
                    end
                    newX = tempX + newSpeed
                end
                table.insert(curves.slot,{oldY = newY,oldX = newX,oldSpeed = newSpeed})
            end
            if (#curves.slot == 200) then table.remove(curves.slot,1) end
            for index = 1,#curves.slot do
                local color = nil
                if (curves.slot[index].oldSpeed < 0) then color = "#008800" else color = "#0000ff" end
                gui.box(curves.slot[index].oldX-1, curves.slot[index].oldY-1,
                        curves.slot[index].oldX+1, curves.slot[index].oldY+1, color)
            end
            for index = 1,#curves.slot do
                gui.pixel(curves.slot[index].oldX,curves.slot[index].oldY,"white")
            end
        end
    end
end

emu.registerafter(NGRAMview)
--[[
function GetCollision(X, Y)
    -- how the game does it
    local temp = GetCell(X,Y)
    temp = memory.readbyte(0x300+temp)
    if (AND(Y,0x10) ~= 0)
    then temp = AND(temp,0xF)
    else temp = SHIFT(temp,4)
    end
    temp = memory.readbyte(0xE782+temp)
    return temp
end
--]]
--[[
function Within(ryuX,ryuY,cellX,cellY)
    if  (ryuX > cellX) and (ryuX <= cellX+16)
    and (ryuY > cellY) and (ryuY <= cellY+16)
    then return "#00ff00aa"
    else return "#00ff0044"
    end
end
--]]