--# Main
function setup()
    displayMode(FULLSCREEN)
    s = Scene()
    e = Editor(64)
    s:add(Background())
    s:add(e)
    s:add(DPad(e))
    s:add(SelectTile(e))
end

function draw()
    background(40, 40, 50)
    s:draw()
end

function touched(touch)
    s:touched(touch)
end


--# Scene
Scene = class()

function Scene:init()
    self.layers = {}
end

function Scene:add(l)
    table.insert(self.layers, l)
end

function Scene:draw()
    for i,l in ipairs(self.layers) do
        l:draw()
    end
end

function Scene:touched(touch)
    -- call touch function from top layer and down until one returns true
    for i = #self.layers, 1,-1 do
        local l = self.layers[i]
        if l.touched ~= nil then
            if l:touched(touch) == true then
                return
            end
        end
    end
end

--# Editor
Editor = class()

function Editor:init(tilesize)
    self.w = tilesize
    self.tile = 1 -- tile to draw
    -- camera position
    self.c = vec2(0,0)
    self.grid = Grid(self.w)
    self.level = Level("level",self.w)
end

function Editor:draw()
    pushMatrix()
    translate(self.c.x, self.c.y)
    self.grid:draw(self.c)
    self.level:draw()
    popMatrix()
end

function Editor:move(delta)
    self.c = self.c - delta
end

function Editor:selectTile(i)
    self.tile = i
end

function Editor:touched(touch)
    if touch.state == ENDED then
        local t = vec2(touch.x, touch.y) - self.c
        local tx,ty = math.floor(t.x/self.w), math.floor(t.y/self.w)
        self.level:toggle(tx,ty,self.tile)
    end
end



--# Grid
-- Draw a dashed grid that follows the camera
Grid = class()

function Grid:init(tilesize)
    local w = tilesize
    local mx = math.ceil(math.max(WIDTH, HEIGHT)/w) * w
 
    -- create dashed grid image   
    self.dash = image(w,w)
    setContext(self.dash)
    stroke(0, 0, 0, 255)
    strokeWidth(3)
    for d = 10,w,10 do
        line(d-5,0,d,0)
        line(0,d-5,0,d)
    end
    setContext()
    
    self.m = mesh()
    self.m.texture = self.dash
    for y = -mx,mx,w do
        for x = -mx,mx,w do
            self.m:addRect(x-w/2,y-w/2,w,w)
        end
    end
    
    self.mx = mx
end

function Grid:draw(camera)
    local dx = math.floor(camera.x /self.mx)
    local dy = math.floor(camera.y /self.mx)
    pushMatrix()
    -- move dashed grid so its always in view
    translate(-dx*self.mx, -dy*self.mx)
    self.m:draw()
    popMatrix()
end
--# Background
-- animated background
Background = class()

function Background:init(x)
    local m = mesh()
    m.shader = makePattern()
    m.texture = readImage(asset.builtin.Blocks.Lava)
    m:addRect(WIDTH/2,HEIGHT/2,WIDTH,HEIGHT)
    m:setRectTex(1,0,0,5,5)
    self.m = m
end

function Background:draw()
    self.m.shader.time = ElapsedTime;
    self.m:draw()
end

function makePattern()
    pattern = shader()
    pattern.vertexProgram = [[
    uniform mat4 modelViewProjection;
    attribute vec4 position;
    attribute vec2 texCoord;
    varying highp vec2 vTexCoord;
    
    void main()
    {
        vTexCoord = texCoord;
        gl_Position = modelViewProjection * position;
    }
    ]]
    pattern.fragmentProgram = [[
    uniform lowp sampler2D texture;
    uniform highp float time;
    varying highp vec2 vTexCoord;
    
    void main()
    {
        lowp vec4 col = texture2D(texture, 
                        mod(vTexCoord+vec2(time,0), vec2(1.,1.)));
        gl_FragColor = col;
    }
    ]]
    return pattern
end


--# DPad
-- joystick to control the camera
DPad = class()

function DPad:init(listener)
    local w, hw = 128, 64
    self.pad = image(w,w)
    setContext(self.pad)
    fill(219, 183, 183, 185)
    stroke(0, 0, 0, 194)
    strokeWidth(3)
    ellipse(w/2,w/2,w)
    setContext()
    
    self.m = mesh()
    self.m.texture = self.pad
    self.m:addRect(hw,hw,w,w)
 
    self.mc = mesh()
    self.mc.texture = self.pad
    self.mc:addRect(0,0,hw,hw)
    self.w, self.hw = w, hw
    self.c = vec2(hw,hw)
    self.pressed = false
    self.cb = listener 
end

function DPad:draw()
    self.m:draw()
    pushMatrix()
    translate(self.c.x, self.c.y)
    self.mc:draw()
    popMatrix()

    if self.pressed and self.cb then               
        self.cb:move(self.dv*DeltaTime*15)
    end
end

function DPad:touched(touch)
    local hw = self.hw
    if touch.state == ENDED and self.pressed then
        self.pressed = false
        tween(.1,self.c,{x=hw,y=hw})
        return true
    end
    
    local t = vec2(touch.x, touch.y)
    local c = vec2(hw,hw)
    local dist = t:dist(c)
    if (dist < hw and touch.state == BEGAN) or 
        self.pressed then
        local v = (t - c):normalize() * math.min(hw/2, dist)
        self.c = c + v
        self.dv = v
        self.pressed = true
        return true
    end
end


--# Level
-- Model for a tilemap level
-- the level is stored in a Table
-- where the coordinate x,y is
-- encoded as x + y*mapsize and
-- x,y=0,0 is in the center of the map
-- The level is drawn with one mesh for every available tile, could be replaced with a sprite atlas  
Level = class()

function Level:init(name,tilesize)
    self.name=name
    self.size=1024
    self.w=tilesize
    self.data = {}
    self:load(name)
    self:update()
end

function Level:toggle(x,y,tile)
    local key=self:encode(x,y)
    local d = self.data
    if d[key] ~= tile then
        d[key]=tile
    else
        d[key]=nil
    end
    self:update()
    self:save()
end

function Level:encode(x,y)
    -- x,y as a key in the array
    local s=self.size
    return (x+s/2) + (y+s/2)*s
end
function Level:decode(index)
    local s=self.size
    local x = index%s
    local y = (index - x)/s
    return x-s/2,y-s/2
end

function Level:draw()
    for i,v in ipairs(self.ts) do
        v:draw()
    end
end

-- recreate the meshes on update
function Level:update()
    local w = self.w
    local hw = w/2
    self.ts = {}
    for i,v in ipairs(atlas) do
        local m = mesh()
        m.texture = v
        table.insert(self.ts, m)
    end

    for index,v in pairs(self.data) do
        local x,y=self:decode(index)
        self.ts[v]:addRect(x*w+hw, y*w+hw,w,w)
    end
end

function Level:save()
    local js = json.encode(self.data)
    saveProjectData(self.name,js)
end

function Level:load(name)
    local js=readProjectData(name)
    if js ~= nil then
        self.data ={}
        -- need to transform keys to int
        for i,v in pairs(json.decode(js)) do
            self.data[tonumber(i)]=v
        end
    end
end

-- The available tiles
atlas = {
    readImage(asset.builtin.Blocks.Redstone),
    readImage(asset.builtin.Blocks.Dirt_Grass),
    readImage(asset.builtin.Blocks.Wood),
    readImage(asset.builtin.Blocks.Greystone_Sand),
    readImage(asset.builtin.Blocks.Leaves)
}

--# SelectTile
-- ui to select tile to draw with
SelectTile = class()

function SelectTile:init(cb)
    self.curr = 1
    self.cb = cb
end

function SelectTile:draw()
    local w=64*#atlas
    rectMode(CORNER)
    pushMatrix()
    translate(WIDTH/2-w/2,HEIGHT-64)
    fill(61, 124)
    rect(0,0,w,64)
    fill(255, 150)
    rect(self.curr*64-64,0,64,64)
    for i,v in ipairs(atlas) do
        sprite(v,-32+i*64,32,50,50)
    end

    popMatrix()
end

function SelectTile:touched(touch)
    local w = 64*#atlas
    local t = vec2(touch.x,touch.y)
    if t.y > HEIGHT- 64 then
        for i,v in ipairs(atlas) do
            local x,y = WIDTH/2-w/2,HEIGHT-32
            x=x-32+i*64
            if vec2(x,y):dist(t)<32 then
                self.curr = i
                self.cb:selectTile(i)
                return true
            end
        end
    end
end