-- Urho2D physics Constraints sample.
-- This sample is designed to help understanding and chosing the right constraint.
-- This sample demonstrates:
--      - Creating physics constraints
--      - Creating Edge and Polygon Shapes from vertices
--      - Displaying physics debug geometry and constraints' joints
--      - Using SetOrderInLayer to alter the way sprites are drawn in relation to each other
--      - Using Text3D to display some text affected by zoom
--      - Setting the background color for the scene

require "LuaScripts/Utilities/Sample"

local camera = nil

function Start()
    SampleStart()
    CreateScene()
    input.mouseVisible = true -- Show mouse cursor
    CreateInstructions()
    -- Set the mouse mode to use in the sample
    SampleInitMouseMode(MM_FREE)
    SubscribeToEvents()
    print(PIXEL_SIZE)
end

function CreateLetterSprite(x,y,z,c,color,size)
    local node = scene_:CreateChild("Background")
    local t=node:CreateComponent("Text3D")
    t.text=c
    t.font=cache:GetResource("Font", "Fonts/BlueHighway.ttf")
    t.fontSize=size
    t.textEffect=TE_STROKE
    t.color=color
    t.horizontalAlignment=HA_CENTER
    t.verticalAlignment=VA_CENTER
    t.effectColor=Color(0,0,0)
    node.position=Vector3(x,y,z)
    return node
end

function CreateScene()
    scene_ = Scene()
    scene_:CreateComponent("Octree")
    scene_:CreateComponent("DebugRenderer")

    -- Create camera
    cameraNode = scene_:CreateChild("Camera")
    cameraNode.position = Vector3(0, 0, 0) -- Note that Z setting is discarded; use camera.zoom instead (see MoveCamera() below for example)
    camera = cameraNode:CreateComponent("Camera")
    camera.orthographic = true
    camera.orthoSize = graphics.height * 0.01
    camera.zoom = 1 -- Set zoom according to user's resolution to ensure full visibility (initial zoom (1.2) is set for full visibility at 1280x800 resolution)
    renderer:SetViewport(0, Viewport:new(scene_, camera))
    renderer.defaultZone.fogColor = Color(0.1, 0.1, 0.1) -- Set background color for the scene

    local x,y
    for x=0,10,1 do
        for y=0,10,1 do
            local n=CreateLetterSprite(x*0.8,y*0.8,1, '#', Color(0.5,0.5,0.5), 100)
        end
    end

    dude=CreateLetterSprite(5*0.5, 5*0.8, 0.5, '@', Color(0.5,0.5,1), 100)
end


function CreateInstructions()
    -- Construct new Text object, set string to display and font to use
    local instructionText = ui.root:CreateChild("Text")
    instructionText:SetText("Use WASD keys and mouse to move, Use PageUp PageDown to zoom.\n Space to toggle debug geometry and joints - F5 to save the scene.")
    instructionText:SetFont(cache:GetResource("Font", "Fonts/Anonymous Pro.ttf"), 15)
    instructionText.textAlignment = HA_CENTER -- Center rows in relation to each other

    -- Position the text relative to the screen center
    instructionText.horizontalAlignment = HA_CENTER
    instructionText.verticalAlignment = VA_CENTER

    instructionText:SetPosition(0, ui.root.height / 4)
end

function MoveCamera(timeStep)
    if ui.focusElement ~= nil then return end -- Do not move if the UI has a focused element (the console)

    local MOVE_SPEED = 4 -- Movement speed as world units per second

    -- Read WASD keys and move the camera scene node to the corresponding direction if they are pressed
    if input:GetKeyDown(KEY_W) then cameraNode:Translate(Vector3(0, 1, 0) * MOVE_SPEED * timeStep) end
    if input:GetKeyDown(KEY_S) then cameraNode:Translate(Vector3(0, -1, 0) * MOVE_SPEED * timeStep) end
    if input:GetKeyDown(KEY_A) then cameraNode:Translate(Vector3(-1, 0, 0) * MOVE_SPEED * timeStep) end
    if input:GetKeyDown(KEY_D) then cameraNode:Translate(Vector3(1, 0, 0) * MOVE_SPEED * timeStep) end

    if input:GetKeyDown(KEY_PAGEUP) then camera.zoom = camera.zoom * 1.01 end -- Zoom In
    if input:GetKeyDown(KEY_PAGEDOWN) then camera.zoom = camera.zoom * 0.99 end -- Zoom Out
end

function SubscribeToEvents()
    SubscribeToEvent("Update", "HandleUpdate")
    SubscribeToEvent("PostRenderUpdate", "HandlePostRenderUpdate")
    SubscribeToEvent("MouseButtonDown", "HandleMouseButtonDown")
    if touchEnabled then SubscribeToEvent("TouchBegin", "HandleTouchBegin3") end
    -- Unsubscribe the SceneUpdate event from base class to prevent camera pitch and yaw in 2D sample
    UnsubscribeFromEvent("SceneUpdate")
end

function HandleUpdate(eventType, eventData)
    local timestep = eventData["TimeStep"]:GetFloat()
    MoveCamera(timestep) -- Move the camera according to frame's time step
    if input:GetKeyPress(KEY_SPACE) then drawDebug = not drawDebug end -- Toggle debug geometry with space
    if input:GetKeyPress(KEY_F5) then scene_:SaveXML(fileSystem:GetProgramDir().."Data/Scenes/Constraints.xml") end -- Save scene
    local campos=cameraNode.position
    dude.position=Vector3(campos.x, campos.y, dude.position.z)
end

function HandlePostRenderUpdate(eventType, eventData)
    if drawDebug then physicsWorld:DrawDebugGeometry() end
end

function HandleMouseButtonDown(eventType, eventData)
    local rigidBody = physicsWorld:GetRigidBody(input.mousePosition.x, input.mousePosition.y) -- Raycast for RigidBody2Ds to pick
    if rigidBody ~= nil then
        pickedNode = rigidBody.node
        local staticSprite = pickedNode:GetComponent("StaticSprite2D")
        staticSprite.color = Color(1, 0, 0, 1) -- Temporary modify color of the picked sprite

        -- ConstraintMouse2D - Temporary apply this constraint to the pickedNode to allow grasping and moving with the mouse
        local constraintMouse = pickedNode:CreateComponent("ConstraintMouse2D")
        constraintMouse.target = GetMousePositionXY()
        constraintMouse.maxForce = 1000 * rigidBody.mass
        constraintMouse.collideConnected = true
        constraintMouse.otherBody = dummyBody  -- Use dummy body instead of rigidBody. It's better to create a dummy body automatically in ConstraintMouse2D
    end
    SubscribeToEvent("MouseMove", "HandleMouseMove")
    SubscribeToEvent("MouseButtonUp", "HandleMouseButtonUp")
end

function HandleMouseButtonUp(eventType, eventData)
    if pickedNode ~= nil then
        local staticSprite = pickedNode:GetComponent("StaticSprite2D")
        staticSprite.color = Color(1, 1, 1, 1) -- Restore picked sprite color

        pickedNode:RemoveComponent("ConstraintMouse2D") -- Remove temporary constraint
        pickedNode = nil
    end
    UnsubscribeFromEvent("MouseMove")
    UnsubscribeFromEvent("MouseButtonUp")
end

function GetMousePositionXY()
    local screenPoint = Vector3(input.mousePosition.x / graphics.width, input.mousePosition.y / graphics.height, 0)
    local worldPoint = camera:ScreenToWorldPoint(screenPoint)
    return Vector2(worldPoint.x, worldPoint.y)
end

function HandleMouseMove(eventType, eventData)
    if pickedNode ~= nil then
        local constraintMouse = pickedNode:GetComponent("ConstraintMouse2D")
        constraintMouse.target = GetMousePositionXY()
    end
end

function HandleTouchBegin3(eventType, eventData)
    local rigidBody = physicsWorld:GetRigidBody(eventData["X"]:GetInt(), eventData["Y"]:GetInt()) -- Raycast for RigidBody2Ds to pick
    if rigidBody ~= nil then
        pickedNode = rigidBody.node
        local staticSprite = pickedNode:GetComponent("StaticSprite2D")
        staticSprite.color = Color(1, 0, 0, 1) -- Temporary modify color of the picked sprite
        local rigidBody = pickedNode:GetComponent("RigidBody2D")

        -- ConstraintMouse2D - Temporary apply this constraint to the pickedNode to allow grasping and moving with touch
        local constraintMouse = pickedNode:CreateComponent("ConstraintMouse2D")
        constraintMouse.target = camera:ScreenToWorldPoint(Vector3(eventData["X"]:GetInt() / graphics.width, eventData["Y"]:GetInt() / graphics.height, 0))
        constraintMouse.maxForce = 1000 * rigidBody.mass
        constraintMouse.collideConnected = true
        constraintMouse.otherBody = dummyBody  -- Use dummy body instead of rigidBody. It's better to create a dummy body automatically in ConstraintMouse2D
        constraintMouse.dampingRatio = 0
    end
    SubscribeToEvent("TouchMove", "HandleTouchMove3")
    SubscribeToEvent("TouchEnd", "HandleTouchEnd3")
end

function HandleTouchMove3(eventType, eventData)
    if pickedNode ~= nil then
        local constraintMouse = pickedNode:GetComponent("ConstraintMouse2D")
        constraintMouse.target = camera:ScreenToWorldPoint(Vector3(eventData["X"]:GetInt() / graphics.width, eventData["Y"]:GetInt() / graphics.height, 0))
    end
end

function HandleTouchEnd3(eventType, eventData)
    if pickedNode ~= nil then
        local staticSprite = pickedNode:GetComponent("StaticSprite2D")
        staticSprite.color = Color(1, 1, 1, 1) -- Restore picked sprite color

        pickedNode:RemoveComponent("ConstraintMouse2D") -- Remove temporary constraint
        pickedNode = nil
    end
    UnsubscribeFromEvent("TouchMove")
    UnsubscribeFromEvent("TouchEnd")
end

-- Create XML patch instructions for screen joystick layout specific to this sample app
function GetScreenJoystickPatchString()
    return
        "<patch>" ..
        "    <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/attribute[@name='Is Visible']\" />" ..
        "    <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Zoom In</replace>" ..
        "    <add sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]\">" ..
        "        <element type=\"Text\">" ..
        "            <attribute name=\"Name\" value=\"KeyBinding\" />" ..
        "            <attribute name=\"Text\" value=\"PAGEUP\" />" ..
        "        </element>" ..
        "    </add>" ..
        "    <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/attribute[@name='Is Visible']\" />" ..
        "    <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Zoom Out</replace>" ..
        "    <add sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]\">" ..
        "        <element type=\"Text\">" ..
        "            <attribute name=\"Name\" value=\"KeyBinding\" />" ..
        "            <attribute name=\"Text\" value=\"PAGEDOWN\" />" ..
        "        </element>" ..
        "    </add>" ..
        "</patch>"
end