-- Lesson 26:  Characters That Move Themselves.  The finished script, exactly as the lesson ends.
local ROOM         = 20
local WALL_HEIGHT  = 2
local AGENT_RADIUS = 0.4
local AGENT_HEIGHT = 1.8
local WALK_SPEED   = 2.2

sceneEnable(true)
sceneSetBackground(28, 32, 42, 255)
sceneSetAmbient(80, 86, 100)

local floorLook = materialNew()
materialSetColor(floorLook, 96, 102, 110)
materialSetRoughness(floorLook, 0.9)

local wallLook = materialNew()
materialSetColor(wallLook, 150, 128, 104)
materialSetRoughness(wallLook, 0.8)

local walkerLook = materialNew()
materialSetColor(walkerLook, 225, 85, 60)
materialSetEmissive(walkerLook, 70, 18, 10)

local wandererLook = materialNew()
materialSetColor(wandererLook, 80, 150, 225)
materialSetEmissive(wandererLook, 10, 30, 70)

local ground = nodeNew()
nodeSetMesh(ground, meshPlane(ROOM, ROOM), floorLook)

local wallMesh = meshBox(1, WALL_HEIGHT, 1)
local walls    = {}


function addWall(x, z, width, depth)
    local wall = nodeNew()
    nodeSetMesh(wall, wallMesh, wallLook)
    nodeSetScale(wall, width, 1, depth)
    nodeSetPosition(wall, x, WALL_HEIGHT / 2, z)
    walls[#walls + 1] = wall
end


function makeWalker(x, z, look)
    local walker = nodeNew()
    nodeSetPosition(walker, x, 0, z)
    local body = nodeNew()
    nodeSetParent(body, walker)
    nodeSetMesh(body, meshBox(0.7, AGENT_HEIGHT, 0.7), look)
    nodeSetPosition(body, 0, AGENT_HEIGHT / 2, 0)
    local nose = nodeNew()
    nodeSetParent(nose, body)
    nodeSetMesh(nose, meshSphere(0.22, 16), look)
    nodeSetPosition(nose, 0, 0.4, -0.45)
    return walker
end


addWall(-4, 0, 12, 0.6)
addWall(7.5, 0, 5, 0.6)
addWall(-3, -6, 0.6, 8)

local nav = navNew(AGENT_RADIUS, AGENT_HEIGHT, 45, 0.3)
navAddNode(nav, ground)
for _, wall in ipairs(walls) do
    navAddNode(nav, wall)
end
navBuild(nav)

local walker      = makeWalker(-7, 7, walkerLook)
local walkerAgent = navAgentNew(nav, walker, AGENT_RADIUS, AGENT_HEIGHT, WALK_SPEED)

local wanderer      = makeWalker(6, -6, wandererLook)
local wandererAgent = navAgentNew(nav, wanderer, AGENT_RADIUS, AGENT_HEIGHT, 1.4)

local posts = {
    {  7, 0,  7 },
    {  7, 0, -7 },
    { -7, 0, -7 },
    { -7, 0,  7 },
    { 30, 0, 30 }
}
local post    = 0
local message = "Button 1 sends the red one somewhere."

local sun = lightNew(LIGHT_DIRECTIONAL)
nodeSetPosition(sun, 8, 14, 6)
nodeLookAt(sun, 0, 0, 0)
lightSetIntensity(sun, 3.5)
lightSetShadow(sun, true)

local camera = nodeNew()
nodeSetPosition(camera, 0, 17, 19)
nodeLookAt(camera, 0, 0, 0)
cameraSet(camera)
cameraSetPerspective(55, 0.1, 120)

navAgentMoveTo(wandererAgent, navRandomPoint(nav))


function onInputPressed(what)
    if what ~= SWITCH_BUTTON1 then
        return
    end
    post = post % #posts + 1
    local target = posts[post]
    if navAgentMoveTo(walkerAgent, target[1], target[2], target[3]) then
        message = string.format("Walking to post %d.", post)
    else
        message = string.format("No path to post %d.  Staying put.", post)
    end
end


function onNavArrived(agent)
    if agent == wandererAgent then
        navAgentMoveTo(agent, navRandomPoint(nav))
    else
        message = string.format("Arrived at post %d.", post)
    end
end


function onOverlayUpdate()
    overlayClear()
    navDraw(nav, 0, 170, 190)

    local target = posts[post]
    if target ~= nil then
        local x, y, z = nodeGetWorldPosition(walker)
        local route   = navPath(nav, x, y, z, target[1], target[2], target[3])
        if route ~= nil then
            for i = 2, #route do
                local a = route[i - 1]
                local b = route[i]
                lineDraw(a[1], a[2] + 0.1, a[3], b[1], b[2] + 0.1, b[3], 255, 215, 60)
            end
        end
    end

    local vx, vy, vz = navAgentGetVelocity(walkerAgent)
    local speed      = math.sqrt(vx * vx + vz * vz)
    overlayPrint(2, 2, message)
    overlayPrint(2, 4, string.format("Speed %.2f", speed))
    return OVERLAY_UPDATED
end