module Here4.Vehicle.DreamBird exposing (drive, overlay)

import Here4.Orientation as Orientation exposing (..)
import Here4.Body exposing (..)
import Here4.Model as Model
import Here4.Ground exposing (Ground)
import Here4.Vehicle exposing (Driveable)
import Html exposing (Html)
import Html.Attributes as Html
import FontAwesome
import Color exposing (white)
import Math.Vector3 exposing (..)
import Math.Vector3 as V3


----------------------------------------------------------------------
-- DreamBird


drive : Driveable vehicle -> Vec3 -> Ground -> Model.Inputs -> Moving a -> Moving a
drive attributes dimensions ground inputs body =
    let
        eyeLevel pos =
            1.8 + ground.elevation pos

        motion0 =
            { position = body.position, orientation = body.orientation, velocity = body.velocity }

        motion =
            move attributes ground eyeLevel inputs motion0
    in
        { body
            | position = motion.position
            , orientation = motion.orientation
            , velocity = motion.velocity
        }


move : Driveable vehicle -> Ground -> Model.EyeLevel -> Model.Inputs -> Model.Motion -> Model.Motion
move attributes ground eyeLevel inputs motion =
    motion
        |> fly attributes.speed eyeLevel inputs
        |> flyPhysics eyeLevel inputs.dt
        |> keepWithinbounds ground attributes.radius



-- http://www.dtic.mil/dtic/tr/fulltext/u2/a152616.pdf


fly : Float -> Model.EyeLevel -> Model.Inputs -> Model.Motion -> Model.Motion
fly speed eyeLevel inputs motion =
    let
        thrust =
            clamp -1.0 1.0 <|
                inputs.my
                    + inputs.rightTrigger
                    - inputs.leftTrigger

        yaw =
            0.5 * inputs.mx * inputs.dt

        pitch =
            -0.8 * inputs.y * inputs.dt

        roll =
            1.2 * inputs.x * inputs.dt

        orpy =
            fromRollPitchYaw ( roll, pitch, yaw )

        orientation =
            followedBy motion.orientation orpy

        orient =
            rotateBodyV orientation

        dv =
            V3.scale (speed * thrust * inputs.dt) <| orient V3.k

        du =
            V3.scale (4 * thrust * inputs.dt) <| orient V3.j

        dv_ =
            add dv du

        vel =
            add (V3.scale 0.8 dv_) (V3.scale 0.95 motion.velocity)
    in
        { motion
            | orientation = orientation
            , velocity = vel
        }


flyPhysics : Model.EyeLevel -> Float -> Model.Motion -> Model.Motion
flyPhysics eyeLevel dt motion =
    let
        pos =
            add motion.position (V3.scale dt motion.velocity)

        p =
            toRecord pos

        e =
            eyeLevel pos

        ( pos_, dv ) =
            if p.y < e then
                ( vec3 p.x e p.z, vec3 0 0 0 )
            else
                ( pos, vec3 0 0 0 )
    in
        { motion | position = pos_, velocity = add motion.velocity dv }


keepWithinbounds ground radius motion =
    { motion | position = ground.bounds radius motion.position }


overlay : Html msg
overlay =
    let
        textStyle =
            Html.style
                [ ( "font-family", "Verdana, Geneva, sans-serif" )
                , ( "color", "#fff" )
                , ( "font-size", "xx-large" )
                , ( "text-shadow", "1px 0 0 #000, 0 -1px 0 #000, 0 1px 0 #000, -1px 0 0 #000" )
                , ( "z-index", "1" )
                ]

        textLeft =
            Html.style [ ( "text-align", "left" ) ]

        textCenter =
            Html.style [ ( "text-align", "center" ) ]
    in
        Html.div []
            [ Html.div
                [ textStyle
                , textLeft
                , Html.style
                    [ ( "margin-left", "3em" ) ]
                ]
                [ Html.i [] [ Html.text "Dreambird" ]
                , Html.text " controls:"
                ]
            , Html.table
                [ textStyle
                , textCenter
                , Html.style
                    [ ( "width", "80%" )
                    , ( "height", "60%" )
                    , ( "margin", "auto" )
                    ]
                ]
                [ Html.thead []
                    [ Html.tr []
                        [ Html.th [] [ Html.text "" ]
                        , Html.th [] [ FontAwesome.keyboard_o white 48 ]
                        , Html.th [] [ FontAwesome.gamepad white 48 ]
                        ]
                    ]
                , Html.tbody []
                    [ Html.tr []
                        [ Html.th [ textLeft ] [ Html.text "Thrust +/-" ]
                        , Html.td [] [ Html.text "Arrow up, down" ]
                        , Html.td []
                            [ Html.text "Right,left triggers"
                            , Html.br [] []
                            , Html.text "Left stick up, down"
                            ]
                        ]
                    , Html.tr []
                        [ Html.th [ textLeft ] [ Html.text "Yaw left, right" ]
                        , Html.td [] [ Html.text "Arrow left, right" ]
                        , Html.td [] [ Html.text "Left stick left, right" ]
                        ]
                    , Html.tr []
                        [ Html.th [ textLeft ] [ Html.text "Pitch up, down" ]
                        , Html.td [] [ Html.text "W, S" ]
                        , Html.td [] [ Html.text "Right stick up, down" ]
                        ]
                    , Html.tr []
                        [ Html.th [ textLeft ] [ Html.text "Roll left, right" ]
                        , Html.td [] [ Html.text "A, D" ]
                        , Html.td [] [ Html.text "Right stick left, right" ]
                        ]
                    ]
                ]
            ]