namespace LivingVillage.Desktop

open LivingVillage.Kernel.Sim
open LivingVillage.Desktop.VillagePresentation

module VillageArt =

    type PropKind =
        | WhiteWallDarkTileHouse
        | StoneBridge
        | Bamboo
        | VegetableGarden

    type TileKind =
        | RiverWater
        | StonePaving

    type ArtProp =
        { Kind: PropKind
          Position: TilePosition }

    type ArtTile =
        { Kind: TileKind
          Position: TilePosition }

    type JiangnanArtPlan =
        { Props: ArtProp list
          Tiles: ArtTile list }

    type NpcVisualVariant =
        | IndigoRobe
        | OchreVest
        | JadeSash

    type FacingDirection =
        | NorthFacing
        | SouthFacing
        | WestFacing
        | EastFacing

    type AnimationFrame =
        | FrameOne
        | FrameTwo

    type NpcSpriteSpec =
        { Variant: NpcVisualVariant
          Direction: FacingDirection
          Frame: AnimationFrame }

    let private position x y : TilePosition =
        { X = x
          Y = y }

    let private prop kind x y : ArtProp =
        { Kind = kind
          Position = position x y }

    let private tile kind x y : ArtTile =
        { Kind = kind
          Position = position x y }

    let samplePlan () : JiangnanArtPlan =
        { Props =
            [ prop WhiteWallDarkTileHouse 6 4
              prop StoneBridge 10 4
              prop Bamboo 3 2
              prop VegetableGarden 8 7 ]
          Tiles =
            [ tile RiverWater 10 2
              tile RiverWater 10 3
              tile StonePaving 4 5
              tile StonePaving 5 5
              tile StonePaving 6 5 ] }

    let private positiveModulo divisor value =
        let remainder = value % divisor
        if remainder < 0 then remainder + divisor else remainder

    let npcVisualVariant (NpcId npcId) : NpcVisualVariant =
        match positiveModulo 3 npcId with
        | 0 -> IndigoRobe
        | 1 -> OchreVest
        | _ -> JadeSash

    let private positiveModulo64 divisor value =
        let remainder = value % divisor
        if remainder < 0L then remainder + divisor else remainder

    let animationFrame (tick: int64) : AnimationFrame =
        if positiveModulo64 8L tick < 4L then FrameOne else FrameTwo

    let npcSpriteSpec (npcId: NpcId) (direction: FacingDirection) (tick: int64) : NpcSpriteSpec =
        { Variant = npcVisualVariant npcId
          Direction = direction
          Frame = animationFrame tick }