# tiles_test.ludic - ludic.nav's map in tiles: a 128 m meadow as four 64 m tiles, one of them under
# water. A path crosses the tiles' seams, the water's tile has no polygons and nothing inside it is
# a way's end, and the set saved and loaded answers as the built one did.
import "ludic.nav"
import "ludic.base"
import "fakes/meadow.ludic"
program TilesTest {
  numbers float

  # four tiles over ground(128), the far corner's squares (x and z past 64) under water when wet
  function map(nav_st: mut NavState, wet: bool) -> int {
    let g = ground(128, 0)
    if wet {
      for j in 64 .. 128 { for i in 64 .. 128 { g.area[(j * 128 + i) * 2] = 0 } }
      for j in 64 .. 128 { for i in 64 .. 128 { g.area[(j * 128 + i) * 2 + 1] = 0 } }
    }
    g.cyl = post_at(96.0, 20.0, 2.0)
    g.nc = 1
    expect(nav_tiled(nav_st, NAV_PERSON, 0.0, 0.0, 64.0, 16, 4096))
    var empty = 0
    for tz in 0 .. 2 {
      for tx in 0 .. 2 {
        let p = nav_tile_build(nav_st, NAV_PERSON, tx, tz, g, new NavConfig)
        expect(p >= 0)
        if p == 0 { empty += 1 }
      }
    }
    return empty
  }
  function last_x(nav_st: NavState) -> float { return nav_corner_x(nav_st, nav_corners(nav_st) - 1) }
  function last_z(nav_st: NavState) -> float { return nav_corner_z(nav_st, nav_corners(nav_st) - 1) }

  test "a path crosses the tiles' seams and goes round the post in the far tile" (nav_st: mut NavState) {
    expect_eq(map(nav_st, false), 0)
    expect(nav_polygons(nav_st, NAV_PERSON) > 0)
    let n = nav_path(nav_st, NAV_PERSON, 0, 10.0, 0.0, 20.0, 120.0, 0.0, 20.0)
    expect(n >= 3)
    expect(not nav_partial(nav_st, NAV_PERSON))
    expect(Math.abs(last_x(nav_st) - 120.0) < 0.1)
    let d = nav_path(nav_st, NAV_PERSON, 0, 10.0, 0.0, 10.0, 120.0, 0.0, 120.0)
    expect(d >= 2)
    expect(not nav_partial(nav_st, NAV_PERSON))
  }

  test "a tile under water has no polygons: a way into it is none, the shore beside it is reached" (nav_st: mut NavState) {
    expect_eq(map(nav_st, true), 1)
    expect(not nav_nearest(nav_st, NAV_PERSON, 100.0, 0.0, 100.0))
    expect_eq(nav_path(nav_st, NAV_PERSON, 0, 10.0, 0.0, 10.0, 70.0, 0.0, 70.0), -1)
    expect(nav_path(nav_st, NAV_PERSON, 0, 10.0, 0.0, 10.0, 62.0, 0.0, 70.0) >= 2)
    expect(not nav_partial(nav_st, NAV_PERSON))
    expect(Math.abs(last_z(nav_st) - 70.0) < 0.1)
  }

  test "the tiles saved and loaded answer as the built ones did" (nav_st: mut NavState) {
    map(nav_st, true)
    let path = Os.temp_dir() + "/ludic_nav_tiles.navmesh"
    expect(nav_save_file(nav_st, NAV_PERSON, path))
    expect(nav_load_file(nav_st, NAV_LARGE, path))
    expect_eq(nav_polygons(nav_st, NAV_LARGE), nav_polygons(nav_st, NAV_PERSON))
    let a = nav_path(nav_st, NAV_PERSON, 0, 10.0, 0.0, 20.0, 120.0, 0.0, 20.0)
    let ax = last_x(nav_st)
    let b = nav_path(nav_st, NAV_LARGE, 0, 10.0, 0.0, 20.0, 120.0, 0.0, 20.0)
    expect_eq(a, b)
    expect_near(last_x(nav_st), ax, 0.0001)
  }

  test "a saved mesh as an index: only the tiles near a player are in, and they come and go" (nav_st: mut NavState) {
    expect_eq(map(nav_st, false), 0)
    let path = Os.temp_dir() + "/ludic_nav_resident.navmesh"
    expect(nav_save_file(nav_st, NAV_PERSON, path))
    nav_reset(nav_st)
    expect(nav_load_index(nav_st, NAV_PERSON, path))
    expect_eq(nav_tiles_in(nav_st, NAV_PERSON), 0)
    expect(not nav_nearest(nav_st, NAV_PERSON, 20.0, 0.0, 20.0))
    let xs = floats(1)
    let zs = floats(1)
    xs[0] = 20.0
    zs[0] = 20.0
    expect_eq(nav_tiles_keep(nav_st, NAV_PERSON, xs, zs, 1, 60.0, 90.0), 1)
    expect_eq(nav_tiles_in(nav_st, NAV_PERSON), 1)
    expect(nav_nearest(nav_st, NAV_PERSON, 20.0, 0.0, 20.0))
    expect(not nav_nearest(nav_st, NAV_PERSON, 100.0, 0.0, 100.0))
    xs[0] = 64.0
    zs[0] = 64.0
    expect_eq(nav_tiles_keep(nav_st, NAV_PERSON, xs, zs, 1, 60.0, 90.0), 3)
    expect_eq(nav_tiles_in(nav_st, NAV_PERSON), 4)
    expect(nav_path(nav_st, NAV_PERSON, 0, 10.0, 0.0, 20.0, 120.0, 0.0, 20.0) >= 3)
    expect(not nav_partial(nav_st, NAV_PERSON))
    xs[0] = 110.0
    zs[0] = 110.0
    expect_eq(nav_tiles_keep(nav_st, NAV_PERSON, xs, zs, 1, 60.0, 90.0), 1)
    expect_eq(nav_tiles_in(nav_st, NAV_PERSON), 3)
    expect(not nav_nearest(nav_st, NAV_PERSON, 20.0, 0.0, 20.0))
    nav_reset(nav_st)
    expect_eq(nav_tiles_in(nav_st, NAV_PERSON), 0)
  }

  # the descriptors this process holds open (macOS and Linux list them under /dev/fd)
  function open_files() -> int { return len(Fs.list("/dev/fd")) }

  test "an index loaded again twenty times, its tiles in each time, holds the heap, the files and the tiles" (nav_st: mut NavState) {
    expect_eq(map(nav_st, false), 0)
    let path = Os.temp_dir() + "/ludic_nav_swap.navmesh"
    expect(nav_save_file(nav_st, NAV_PERSON, path))
    let xs = floats(1)
    let zs = floats(1)
    xs[0] = 64.0
    zs[0] = 64.0
    expect(nav_load_index(nav_st, NAV_PERSON, path))
    nav_tiles_keep(nav_st, NAV_PERSON, xs, zs, 1, 60.0, 90.0)
    let files = open_files()
    let heap = Os.heap_bytes()
    for k in 0 .. 20 {
      expect(nav_load_index(nav_st, NAV_PERSON, path))
      nav_tiles_keep(nav_st, NAV_PERSON, xs, zs, 1, 60.0, 90.0)
    }
    let grew = Os.heap_bytes() - heap
    let now = open_files()
    print(`nav swap: twenty loads, heap {grew} bytes, files open {files} -> {now}, tiles in {nav_tiles_in(nav_st, NAV_PERSON)}`)
    expect(grew == long(0))
    expect_eq(now, files)
    expect_eq(nav_tiles_in(nav_st, NAV_PERSON), 4)
    nav_reset(nav_st)
    expect_eq(open_files(), files - 1)
  }
}