@tool
extends CanvasGroup

## Отображение карт WEB Mercator

const MIN_ZOOM: float = 2.0
const MAX_ZOOM: float = 19.0
const TEST_COORDS: = [ Vector2(0, 0), Vector2(1, 0), Vector2(0, 1), Vector2(1, 1) ]
var test_coords_i: = 3


#http://10.1.1.220/osm_tiles/0/0/0.png
#https://tile.openstreetmap.org/{z}/{x}/{y}.png
@export var base_url: String = 'https://tile.openstreetmap.org/{z}/{x}/{y}.png':
    set(v):
        if base_url != v:
            base_url = v
            _clean_all()
            queue_redraw()

@export var zoom_step: float = 0.025
@export var tile_width: float = 256.0
@export var tile_height: float = 256.0
@export_range(1, 1000, 1) var max_concurrent_requests:int = 5
@export_range(100, 100000, 1) var max_cached_tiles: int = 200
@export_range(0, 25, 1) var max_zoom_level: int = 21
@export_color_no_alpha() var back_color: = Color.BLACK
@export var animation_time: float = 1.0


@export var size: Vector2i = Vector2i(400, 400):
    set(v):
        $canvas.size = v
        _on_resize()
        queue_redraw()
    get:
        return $canvas.size


@export var ax: float = 0.0:
    set(v):
        _xyz.x = v
        queue_redraw()
    get:
        return _xyz.x


@export var ay: float = 0.0:
    set(v):
        _xyz.y = v
        queue_redraw()
    get:
        return _xyz.y


@export var az: float = 0.0:
    set(v):
        _xyz.z = v
        queue_redraw()
    get:
        return _xyz.z


var _xyz: Vector3 = Vector3(0, 0, MIN_ZOOM)
var _cache: Dictionary = {}
var _queue: Dictionary = {}
var _dragging: bool = false
var _drag_pos: Vector2 = Vector2.ZERO
var _last_cache_check: float = 0
var _rollover: bool = false
var _marks: Dictionary = {}
var _req_count: = 0
var image: = Image.new()
var image_load_proc: Callable
var now: = 0
var spr_mask: = Sprite2D.new()
var visible_marks_count: = 0
var mouse_wheel_count: = 0
var map_server_available: = false


## Вызывается после того, как загрузка плиток завершена
signal load_completed()

## Вызывается при запуске загрузки плиток
signal load_started()

## Вызывается при получении ответа от сервера карт
signal map_server_online()

## Вызывается при отсутствии ответа от сервера карт
signal map_server_offline()

const image_load_proc_names = {
    'png':  'load_png_from_buffer',
    'jpg':  'load_jpg_from_buffer',
    'tga':  'load_tga_from_buffer',
    'webp': 'load_webp_from_buffer' }


@export_enum('png', 'jpg', 'jpeg', 'tga', 'webp') var image_type: String = 'png':
    set(v): image_load_proc = Callable(image, image_load_proc_names[v])


func _ready():
    $canvas.connect('mouse_entered', func(): _rollover = true)
    $canvas.connect('mouse_exited',  func(): _rollover = false)
    _on_resize()
    image_type = 'png'
    spr_mask.name = StringName('spr_mask')
    spr_mask.material = CanvasItemMaterial.new()
    spr_mask.material.blend_mode = CanvasItemMaterial.BLEND_MODE_SUB
    spr_mask.add_to_group('gui_items')
    $canvas.add_child(spr_mask)


func _on_resize() -> void:
    var img_mask: = Image.create($canvas.size.x, $canvas.size.y, false, Image.FORMAT_RGBA8)
    var c = $canvas.size / 2.0
    var r = min($canvas.size.x, $canvas.size.y) / 2.0
    var color = Color.WHITE
    var sz = img_mask.get_size()
    for x in sz.x:
        for y in sz.y:
            var dist = c.distance_to(Vector2(x, y))
            color.a = smoothstep(r - 2.0, r + 2.0, dist)
            img_mask.set_pixel(x, y, color)
    spr_mask.texture = ImageTexture.create_from_image(img_mask)
    spr_mask.position = $canvas.position + $canvas.size / 2.0


## Создаёт новую отметку из координат экрана
func add_mark_from_screen_pos(id: int, x: float, y: float, mark: Node):
    if _marks.has(id):
        return false
    var wrld_pos = screen_to_world(_xyz, x, y)
    var p = world_to_tile(wrld_pos.x, wrld_pos.y, _xyz.z)
    var tile_index = xyz_to_idx(p.x, p.y, _xyz.z)
    var dot = { 'position': wrld_pos, 'tile_index': tile_index, 'mark': mark }
    _marks[id] = dot
    add_child(mark)
    fix_mark_position(dot)
    return true


func get_marks_count(): return _marks.size()


func delete_mark(id: int):
    if not _marks.has(id):
        return false
    _marks[id].mark.queue_free()
    _marks.erase(id)
    queue_redraw()


## Создаёт новую отметку из долготы и широты
func add_mark_from_lon_lat(id: int, lon: float, lat: float, mark: Node, gap_size: float = 32):
    if _marks.has(id):
        return false
    var wrld_pos = lonlat_to_world(lon, lat)
    var scr_pos = world_to_screen(wrld_pos.x, wrld_pos.y)
    mark.set_global_position(scr_pos)
    _marks[id] = {'position': wrld_pos, 'mark': mark, 'gap_size': gap_size }
    add_child(mark)
    queue_redraw()
    return true


## Возвращает новую позицию для точки, если она выходит из поля видимости
func fix_mark_position(dot):
    if is_mark_visible(dot):
        return
    var v = 2 * tile_width * pow(2, _xyz.z)
    if dot.position.x < _xyz.x - $canvas.size.x / v:
        dot.position.x = _xyz.x - $canvas.size.x / v
    elif dot.position.x > _xyz.x + $canvas.size.x / v:
        dot.position.x = _xyz.x + $canvas.size.x / v


func is_mark_visible(dot):
    var screen_pos = world_to_screen(dot.position.x, dot.position.y)
    return screen_pos.x > 0 and screen_pos.x < $canvas.size.x


func _input(e):
    var lmp = get_local_mouse_position()
    if not _rollover:
        return
    if e is InputEventMouseButton:
        if e.pressed:
            if e.button_index == MOUSE_BUTTON_WHEEL_DOWN:
                mouse_wheel_count -= 1
                queue_redraw()
            elif e.button_index == MOUSE_BUTTON_WHEEL_UP:
                mouse_wheel_count += 1
                queue_redraw()

        if e.button_index == MOUSE_BUTTON_LEFT:
            _dragging = e.pressed
            _drag_pos = screen_to_world(_xyz, lmp.x, lmp.y)


    elif e is InputEventMouseMotion:
        if _dragging:
            var wp = screen_to_world(_xyz, lmp.x, lmp.y)
            var diff = _drag_pos - wp
            _xyz.x += diff.x
            _xyz.y += diff.y
            queue_redraw()


## Возвращает true, если видна область за краем карты
func is_border_visible():
    var z = min(max_zoom_level, _xyz.z)
    return screen_to_tile(0, 0, z).y != 0


func multiply_zoom(multiplier: float, pivot: Vector2):
    var p1: = screen_to_world(_xyz, pivot.x, pivot.y)
    _xyz.z = clampf(_xyz.z * multiplier, MIN_ZOOM, MAX_ZOOM)
    var p2: = screen_to_world(_xyz, pivot.x, pivot.y)
    _xyz.x -= p2.x - p1.x
    _xyz.y -= p2.y - p1.y


func set_zoom(zoom: float, pivot=null):
    if pivot == null:
        pivot = $canvas.size / 2.0

    var p1: = screen_to_world(_xyz, pivot.x, pivot.y)
    _xyz.z = clampf(zoom,  MAX_ZOOM, MIN_ZOOM)
    var p2: = screen_to_world(_xyz, pivot.x, pivot.y)
    _xyz.x -= p2.x - p1.x
    _xyz.y -= p2.y - p1.y


func _draw():

    var lmp = get_local_mouse_position()
    if mouse_wheel_count > 0:
        multiply_zoom(1.0 + zoom_step, lmp)
        mouse_wheel_count -= 1
    elif mouse_wheel_count < 0:
        multiply_zoom(1.0 - zoom_step, lmp)
        mouse_wheel_count += 1

    var z = min(max_zoom_level, _xyz.z)
    var t1 = screen_to_tile(0, 0, z)
    var t2 = screen_to_tile($canvas.size.x, $canvas.size.y, z)
    for tx in range(t1.x, t2.x + 1):
        for ty in range(t1.y, t2.y + 1):
            _draw_tile(tx, ty, z)

    var n = pow(2, z)
    var dx = n * tile_width
    var c = $canvas.size / 2.0
    var r = min($canvas.size.x, $canvas.size.y) / 2.0
    visible_marks_count = 0
    for dot in _marks.values():
        var pos = world_to_screen(dot.position.x, dot.position.y)
        if pos.x >= 0:
            pos.x = fmod(pos.x, dx)
        else:
            pos.x = -pos.x - 1
            pos.x = int(dx - 1) - fmod(pos.x, dx)
        dot.mark.position = pos
        dot.mark.visible = c.distance_to(pos) < (r - dot.gap_size)
        visible_marks_count += int(dot.mark.visible)


func _clean_all():
    _queue.clear()
    _cache.clear()
    _marks.clear()
    _req_count = 0
    for c in get_children().filter(func (item): return not item.is_in_group('gui_items')):
        remove_child(c)
        c.queue_free()


# get the tile from queue with the newest timestamp
func get_next_in_queue():
    var tile = null
    for idx in _queue:
        var t = _queue.get(idx)
        if not tile or t.t > tile.t:
            tile = t
    return tile


# delete oldest tiles from cache
func _clean_cache():
    var overflow = _cache.size() - max_cached_tiles
    if overflow <= 0:
        return

    var vals = _cache.values()
    vals.sort_custom(func(t1, t2): return t1.t < t2.t)
    for i in overflow:
        _cache.erase(vals[i].i)


func _process(delta):
    now += delta

    # if cache is overflowing - clean it
    if not _last_cache_check or now - _last_cache_check > 5:
        _last_cache_check = now
        _clean_cache()

    while not _queue.is_empty() and (_req_count < max_concurrent_requests):

        var tile = get_next_in_queue()
        if not tile:
            break

        var req = HTTPRequest.new()
        _req_count += 1
        req.set_meta('tile', tile)
        add_child(req)
        req.name = NodePath(str(tile.i))

        _queue.erase(tile.i)
        req.request_completed.connect(_response.bind(req, tile))

        if req.request(tile.url) != OK:
            tile.t = now
            remove_child(req)
            req.queue_free()
            _req_count -= 1
            push_error('ошибка: запрос плитки \"%s\" не отправлен' % tile.url)
        if _queue.is_empty():
            emit_signal('load_completed')


# result, response_code, headers, body
func _response(result, code, headers: Array, body: PackedByteArray, req, tile: Tile):

    _req_count -= 1
    remove_child(req)
    req.queue_free()

    if result != HTTPRequest.RESULT_SUCCESS:
        if map_server_available:
            map_server_available = false
            emit_signal('map_server_offline')
        _queue[tile.i] = tile
        return

    if not map_server_available:
        map_server_available = true
        emit_signal('map_server_online')

    if code == 404:
        push_error('ошибка: на сервере нет \"%s\"' % tile.url)
        return

    if Error.OK != image_load_proc.call(body):
        push_error('ошибка: не удалось получить изображение (неверный формат?) из \"%s\"' % tile.url)
        return

    # create texture from image and add it to the cache
    tile.texture = ImageTexture.create_from_image(image)
    _cache[tile.i] = tile

    # redraw the map
    queue_redraw()


func _draw_subtile(tx: int, ty: int, tz: int, origx: int, origy: int, origz: float) -> bool:
    var subtile = get_tile(tx, ty, tz)
    if not subtile:
        return false

    var p1 = tile_to_screen(origx, origy, origz)
    var p2 = tile_to_screen(origx + 1, origy + 1, origz)
    var x1 = tile_to_screen(tx, ty, tz)
    var x2 = tile_to_screen(tx + 1, ty + 1, tz)

    var xdiff = x2.x - x1.x
    var xrat1 = (p1.x - x1.x) / xdiff
    var xrat2 = (p2.x - x1.x) / xdiff
    var xwidth = xrat2 - xrat1

    var ydiff = x2.y - x1.y
    var yrat1 = (p1.y - x1.y) / ydiff
    var yrat2 = (p2.y - x1.y) / ydiff
    var yheight = yrat2 - yrat1

    var rect = Rect2(xrat1 * tile_width, yrat1 * tile_height, xwidth * tile_width, yheight * tile_height)
    if subtile.texture:
        draw_texture_rect_region(subtile.texture, Rect2(p1, p2 - p1), rect)
        return true
    return false


func _draw_tile(tx: int, ty: int, z: float):
    var tz = floor(z)
    var p1 = tile_to_screen(tx, ty, z)
    var p2 = tile_to_screen(tx + 1, ty + 1, z)
    var tile = get_tile(tx, ty, tz)
    if tile:
        if tile.texture:
            draw_texture_rect(tile.texture, Rect2(p1, p2 - p1), false, Color.WHITE, false)
        else:
            var zzz = tz
            var txx = tx
            var tyy = ty
            while zzz > 1:
                zzz -= 1
                txx = floor(txx / 2.0)
                tyy = floor(tyy / 2.0)
                if _draw_subtile(txx, tyy, zzz, tx, ty,z):
                    break


## convert lon/lat to world coords
func lonlat_to_world(lon: float, lat: float) -> Vector2:
    var x = lon / 180.0
    var latsin = sin(deg_to_rad(lat) * sign(lat))
    var y = (sign(lat) * (log((1.0 + latsin) / (1.0 - latsin)) / 2.0)) / PI
    return Vector2(x, y)


## convert lon/lat to screen coords
func lonlat_to_screen(lon: float, lat: float) -> Vector2:
    var w = lonlat_to_world(lon, lat)
    return world_to_screen(w.x, w.y)


## convert lon/lat to tile coords
func lonlat_to_tile(lon: float, lat: float, z: float) -> Vector2:
    var w = lonlat_to_world(lon,lat)
    return world_to_tile(w.x, w.y, z)


## convert world coords to lon/lat
func world_to_lonlat(wx: float, wy: float) -> Vector2:
    var lon = wx * 180.0
    var lat = rad_to_deg(atan(sinh(wy * PI)))
    return Vector2(lon, lat)


## convert screen coords to lon/lat
func screen_to_lonlat(sx: float, sy: float) -> Vector2:
    var w = screen_to_world(_xyz, sx, sy)
    return world_to_lonlat(w.x, w.y)


## convert tile coords to lon/lat
func tile_to_lonlat(tx: float, ty: float, tz: float) -> Vector2:
    var w = tile_to_world(tx, ty, tz)
    return world_to_lonlat(w.x, w.y)


## convert screen coords to world coords
func screen_to_world(xyz: Vector3, sx: float, sy: float) -> Vector2:
    var n = pow(2.0, xyz.z)
    var span_w = n * tile_width
    var span_h = n * tile_height
    var px = sx - $canvas.size.x / 2 + span_w / 2
    var py = sy - $canvas.size.y / 2 + span_h / 2
    var xr = px / span_w
    var yr = py / span_h
    var x = (xr * 2.0 - 1.0) + xyz.x
    var y = ((-yr * 2.0) + 1.0) + xyz.y
    return Vector2(x, y)


## convert screen coords to tile coords
func screen_to_tile(sx: float, sy: float, z: float) -> Vector2:
    var world = screen_to_world(_xyz, sx, sy)
    return world_to_tile(world.x, world.y, z)


## convert tile coords to screen coords
func tile_to_screen(tx: float, ty: float, tz: float) -> Vector2:
    var w = tile_to_world(tx, ty, tz)
    return world_to_screen(w.x, w.y)


## convert tile coords to world coords
func tile_to_world(tx: float, ty: float, tz: float) -> Vector2:
    var n = pow(2.0, floor(tz))
    var x = (tx / n) * 2.0 - 1.0
    var y = -((ty / n) * 2.0 - 1.0)
    return Vector2(x, y)


## convert world coords to tile coords
func world_to_tile(wx: float, wy: float, z: float) -> Vector2:
    var n: = pow(2.0, floor(z))
    var tx: = ((wx + 1.0) / 2.0) * n
    var ty: = ((-wy + 1.0) / 2.0) * n
    tx = floor(tx)
    ty = floor(ty)
    return Vector2(tx, ty)


## convert world coords to screen coords
func world_to_screen(wx: float, wy: float) -> Vector2:
    var n: = pow(2.0, _xyz.z)
    var w: = n * tile_width
    var h: = n * tile_height
    var xr: = ((wx - _xyz.x) + 1.0) / 2.0
    var yr: = (-(wy - _xyz.y) + 1.0) / 2.0
    var x = w * xr - w / 2.0 + $canvas.size.x / 2.0
    var y = h * yr - h / 2.0 + $canvas.size.y / 2.0
    return Vector2(x, y)


## get the tile index from xyz tile coords
func xyz_to_idx(x: float, y: float, z: float) -> int:
    var i: = (pow(4.0, z) - 1.0) / 3.0
    var n: = pow(2.0, z)
    return int(i + (y * n + x))


func get_tile(x: int, y: int, z: int, create: bool = true) -> Tile:

    var n = pow(2, z)
    if x >= 0:
        x %= int(n)
    else:
        x = -x - 1
        x = int(n - 1) - (x % int(n))

    # out of bounds
    if z < 0 or y < 0 or y >= n:
        return null

    # get tile index
    var idx = xyz_to_idx(x, y, z)
    var tile = null

    # retrieve from current requests...
    var req = get_node_or_null(NodePath(str(idx)))
    if req:
        tile = req.get_meta('tile')
        tile.t = now
        return tile

    # retrieve from cache
    tile = _cache.get(idx)
    if tile:
        tile.t = now
        return tile

    # retrieve from queue
    tile = _queue.get(idx)
    if tile:
        tile.t = now
        return tile

    # create a new tile - add it to queue
    var queue_size: = _queue.size()
    if create and (not $canvas/player.is_playing()):
        tile = Tile.new(idx, x, y, z)
        tile.url = base_url.replace('{x}', str(x)).replace('{y}', str(y)).replace('{z}', str(z))
        tile.t = now
        _queue[idx] = tile

    if queue_size == 0 and _queue.size():
        emit_signal('load_started')

    return tile


func lonlat_to_dms(lon: float, lat: float) -> String:
    var pf = 'N' if lat >= 0 else 'S'
    lat = abs(lat)
    var deg = floor(lat)
    var minute = (lat - deg) * 60
    var second = (minute - floor(minute)) * 60
    var text = ('%02d' % deg) + ('%02d' % floor(minute)) + ('%02d' % floor(second)) + pf + ' '

    pf = 'E' if lon >= 0 else 'W'
    lon = abs(lon)
    deg = floor(lon)
    minute = (lon - deg) * 60
    second = (minute - floor(minute)) * 60
    text += ('%02d' % deg) + ('%02d' % floor(minute)) + ('%02d' % floor(second)) + pf

    return text


class Tile:
    var i: int = 0
    var x: int = 0
    var y: int = 0
    var z: int = 0
    var t: int = 0
    var url: String = ''
    var texture: Texture2D = null

    func _init(i0: int, x0: int, y0: int, z0: int):
        self.i = i0
        self.x = x0
        self.y = y0
        self.z = z0


func haversine_m(lat1, lon1, lat2, lon2):
    # Радиус Земли в метрах
    var R: = 6372795.0
    # Преобразование градусов в радианы
    var rlat1: = deg_to_rad(lat1)
    var rlon1: = deg_to_rad(lon1)
    var rlat2: = deg_to_rad(lat2)
    var rlon2: = deg_to_rad(lon2)
    var cl1: = cos(rlat1)
    var cl2: = cos(rlat2)
    var sl1: = sin(rlat1)
    var sl2: = sin(rlat2)
    var delta: = rlon2 - rlon1
    var cdelta: = cos(delta)
    var sdelta: = sin(delta)
    # вычисления длины большого круга
    var y: = sqrt(pow(cl2 * sdelta, 2) + pow(cl1 * sl2 - sl1 * cl2 * cdelta, 2))
    var x: = sl1 * sl2 + cl1 * cl2 * cdelta
    var ad: = atan2(y, x)
    var dist: = ad * R
    return dist


func remove_closest_dot(screen_pos):
    var closest_dot = find_at_screen_position(screen_pos)
    if not closest_dot:
        return
    remove_child(closest_dot.mark)
    closest_dot.mark.queue_free()
    _marks.erase(closest_dot)


func find_at_screen_position(screen_pos: Vector2):
    var closest_dot = null
    var closest_l = null
    var closest_distance = INF
    for mark in _marks.values():
        var dot_screen_pos = world_to_screen(mark.position.x, mark.position.y)
        var distance = dot_screen_pos.distance_to(screen_pos)
        if distance < closest_distance:
            closest_distance = distance
            closest_dot = mark
    return closest_dot


func clear() -> void:
    _clean_all()
    queue_redraw()


func set_coordinates(lon: float, lat: float):
    var anim: Animation = $canvas/player.get_animation('goto')
    var wrld_pos = lonlat_to_world(lon, lat)

    anim.track_insert_key(0, 0, _xyz.x)
    anim.track_insert_key(1, 0, _xyz.y)

    anim.track_insert_key(0, animation_time, wrld_pos.x)
    anim.track_insert_key(1, animation_time, wrld_pos.y)

    anim.length = animation_time
    $canvas/player.play('goto')


func blend_mask(val: bool) -> void:
    spr_mask.visible = val
    queue_redraw()