local area = require("__flib__/area")
local table = require("__flib__/table")

local bring_to_front = rendering.bring_to_front
local destroy = rendering.destroy
local draw_line = rendering.draw_line
local draw_rectangle = rendering.draw_rectangle
local draw_text = rendering.draw_text
local set_color = rendering.set_color
local set_draw_on_ground = rendering.set_draw_on_ground
local set_from = rendering.set_from
local set_left_top = rendering.set_left_top
local set_right_bottom = rendering.set_right_bottom
local set_target = rendering.set_target
local set_text = rendering.set_text
local set_time_to_live = rendering.set_time_to_live
local set_to = rendering.set_to
local set_visible = rendering.set_visible
local set_width = rendering.set_width

local tape = {}

local opposite_corners = {
  left_top = "right_bottom",
  left_bottom = "right_top",
  right_top = "left_bottom",
  right_bottom = "left_top",
}

--- @param objects TapeObjects
--- @param func fun(id: uint64, ...)
local function apply_to_all_objects(objects, func, ...)
  for _, v in pairs(objects) do
    if type(v) == "table" then
      apply_to_all_objects(v, func, ...)
    else
      func(v, ...)
    end
  end
end

--- @param player_index uint
--- @param tape_data TapeData
--- @param visual_settings VisualSettings
local function create_objects(player_index, tape_data, visual_settings)
  local TapeArea = tape_data.Area
  --- @class TapeObjects
  local objects = {
    background = draw_rectangle({
      color = visual_settings.tape_background_color,
      filled = true,
      left_top = TapeArea.left_top,
      right_bottom = TapeArea.right_bottom,
      surface = tape_data.surface,
      players = { player_index },
      draw_on_ground = visual_settings.draw_tape_on_ground,
    }),
    border = draw_rectangle({
      color = visual_settings.tape_border_color,
      width = visual_settings.tape_line_width,
      filled = false,
      left_top = TapeArea.left_top,
      right_bottom = TapeArea.right_bottom,
      surface = tape_data.surface,
      players = { player_index },
      draw_on_ground = visual_settings.draw_tape_on_ground,
    }),
    labels = {
      x = draw_text({
        text = tostring(TapeArea:width()),
        surface = tape_data.surface,
        target = { x = TapeArea:center().x, y = TapeArea.left_top.y - 0.85 },
        color = visual_settings.tape_label_color,
        scale = 1.5,
        alignment = "center",
        visible = false,
        players = { player_index },
      }),
      y = draw_text({
        text = tostring(TapeArea:height()),
        surface = tape_data.surface,
        target = { x = TapeArea.left_top.x - 0.85, y = TapeArea:center().y },
        color = visual_settings.tape_label_color,
        scale = 1.5,
        orientation = 0.75,
        alignment = "center",
        visible = false,
        players = { player_index },
      }),
    },
    lines = {
      { x = {}, y = {} },
      { x = {}, y = {} },
      { x = {}, y = {} },
      { x = {}, y = {} },
    },
  }
  return objects
end

--- @param player_index uint
--- @param tape_data TapeData
--- @param tape_settings TapeSettings
--- @param visual_settings VisualSettings
local function update_objects(player_index, tape_data, tape_settings, visual_settings)
  local TapeArea = tape_data.Area
  local objects = tape_data.objects

  local background = objects.background
  set_left_top(background, TapeArea.left_top)
  set_right_bottom(background, TapeArea.right_bottom)

  local border = objects.border
  set_left_top(border, TapeArea.left_top)
  set_right_bottom(border, TapeArea.right_bottom)

  local center = TapeArea:center()
  local height = TapeArea:height()
  local width = TapeArea:width()

  local x_label = objects.labels.x
  set_text(x_label, tostring(width))
  set_target(x_label, { x = center.x, y = TapeArea.left_top.y - 0.85 })
  if width > 1 then
    set_visible(x_label, true)
  else
    set_visible(x_label, false)
  end

  local y_label = objects.labels.y
  set_text(y_label, tostring(height))
  set_target(y_label, { x = TapeArea.left_top.x - 0.85, y = center.y })
  if height > 1 then
    set_visible(y_label, true)
  else
    set_visible(y_label, false)
  end

  -- GRID LINES

  local function delete_lines(axis, grid_index)
    apply_to_all_objects(objects.lines[grid_index][axis], destroy)
    objects.lines[grid_index][axis] = {}
  end

  local function delete_grid(grid_index)
    delete_lines("x", grid_index)
    delete_lines("y", grid_index)
  end

  -- TODO: optimize to not touch lines that don't need updating
  local function update_lines(axis, grid_index, grid_step)
    local lines = objects.lines[grid_index][axis]

    -- iterate from the origin corner outwards
    local start = TapeArea[tape_data.origin_corner][axis]
    local finish = TapeArea[opposite_corners[tape_data.origin_corner]][axis]

    local i = 0

    if (axis == "x" and width or height) > 1 then
      for pos = start, finish, start < finish and grid_step or -grid_step do
        local from, to
        if axis == "x" then
          from = { x = pos, y = TapeArea.left_top.y }
          to = { x = pos, y = TapeArea.right_bottom.y }
        else
          from = { x = TapeArea.left_top.x, y = pos }
          to = { x = TapeArea.right_bottom.x, y = pos }
        end

        i = i + 1
        local line = lines[i]
        if line then
          set_from(line, from)
          set_to(line, to)
          bring_to_front(line)
        else
          lines[i] = draw_line({
            color = visual_settings["tape_line_color_" .. grid_index],
            width = visual_settings.tape_line_width,
            from = from,
            to = to,
            surface = tape_data.surface,
            players = { player_index },
            draw_on_ground = visual_settings.draw_tape_on_ground,
          })
        end
      end
    end

    for j = i + 1, #lines do
      destroy(lines[j])
      lines[j] = nil
    end
  end

  local function update_grid(grid_index, grid_step)
    update_lines("x", grid_index, grid_step)
    update_lines("y", grid_index, grid_step)
  end

  -- base grid
  update_grid(1, 1)

  local mode = tape_settings.mode
  if mode == "subgrid" then
    local subgrid_size = tape_settings.subgrid_divisor
    update_grid(2, subgrid_size)
    update_grid(3, subgrid_size ^ 2)
    update_grid(4, subgrid_size ^ 3)
  elseif mode == "split" then
    local num_splits = tape_settings.split_divisor
    update_lines("x", 2, width / num_splits)
    update_lines("y", 2, height / num_splits)
    update_lines("x", 3, width / 2)
    update_lines("y", 3, height / 2)
    delete_grid(4)
  end

  bring_to_front(border)
end

--- @param player LuaPlayer
--- @param player_table PlayerTable
--- @param origin MapPosition
--- @param surface LuaSurface
function tape.start_draw(player, player_table, origin, surface)
  -- TODO: Convert to flib bounding-box module
  local TapeArea = area.from_position(origin):ceil():corners()
  --- @class TapeData
  local tape_data = {
    Area = TapeArea,
    last_position = origin,
    last_update_tick = game.ticks_played,
    origin = origin,
    origin_corner = "left_top",
    surface = surface,
  }
  tape_data.objects = create_objects(player.index, tape_data, player_table.visual_settings)
  player_table.tapes.drawing = tape_data
  player_table.flags.drawing = true
end

--- @param player LuaPlayer
--- @param player_table PlayerTable
--- @param new_position MapPosition?
--- @param is_ghost boolean?
function tape.update_draw(player, player_table, new_position, is_ghost)
  local tape_data = player_table.tapes.drawing
  local TapeArea = area.load(tape_data.Area)
  local origin = tape_data.origin

  if new_position then
    if not is_ghost then
      if math.abs(new_position.x - origin.x) >= math.abs(new_position.y - origin.y) then
        new_position.y = math.floor(origin.y)
      else
        new_position.x = math.floor(origin.x)
      end

      -- if the new position is the same as the last, don't actually do anything
      local last_position = tape_data.last_position
      if new_position.x == last_position.x and new_position.y == last_position.y then
        return
      end
    end
    tape_data.last_position = new_position
  else
    new_position = tape_data.last_position
  end

  tape_data.last_update_tick = game.ticks_played

  -- update area corners
  local x_less = new_position.x < origin.x
  local y_less = new_position.y < origin.y
  TapeArea.left_top = {
    x = math.floor(x_less and new_position.x or origin.x),
    y = math.floor(y_less and new_position.y or origin.y),
  }
  TapeArea.right_bottom = {
    x = math.ceil(x_less and origin.x or new_position.x),
    y = math.ceil(y_less and origin.y or new_position.y),
  }
  TapeArea:corners()
  -- update origin corner
  local new_origin_corner = ((x_less and "right" or "left") .. "_" .. (y_less and "bottom" or "top"))
  tape_data.origin_corner = new_origin_corner

  update_objects(player.index, tape_data, player_table.tape_settings, player_table.visual_settings)
end

--- @param player LuaPlayer
--- @param player_table PlayerTable
--- @param auto_clear boolean
function tape.complete_draw(player, player_table, auto_clear)
  local tapes = player_table.tapes
  local tape_data = tapes.drawing
  local TapeArea = tape_data.Area
  local objects = tape_data.objects

  player_table.flags.drawing = false

  -- immediately destroy the tape if it is 1x1
  if TapeArea:height() == 1 and TapeArea:width() == 1 then
    apply_to_all_objects(objects, destroy)
    tapes.drawing = nil
    return
  end

  tape_data.last_position = nil

  if auto_clear then
    apply_to_all_objects(objects, set_time_to_live, player_table.visual_settings.tape_clear_delay * 60)
    -- update to fix draw order
    update_objects(player.index, tape_data, player_table.tape_settings, player_table.visual_settings)
  else
    -- copy settings into tape so they can be changed later
    tape_data.settings = table.deep_copy(player_table.tape_settings)
    tapes[#tapes + 1] = tape_data
  end

  if player_table.visual_settings.log_selection_area then
    player.print(TapeArea:width() .. "x" .. TapeArea:height())
  end
  tapes.drawing = nil
end

--- @param player_table PlayerTable
function tape.cancel_draw(player_table)
  player_table.flags.drawing = false

  local tape_data = player_table.tapes.drawing
  apply_to_all_objects(tape_data.objects, destroy)
  player_table.tapes.drawing = nil
end

--- @param player_table PlayerTable
--- @param tape_index number
function tape.delete(player_table, tape_index)
  local tapes = player_table.tapes
  local tape_data = tapes[tape_index]
  apply_to_all_objects(tape_data.objects, destroy)
  if player_table.flags.editing then
    tape.exit_edit_mode(player_table)
  end
  table.remove(tapes, tape_index)
end

--- @param player_index uint
--- @param TapeArea BoundingBox
--- @param surface LuaSurface
local function create_highlight_box(player_index, TapeArea, surface)
  return surface.create_entity({
    name = "tl-highlight-box",
    position = TapeArea:center(),
    bounding_box = area.expand(TapeArea:strip(), 0.3),
    cursor_box_type = "electricity",
    render_player_index = player_index,
    blink_interval = 30,
  })
end

--- @param player LuaPlayer
--- @param player_table PlayerTable
--- @param tape_index number
function tape.enter_edit_mode(player, player_table, tape_index)
  local tape_data = player_table.tapes[tape_index]
  local TapeArea = area.load(tape_data.Area)

  tape_data.highlight_box = create_highlight_box(player.index, TapeArea, tape_data.surface)

  player_table.flags.editing = true
  player_table.tapes.editing = tape_data
end

--- @param player_table PlayerTable
function tape.exit_edit_mode(player_table)
  local tape_data = player_table.tapes.editing
  tape_data.highlight_box.destroy()
  tape_data.last_position = nil
  player_table.flags.editing = false
  player_table.tapes.editing = nil
end

--- @param player_index uint
--- @param player_table PlayerTable
--- @param mode string
--- @param divisor number
function tape.edit_settings(player_index, player_table, mode, divisor)
  local tape_data = player_table.tapes.editing
  tape_data.settings.mode = mode
  tape_data.settings[mode .. "_divisor"] = divisor

  update_objects(player_index, tape_data, tape_data.settings, player_table.visual_settings)
end

--- @param player LuaPlayer
--- @param player_table PlayerTable
--- @param new_position MapPosition
--- @param surface LuaSurface
function tape.move(player, player_table, new_position, surface)
  local tape_data = player_table.tapes.editing
  if surface ~= tape_data.surface then
    return
  end

  local TapeArea = area.load(tape_data.Area)

  local last_position = tape_data.last_position
  if last_position then
    -- calculate delta
    local delta = {
      x = new_position.x - last_position.x,
      y = new_position.y - last_position.y,
    }
    -- move area and origin
    TapeArea:move(delta):corners()
    tape_data.origin = {
      x = tape_data.origin.x + delta.x,
      y = tape_data.origin.y + delta.y,
    }
    -- update last updated tick
    tape_data.last_update_tick = game.ticks_played
    -- update render objects
    update_objects(player.index, tape_data, tape_data.settings, player_table.visual_settings)
    -- update highlight box
    tape_data.highlight_box.destroy()
    tape_data.highlight_box = create_highlight_box(player.index, TapeArea, tape_data.surface)
    tape_data.last_position = new_position
  elseif TapeArea:contains_position(new_position) then
    tape_data.last_position = new_position
  end
end

--- @param player_table PlayerTable
function tape.complete_move(player_table)
  player_table.tapes.editing.last_position = nil
end

--- @param tape_data TapeData
--- @param settings VisualSettings
function tape.update_visual_settings(tape_data, settings)
  local objects = tape_data.objects

  local line_width = settings.tape_line_width
  local draw_on_ground = settings.draw_tape_on_ground

  local background = objects.background
  set_color(background, settings.tape_background_color)
  set_draw_on_ground(background, draw_on_ground)

  local border = objects.border
  set_color(border, settings.tape_border_color)
  set_draw_on_ground(border, draw_on_ground)
  set_width(border, line_width)

  set_color(objects.labels.x, settings.tape_label_color)
  set_color(objects.labels.y, settings.tape_label_color)

  -- GRID LINES

  local lines = objects.lines
  apply_to_all_objects(lines, set_draw_on_ground, draw_on_ground)
  apply_to_all_objects(lines, set_width, line_width)

  apply_to_all_objects(lines[1], set_color, settings.tape_line_color_1)
  apply_to_all_objects(lines[2], set_color, settings.tape_line_color_2)
  apply_to_all_objects(lines[3], set_color, settings.tape_line_color_3)
  apply_to_all_objects(lines[4], set_color, settings.tape_line_color_4)
end

return tape