local tilesheet = require "lib.tilesheet"
local utf8 = require "utf8"
local utility = require "lib.utility"

local window_width, window_height = love.graphics.getDimensions()

local tiles, tiles_json, tile_image, tile_usage
local current_text, current_prompt = "", ""

local current_quad
local current_x, current_y = 1, 1

local flag_new_file -- this automatically chooses a JSON file location for new files

local prompts = {
  start_new = "Drag and drop an image or JSON file to name tiles."
  tile_size = "Enter the tile_size for this tilesheet:",
  enter_name = "Enter the name for this tile (leave empty to skip):",
}
current_prompt = prompts.start_new



local get_tile_usage = function(tiles_json, tile_image)
  local image_width, image_height = tile_image:getDimensions()
  local tile_usage = {}
  for x = 1, image_width / tiles_json.tile_size do
    tile_usage[x] = {}
    for y = 1, image_height / tiles_json.tile_size do
      tile_usage[x][y] = false
    end
  end

  for name, tile_data in pairs(tiles_json.tiles) do
    tile_usage[tile_data.x][tile_data.y] = true
  end

  return tile_usage
end

local next_unused_tile = function(tiles_json, tile_image, tile_usage)
  local tile_size = tiles_json.tile_size
  for x = current_x, #tile_usage do
    for y = current_y, #tile_usage[1] do
      if not tile_usage[x][y] then
        current_x = x
        current_y = y
        current_quad = love.graphics.newQuad( (x - 1) * tile_size, (y - 1) * tile_size, tile_size, tile_size, tile_image )
        return current_quad
      end
    end
  end
end



function love.load()
  love.keyboard.setKeyRepeat(true)
end

function love.draw()
  love.graphics.printf(current_prompt, 0, 0, window_width)
  love.graphics.printf(current_text, 0, 20, window_width) -- lazy magic number

  if current_quad then
    love.graphics.draw(tile_image, current_quad, 0, 40) -- lazy magic number
  end
end

function love.textinput(character)
  current_text = current_text .. character
end

function love.keypressed(key)
  if key == "escape" then
    love.event.quit()
  elseif key == "backspace" then
    local byteoffset = utf8.offset(current_text, -1)
    if byteoffset then
      current_text = current_text:sub(1, byteoffset - 1)
    end
  elseif key == "enter" then
    -- end of a textinput; what to do depends on what was being asked
    if current_prompt == prompts.tile_size then
      tiles_json.tile_size = tonumber(current_text)
      current_text = ""
      tile_usage = get_tile_usage(tiles_json, tile_image)
      if next_unused_tile(tiles_json, tile_image, tile_usage) then
        current_prompt = prompts.enter_name
      end
    elseif current_prompt == prompts.enter_name then
      if #current_text > 0 then
        tiles_json.tiles[current_text] = { x = current_x, y = current_y, }
      end
      tile_usage[current_x][current_y] = true
      current_text = ""
      if not (next_unused_tile(tiles_json, tile_image, tile_usage)) then
        if flag_new_file then
          utility.save_data(tiles_json, tiles_json.image_path .. ".json")
        else
          utility.save_data(tiles_json)
        end
        current_prompt = prompts.start_new
      end
    end
  end
end

function love.filedropped(file_path)
  if file_path:sub(-5) == ".json" then
    tiles_json = utility.load_data(file_path)
    flag_new_file = false
    tiles, tile_image = tilesheet(tiles_json)
    tile_usage = get_tile_usage(tiles_json, tile_image)
    if next_unused_tile(tiles_json, tile_image, tile_usage) then
      current_prompt = prompts.enter_name
    end
  else
    tiles_json = {
      image_path = file_path,
      -- tile_size is not defined yet
    }
    flag_new_file = true
    tiles, tile_image = tilesheet(file_path)
    current_prompt = prompts.tile_size
    current_text = ""
  end
end