-- Squaresville terrain.lua
-- Copyright Duane Robertson (duane@duanerobertson.com), 2017
-- Distributed under the LGPLv2.1 (https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html)


local stone = {}
stone[minetest.get_content_id('default:stone')] = true
stone[minetest.get_content_id('default:sandstone')] = true
stone[minetest.get_content_id('default:desert_stone')] = true
local cave_fill = {}
cave_fill[minetest.get_content_id('air')] = true
cave_fill[minetest.get_content_id('default:water_source')] = true
local math_random = math.random


--minetest.register_ore({
--  ore_type       = "scatter",
--  ore            = "default:meselamp",
--  wherein         = {"default:stone", "default:sandstone"},
--  clust_scarcity = DEBUG and (2 * 2 * 2) or (6 * 6 * 6),
--  clust_num_ores = 1,
--  clust_size     = 1,
--  y_min           = squaresville.baseline + squaresville.extent_bottom,
--  y_max           = squaresville.baseline - 200,
--})

minetest.register_ore({
  ore_type        = "blob",
  ore             = "default:desert_stone",
  wherein         = {"default:stone", "default:sandstone"},
  clust_scarcity  = 14 * 14 * 14,
  clust_size      = 15,
  y_min           = squaresville.baseline + squaresville.extent_bottom,
  y_max           = squaresville.baseline - 200,
  noise_threshold = 0.0,
  noise_params    = {
    offset = 0.2,
    scale = 0.2,
    spread = {x = 15, y = 15, z = 15},
    seed = 8401,
    octaves = 1,
    persist = 0.0
  },
})

minetest.register_ore({
  ore_type        = "blob",
  ore             = "default:sandstone",
  wherein         = {"default:stone", "default:desert_stone"},
  clust_scarcity  = 14 * 14 * 14,
  clust_size      = 15,
  y_min           = squaresville.baseline + squaresville.extent_bottom,
  y_max           = squaresville.baseline - 200,
  noise_threshold = 0.0,
  noise_params    = {
    offset = 0.2,
    scale = 0.2,
    spread = {x = 15, y = 15, z = 15},
    seed = -8771,
    octaves = 1,
    persist = 0.0
  },
})

minetest.register_ore({
  ore_type        = "blob",
  ore             = "default:desert_stone",
  wherein         = {"default:stone", "default:sandstone"},
  clust_scarcity  = 14 * 14 * 14,
  clust_size      = 15,
  y_min           = squaresville.baseline_ruin + squaresville.extent_bottom_ruin,
  y_max           = squaresville.baseline_ruin - 200,
  noise_threshold = 0.0,
  noise_params    = {
    offset = 0.5,
    scale = 0.3,
    spread = {x = 15, y = 15, z = 15},
    seed = 8401,
    octaves = 1,
    persist = 0.0
  },
})

minetest.register_ore({
  ore_type        = "blob",
  ore             = "default:sandstone",
  wherein         = {"default:stone", "default:desert_stone"},
  clust_scarcity  = 14 * 14 * 14,
  clust_size      = 15,
  y_min           = squaresville.baseline_ruin + squaresville.extent_bottom_ruin,
  y_max           = squaresville.baseline_ruin - 200,
  noise_threshold = 0.0,
  noise_params    = {
    offset = 0.5,
    scale = 0.3,
    spread = {x = 15, y = 15, z = 15},
    seed = -8771,
    octaves = 1,
    persist = 0.0
  },
})

local max_height = squaresville.max_height

local cave_1_map = {}
local cave_1_noise, river_noise
local cave_2_map = {}
local cave_2_noise, river_noise
local node = squaresville.node


squaresville.caves = function(minp, maxp, data, p2data, area, remove_this_node, baseline, heightmap)
  if not (minp and maxp and data and p2data and area and node and type(data) == 'table' and type(p2data) == 'table') then
    return
  end

  local max_height = -squaresville.max_height
  for i = 1, #heightmap do
    if heightmap[i] and heightmap[i] > max_height then
      max_height = heightmap[i]
    end
  end

  if minp.y > math.max(max_height, baseline) then
    return
  end

  if not squaresville.csize then
    squaresville.csize = vector.add(vector.subtract(maxp, minp), 1)

    if not squaresville.csize then
      return
    end
  end

  if not (cave_1_noise and cave_2_noise) then
    cave_1_noise = minetest.get_perlin_map(squaresville.cave_2_p, {x=squaresville.csize.x, y=squaresville.csize.z})
    cave_2_noise = minetest.get_perlin_map(squaresville.cave_2_p, {x=squaresville.csize.y + 2, y=squaresville.csize.z})

    if not (cave_1_noise and cave_2_noise) then
      return
    end
  end

  cave_1_map = cave_1_noise:get2dMap_flat({x=minp.x, y=minp.z}, cave_1_map)
  cave_2_map = cave_2_noise:get2dMap_flat({x=minp.y - 1, y=math.floor(minp.z / squaresville.csize.z)}, cave_2_map)

  local index1 = 0
  for z = minp.z, maxp.z do
    local open_z_1 = math_random(6)
    local open_z_2 = math_random(8, 12)
    for x = minp.x, maxp.x do
      index1 = index1 + 1
      local ivm = area:index(x, minp.y - 1, z)
      local index2 = 0
      local height = heightmap[index1] or baseline
      local cave_top = height - 17
      local water_or_lava = -1

      if maxp.y < baseline then
        water_or_lava = math.floor(math.abs(baseline - maxp.y) / 25)
      end

      --local cave_top_1 = cave_top
      --local off = 0
      --if (not squaresville.in_town) and x % 20 < 10 and z % 20 < open_z_2 and z % 20 > open_z_1 then
      --  cave_top_1 = cave_top + 19
      --  off = z % 20
      --  if index1 + off > #cave_1_map then
      --    off = 0
      --  end
      --end

      for y = minp.y - 1, maxp.y + 1 do
        index2 = index2 + 1
        if y < cave_top or ((not squaresville.in_town) and y <= height + 1 and y >= cave_top and y < 10) then
          if cave_1_map[index1] * cave_2_map[index2] > 0.2 - math.min(0, cave_top - y) / 10 then
            if maxp.y > baseline or cave_2_map[index2] > 0 then
              data[ivm] = node['air']
            else
              if y % 1000 > water_or_lava then
                data[ivm] = node['default:water_source']
              else
                data[ivm] = node['default:lava_source']
              end
            end
          elseif y < cave_top and cave_2_map[index2] > 0.65 then
            data[ivm] = node['default:sandstone']
          end
        end

        ivm = ivm + area.ystride
      end

      ivm = area:index(x, minp.y - 1, z)
      local glow, timer = nil, math_random(200)
      for y = minp.y - 1, maxp.y + 1 do
        if y > maxp.y then
          glow = nil
          timer = 9999
        elseif timer <= 0 then
          if glow then
            glow = nil
            timer = math_random(200)
          else
            glow = true
            timer = math_random(20)
          end
        else
          timer = timer - 1
        end

        if y < cave_top then
          local sr = math_random(6)
          if stone[data[ivm]] and cave_fill[data[ivm + area.ystride]] and sr == 1 then
            data[ivm] = node['default:dirt']
            if data[ivm + area.ystride] == node['air'] then
              sr = math_random(5)
              if sr == 1 then
                data[ivm + area.ystride] = node['flowers:mushroom_brown']
              elseif sr == 2 then
                data[ivm + area.ystride] = node['flowers:mushroom_red']
              end
            elseif math_random(4) == 1 then
              data[ivm + area.ystride] = node['squaresville:wet_fungus']
            end
          elseif stone[data[ivm]] and (cave_fill[data[ivm - 1]] or cave_fill[data[ivm + 1]] or cave_fill[data[ivm - area.zstride]] or cave_fill[data[ivm + area.zstride]] or ((cave_fill[data[ivm - area.ystride]] or cave_fill[data[ivm + area.ystride]]) and sr == 2)) and glow then
            data[ivm] = node['squaresville:crystal_glow']
          end
        end

        ivm = ivm + area.ystride
      end
    end
  end
end