local R = mcl_levelgen.build_random_spread_placement
local merge = table.merge
local mathabs = math.abs
local jigsaw_create_start = mcl_levelgen.jigsaw_create_start

local function uniform_height (min_inclusive, max_inclusive)
	local diff = max_inclusive - min_inclusive + 1
	return function (rng)
		return rng:next_within (diff) + min_inclusive
	end
end

local cid_pottery_sherds
local cid_bulb_oxidized_on_preserved
local cid_bulb_weathered_on_preserved
local cid_bulb_exposed_on_preserved
local cid_bulb_on_preserved

local function initialize_cids ()
	cid_pottery_sherds = core.get_content_id ("mcl_pottery_sherds:pot")
	cid_bulb_oxidized_on_preserved = core.get_content_id ("mcl_copper:bulb_oxidized_on_preserved")
	cid_bulb_weathered_on_preserved = core.get_content_id ("mcl_copper:bulb_weathered_on_preserved")
	cid_bulb_exposed_on_preserved = core.get_content_id ("mcl_copper:bulb_exposed_on_preserved")
	cid_bulb_on_preserved = core.get_content_id ("mcl_copper:bulb_on_preserved")
end

if core.register_on_mods_loaded then
	core.register_on_mods_loaded (initialize_cids)
else
	initialize_cids ()
end

local function apply_copper_bulb_degradation (x, y, z, rng, cid_existing, param2_existing,
					cid, param2)
	if cid == cid_bulb_on_preserved and rng:next_float () < 0.1 then
		return cid_bulb_oxidized_on_preserved, param2
	elseif cid == cid_bulb_on_preserved and rng:next_float () < 0.33333334 then
		return cid_bulb_weathered_on_preserved, param2
	elseif cid == cid_bulb_on_preserved and rng:next_float () < 0.5 then
		return cid_bulb_exposed_on_preserved, param2
	else
		return cid, param2
	end
end

local copper_bulb_processor = {
	apply_copper_bulb_degradation
}

local function L (template, weight, processors)
	processors = merge (copper_bulb_processor, processors or {})
	return {
		projection = "rigid",
		template = mcl_levelgen.prefix .. "/templates/" .. template .. ".dat",
		weight = weight,
		ground_level_delta = 0,
		processors = processors,
	}
end

------------------------------------------------------------------------
-- Trial Chambers.
------------------------------------------------------------------------

mcl_levelgen.register_loot_table ("mcl_levelgen:trial_chambers_chest_entrance_loot", {
	{
		stacks_min = 2,
		stacks_max = 3,
		items = {
			{ itemstring = "mcl_bows:arrow", weight = 10, amount_min = 5, amount_max = 10 },
			{ itemstring = "mcl_honey:honeycomb", weight = 10, amount_min = 2, amount_max = 8 },
			{ itemstring = "mcl_tools:axe_wood", weight = 10, amount_min = 1, amount_max = 1 },
			{ itemstring = "mcl_core:stick", weight = 5, amount_min = 2, amount_max = 5 },
			{ itemstring = "mcl_vaults:trial_key", weight = 1 },
		}
	}
})

mcl_levelgen.register_loot_table ("mcl_levelgen:trial_chambers_chest_intersection_loot", {
	{
		stacks_min = 1,
		stacks_max = 3,
		items = {
			{ itemstring = "mcl_amethyst:amethyst_shard", weight = 20, amount_min = 8, amount_max = 20 },
			{ itemstring = "mcl_cake:cake", weight = 20, amount_min = 1, amount_max = 4 },
			{ itemstring = "mcl_core:ironblock", weight = 20, amount_min = 1, amount_max = 2 },
			{ itemstring = "mcl_core:diamond", weight = 10, amount_min = 1, amount_max = 2 },
			{ itemstring = "mcl_core:emeraldblock", weight = 5, amount_min = 1, amount_max = 3 },
			{ itemstring = "mcl_tools:axe_diamond", weight = 5 },
			{ itemstring = "mcl_tools:pick_diamond", weight = 5 },
			{ itemstring = "mcl_core:diamondblock", weight = 1 },
		}
	}
})

mcl_levelgen.register_loot_table ("mcl_levelgen:trial_chambers_chest_supply_loot", {
	{
		stacks_min = 3,
		stacks_max = 5,
		items = {
			{ itemstring = "mcl_bows:arrow", weight = 2, amount_min = 4, amount_max = 14 },
			{ itemstring = "mcl_lush_caves:glow_berry", weight = 2, amount_min = 2, amount_max = 10 },
			{ itemstring = "mcl_farming:potato_item_baked", weight = 2, amount_min = 2, amount_max = 4 },
			{ itemstring = "mcl_tools:pick_stone", weight = 2, amount_min = 1, amount_max = 1 },
			{ itemstring = "mcl_deepslate:tuff", weight = 1, amount_min = 5, amount_max = 10 },
			{ itemstring = "mcl_potions:poison_arrow", weight = 1, amount_min = 4, amount_max = 8 },
			{ itemstring = "mcl_potions:slowness_arrow", weight = 1, amount_min = 4, amount_max = 8 },
			{ itemstring = "mcl_core:acaciawood", weight = 1, amount_min = 3, amount_max = 6 },
			{ itemstring = "mcl_torches:torch", weight = 1, amount_min = 3, amount_max = 6 },
			{ itemstring = "mcl_bone_meal:bone_meal", weight = 1, amount_min = 2, amount_max = 5 },
			{ itemstring = "mcl_lush_caves:moss", weight = 1, amount_min = 2, amount_max = 5 },
			{ itemstring = "mcl_potions:regeneration", weight = 1, amount_min = 2 },
			{ itemstring = "mcl_potions:strength", weight = 1, amount_min = 2 },
			{ itemstring = "mcl_mobitems:milk_bucket", weight = 1 },
		}
	}
})

mcl_levelgen.register_loot_table ("mcl_levelgen:trial_chambers_barrel_intersection_loot", {
	{
		stacks_min = 1,
		stacks_max = 3,
		items = {
			{ itemstring = "mcl_trees:wood_bamboo", weight = 10, amount_min = 5, amount_max = 15 },
			{ itemstring = "mcl_farming:potato_item_baked", weight = 10, amount_min = 6, amount_max = 10 },
			{ itemstring = "mcl_tools:axe_gold", weight = 4 },
			{ itemstring = "mcl_tools:pick_gold", weight = 4 },
			{ itemstring = "mcl_core:diamond", weight = 1, amount_min = 1, amount_max = 3 },
			{ itemstring = "mcl_buckets:bucket_empty", weight = 1, amount_min = 1, amount_max = 2 },
			{ itemstring = "mcl_compass:compass", weight = 1 },
			{ itemstring = "mcl_tools:pick_diamond", weight = 1 },
			{
				itemstring = "mcl_tools:axe_diamond", weight = 1,
				func = function (stack, pr)
					mcl_enchanting.enchant_uniform_randomly (stack, {"soul_speed"}, pr)
				end,
			},
		}
	}
})

mcl_levelgen.register_loot_table ("mcl_levelgen:trial_chambers_barrel_corridor_loot", {
	{
		stacks_min = 1,
		stacks_max = 3,
		items = {
			{ itemstring = "mcl_deepslate:tuff", weight = 3, amount_min = 8, amount_max = 20 },
			{ itemstring = "mcl_bamboo:scaffolding", weight = 2, amount_min = 2, amount_max = 10 },
			{ itemstring = "mcl_trees:wood_bamboo", weight = 2, amount_min = 3, amount_max = 6 },
			{ itemstring = "mcl_torches:torch", weight = 2, amount_min = 3, amount_max = 6 },
			{ itemstring = "mcl_signs:hanging_sign_bamboo", weight = 2, amount_min = 1, amount_max = 4 },
			{ itemstring = "mcl_throwing:ender_pearl", weight = 2, amount_min = 1, amount_max = 2 },
			{ itemstring = "mcl_tools:axe_stone", weight = 2 },
			{ itemstring = "mcl_tools:pick_stone", weight = 2 },
			{ itemstring = "mcl_honey:honeycomb", weight = 1, amount_min = 2, amount_max = 8 },
			{
				itemstring = "mcl_tools:axe_iron", weight = 1,
				func = function (stack, pr)
					mcl_enchanting.enchant_uniform_randomly (stack, {"soul_speed"}, pr)
				end,
			},
		}
	}
})

mcl_levelgen.register_loot_table ("mcl_levelgen:trial_chambers_dispenser_chamber_loot", {
	{
		stacks_min = 1,
		stacks_max = 1,
		items = {
			{ itemstring = "mcl_fire:fire_charge", weight = 6, amount_min = 4, amount_max = 8 },
			{ itemstring = "mcl_throwing:snowball", weight = 6, amount_min = 4, amount_max = 8 },
			{ itemstring = "mcl_bows:arrow", weight = 4, amount_min = 4, amount_max = 8 },
			{ itemstring = "mcl_buckets:bucket_water", weight = 4 },
			{ itemstring = "mcl_throwing:egg", weight = 2, amount_min = 4, amount_max = 8 },
			{ itemstring = "mcl_potions:healing_lingering", weight = 1, amount_min = 2, amount_max = 5 },
			{ itemstring = "mcl_potions:poison_lingering", weight = 1, amount_min = 2, amount_max = 5 },
			{ itemstring = "mcl_potions:slowness_lingering", weight = 1, amount_min = 2, amount_max = 5 },
			{ itemstring = "mcl_potions:weakness_lingering", weight = 1, amount_min = 2, amount_max = 5 },
			{ itemstring = "mcl_potions:poison_splash", weight = 1, amount_min = 2, amount_max = 5 },
			{ itemstring = "mcl_potions:slowness_splash", weight = 1, amount_min = 2, amount_max = 5 },
			{ itemstring = "mcl_potions:weakness_splash", weight = 1, amount_min = 2, amount_max = 5 },
		}
	}
})

mcl_levelgen.register_loot_table ("mcl_levelgen:trial_chambers_dispenser_corridor_loot", {
	{
		stacks_min = 1,
		stacks_max = 1,
		items = {
			{ itemstring = "mcl_bows:arrow", weight = 1, amount_min = 4, amount_max = 8 }
		}
	}
})

------------------------------------------------------------------------
-- Template pools
------------------------------------------------------------------------

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_ends", {
	elements = {
		L ("trial_chambers_corridor_end_1", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_chambers", {
	elements = {
		L ("trial_chambers_corridor_chamber_1", 1),
		L ("trial_chambers_corridor_chamber_2", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_big_chambers", {
	elements = {
		L ("trial_chambers_corridor_chamber_1", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_hallway_1_entrances", {
	elements = {
		L ("trial_chambers_hallway_1_entrance_1", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_hallway_1_slices", {
	elements = {
		L ("trial_chambers_hallway_1_slice_1", 2),
		L ("trial_chambers_hallway_1_slice_2", 2),
		L ("trial_chambers_hallway_1_slice_3", 2),
		L ("trial_chambers_hallway_1_slice_4", 2),
		L ("trial_chambers_hallway_1_exit_1",  3),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_intersections", {
	elements = {
		L ("trial_chambers_corridor_intersection_1", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_branches", {
	elements = {
		L ("trial_chambers_branch_1", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_branch_lefts", {
	elements = {
		L ("trial_chambers_branch_left_1", 1), -- chamber
		L ("trial_chambers_branch_left_2", 1), -- empty
		L ("trial_chambers_branch_left_3", 1), -- chest
		L ("trial_chambers_branch_left_4", 1), -- upstair
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_branch_rights", {
	elements = {
		L ("trial_chambers_branch_right_1", 1), -- chamber
		L ("trial_chambers_branch_right_2", 1), -- empty
		L ("trial_chambers_branch_right_3", 1), -- chest
		L ("trial_chambers_branch_right_4", 1), -- upstair
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_branch_upstair_addons", {
	elements = {
		L ("trial_chambers_branch_upstair_addon_1", 1), -- treasure
		L ("trial_chambers_branch_upstair_addon_2", 1), -- empty
		L ("trial_chambers_branch_upstair_addon_2", 1), -- chamber
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_hallway_2_entrances", {
	elements = {
		L ("trial_chambers_hallway_2_entrance_1", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_hallway_2_slices", {
	elements = {
		L ("trial_chambers_hallway_2_slice_1", 2),
		L ("trial_chambers_hallway_2_slice_2", 2),
		L ("trial_chambers_hallway_2_slice_3", 2),
		L ("trial_chambers_hallway_2_slice_4", 2),
		L ("trial_chambers_hallway_2_exit_1",  3),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_atriums", {
	elements = {
		L ("trial_chambers_corridor_atrium_1", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_entrances", {
	elements = {
		L ("trial_chambers_corridor_entrance_1", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_decor_bigs", {
	elements = {
		L ("trial_chambers_decor_big_oak_tree", 1),
		L ("trial_chambers_decor_big_fountain", 1),
	},
})

if not mcl_levelgen.is_levelgen_environment
	and mcl_levelgen.register_notification_handler then

	local v = vector.zero ()
	local level_to_minetest_position
		= mcl_levelgen.level_to_minetest_position

	local decorated_pot_loot_table = {{
		stacks_min = 1,
		stacks_max = 1,
		items = {
			{ itemstring = "mcl_core:emerald", weight = 125, amount_min = 1, amount_max = 3 },
			{ itemstring = "mcl_bows:arrow", weight = 100, amount_min = 2, amount_max = 8 },
			{ itemstring = "mcl_core:iron_ingot", weight = 100, amount_min = 1, amount_max = 2 },
			{ itemstring = "mcl_vaults:trial_key", weight = 10 },
			{ itemstring = "mcl_core:diamond", weight = 5, amount_min = 1, amount_max = 2 },
			{ itemstring = "mcl_core:emeraldblock", weight = 5 },
			{ itemstring = "mcl_jukebox:record_mellohi", weight = 5 },
			{ itemstring = "mcl_core:diamondblock", weight = 1 },
		}
	}}
	local faces = {"flow", "guster", "scrape"}

	local function handle_decorated_pot_loot_and_faces (_, data)
		local pr = PcgRandom (data.loot_seed)
		v.x, v.y, v.z = level_to_minetest_position (data.x, data.y, data.z)
		mcl_structures.construct_nodes (v, v, {
			"mcl_pottery_sherds:pot",
		})
		local meta = core.get_meta (v)
		if core.get_node (v).name == "mcl_pottery_sherds:pot" then
			local items = mcl_loot.get_multi_loot (decorated_pot_loot_table, pr)
			local face = faces[pr:next (1, 3)]
			local random_face = core.serialize ({face, face, face, face})
			meta:set_string ("loot", items[1]:get_name ())
			meta:set_string ("pot_faces", random_face)
		end
	end

	mcl_levelgen.register_notification_handler ("mcl_levelgen:trial_chambers_decorated_pots_loot_faces",
						    handle_decorated_pot_loot_and_faces)
end

local notify_generated = mcl_levelgen.notify_generated

local function add_loot_and_random_faces (x, y, z, rng, cid_existing,
			       param2_existing, cid, param2)
	if cid == cid_pottery_sherds then
		notify_generated ("mcl_levelgen:trial_chambers_decorated_pots_loot_faces", x, y, z, {
			loot_seed = mathabs (rng:next_integer ()),
			x = x,
			y = y,
			z = z,
		})
	end
	return cid, param2
end

local decorated_pot_processor = {
	add_loot_and_random_faces
}

-- Decorated pots in hallways
mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_decor_pots", {
	elements = {
		L ("trial_chambers_decor_pots_empty",   24),
		L ("trial_chambers_decor_pots_regular", 2, decorated_pot_processor),
		L ("trial_chambers_decor_barrel",       1),
	}
})

-- Decorated pots in corridor
mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_decor_pots_2", {
	elements = {
		L ("trial_chambers_decor_pots_regular", 1, decorated_pot_processor),
	}
})

-- FIXME: Implement breeze mobs
-- mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_breeze_spawners", {
-- 	elements = {
-- 		L ("trial_chambers_spawner_breeze", 1),
-- 	}
-- })

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_melee_spawners", {
	elements = {
		L ("trial_chambers_spawner_zombie", 1),
		L ("trial_chambers_spawner_husk",   1),
		L ("trial_chambers_spawner_spider", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_small_melee_spawners", {
	elements = {
		L ("trial_chambers_spawner_slime",       1),
		L ("trial_chambers_spawner_silverfish",  1),
		L ("trial_chambers_spawner_baby_zombie", 1),
		L ("trial_chambers_spawner_cave_spider", 1),
	},
})

mcl_levelgen.register_template_pool ("mcl_levelgen:trial_chambers_ranged_spawners", {
	elements = {
		L ("trial_chambers_spawner_stray",    1),
		L ("trial_chambers_spawner_skeleton", 1),
		-- FIXME: L ("trial_chambers_spawner_bogged",   1),
	},
})

------------------------------------------------------------------------
-- Trial Chambers structure registration.
------------------------------------------------------------------------

local trial_chambers_biomes = {
	"#is_overworld",
}

mcl_levelgen.modify_biome_groups (trial_chambers_biomes, {
	has_trial_chambers = true,
})

mcl_levelgen.register_structure ("mcl_levelgen:trial_chambers", {
	step = mcl_levelgen.UNDERGROUND_STRUCTURES,
	create_start = jigsaw_create_start,
	terrain_adaptation = "encapsulate",
	biomes = mcl_levelgen.build_biome_list ({"#has_trial_chambers",}),
	max_distance_from_center = 116,
	size = 20,
	start_height = uniform_height (-40, -20),
	start_pool = "mcl_levelgen:trial_chambers_ends",
})

mcl_levelgen.register_structure_set ("mcl_levelgen:trial_chambers", {
	structures = {
		"mcl_levelgen:trial_chambers",
	},
	placement = R (1.0, "default", 34, 12, 94251327, "linear", nil, nil),
})
