require "benchmark"
require "./utilities.cr"
require "./db-cars.cr"

# List of environment variables and default values:
# ENV["CARNAME"]          rescue "Corvet-#{(db_size/2).to_i}"
# ENV["CARCOLOR"]         rescue "red"
# ENV["CARKEYWORD"]       rescue "spacious"
# ENV["DBSIZE"]           rescue 50_000
# ENV["DBSIZE_START"]     rescue 1_000
# ENV["DBSIZE_INCREMENT"] rescue 1_000
# ENV["REPORT_DIR"]       rescue "results"
# ENV["NBRUN"]            rescue 100
# ENV["MAXINDEXES"]       rescue 5_000

class DODB::Storage(V)
	def empty_db
		while pop
		end
	end
end

class Context
	class_property report_dir = "results"
	class_property max_indexes = 5_000
	class_property nb_run      = 100
	class_property from        = 1_000
	class_property to          = 50_000
	class_property incr        = 1_000
end

# To simplify the creation of graphs, it's better to have fake data for
# partitions and tags that won't be actually covered.
# 0 means the absence of data.
def fake_report(name)
	durations = Array(Int32).new Context.nb_run, 0
	File.open("#{Context.report_dir}/#{name}.raw", "w") do |file|
		durations.each do |d|
			file.puts d
		end
	end
	puts "#{name}: no report"
end
def report(storage, name, &block)
	durations = run_n_times Context.nb_run, &block
	File.open("#{Context.report_dir}/#{name}.raw", "w") do |file|
		durations.each do |d|
			file.puts d
		end
	end
	avr = durations.reduce { |a, b| a + b }  / Context.nb_run
	puts "#{name}: #{avr}"
	avr
end

def long_operation(text)
	STDOUT.write "#{text}\r".to_slice
	yield
	STDOUT.write "                                      \r".to_slice
end

def verbose_add_cars(storage, nbcars, name, max_indexes)
	long_operation "add #{nbcars} values to #{name}" do
		add_cars storage, nbcars, max_indexes: max_indexes
	end
end

#  Add first entries, then loop: speed tests, add entries.
def prepare_env(storage, name, s_index, s_partition, s_tags, &)
	verbose_add_cars storage, Context.from, name, max_indexes: Context.max_indexes

	current = Context.from
	to = Context.to
	incr = Context.incr

	while current < to
		yield storage, current, name, s_index, s_partition, s_tags

		break if current + incr >= to

		verbose_add_cars storage, incr, name, max_indexes: Context.max_indexes
		current += incr
	end

	long_operation "removing #{name} data" { storage.rm_storage_dir }
end

def batch()
	cars_ram      = DODB::RAMOnlySpecDataBase(Car).new
	cars_cached   = DODB::CachedSpecDataBase(Car).new
	cars_semi     = DODB::SpecDataBase(Car).new "-semi"
	cars_uncached = DODB::SpecDataBase(Car).new

	ram_Sby_name,      ram_Sby_color,      ram_Sby_keywords      = ram_indexes      cars_ram
	cached_Sby_name,   cached_Sby_color,   cached_Sby_keywords   = cached_indexes   cars_cached
	semi_Sby_name,     semi_Sby_color,     semi_Sby_keywords     = cached_indexes   cars_semi
	uncached_Sby_name, uncached_Sby_color, uncached_Sby_keywords = uncached_indexes cars_uncached

	fn = ->(storage : DODB::Storage(Car),
			current_db_size : Int32,
			name : String,
			search_name : DODB::Index::Index(Car),
			search_color : DODB::Index::Partition(Car),
			search_keywords : DODB::Index::Tags(Car)) {

		name_to_search    = ENV["CARNAME"]    rescue "Corvet-#{(current_db_size/2).to_i}"
		color_to_search   = ENV["CARCOLOR"]   rescue "red"
		keyword_to_search = ENV["CARKEYWORD"] rescue "spacious"
		puts "NEW BATCH: db-size #{current_db_size}, name: '#{name_to_search}', color: '#{color_to_search}', tag: '#{keyword_to_search}'"
		report(storage, "#{name}_#{current_db_size}_index") do
			corvet = search_name.get name_to_search
		end
		if current_db_size <= Context.max_indexes
			report(storage, "#{name}_#{current_db_size}_partitions") do
				corvet = search_color.get? color_to_search
			end
			report(storage, "#{name}_#{current_db_size}_tags") do
				corvet = search_keywords.get? keyword_to_search
			end
		else
			fake_report("#{name}_#{current_db_size}_partitions")
			fake_report("#{name}_#{current_db_size}_tags")
		end
	}

	prepare_env cars_cached,   "cached",   cached_Sby_name, cached_Sby_color, cached_Sby_keywords, &fn
	prepare_env cars_ram,      "ram",      ram_Sby_name, ram_Sby_color, ram_Sby_keywords, &fn
	prepare_env cars_semi,     "semi",     semi_Sby_name, semi_Sby_color, semi_Sby_keywords, &fn
	prepare_env cars_uncached, "uncached", uncached_Sby_name, uncached_Sby_color, uncached_Sby_keywords, &fn
end

def perform_add(storage : DODB::Storage(Car))
	corvet0 = Car.new "Corvet", "red", [ "shiny", "impressive", "fast", "elegant" ]
	i = 0
	perform_benchmark_average Context.nb_run, do
		corvet = corvet0.clone
		corvet.name = "Corvet-#{i}"
		storage << corvet
		i += 1
	end
end

def batch_add()
	cars_ram      = DODB::RAMOnlySpecDataBase(Car).new
	cars_cached   = DODB::CachedSpecDataBase(Car).new
	cars_semi     = DODB::SpecDataBase(Car).new "-semi"
	cars_uncached = DODB::SpecDataBase(Car).new

	ram_indexes      cars_ram
	cached_indexes   cars_cached
	cached_indexes   cars_semi
	uncached_indexes cars_uncached

	avr = perform_add(cars_ram)
	puts "(ram db and indexes) add a value (average on #{Context.nb_run} tries): #{avr}"

	avr = perform_add(cars_cached)
	puts "(cached db and indexes) add a value (average on #{Context.nb_run} tries): #{avr}"

	avr = perform_add(cars_semi)
	puts "(uncached db but cached indexes) add a value (average on #{Context.nb_run} tries): #{avr}"

	avr = perform_add(cars_uncached)
	puts "(uncached db and indexes) add a value (average on #{Context.nb_run} tries): #{avr}"

	cars_ram.rm_storage_dir
	cars_cached.rm_storage_dir
	cars_semi.rm_storage_dir
	cars_uncached.rm_storage_dir
end

ENV["REPORT_DIR"]?.try { |report_dir| Context.report_dir = report_dir }
Dir.mkdir_p Context.report_dir

ENV["MAXINDEXES"]?.try       { |it| Context.max_indexes = it.to_i }
ENV["NBRUN"]?.try            { |it| Context.nb_run      = it.to_i }
ENV["DBSIZE"]?.try           { |it| Context.to          = it.to_i }
ENV["DBSIZE_START"]?.try     { |it| Context.from        = it.to_i }
ENV["DBSIZE_INCREMENT"]?.try { |it| Context.incr        = it.to_i }

pp! Context.nb_run
pp! Context.from
pp! Context.to
pp! Context.incr
pp! Context.max_indexes

batch
batch_add